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| 11. |
Alkene–alkyne metathesis and 1,4-cis-hydrogenation as a route to tetrasubstituted (Z)-olefins |
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Mendeleev Communications,
Volume 10,
Issue 3,
2000,
Page 101-103
Andrei A. Vasil'ev,
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摘要:
Mendeleev Communications Electronic Version, Issue 2, 2000 (pp. 83–124) Alkene–alkyne metathesis and 1,4-cis-hydrogenation as a route to tetrasubstituted (Z)-olefins Andrei A. Vasil’ev,*a Lars Engmanb and Edward P. Serebryakova a N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow, Russian Federation. Fax: + 7 095 135 5328; e-mail: vasiliev@ioc.ac.ru b Department of Organic Chemistry, Institute of Chemistry, Uppsala University, S-751 21 Uppsala, Sweden 10.1070/MC2000v010n03ABEH001303 Stereospecific synthesis of erythro-5-benzyloxy-2,3-dimethylpentan-1-ol, a building block for the preparation of faranal and lasiol, was performed starting from 5-benzyloxypent-2-yn-1-ol using the title methodology followed by 1,2-syn-hydrogenation.Faranal 1 [(3S,4R,6E,10Z)-3,4,7,11-tetramethyltrideca-6,10- dienal, a trail pheromone of the Pharaoh’s ant Monomorium pharaonis],1 and lasiol 2 [(2R*,3R*)-2,3,6-trimethylhept-5-en- 1-ol, the major component of the mandibular gland secretion of the ant Lasius meridionalis]2 both contain a vicinal erythro dimethyl structural motif.For their preparation, the use of suitably substituted building blocks,2–7 stereospecific substituentdirected anti-alkylation of 3-methylalkanolide carbanions8,9 and erythro addition of alkenylmanganese chloride to methyl crotonate10 were described.Syn-1,2-addition of hydrogen to a double bond of a (Z)-1,2-dimethyl tetrasubstituted olefin with heterogeneous catalysis was never attempted for this purpose. Although there are cases where mixtures of syn- and anti-addition products are formed,11 the stereochemistry of hydrogenation of tetrasubstituted olefins is not well investigated.We reasoned that Raney nickel can hydrogenate via syn-1,2-addition (and in an essentially irreversible manner) rather than by hydride transfer. Remarkably, a diimide is practically inert towards tetrasubstituted olefins.12 M.Mori and co-workers have recently developed intermolecular alkene–alkyne metathesis13,14 into a useful method for the preparation of functionalized 2,3-disubtituted butadienes. With our previous experience in the 1,4-cis-hydrogenation of conjugated dienes over (arene)tricarbonylchromium catalysts15,16 (for a review, see ref. 17) we decided to prepare (Z)-tetrasubstituted olefins by this route and to investigate their further transformations into erythro-configured vic-dimethyl derivatives (Scheme 1).The readily available acetate of 5-benzyloxypent-2-yn-1-ol 3,18 upon metathesis with ethylene in CH2Cl2 under the Mori conditions,13,14 afforded target conjugated diene 4 with a maximum conversion of 43%.† Attempts to improve the process were unsuccessful. Thus, running the reaction in an autoclave under a higher ethylene pressure resulted in a low (less than 5%) conversion of the starting material.This may be attributed to the pressure-accelerated degenerate ethylene–ethylene metathesis (due to an increased concentration of ethylene). As a result, this † 1-Acetoxy-5-benzyloxy-2,3-dimethylenepentane 4. A mixture of 1-acetoxy- 5-benzyloxypent-2-yne 3 (0.389 g, 1.67 mmol) and benzylidenebis( tricyclohexylphosphine)dichlororuthenium (Fluka) (0.04 g) in CH2Cl2 (17 ml) was stirred in an ethylene atmosphere for 3 days and treated according to a published procedure.12,13 The crude material was a 43:57 (mol/mol) mixture (1H NMR data) of title compound 4 and unreacted compound 3.Column chromatography (3–5% EtOAc in pentane, SiO2) gave 0.154 g (35%) of compound 4 and 0.196 g (50%) of recovered starting material 3. 1H NMR (CDCl3) d: 2.08 (s, 3H), 2.62 (t, 2H, J 7.0 Hz), 3.61 (t, 2H, J 7.0 Hz), 4.52 (s, 2H), 4.77 (s, 2H), 5.09 (s, 1H), 5.15 (s, 1H), 5.27 (s, 1H), 5.33 (s, 1H), 7.22–7.38 (m, 5H). 13C NMR, d: 21.0 (Me), 34.2 (CH2), 65.1 (CH2), 69.1 (CH2), 72.9 (CH2), 114.1 (CH2), 114.9 (CH2), 127.5 (CH), 127.6 (CH), 128.4 (CH), 138.3 (C), 141.3 (C), 141.6 (C), 170.7 (C).process effectively competes with the reaction between ethylene and acetylenic substrate 3. Fortunately, compounds 3 and 4 could be readily separated by column chromatography, allowing for recycling of compound 3 to accumulate sufficient amounts of diene 4 for further investigations. The 1,4-cis-hydrogenation of diene 4 over (h6-naphthalene)- Cr(CO)6 in THF at 45 °C and 1 atm H2 led cleanly to olefin 5.‡ The (Z)-configuration of the double bond in compound 5 was confirmed by NOE difference experiments.Thus, irradiation of the allylic CH2CH2OBn protons at 2.47 ppm gave effects at 1.74 (3.5%), 3.49 (6.5%) and 4.60 (6.5%) ppm. Also, irradiation of the acetoxymethyl protons at 4.60 ppm gave effects at 1.71 (3%) and 2.47 (4%) ppm.Subsequent attempts to hydrogenate the double bond either in acetate 5 or in the corresponding alcohol 6 over Raney nickel mainly caused cleavage of the allylic C–O bond. To avoid this, allylic alcohol 6 was subjected to consecutive Swern and sodium chlorite oxidations followed by diazomethane esterification.§ Hydrogenation of (Z)- tetrasubstituted acrylate 7 over Raney nickel in propan-2-ol at room temperature and 15 atm H2 proceeded smoothly without affecting the ester function to afford a 90% yield of the erythro- ‡ (Z)-1-Acetoxy-5-benzyloxy-2,3-dimethylpent-2-ene 5 was obtained by hydrogenation (1 atm H2, 45–50 °C, 2 h) of diene 4 (0.154 g, 0.59 mmol) in THF (10 ml) in the presence of (naphthalene)tricarbonylchromium20 (0.03 g).Column chromatography afforded 0.141 g (91%) of compound 5. 1H NMR (CDCl3) d: 1.71 (s, 3H), 1.74 (s, 3H), 2.03 (s, 3H), 2.47 (t, 2H, J 7.2 Hz), 3.49 (t, 2H, J 7.2 Hz), 4.50 (s, 2H), 4.60 (s, 2H), 7.32 (m, 5H). 13C NMR, d: 16.9 (Me), 19.4 (Me), 21.0 (Me), 34.7 (CH2), 65.4 (CH2), 69.0 (CH2), 72.8 (CH2), 125.4 (C), 127.5 (CH, two peaks), 128.3 (CH), 132.5 (C), 138.4 (C), 171.3 (C).CHO OH 1 2 OBn OAc AcO OBn i AcO OBn ii iii HO OBniv, v, vi MeO OBn O vii MeO OBn O viii HO OBn 3 4 5 6 7 8 9 Scheme 1 Reagents and conditions: i, C2H4, PhCH=RuCl2(PCy3)2 , CH2Cl2, room temperature, 35% (based on 3 used) and 70% (based on 3 recovered); ii, H2 (1 atm), (C10H8 )Cr(CO)3, THF, 45 °C, 91%; iii, MeOH, K2CO3, room temperature; iv, DMSO, (COCl)2, CH2Cl2, then Et3N, –50 °C; v, NaClO2, 1-methylcyclohexene, ButOH, NaH2PO4, room temperature; vi, CH2N2 , Et2O, 65% (5 to 7); vii, H2 (15 atm), Ni, PriOH, room temperature; viii, LiAlH4, Et2O, 74% (7 to 9).Mendeleev Communications Electronic Version, Issue 3, 2000 (pp. 83–124) isomer 8.¶ The configuration of compound 8 was proven by the transformation (LiAlH4 reduction into alcohol 9 and debenzylation over H2–Pd/C) into known erythro-2,3-dimethylpentane- 1,5-diol.19,†† After transformation of the alcohol into an iodide and coupling with an appropriate alkenyllithium reagent,3,6 erythro-5-benzyloxy- 2,3-dimethylpentan-1-ol 9 may serve as a building block in the synthesis of racemic faranal 1.On the other hand, manipulations with the protective groups in compound 9 provide an opportunity to synthesise lasiol 2 (see ref. 2 for the methodology). Although the route from compound 3 to 9 gives only a 30% yield over eight steps,‡‡ it is still a competitive method for the synthesis of erythro-configured compounds. In conclusion, transition metal catalysed metathesis and cishydrogenation reactions provide a new useful approach to functionalized (Z)-tetrasubstituted olefins.This work was supported by the Russian Foundation for Basic Research (grant no. 99-03-32992), the Royal Swedish Academy of Sciences (a research grant for cooperation between Sweden and the former Soviet Union) and the Swedish Natural Science Research Council. § Methyl (Z)-5-benzyloxy-2,3-dimethylpent-2-enoate 7. Acetate 5 (0.491 g, 1.87 mmol) was stirred overnight in MeOH in the presence of K2CO3. The crude alcohol 6 thus obtained was subjected to the standard Swern oxidation.21 The resulting crude aldehyde was then oxidised with NaClO2 to the corresponding carboxylic acid,22 which was esterified by treatment with diazomethane. Column chromatography afforded 0.303 g (65%) of ester 7. 1H NMR (CDCl3) d: 1.84 (s, 3H), 1.85 (s, 3H), 2.73 (t, 2H, J 7.1 Hz), 3.61 (t, 2H, J 7.1 Hz), 3.70 (s, 3H), 4.52 (s, 2H), 7.26 (m, 1H), 7.33 (m, 4H). 13C NMR, d: 15.9 (Me), 21.2 (Me), 36.6 (CH2), 51.3 (Me), 69.3 (CH2), 72.7 (CH2), 124.2 (C), 127.4 (CH), 127.5 (CH), 128.3 (CH), 138.6 (C), 144.1 (C), 169.6 (C). ¶ erythro-5-Benzyloxy-2,3-dimethylpentan-1-ol 9. Unsaturated ester 7 (0.240 g, 0.97 mmol) was hydrogenated (15 atm H2, 20 °C, 7 h) in propan-2-ol (15 ml) in the presence of Raney nickel (0.3 g).The filtration and evaporation of the solvent left crude methyl erythro-5-benzyloxy- 2,3-dimethylpentanoate 8 containing ca. 10% impurities. 1HNMR (CDCl3) d: 0.91 (d, 3H, J 6.9 Hz), 1.13 (d, 3H, J 7.0 Hz), 1.42 (m, 1H), 1.80 (m, 1H), 1.93 (m, 1H), 2.40 (m, 1H), 3.51 (m, 2H), 3.65 (s, 3H), 4.48 and 4.50 (AB system, 2H, J 12.0 Hz), 7.28 (m, 1H), 7.34 (m, 4H). 13C NMR, d: 14.0 (Me), 17.0 (Me), 33.2 (CH), 33.4 (CH2), 44.5 (CH), 51.3 (Me), 68.4 (CH2), 72.9 (CH2), 127.5 (CH), 127.6 (CH), 128.4 (CH), 138.6 (C), 176.4 (C). Reduction with LiAlH4 followed by column chromatography afforded 0.160 g (74%) of erythro alcohol 9 as a colourless oil. 1H NMR (CDCl3) d: 0.85 (d, 3H, J 6.9 Hz), 0.91 (d, 3H, J 6.9 Hz), 1.32 (m, 1H), 1.64 (m, 1H), 1.77 (m, 2H), 3.45 (m, 2H), 3.55 (m, 2H), 4.50 and 4.52 (AB system, 2H, J 11.6 Hz), 1.26–1.37 (m, 5H). 13C NMR, d: 12.7 (Me), 17.4 (Me), 30.9 (CH), 31.9 (CH2), 40.3 (CH), 65.8 (CH2), 69.2 (CH2), 73.0 (CH2), 127.6 (CH), 127.7 (CH), 128.4 (CH), 138.3 (C).†† 13C NMR (D2O) d: 13.5 (Me), 16.8 (Me), 31.1 (CH), 34.9 (CH2), 40.4 (CH), 61.0 (CH2), 65.6 (CH2). An authentic sample of the same diol was obtained by the LiAlH4 reduction of cis-3,4-dimethylpentan-5-olide.5 ‡‡To reduce the number of steps, we tried to use both methyl 5-benzyloxypent- 2-ynoate and 5-benzyloxypent-2-ynal dimethyl acetal in the metathesis.However, they remained unchanged (cf. ref. 14). References 1 (a) M. Kobayashi, T. Koyama, K. Ogura, S. Seto, F. J. Ritter and I. E. M. Brüggemann-Rotgans, J.Am. Chem. Soc., 1980, 102, 6602; (b) F. J. Ritter, I. E. M. Brüggemann-Rotgans, P. E. J. Verwiel, C. J. Persons and E. Talman, Tetrahedron Lett., 1977, 30, 2617; (c) T. Koyama, M. Matsubara and K. Ogura, Naturwissenschaften, 1983, 70, 469. 2 H. A. Lloyd, T. H. Jones, A. Hefetz and J. Tengoe, Tetrahedron Lett., 1990, 31, 5559. 3 R. Baker, D. C. Billington and N.Ekanayake, J. Chem. Soc., Perkin Trans. 1, 1983, 1387. 4 D. W. Knight and B. Ojhara, J. Chem. Soc., Perkin Trans. 1, 1983, 955. 5 K. Mori and H. Ueda, Tetrahedron, 1982, 38, 1227. 6 K. Mori and N. Murata, Liebigs Ann. Chem., 1995, 2089. 7 T. Kasai, H. Watanabe and K. Mori, Bioorg. Med. Chem., 1993, 1, 67. 8 L. Poppe, L. Novak, P. Kolonits, A. Bata and C. Szantay, Tetrahedron, 1988, 44, 1477. 9 S. Kuwahara, Y. Shibata and A. Hiramatsu, Liebigs Ann. Chem., 1992, 993. 10 A. N. Kasatkin, T. Yu. Romanova, I. P. Podlipchuk and G. A. Tolstikov, Khim. Prir. Soedin., 1993, 459 [Chem. Nat. Compd. (Engl. Transl.), 1993, 23, 397]. 11 (a) E. Ott, Chem. Ber., 1928, 61, 2124; (b) S. Siegel and B. Dmuchovsky, J. Am. Chem. Soc., 1964, 86, 2192. 12 D. J. Pasto and R. T. Tayor, Org.React., 1991, 40, 91. 13 A. Kinoshita, N. Sakakibara and M. Mori, J. Am. Chem. Soc., 1997, 119, 12388. 14 A. Kinoshita, N. Sakakibara and M. Mori, Tetrahedron, 1999, 55, 8155. 15 (a) A. A. Vasil’ev, A. L. Vlasyuk, G. V. Kryshtal and E. P. Serebryakov, Izv. Akad. Nauk, Ser. Khim., 1995, 2026 (Russ. Chem. Bull, 1995, 44, 1946); (b) A. A. Vasil’ev and E. P. Serebryakov, Izv. Akad. Nauk, Ser. Khim., 1996, 2350 (Russ. Chem. Bull, 1996, 45, 2232). 16 (a) A. A. Vasil’ev, G. V. Kryshtal and E. P. Serebryakov, Mendeleev Commun., 1995, 41; (b) A. A. Vasil’ev, A. A. Vlasyuk, G. L. Gamalevich and E. P. Serebryakov, Bioorg. Med. Chem., 1996, 4, 389; (c) A. A. Vasil’ev, L. Engman and E. P. Serebryakov, Acta Chem. Scand., 1999, 53, 611. 17 M. Sodeoka and M. Shibasaki, Synthesis, 1993, 643. 18 W. S. Johnson, N. P. Jensen, J. Hooz and E. J. Leopold, J. Am. Chem. Soc., 1968, 90, 5872. 19 R. L. Willer and E. L. Eliel, J. Am. Chem. Soc., 1977, 99, 1925. 20 M. Uemura, T. Minami, K. Hirotsu and Y. Hayashi, J. Org. Chem., 1989, 54, 469. 21 A. J. Mancuso, S.-L. Huang and D. Swern, J. Org. Chem., 1978, 43, 2480. 22 B. S. Bal, W. E. Childers and H. W. Pinnick, Tetrahedron, 1981, 37, 2091. Received: 17th March 2000; Com. 00/1629
ISSN:0959-9436
出版商:RSC
年代:2000
数据来源: RSC
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Molecular structure of tris(aziridino)methane in the gas phase and crystalline state |
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Mendeleev Communications,
Volume 10,
Issue 3,
2000,
Page 103-106
Vladimir P. Novikov,
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摘要:
Mendeleev Communications Electronic Version, Issue 2, 2000 (pp. 83–124) Molecular structure of tris(aziridino)methane in the gas phase and crystalline state Vladimir P. Novikov,*a Marwan Dakkouri,b Alexey V. Golubinskii,a Mikhail V. Popik,a Lev V. Vilkov,a Pavel E. Dormov,c Konstantin A. Lyssenkod and Remir G. Kostyanovsky*c a Department of Chemistry, M. V. Lomonosov Moscow State University, 119899 Moscow, Russian Federation.Fax: +7 095 932 8846; e-mail: VPNovikov@phys.chem.msu.ru b Department of Electrochemistry, University of Ulm, 89069 Ulm, Germany. Fax: +49 731 502 5409; e-mail: marwan.dakkouri@chemie.uni-ulm.de c N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow, Russian Federation. Fax: +7 095 137 3227; e-mail: kost@center.chph.ras.ru d A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 117813 Moscow, Russian Federation. Fax:+7 095 135 5085; e-mail:kostya@xrlab.ineos.ac.ru 10.1070/MC2000v010n03ABEH001311 Tris(aziridino)methane has the preferred gauche–gauche–gauche conformation of C3 symmetry unlike the anti–anti–anti conformation of C3v symmetry in the crystal.Molecules possessing C3 symmetry are attractive test objects in many areas of chemistry,1 including the analysis of conformational equilibria, stereodynamics and stereoelectronic effects. Well-known examples related to the title compound are tris- (dialkylamino)methanes,2 trialkoxymethanes,3 trialkylmethanes,4 trialkylamines,5 triarylmethanes and triarylamines.6 Note that some of these molecules occur preferably in other symmetry forms than the C3 symmetry.We studied the molecular structure of tris(aziridino)methane† 1 by gas electron diffraction,‡ ab initio calculations§ and X-ray diffraction.¶ This compound is of interest because, in contrast to tris(dialkylamino)methanes,2 inversion of the aziridine nitrogen in 1 is hindered, and the electron-donor ability of its lone pair is weakened. Nevertheless, it was found that the participation of † The sample of 1 was synthesised using the published procedure7(a) and distilled in a vacuum, bp 50 °C (1 mmHg), mp 28.0–28.5 °C. 1H NMR (C6D6, 40 °C) d: 1.40 (br. s, 6H, cis-Ha of the ring relative to N–CH), 1.56 (br. s, 6H, trans-Hb of the ring relative to N–CH), 2.56 (s, 1H, HC). 13C NMR (C6D6, 40 °C) d: 22.80 (ddm, CH2N, 1JCHa 165.5 Hz, 1JCHb 176.0 Hz), 99.30 (ddm, CH, 1J 155.3 Hz).7(c) A sample of 1 was placed in a sealed evacuated (1 Torr) NMR tube; next, the sample was sublimed to the opposite cold end of the tube.Then the tube 50 mm long was cut off and used in electron diffraction experiment. An ampoule containing well-formed crystals was cooled with liquid nitrogen, then opened and a single crystal suitable for X-ray study was chosen.‡ The electron-diffraction photographs were obtained on an EG-100M unit with an accelerating voltage of 50 kV for two nozzle–photoplate distances (169.5 and 375.0 mm) at 20 °C. The electron wavelength was calibrated by the internal gas standard method9 using the data for benzene.10 According to our estimations, the scale error did not exceed 0.07%. The tracing of the plates and the data reduction are described elsewhere.11 Total scattering intensities were obtained in the ranges s = 2.25–16.875 and 8.25–40.0 Å–1.§ Ab initio quantum-chemical calculations for 1 were carried out by the following methods: HF/6-31G**, B3PW91/6-31G* and MP2/6-31G** using the programs SPARTAN 5.112(a) and GAUSSIAN 98.12(b) ¶ Crystallographic data for 1 at 110 K: crystals of C7H13N3 are hexagonal, space group P63, a = b = 13.249(3) Å, c = 7.846(3) Å, V = = 1192.8(5) Å3, Z = 6, M= 139.20, dcalc = 1.163 g cm–3, m(MoKa) = = 0.074mm–1, F(000) = 456.Intensities of 4904 reflections were measured with a Smart 1000 CCD diffractometer at 110 K [l(MoKa) = = 0.71072 Å, w-scans with a 0.4° step in w and 20 s per frame exposure, 2q < 55°] and 1799 independent reflections (Rint = 0.0598) were used in further refinement.The structure was solved by a direct method and refined by the full-matrix least-squares technique against F2 in the anisotropic- isotropic approximation. Hydrogen atoms were located from the Fourier synthesis and refined in the isotropic approximation.The refinement converged to wR2 = 0.2135 and GOF = 1.031 for all independent reflections [R1 = 0.0784 was calculated against F for 1165 observed reflections with I > 2s(I)]. All calculations were performed using SHELXTL PLUS 5.0 on IBM PC AT. Atomic coordinates, bond lengths, bond angles and thermal parameters have been deposited at the Cambridge Crystallographic Data Centre (CCDC).For details, see ‘Notice to Authors’, Mendeleev Commun., Issue 1, 2000. Any request to the CCDC for data should quote the full literature citation and the reference number 1135/66. stereoelectronic effects enhances the nitrogen inversion when the s-acceptor X is placed in the a-position (>N–C–X).8 It should be noted that the stereoelectronic (anomeric) effect was interpreted8( a) in terms of the n(N)–s*CX interaction for the first time.It was shown8(c) that the nitrogen inversion is facilitated only in the case of anti-periplanar orientation of the aziridine lone pair at the nitrogen atom relative to the CX bond. The barrier to the nitrogen inversion decreases on going from aziridinodimethylaminomethane (18.3 kcal mol–1)8(c) to 1 (17.1 kcal mol–1)7(c) and bis(aziridino)methoxymethane (16.5 kcal mol–1).7(c) Therefore, it is reasonable to expect that the conformation of 1 is stabilised by the anomeric effect. Conformational analysis of 1 is rather complicated because there are three rotating groups attached to a single C–H centre.The position of each of aziridine rings can be defined by the torsional angle j between the lone pair†† and the central C–H bond, where j = 0° corresponds to the eclipsed position of the lone pair and the C–H bond.For each of aziridine rings, there are three likely staggered positions labeled as a, g and g– (Figure 1). With 3 groups, the molecule has 3×3×3 = 27 staggered conformations, which reduce to 7 since the remaining 20 are either degenerated or enantiomeric forms (Table 1).The statistical weight of the conformations varies from 6 to 1 when the symmetry decreases from C3v to C1. According to ab initio calculations, g,g,g is the most stable conformation, as illustrated in Figure 2. The energy difference between the g,g,g conformation and the next a,g,g lower in energy is equal to 2.70, 1.93 and 2.14 kcal mol–1 as found by ††We assumed that the C–N(CH2)2 unit and the lone pair have the CS local symmetry with a common plane of symmetry.Therefore, here and below the torsional angles involving the lone pair were calculated with respect to this plane of symmetry. N N(CH2)2 (CH2)2N H N N(CH2)2 (CH2)2N H N N(CH2)2 (CH2)2N H (a) anti, j = 180° (g) gauche, j = 60° (g–) gauche, j = –60° j j Figure 1 Staggered conformations of tris(aziridino)methane.Mendeleev Communications Electronic Version, Issue 3, 2000 (pp. 83–124) the HF/6-31G**, B3PW91/6-31G* and MP2/6-31G** calculations, respectively. In the structural analysis based on the electron diffraction data, all seven models were investigated. To describe the molecular geometry of 1, we used the following assumptions based on the ab initio results: (1) all aziridine rings exhibit local C2v symmetry, and their structural parameters are identical; (2) three HCmethN fragments have local C3v symmetry.Accordingly, 12 geometrical parameters were used to describe the molecular geometry of 1: the Cmeth–N, Cring–N, C–C, C–Hmeth and C–Hring bond lengths, the HCmethN, CmethNCring, CCH and NCHring valence angles and the j1, j2 and j3 rotational angles for each ring.The amplitudes of vibrations and the perpendicular vibrational corrections were calculated from the scaled force field obtained from the HF/6-31G** calculations. For each of models 1–7, bond lengths and valence and torsional angles were refined with the initial values taken from ab initio calculations. As can be seen in Table 1 and Figure 3, the best agreement with the experiment is achieved for models 2 and 5 having g,g,g and a,g,g conformations.Based on the theoretical and experimental results, the g,g,g– conformer (model 6) seems to be less favourable. Apparently, this is the result of repulsive ring hydrogen–hydrogen interactions. The H···H nonbonded distances between the neighbouring aziridine rings of less than 0.8 Å support this way of rationalization.That is significantly less than the sum of van der Waals radii (2.40 Å). Therefore, model 6 was excluded from analysis, and only models 2 and 5 were refined using the standard procedure of structural analysis,13 which includes the background correction and refinement of mean-square amplitudes. At the final stage of structural analysis, model 2 was found to agree with the experimental data appreciably better than model 5.Note that a simultaneous refinement of the Cmeth–N, Cring–N and C–C bond lengths led to correlation coefficients up to 95%. Accordingly, they were varied using fixed differences between them obtained from ab initio calculations. The structural results obtained by electron diffraction analysis are compared with the calculated data in Table 2.Note that the valence angles around the central carbon atom of 1 differ considerably from the tetrahedral value 109.5°: �HCN 104.4(14)° and �NCN 114.0(11)°. The difference between the experimental (ra) and theoretical (re) j values is obviously due to the effect of torsional vibrations around C–N bonds. The experimental and theoretical values of the remaining geometrical parameters agree fairly good.Depending on the ab initio method, the deviations in bond lengths and bond angles vary in the ranges 0.008–0.02 Å and 2–3°, respectively. The aziridine ring geometry obtained for 1 indicates shortening of the Cring–N bond and elongation of the ring C–C bond by 0.010–0.015 Å as compared with the aziridine molecule where rs(C–N) = 1.475(3) Å and rs(C–C) = = 1.481(3) Å.14 aFor the tetrahedral configuration of bonds at the central C atom.bFor the optimised geometry of each conformation. cThe zero-point energy corrections were not included. Table 1 Conformations of tris(aziridino)methane; the R-factors and energy differences (DE) were found by the HF/6-31G** calculations. No. Definition Statistical weight Torsional anglea/° Symmetry R-factorb (%) DEb,c/kcal mol–1 j1 j2 j3 1 a,a,a 1 180 180 180 C3v 21.2 7.0 2 g,g,g 2 60 60 60 C3 5.6 0.0 3 a,g–,g 3 180 –60 60 CS 12.4 17.6 4 a,g,g– 3 180 60 –60 CS 10.6 6.4 5 a,g,g 6 180 60 60 C1 7.3 2.7 6 g,g,g– 6 60 60 –60 C1 8.8 14.5 7 a,a,g 6 180 180 60 C1 9.8 3.9 Figure 2 The g,g,g conformation of tris(aziridino)methane in the gas phase.H(20) H(19) C(13) H(22) H(23) C(21) N(9) C(3) N(2) C(8) H(10) H(6) C(1) H(7) H(11) N(4) H(17) C(5) H(15) H(16) H(14) H(18) aThe error limits are 3s, the parameters in braces were refined with fixed differences taken from ab initio calculations.bCalculated from independent geometrical parameters. Table 2 Geometry parameters of the g,g,g conformation of tris(aziridino)- methane (r/Å, �/°) obtained by gas electron diffraction (GED) and the HF/6-31G** calculations.Parametera GED (ra) Calculated (re) r(Cmeth–N) 1.471 (2) 1.449 r(Cring–N) 1.464 1.442av r(C–C) 1.497 1.475 �H–C–N 104.4(14) 106.1 �Cmeth–N–Cring 115.9(14) 120.1 j1 59.3 (17) 78 j2 59.3 78 j3 59.3 78 �N–C–Nb 114.0(11) 112.6 �lone pair–N–C–Nb 172.6(51) 166.3 R-factor 5.63% f(r) 0 1 2 3 4 5 6 r/Å a,a,a g,g,g a,g–,g a,g,g– a,g,g g,g,g– a,a,g Figure 3 Experimental (—) and theoretical ( ) radial distribution curves for models 1–7 (Table 1).Mendeleev Communications Electronic Version, Issue 2, 2000 (pp. 83–124) We can conclude that the g,g,g conformation is preferable for 1 in the gas phase. This result is consistent with the NMR data for tris(dialkylamino)methanes.2(a) Based on these data, less crowded triple rotors prefer a g,g,g conformation, while more crowded ones adopt an a,g,g arrangement. The predominance of the conformation obtained for 1 is consistent with the occurrence of the anomeric effect n(N)–s*CN.This result is supported by the orientation of lone pair relative to the (H)C–N bond, which is close to anti-periplanar: the lone pair–N–C–N dihedral angle is equal to 172.6±5.1° (exp.) or 166.3° (HF/6-31G** calculations).The X-ray study revealed that three independent molecules of 1 lie on the crystallographic C3 axis, and each of them has the a,a,a conformation of approximately C3v symmetry, as shown in Figure 4. This conformation is characterised by a much higher energy than the g,g,g conformation found in the gas phase (Table 1) and is evidently stabilised by the intermolecular Cring–H···N bonding in a crystal [r(Cring–H···N) = = 2.54 Å, �Cring–H···N = 145°].The remarkable difference between the NCN bond angles in the crystal and gas phase, 106.8° and 114.0°, respectively, should also be noted. With j = 176°, as determined in the crystal, the nitrogen lone pair orientation clearly indicates that only the n(N)–s*CH interaction is possible in the crystal unlike the anomeric effect n(N)– s*CN in the gas.Thus, the packing and stereoelectronic effects can dramatically change the conformation of 1 in the crystalline state as compared with the gas phase. The work was supported by the Russian Foundation for Basic Research (grant nos. 99-03-04004 and 00-15-97346) and Deutsche Forschungsgemeinschaft (DFG grant no. 436 RUS 113/69/3). References 1 (a) Ch. Moberg, Angew. Chem., Int. Ed. Engl., 1998, 37, 248; (b) M. M. Conn and J. Rebek, Chem. Rev., 1997, 97, 1647; (c) A. R. A. Palmans, J. A. J. M. Vekemans, E. E. Havinga and E. W. Meijer, Angew. Chem., Int. Ed. Engl., 1997, 36, 2648; (d) J. Gross, G. Harder, A. Siepen, J. Harren, F. Vogtle, H. Stephan, K. Gloe, B. Ahlers, K.Cammann and K. Rissanen, Chem. Eur. J., 1996, 2, 1585; (e) M. Fujita, N. Fujita, K. Ogura and K. Yamaguchi, Nature, 1999, 400, 52. 2 (a) J. E. Anderson, D. Casarini and L. Lunazzi, J. Org. Chem., 1996, 61, 1290; (b) I. Chao and J.-C. Chen, Angew. Chem., Int. Ed. Engl., 1996, 35, 195; (c) P. Seiler, G. R.Weisman, E. D. Glendening, F.Weinhold, V. B. Johnson and J. D. Dunitz, Angew.Chem., Int. Ed. Engl., 1987, 26, 1175. 3 (a) A. Spelbos, F. C. Mijlhoff and D. H. Faber, J. Mol. Struct., 1977, 41, 47; (b) N. Beaulieu and P. Deslongchamps, Can. J. Chem., 1980, 58, 875; (c) P. Deslongchamps, Tetrahedron, 1975, 31, 2463. 4 (a) I. Columbus and S. E. Biali, J. Org. Chem., 1993, 58, 7029; (b) J. E. Anderson, K. H. Koon and J. E. Parkin, Tetrahedron, 1985, 41, 561. 5 (a) M. Gaensslen, U. Gross, H. Oberhammer and S. Ridiger, Angew. Chem., Int. Ed. Engl., 1992, 31, 1467; (b) H. Bock, I. Goebel, Z. Havlas, S. Liedle and H. Oberhammer, Angew. Chem., Int. Ed. Engl., 1991, 30, 187; (c) C. H. Bushweller, in Acyclic Organonitrogen Stereodynamics, eds. J. B. Lambert and Y. Takeuchi, VCH, New York, 1992, ch. 1, p. 1. 6 K. S. Hayes, M. Nagumo, J. F. Blount and K.Mislow, J. Am. Chem. Soc., 1980, 102, 2773. 7 (a) W. Funke, Liebigs Ann. Chem., 1969, 725, 15; (b) R. G. Kostyanovsky, Yu. I. Elnatanov and Kh. Hafizov, Izv. Akad. Nauk SSSR, Ser. Khim., 1970, 1918 (Bull. Acad. Sci. USSR, Div. Chem. Sci., 1970, 19, 1815); (c) R. G. Kostyanovsky, R. K. Alekperov, G. K. Kadorkina and I. I. Chervin, Izv. Akad. Nauk SSSR, Ser. Khim., 1987, 2523 (Bull.Acad. Sci. USSR, Div. Chem. Sci., 1987, 36, 2343). 8 (a) V. F. Bystrov, R. G. Kostyanovsky, O. A. Pansin, A. U. Stepanyants and O. A. Yuzhakova, Opt. Spektrosk., 1965, 19, 217. (Engl. Transl.), 1965, 19, 122]; (b) R. G. Kostyanovsky, Z. E. Samojlova and I. I. Chervin, Tetrahedron Lett., 1968, 3025; (c) V. F. Rudchenko, S. M. Ignatov, I. I. Chervin, V. S. Nosova and R.G. Kostyanovsky, Izv. Akad. Nauk SSSR, Ser. Khim., 1986, 1153 (Bull. Acad. Sci. USSR, Div. Chem. Sci., 1986, 35, 1045). 9 A. V. Golubinskii, L. V. Vilkov, V. S. Mastryukov and V. P. Novikov, Vestn. Mosk. Univ., Ser. 2: Khim., 1979, 20, 99 (in Russian). 10 K. Tamagava, T. Iijima and M. Kimura, J. Mol. Struct., 1976, 30, 243. 11 M. V. Popik, Kristallografiya, 1994, 39, 332 [Crystallogr. Rep.(Engl. Transl.), 1994, 39, 286]. 12 (a) SPARTAN version 5.1, Wavefunction, Inc., Irvine, CA 92612, USA; (b) M. J. Frisch, G. W. Trucks, H. B. Schlegel, P. M. W. Gill, B. G. Johnson, M. A. Robb, J. R. Cheeseman, T. A. Keith, G. A. Petersson, J. A. Montgomery, K. Raghavachari, M. A. Al-Laham, V. G. Zakrzewski, J. V. Ortiz, J. B. Foresman, J. Cioslowski, B. B. Stefanov, D. J. Defrees, A. Nanayakkara, M. Challacombe, C. Y. Peng, P. Y. Ayala, W. Chen, M. W. Wong, J. L. Andres, E. S. Replogle, R. Gomperts, R. L. Martin, D. J. Fox, J. S. Binkley, J. Baker, J. P. Stewart, M. Head-Gordon, G. Gonzalez and J. A. Pople, GAUSSIAN 98, Gaussian Inc., Pittsburg PA, USA. 13 V. P. Novikov, S. Samdal and L. V. Vilkov. J. Mol. Struct., 1997, 413– 414, 279. 14 B. Bak and S. Skaarup, J. Mol. Struct., 1971, 10, 385. Figure 4 The a,a,a conformation of tris(aziridino)methane in a crystal. The average bond lengths and angles for three independent molecules are r(Cmeth–N) = 1.461(4) Å, r(Cring–N) = 1.476(6) Å, r(C–C) = 1.485(7) Å, �Cmeth–N–Cring = 114.2(4)°, �H–C–N = 112.0°, �N–C–N = 106.8° and j = 176°. H(20) C(19) H(13) H(22) H(23) H(21) N(10) C(1) N(3) H(8) H(9) H(6) C(12) H(7) C(11) C(4) N(17) C(5) H(15) H(16) H(14) C(18) Received: 30th March 2000; Com. 0
ISSN:0959-9436
出版商:RSC
年代:2000
数据来源: RSC
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| 13. |
Chirality-directed self-assembling of long-chain dialkyl 3,7-diazabicyclo[3.3.1]nonane-2,6-dione-1,5-dicarboxylates |
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Mendeleev Communications,
Volume 10,
Issue 3,
2000,
Page 106-108
Remir G. Kostyanovsky,
Preview
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摘要:
Mendeleev Communications Electronic Version, Issue 2, 2000 (pp. 83–124) Chirality-directed self-assembling of long-chain dialkyl 3,7-diazabicyclo[3.3.1]nonane-2,6-dione-1,5-dicarboxylates Remir G. Kostyanovsky,*a Konstantin A. Lyssenko,b Irina A. Bronzova,a Oleg N. Krutius,a Yurii A. Strelenkoc and Alexander A. Korlyukovb a N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow, Russian Federation.Fax: +7 095 938 2156; e-mail: kost@center.chph.ras.ru b A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 117813 Moscow, Russian Federation. Fax: +7 095 135 5085; e-mail: kostya@xray.ac.ru c N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow, Russian Federation. Fax: +7 095 135 5328; e-mail: strel@nmr.ioc.ac.ru 10.1070/MC2000v010n03ABEH001294 Dihexyl and didodecyl 3,7-diazabicyclo[3.3.1]nonane-2,6-dione-1,5-dicarboxylates 4a,b were synthesised, and the self-assembling of the molecules of strictly alternating configurations was observed in a crystal of bis-lactam 4b, which resulted in formation of H-bonded heterochiral polymer tapes of a diagonal zigzag type combined into monomolecular layers separated by hydrophobic groups.Bicyclic bis-lactams of C2 symmetry hold much promise for building supramolecular structures.1–8 It was shown recently6 that bis-lactam A in crystal is self-assembled into heterochiral H-bonded tapes of a diagonal zigzag type. The first similar motive of structure was reported for cyclo-di-b-alanine3,9 and then for bis-lactams of the [2.2.2],1,2,4,8 [3.3.0]5 and [3.3.1]6 series.Are the long-chained dialkyl dicarboxylates of bis-lactams capable of similar self-assembling in a crystal? This is an intriguing question because the interlayered suprastructures containing hydrophobic long alkyl chains are of interest in relation to the possibilities for creating monomolecular coats, surfactants, liquid crystals and other useful materials.In this work, an affirmative answer to the above question is given. Dihexyl and didodecyl 3,7-diazabicyclo[3.3.1]nonane-2,6- dione-1,5-dicarboxylates 4a,b were synthesised on the basis of bis-lactam 16 (Scheme 1).† The structures of 4a,b were confirmed by 1H and 13C NMR spectra, which are in good agreement with published data for similar compounds.6,7 The molecular and crystal structures of bis-lactam 4b were studied by X-ray diffraction.‡ In the basic geometric parameters of the skeleton, compound 4b is almost identical to its diethyl analogue A studied previously.6 Moreover, a comparison of the crystal structures of 4b and A indicates that the main packing motive remained unchanged upon the introduction of long-chain substituents.Likewise in a crystal of A, the molecules of 4b are linked in a crystal by N–H···O bonds into heterochiral infinite tapes of a diagonal zigzag type directed along the crystallographic axis b (Figure 1). In turn, the diagonal zigzags are combined by C–H···O contacts into layers parallel to the crystallographic plane ab (Figure 2). The distance between parallel zigzags is 7.04 Å, they are inclined to the plane ab at an angle of 54°.The C12-substituents are emerged from both sides of the plane and drawn out along the crystallographic directions [011] [O(11)–C(23)] and [011] [O(25)–C(37)]. Thus, the crystal structure of 4b is constructed from parallel layers with hydrophobic coatings formed by C12-substituents (Figure 3), the thickness is about 31 Å.The conformations of C12O-substituents are somewhat different. Thus, a deviation from the all-trans conformation in the chain O(11)–C(23) is observed for the terminal atoms C(22) and C(23) disordered at two positions, whereas in the chain O(25)–C(37) a deviation from the trans configuration is observed for the fragment O(26)–C(29). This can be caused by the participation of the O(4) atom in the formation of the above strong C–H···O contact that results in a distortion of the torsion † NMR spectra were recorded on Bruker WM 400, AM 300 and WM 250 spectrometers.All new compounds gave satisfactory elemental analysis data. 1: was obtained by known method,5 52.3% yield, mp 198–200 °C. 2: a mixture of 0.98 g (3.3 mmol) of diester 1 and 0.48 g (8.5 mmol) of KOH in 15 ml of a mixture of EtOH and H2O (2:1) was kept for 2 days at 20 °C and then for 1.5 h at 4 °C.The salt precipitate was separated, washed with EtOH and dried in air. Yield 0.82 g (78.4%). 1H NMR (CD3OD) d: 2.64 (s, 2H, 9-CH2), 3.60 (m, 4H, 4,8-CH2, AB, Dn 16.0, 2J –8.0 Hz), 4.48 (m, 4H, 3,7-NCH2, AB, Dn 172.0, 2J –14.6 Hz), 6.82 and 7.13 (m, 8H, 2C6H4). 3a: a mixture of 0.41 g (1.29 mmol) of 2, 15 mg of 18-crown-6 and 0.55 g (1.35 mmol) of hexyl bromide in 10 ml of dry DMF was boiled (9 h), cooled, diluted with a 10-fold excess of H2O, and extracted with diethyl ether (2×150 ml). The extract was dried over MgSO4 and evaporated. The ester was isolated as a light yellow oil and purified by gradient chromatography on silica [L40/100, eluent: hexane–ethyl acetate (5–15%)] in a yield of 0.19 g (36.6%). 1H NMR (CDCl3) d: 0.88 (t, 6H, 2MeCH2, 2J 6.7 Hz), 1.28 [m, 12H, 2(CH2)3Me], 1.63 (m, 4H, 2CH2CH2O), 2.60 (s, 2H, 9-CH2), 3.71 (m, 4H, 4,8-CH2, AB, Dn 16.0, 2J –12.8 Hz), 3.80 (s, 6H, 2MeO), 4.17 (m, 4H, 2CH2O), 4.51 (m, 4H, 3,7-NCH2, AB, Dn 264.0, 2J –14.5 Hz), 6.83 and 7.13 (m, 8H, 2C6H4). 13C NMR (CDCl3) d: 14.0 (2MeC), 22.47, 25.40, 28.31, 31.35 [2(CH2)4], 33.64, (9-CH2), 50.01 (3,7-NCH2), 50.10 (1,5-C), 52.91 (4,8-CH2), 55.19 (2MeO), 66.14 (2CH2O), 114.10, 127.84, 129.31, 159.18 (C6H4), 166.36, 168.92 (2,6-CO, 2CO2). 3b: was obtained similarly to 3a and isolated as a light yellow oil in 85.2% yield. 1H MNR (CDCl3) d: 0.85 (t, 6H, 2MeCH2, 3J 6.9 Hz), 1.25 [m, 36H, 2(CH2)9Me], 1.60 (m, 4H, 2CH2CH2O), 2.58 (s, 2H, 9-CH2), 3.68 (m, 4H, 4,8-CH2, AB, Dn 28.0, 2J –12.6 Hz), 3.77 (s, 6H, 2MeO), 4.15 (m, 4H, 2CH2O), 4.51 (m, 4H, 3,7-NCH2, AB, Dn 254.0, 2J –14.4 Hz), 6.81 and 7.11 (m, 8H, 2C6H4). 13C NMR (CDCl3) d: 14.13 (2MeC), 22.70, 25.77, 28.39, 29.36, 29.45, 29.51, 29.65, 31.92 [2(CH2)10], 33.65, (9-CH2), 50.04 (3,7-NCH2), 50.13 (1,5-C), 52.93 (4,8-CH2), 55.20 (2MeO), 66.18 (2CH2O), 114.15, 127.88, 129.34, 159.24 (C6H4), 166.44, 168.97 (2,6-CO, 2CO2).C(1) C(2) N(3) C(4) C(5) C(6) N(7) C(8) C(9) C(10) O(11) C(12) C(13) C(14) C(15) C(16) C(17) C(18) C(19) C(20) C(21) C(22) C(23) C(24) O(25) O(3) O(2) H(3) H(7) O(4) C(26) C(27) C(28) C(29) C(30) C(31) C(32) C(33) C(34) C(35) C(36) C(37) Figure 1 The general view of 4b and formation of the diagonal zigzag tape in the crystal structure.O(1)Mendeleev Communications Electronic Version, Issue 3, 2000 (pp. 83–124) ‡ Crystallographic data for 4b: at 110 K, crystals of C33H58N2O6 are triclinic, space group P , a = 9.7081(5), b = 11.0367(6), c = 17.1644(8) Å, a = 78.115(1), b = 74.050(1), g = 71.604(1)°, V = 1663.5(2) Å3, Z = 2, M= 578.81, dcalc = 1.156 g cm–3, m(MoKa) = 0.078 mm–1, F(000) = 636. Intensities of 15442 reflections were measured with a Smart 1000 CCD diffractometer at 110 K [l(MoKa) = 0.71072 Å, w-scans with a 0.3° step in w and 10 s per frame exposure, 2q < 60°], and 7620 independent reflections (Rint = 0.0272) were used in further refinement.The structure was solved by a direct method and refined by the full-matrix leastsquares technique against F2 in the anisotropic–isotropic approximation.The analysis of electron density synthesis have revealed additional maxima in the terminal part of the O(11)–C(20) moiety, which was interpreted as a disorder. The refinement of the occupancies for C(22), C(23) and C(22'), C(23') leads to 0.40 and 0.60, respectively. Hydrogen atoms were located from the Fourier synthesis and refined in the isotropic approximation. The refinement converged to wR2 = 0.1312 and GOF = = 0.863 for all independent reflections [R1 = 0.0483 was calculated against F for 4693 observed reflections with I > 2s(I)].All calculations were performed using the SHELXTL PLUS 5.0 program on IBM PC AT. Atomic coordinates, bond lengths, bond angles and thermal parameters have been deposited at the Cambridge Crystallographic Data Centre (CCDC).For details, see ‘Notice to Authors’, Mendeleev Commun., Issue 1, 2000. Any request to the CCDC for data should quote the full literature citation and the reference number 1135/65. angle O(25)–C(26)–C(27)–C(28) to 73.2° against 173.9° for O(11)–C(12)–C(13)–C(14). Apparently, this contact also affects the geometry of N–H···O bonds making the N(4)···O(2) distance longer than N(7)···O(1); this elongation was not observed in the case of A.6 This work was supported by INTAS (grant no. 157) and the Russian Foundation for Basic Research (grant nos. 00-03-32738 and 00-03-32807a). References 1 J.-M.Lehn, Supramolecular Chemistry, VCH, Weinheim, 1995. 2 M.-J. Brienne, J. Gabard, M. Leclercq, J.-M. Lehn, M. Cesario, C.Pascard, M. Cheve and G. Dutruc-Rosset, Tetrahedron Lett., 1994, 35, 8157. 3 J. C. MacDonald and G. M. Whitesides, Chem. Rev., 1994, 94, 2383. 4 R. G. Kostyanovsky, Yu. I. El’natanov, O. N. Krutius, I. I. Chervin and K. A. Lyssenko, Mendeleev Commun., 1998, 228. 5 R. G. Kostyanovsky, Yu. I. El’natanov, O. N. Krutius, K. A. Lyssenko, and Yu. A. Strelenko, Mendeleev Commun., 1999, 70. 6 R. G. Kostyanovsky, K. A. Lyssenko, Yu. I. El’natanov, O. N. Krutius, I. A. Bronzova, Yu. A. Strelenko and V. R. Kostyanovsky, Mendeleev Commun., 1999, 106. 7 R. G. Kostyanovsky, K. A. Lyssenko, D. A. Lenev, Yu. I. El’natanov, O. N. Krutius and I. A. Bronzova, Mendeleev Commun., 1999, 151. 8 R. G. Kostyanovsky, K. A. Lyssenko and D. A. Lenev, Mendeleev Commun., 1999, 154. 9 D. N. J.White and J. D. Dunitz, Israel J. Chem., 1972, 10, 249. 1 4a: H2O (32 ml) and CAN (32.4 g, 59 mmol) were added to a solution of 4.03 g (7.5 mmol) of 3a in 100 ml of MeCN, and the mixture was stirred for 10 min; the orange solution grew muddy and separated into layers. The mixture was kept for 2 days at 20 °C; next, 60 g of NaHCO3 was added in small portions. After the completion of gas evolution, 160 ml of MeCN was added, and the resulting precipitate was rubed with a spatula.The solution was poured off and evaporated, the residue was extracted with diethyl ether (2×160 ml) to separate anisaldehyde and then with ethyl acetate (2×200 ml). The evaporation of the last extract gave an orange oil, which was purified by gradient chromatography on silica [L40/100, eluent: hexane–ethyl acetate (5–30%)] and crystallised from light petroleum in a yield of 24.7%, mp 132–134 °C. 1H NMR (CDCl3) d: 0.88 (t, 6H, 2MeCH2, 3J 7.0 Hz), 1.30 [m, 12H, 2(CH2)3Me], 1.65 (m, 4H, 2CH2CH2O), 2.64 (s, 2H, 9-CH2), 3.73 (m, 4H, 4,8-CH2, ABX, Dn 32.0, 2J –12.7 Hz, 3JHCNH 4.0 Hz), 4.18 (t, 4H, 2CH2O, 3J 6.8 Hz), 7.38 (d, 2H, 3,7-NH, 3JHNCH 4.0 Hz). 13C NMR (CDCl3) d: 14.03 (2MeC), 22.51, 25.41, 28.31, 31.34 [2(CH2)4], 33.15 (9-CH2), 48.38 (3,7-NCH2), 49.36 (1,5-C), 66.42 (2CH2O), 168.62 (1,5-CCO), 169.20 (2,6-CO). 4b: was obtained similarly to 4a, 36.5% yield, mp 89–90 °C (from MeOH). 1H NMR (CDCl3) d: 0.88 (t, 6H, 2MeCH2, 3J 7.0 Hz), 1.27 [m, 36H, 2 (CH2)9Me], 1.65 (m, 4H, 2CH2CH2O), 2.65 (s, 2H, 9-CH2), 3.77 (m, 4H, 4,8-CH2, AB, Dn 38.0, 2J –12.6 Hz, 3JHNCH 4.0 Hz), 4.17 (m, 4H, 2CH2O), 6.74 (d, 2H, 3,7-NH, 3JHNCH 4.0 Hz). 13C NMR (CDCl3) d: 14.16 (2MeC), 22.73, 25.76, 28.39, 29.23, 29.40, 29.52, 29.67, 31.95 [2(CH2)10], 33.20, (9-CH2), 48.49 (3,7-NCH2), 49.43 (1,5-C), 66.46 (2CH2O), 168.58 (1,5-CCO), 169.14 (2,6-CO). The product is highly soluble in CHCl3, C6H6, toluene and glyme; less soluble in MeCN, MeOH, EtOH and acetone; poorly soluble in hexane, heptane and undecane (1.28 g in 100 ml), but insoluble in D2O (by 1H NMR data). When crystallising from undecane, no inclusion of the solvent into crystals was observed. N N O CO2Et EtO2C O R R N N O CO2K KO2C O R R 1 2 3 45 6 7 8 9 KOH MeOH A, 1 2 R' Br DMF 18-crown-6 N N O CO2R' R' O2C O R R 3a,b i, CAN MeCN–H2O ii, NaHCO3 N N O CO2R' R' O2C O H H 4a,b A R = H 1–3 R = 4-MeOC6H4CH2 a R' = n-C6H13 b R' = n-C12H25 Scheme 1 O(2) H(3) N(3) N(7) H(7) O(1') O(4'') H(4A) C(4) O(1) H(7') N(7') H(3') N(3') O(2') O(4) H(4A'') Figure 2 The formation of layers parallel to the crystallographic plane ab in the crystal structure of 4b; C10H22 groups are omitted for clarity. Figure 3 The formation of the hydrophobic coated (C12-substituents) layers in the crystal of 4b. Received: 2nd March 2000; Com. 00/1620
ISSN:0959-9436
出版商:RSC
年代:2000
数据来源: RSC
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| 14. |
Synthesis ofN-allylanilines by the reductive allylboration of aromatic nitro compounds |
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Mendeleev Communications,
Volume 10,
Issue 3,
2000,
Page 108-109
Yurii N. Bubnov,
Preview
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摘要:
Mendeleev Communications Electronic Version, Issue 2, 2000 (pp. 83–124) Synthesis of N-allylanilines by the reductive allylboration of aromatic nitro compounds Yurii N. Bubnov,* Dmitrii G. Pershin, Anatolii V. Ignatenko and Mikhail E. Gurskii N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow, Russian Federation. Fax: +7 095 135 5328; e-mail: bor@cacr.ioc.ac.ru 10.1070/MC2000v010n03ABEH001304 A new method for the synthesis of N-allylanilines and N,N-diallylanilines was developed on the basis of triallylborane reactions with aromatic compounds.Nitroarenes react with arylmagnesium1–3 and allylmagnesium3,4 halides to form products of the 1,2-addition at the N=O bond, which afford N,N-disubstituted hydroxylamines,1,3 secondary amines3,4 or nitrones4 depending on conditions of the subsequent treatment.Nitroarenes were alkylated at the ring under the action of aliphatic RMgX.3,5,6 Aniline, PhNHEt, PhNEt2, 2- and 4-EtC6H4NH2, etc., were identified among the products of the reaction between PhNO2 and Et3Al.7 We examined the transformations of nitroaromatic compounds (nitrobenzene, p-chloronitrobenzene, p-nitrobiphenyl and o-nitrobiphenyl) under the action of triallylborane.The reactions were performed by adding a nitroarene to triallylborane (1:3) heated to 80–100 °C (in a toluene or carbon tetrachloride solvent or without a solvent) followed by the treatment of the reaction mixture with an alkaline hydrogen peroxide solution or triethanolamine. We found that diallyl 1 and corresponding N-allylanilines 2a–d and N,N-diallylanilines 3a–d, which can be easily separated by chromatography or by distillation, were the main reaction products.In addition to 1–3, allyl alcohol (< 5%) and diene compounds 4 and 5 (< 5% in total) were identified in the reaction products. The latter resulted from the allylation of amine 2 at the side chain and the aromatic ring, respectively.Thus, triallylborane reacts with nitroarenes by 1,2-addition to the nitro group, and this reaction is the first example of the allylboration of compounds containing N=O bonds. The subsequent reduction of the adduct with an excess of triallylborane resulted in N-allylanilines 2. The redox reaction was accompanied by the generation of allyl radicals, which recombine to form diallyl 1, and radical substitution resulted in minor allylation products such as 3-(hexa-1,5-dienyl)aniline 4.Although the reductive allylboration of aromatic nitro compounds is a complex reaction, this reaction is a simple new route to convert a nitro group in aromatic compounds into an N-allylamine group. The structures of the prepared compounds were confirmed by elemental analysis, mass spectrometry, and 1H and 13C NMR spectroscopy.The chemical shifts d in 1H NMR spectra were measured with reference to the signals of residual chloroform.† This work was supported by the ISTC (project no. 419). † 2a: 60% yield; nD 20 1.5634 (lit.,8 1.5636). 1H NMR (200 MHz, CDCl3) d: 3.90 (br. s, 1H, NH), 3.95 (d, 2H, CH2N, J 5.8 Hz), 5.30–5.55 (m, 2H, CH2=, vinyl), 6.05–6.25 (m, 1H, CH=, vinyl), 6.80 (d, 2H, C2H, Ph, J 7.8 Hz), 6.95 (t, 1H, C4H, Ph, J 7.4 Hz), 7.35–7.45 (m, 2H, C3H, Ph). 13C NMR (50.32 MHz, CDCl3) d: 147.9 (C1, Ph), 135.3 (CH=, vinyl), 129.0 (C3, Ph), 117.25 (C4, Ph), 115.9 (CH2=, vinyl), 112.75 (C2, Ph) 46.25 (CH2N).MS, m/z: 133 (M+). 2b: 63% yield; nD 20 1.5784. 1H NMR (200 MHz, CDCl3) d: 4.00–4.10 (m, 3H, CH2N, NH), 5.40–5.70 (m, 2H, CH2=, vinyl), 6.15–6.35 (m, 1H, CH=, vinyl), 6.85 (d, 2H, C2H, Ph, J 8.8 Hz), 7.45 (d, 2H, C3H, Ph, J 8.8 Hz). 13C NMR (50.32 MHz, CDCl3) d: 146.5 (C1, Ph), 134.9 (CH=, vinyl), 128.9 (C3, Ph), 121.8 (C4, Ph), 116.3 (CH2=, vinyl), 113.9 (C2, Ph), 46.4 (CH2N). MS, m/z: 167 (M+). Found (%): C, 64.66; H, 6.10; N, 8.25; Cl, 21.09. Calc. for C9H10NCl (%): C, 64.44; H, 6.01; N, 8.35; Cl, 21.11. 2c: 60% yield; mp 63–64 °C. 1H NMR (200 MHz, CDCl3) d: 3.70–3.85 (m, 3H, CH2N, NH), 5.10–5.35 (m, 2H, CH2=, vinyl), 5.85–6.05 (m, 1H, CH=, vinyl), 6.65 (d, 2H, C2H, C6H4, J 7.7 Hz), 7.15–7.55 (m, 5H, C6H5, 2H, C3H, C6H4). 13C NMR (50.32 MHz, CDCl3) d: 147.4 (C1, C6H4), 141.4 (C1, C6H5), 135.2 (CH=, vinyl), 130.25 (C4, C6H4) 128.55 (C3, C6H4), 127.8 (C3, C6H5), 126.2 (C2, C6H5), 125.95 (C4, C6H5), 116.2 (CH2=, vinyl), 113.1 (C2, C6H4), 46.4 (CH2N).MS, m/z: 209 (M+). Found (%): C, 85.90; H, 7.46; N, 6.64. Calc. for C15H15N (%): C, 86.08; H, 7.22; N, 6.69. 2d: 46% yield; nD 20 1.6150. 1H NMR (200 MHz, CDCl3) d: 3.90 (d, 2H, CH2N, J 5.4 Hz), 4.25 (br. s, 1H, NH), 5.20–5.40 (m, 2H, CH2=, vinyl), 5.95–6.10 (m, 1H, CH=, vinyl), 6.80–7.60 (m, 9H, Ar). 13C NMR (50.32 MHz, CDCl3) d: 144.7 (C1, C6H4), 139.4 (C1, C6H5), 135.3 (CH=, vinyl), 130.1 (CH, Ar) 129.3 (CH, Ar), 128.8 (CH, Ar), 128.55 (CH, Ar), 127.6 (C2, C6H4), 127.1 (CH, Ar), 117.0 (CH, Ar), 115.7 (CH2=, vinyl), 110.7 (CH, Ar), 46.2 (CH2N). MS, m/z: 209 (M+). Found (%): C, 86.28; H, 7.26; N, 6.84. Calc. for C15H15N (%): C, 86.08; H, 7.22; N, 6.69. 3a: 10% yield; nD 20 1.5548 (lit.,8 1.5538). 1H NMR (200 MHz, CDCl3) d: 4.05 (d, 4H, CH2N, J 4.7 Hz), 5.25–5.35 (m, 4H, CH2=, vinyl), 5.85– 6.05 (m, 2H, CH=, vinyl), 6.70–6.85 (m, 3H, C2H, C4H, Ph), 7.25–7.35 (m, 2H, C3H, Ph). 13C NMR (50.32 MHz, CDCl3) d: 148.6 (C1, Ph), 133.9 (CH=, vinyl), 129.0 (C3, Ph), 116.2 (C4, Ph), 115.85 (CH2=, vinyl), 112.2 (C2, Ph) 52.6 (CH2N). MS, m/z: 173 (M+). 3b: 5.5% yield; nD 20 1.5695. 1H NMR (200 MHz, CDCl3) d: 3.75–3.85 (m, 4H, CH2N), 5.05–5.15 (m, 4H, CH2=, vinyl), 5.55–5.85 (m, 2H, CH=, vinyl), 6.55 (d, 2H, C2H, Ph, J 9.1 Hz), 7.05 (d, 2H, C3H, Ph, J 9.1 Hz). 13C NMR (50.32 MHz, CDCl3) d: 147.2 (C1, Ph), 133.5 (CH=, vinyl), 128.8 (C3, Ph), 121.0 (C4, Ph), 116.1 (CH2=, vinyl), 113.4 (C2, Ph), 52.9 (CH2N). MS, m/z: 207 (M+). R 3B 3 i, 80–100 °C ii, OH–/H2O2 HN N R R 1, 30–35% 2a–d 3a–d a R = H b R = p-Cl c R = p-Ph d R = o-Ph 60% 63% 60% 46% 10% 5.5% 9.5% 15% NO2 NH R 4 NH R 5 Ar NO2 Ar NHMendeleev Communications Electronic Version, Issue 3, 2000 (pp. 83–124) References 1 Y. Yost, H. R. Gutmann and C. C. Muscoplat, J. Chem. Soc. (C), 1971, 2119. 2 D. N. Kursanov and P. A. Solodkov, Zh. Obshch. Khim., 1935, 5, 1487 (in Russian). 3 G. Bartoli, E.Marcantoni, M. Bosco and R. Dalpozzo, Tetrahedron Lett., 1990, 29, 2251. 4 G. Bartoli, E. Marcantoni, M. Petrini and R. Dalpozzo, J. Org. Chem., 1988, 55, 4456. 5 G. Bartoli, M. Bosco, R. Dalpozzo and P. E. Todesco, J. Org. Chem., 1986, 51, 3694. 6 V. I. Savin, Zh. Org. Khim., 1978, 14, 2090 [J. Org. Chem. USSR (Engl. Transl.), 1978, 14, 1947]. 7 R. A. Sadykov, Izv. Akad. Nauk, Ser.Khim., 1998, 1979 (Russ. Chem. Bull., 1998, 47, 1924). 8 C. D. Hurd and W. W. Jenkins, J. Org. Chem., 1957, 22, 1418. 3c: 9.5% yield; nD 20 1.5834. 1H NMR (200 MHz, CDCl3) d: 3.95 (d, 4H, CH2N, J 4.9 Hz), 5.00–5.25 (m, 4H, CH2=, vinyl), 5.65–5.90 (m, 2H, CH=, vinyl), 6.75 (d, 2H, C2H, C6H4, J 9.1 Hz), 7.05–7.55 (m, 7H, Ar). 13C NMR (50.32 MHz, CDCl3) d: 147.8 (C1, C6H4), 141.2 (C1, C6H5), 133.8 (CH=, vinyl), 130.2 (C4, C6H4) 128.6 (C3, C6H4), 127.65 (C3, C6H5), 126.15 (C2, C6H5), 125.9 (C4, C6H5), 116.0 (CH2=, vinyl), 112.45 (C2, C6H4), 52.7 (CH2N). MS, m/z: 249 (M+). 3d: 15% yield; nD 20 1.5842. 1H NMR (200 MHz, CDCl3) d: 3.55 (d, 4H, CH2N, J 6.7 Hz), 5.10–5.20 (m, 4H, CH2=, vinyl), 5.55–5.85 (m, 2H, CH=, vinyl), 7.05–7.75 (m, 9H, Ar). 13C NMR (50.32 MHz, CDCl3) d: 148.55 (C1, C6H4), 141.5 (C, Ar), 136.0 (C, Ar), 135.0 (CH=, vinyl), 131.5 (CH, Ar), 129.0 (CH, Ar), 128.15 (CH, Ar), 127.6 (CH, Ar), 126.55 (CH, Ar), 122.35 (CH, Ar), 121.15 (CH, Ar), 117.1 (CH2=, vinyl), 54.7 (CH2N). MS, m/z: 249 (M+). Received: 17th March 2000; Com. 00/1630
ISSN:0959-9436
出版商:RSC
年代:2000
数据来源: RSC
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Nitrosochlorination of cembrene |
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Mendeleev Communications,
Volume 10,
Issue 3,
2000,
Page 109-111
Alexey V. Tkachev,
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摘要:
Mendeleev Communications Electronic Version, Issue 2, 2000 (pp. 83–124) Nitrosochlorination of cembrene Alexey V. Tkachev*a and Alexey V. Vorobjevb a Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russian Federation. Fax: +7 3832 34 4855; e-mail: atkachev@nioch.nsc.ru b N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russian Federation 10.1070/MC2000v010n03ABEH001240 The reaction of NOCl with cembrene at –50 °C in CH2Cl2 results in 1,2-addition to the conjugated system of double bonds.Cembrene 1 is the most widespread representative of cembranetype diterpenoids.1,2 Of the chemical properties of this natural compound, electrophilic cyclizations and oxidative transformations (Jones oxidation, oxidation by ozone and per acids, autoxidation, etc.) were studied.As a rule, reactions of NOCl with conjugated dienes result in tar-like products or complex mixtures of derivatives. We used the nitrosochlorination of cembrene at the system of conjugated double bonds for preparation of nitrogen-containing derivatives. Cembrene 1 does not form crystalline nitrosochlorides with alkyl nitrites in acidic media or with a solution of NOCl; a complex mixture resulted from the reaction in both cases.A cembrene molecule has two conjugated double bonds and is very reactive towards electrophilic addition. The reaction of cembrene with an NOCl solution completed in a second at –5–0 °C to form a tar. At a lower temperature, adduct 2 was formed, as evidenced by a bluish colour of the reaction mixture.The colour became dark brown on heating to –5–0 °C. The formation of adduct 2 was supported by the isolation of corresponding a-amino oximes after treatment of the reaction mixture with amines (Scheme 1). The amino oximes can be prepared in good yields as described below. A solution of NOCl in CH2Cl2 (1.1 ml, 1.8 mmol cm–3) was added to a solution of 1 (0.545 g, 2.0 mmol) in dry CH2Cl2 (20 ml) with stirring at –50 °C.A blue colour appeared immediately and disappeared after adding morpholine (0.52 g, 6.0 mmol) at the specified temperature. The reaction mixture was allowed to heat spontaneously to room temperature, and a crystalline precipitate was formed. The reaction mixture was heated and allowed to stand at reflux for 5 min.The mixture was diluted with light petroleum (40 ml) and extracted with 1 M aqueous HCl (2×10 ml). The combined acidic extracts were washed with tert-butyl methyl ether (10 ml), neutralised with concentrated aqueous ammonia and extracted with tert-butyl methyl ether (2×10 ml). The combined extracts were dried over MgSO4 and concentrated at reduced pressure to give 0.82 g of the crude product as viscous yellow oil, which became solid at staying for several hours.Crystallization from hexane affords morpholine derivative 4 (0.46 g, 59%).† Derivatives of ethanolamine 5‡ and 1 4 12 16 17 18 19 20 1 NOCl (1 equiv.)/CH2Cl2 –50–40 °C 2 H ON Cl +NR3 – NR3·HCl 3 ON HON N 4 HON NH 5 HON NH·HCl 6 O OH O HN OH NH2 NH2 O 7 N 1 3 12 16 17 18 19 20 15 PCl5 Scheme 1 15 † (1S,2E,4S,7E,11E)-4-(Morpholin-4-yl)cembra-2,7,11-trien-5-one (E)- oxime 4: white crystals (yield 59%) from hexane, mp 141–142 °C; [a]17 580 +305 (c 1.0, CHCl3).NMR spectra were measured on a Bruker AM-400 spectrometer, 400.13 and 100.61 MHz for 1H and 13C, respectively (0.32 mmol cm–3 in CCl4–C6D6, 4:1 v/v, 25 °C). 1H NMR (hereafter, 1H chemical shifts put in square brackets were taken from the 2D heteronuclear 13C–1H chemical shift correlation spectra), d: 1.70 (dddd, H-1, J 9.3, 9.3, 4.4 and 4.3 Hz), 5.20 (dd, H-2, J 15.7 and 9.3 Hz), 5.32 (d, H-3, J 15.7 Hz), 3.44 (dd, H-6, J 13.5 and 10.8 Hz), 3.10 (dm, H-6, J 13.5 Hz, W1/2 7 Hz), 5.47 (dd, H-7, J 10.8 and 3.0 Hz), [2.09, 2.04] (H-9), [2.10, 2.04] (H-10), 4.92 (br.s, H-11, W1/2 11 Hz), [1.90, 1.84] (H-13), [1.47, 1.23] (H-14), 1.49 (dqq, H-15, J 4.3, 6.8 and 6.7 Hz), 0.80 (d, H-16, J 6.7 Hz), 0.78 (d, H-17, J 6.8 Hz), 1.24 (s, H-18), 1.62 (t, H-19, J 1.3 Hz), 1.43 (d, H-20, J 0.8 Hz), 3.56 (dd, CH2OCH2, J 4.6 and 4.6 Hz), 2.51 and 2.20 (2dt, CH2NCH2, J 11.7 and 4.6 Hz), 9.48 (br. s, =NOH). 13C NMR, d: 46.59 (C-1), 133.86 (C-2, 1JC–H 151.5 Hz), 134.74 (C-3, 1JC–H 156.6 Hz, 2,3JC–H 3.7, 3.7 and 3.7 Hz), 66.16 (C-4, 2,3JC–H 2.9, 2.9, 2.9 and 2.9 Hz), 162.97 (C-5), 24.69 (C-6, 1JC–H 129.2 Hz, 2,3JC–H 3.3 Hz), 122.10 (C-7, 1JC–H 157.5 Hz), 133.46 (s, C-8 or C-12), 38.87 (C-9, 1JC–H 127.8 Hz), 23.63 (C-10, 1JC–H 125.3 Hz), 124.92 (C-11, 1JC–H 152.3 Hz), 132.16 (C-12 or C-8), 36.33 (C-13, 1JC–H 126.3 Hz), 28.05 (C-14, 1JC–H 126.4 Hz), 33.86 (C-15, 1JC–H 126.8 Hz), 20.98 (C-16, 1JC–H 124.7 Hz, 2,3JC–H 5×4.8 Hz), 19.68 (C-17, 1JC–H 124.5 Hz, 2,3JC–H 5×4.7 Hz), 11.49 (C-18, 1JC–H 127.0 Hz, 2,3JC–H 4.2 Hz), 15.65 (C-19, 1JC–H 125.0 Hz, 2,3JC–H 8.0, 3.9 and 3.9 Hz), 15.84 (C-20, 1JC–H 124.2 Hz, 2,3JC–H 8.4, 5.2 and 2.8 Hz), 67.79 (CH2OCH2, 1JC–H 142.6 Hz, 2,3JC–H 3.6 and 3.6 Hz), 47.31 (CH2NCH2, 1JC–H 132.6 Hz, 2,3JC–H 4.2 and 4.2 Hz).IR (CHCl3, n/cm–1): 3590 (nO–H). IR (KBr, n/cm–1): 1105 (dO–C), 980 (dCH=CH), 955 (nN–O). MS, m/z (%): 388.30856 (M+, 8), 371 (M+ – OH, 100), 303 (8), 301 (10), 286 (21), 284 (20), 260 (11), 258 (19), 208 (20), 166 (16), 140 (10), 107 (9), 95 (10), 93 (10), 86 (14), 81 (22), 79 (12), 69 (17), 67 (14), 57 (10), 55 (18). Found (%): C, 74.5; H, 10.5; N, 7.3.Calc. for C24H40N2O2 (%): C, 74.18; H, 10.37; N, 7.21.Mendeleev Communications Electronic Version, Issue 3, 2000 (pp. 83–124) benzylamine 6§ were prepared in the same manner. The amino oximes 4–6 exhibit the same properties as other a-amino oximes of terpenic nature:3 they are soluble in dilute aqueous solutions of inorganic acids and can be easily extracted back after neutralization with aqueous ammonia; they loss a tertiary amino group upon heating to 100 °C in toluene (compound 4) to form a mixture of unsaturated ketoximes; they easily undergo the Beckmantype fragmentation.Thus, the treatment4 of a solution of morpholino derivative 4 (0.33 g, 0.85 mmol) in CH2Cl2 with PCl5 (0.21 g, 1.0 mmol) at 10 °C resulted in 0.36 g of a pale yellow oil, which was purified by column chromatography on a silica gel column to give keto nitrile 7 (0.22 g, 86%).¶ The formation of amino oximes 4–6 proceeds via nitroso olefin 3 (as was found for other amino oximes3), which can be considered as a stereochemical analogue of starting cembrene 1.Thus, the conformational behaviour of the molecule of nitroso olefin 3 in a solution should resemble that of the molecule of cembrene 1, which is conformationally homogeneous, having the same conformation in a solution5 and in the crystal state.6 In such a form, double bonds are practically perpendicular to an imaginary plane of the macrocycle. Thus, addition reactions to the double bonds proceed stereoselectively to give products arising from an attack of a reagent from the outside plane of the double bond.7 Therefore, the addition of amines to nitroso olefin 3 should proceed stereochemically similar to the addition of electrophiles to the 4,5-double bond in 1 and lead to the S-configuration of carbon in the 4-position. This reaction stereochemistry was supported by NMR spectroscopy and calculated data.A comparison of chemical shifts and coupling constants for compounds 4–6 shows that all of the compounds have the same conformation of the macrocycle and the same configuration of the C4-carbon.An analysis of the spin–spin couplings 3JH–H for compounds 4–6 allows one to believe that in these molecules the conformation of the fragment containing C1–C4 atoms resembles that of a cembrene molecule: pseudoequatorial isopropyl, protons at C1–C3 and methyl at C-4 are almost in the same plane; H1 and H2 are antiperiplanar.An insignificant difference in the chemical shifts of H6a and H6b protons for ‡ (1S,2E,4S,7E,11E)-4-(2-Hydroxyethylamino)cembra-2,7,11-trien-5-one (E)-oxime 5. White crystals (55% yield) from hexane–CHCl3, mp 139– 141 °C; [a]17 580 +336 (c 1.0, CHCl3). NMR data (0.30 mmol cm–3 in C5D5N). 1H NMR (60 °C) d: 1.81 (dddd, H-1, J 9.9, 9.9, 4.7 and 4.7), 5.46 (dd, H-2, J 15.5 and 9.5 Hz), 5.83 (d, H-3, J 15.5 Hz), 3.68 (dm, H-6, J 13.2 Hz, W1/2 9 Hz), 3.62 (dd, H-6, J 13.2 and 10.2 Hz), 5.84 (dd, H-7, J 10.2 and 3.1 Hz), [2.17, 2.11] (H-9), [2.19, 2.05] (H-10), 5.14 (dd, H-11, J 4.4 and 4.4 Hz), [1.98] (H-13), [1.58] (H-14), 1.31 (dddd, H-14, J 13.6, 10.0, 4.9 and 4.9 Hz), [1.55] (H-15), 0.90 (d, H-16, J 6.8 Hz), 0.87 (d, H-17, J 6.9 Hz), 1.76 (br.s, H-18), 1.71 (br. s, H-19), 1.53 (br. s, H-20), 3.90 (dd, NCH2CH2O, J 5.5 and 5.5 Hz), 3.01 and 2.78 (2dt, NCH2CH2O, J 11.7 and 5.5 Hz), 12.00 (s, =NOH), 3.9 (br. s, CH2OH). 13C NMR (30 °C) d: 46.63 (C-1, 1JC–H 128.6 Hz), 130.67 (C-2, 1JC–H 147.5 Hz), 136.96 and 156.2 (C-3), 61.17 (C-4), 161.65 (C-5), 25.08 (C-6, 1JC–H 131.2 and 128.4 Hz, 2,3JC–H 2.5 Hz), 123.35 (C-7, 1JC–H 156.4 Hz), 133.40 (C-8 or C-12), 39.04 (C-9, 1JC–H 125.2 Hz), 23.59 (C-10, 1JC–H 126.3 Hz), 125.18 (C-11, 1JC–H 152.2 Hz), 132.59 (C-12 or C-8), 36.57 (C-13, 1JC–H 125.5 Hz, 2,3JC–H 7.3, 3.8 and 3.3 Hz), 28.16 (C-14, 1JC–H 124.8 Hz), 33.50 (C-15, 1JC–H 128.8 Hz), 20.83 (C-16, 1JC–H 124.6 Hz, 2,3JC–H 5×4.1 Hz), 19.40 (C-17, 1JC–H 124.6 Hz, 2,3JC–H 5×5.1 Hz), 20.56 (C-18, 1JC–H 127.2 Hz, 2,3JC–H 4.0 Hz), 14.99 (C-19, 1JC–H 125.2 Hz, 2,3JC–H 4.4 and 3.2 Hz), 15.07 (C-20, 1JC–H 125.0 Hz, 2,3JC–H 4.5 and 3.5 Hz), 62.44 (NCH2CH2O, 1JC–H 140.2 Hz, 2,3JC–H 6.9, 4.0 and 4.0 Hz), 46.08 (NCH2CH2O, 1JC–H 132.2 Hz).IR (CCl4, n/cm–1): 3599 (nO–H), 3309 (nN–H), 949 (nN–O). MS, m/z (%): 362.29333 (M+, 2), 346 (23), 345 (M+ – OH, 100), 317 (4), 303 (5), 302 (8), 301 (5), 286 (5), 285 (4), 284 (3), 274 (6), 258 (10), 182 (15), 140 (13), 114 (31), 95 (10), 86 (13), 81 (17), 79 (10), 69 (14), 67 (12), 55 (12), 41 (13). Found (%): C, 73.0; H, 10.5; N, 7.4.Calc. for C22H38N2O2 (%): C, 72.7; H, 10.5; N, 7.7. § (1S,2E,4S,7E,11E)-4-Benzylaminocembra-2,7,11-trien-5-one (E)-oxime hydrochloride 6.A solvate with 0.5 mol of acetonitrile. White crystals (68% yield) from acetonitrile, mp 131.5–133.0 °C (decomp.); [a]20 580 +90 (c 1.0, CHCl3). NMR data (0.25 mmol cm–3 in CDCl3, 30 °C). 1HNMR, d: 1.78 (ddd, H-1, J 8.9, 8.9, 4.8 and 3.7 Hz), 6.08 (dd, H-2, J 16.0 and 8.9 Hz), 5.67 (d, H-3, J 16.0 Hz), 3.16 (dd, H-6, J 15.5 and 7.9 Hz), 3.03 (dd, J 15.5 and 5.3 Hz), 4.97 (dd, H-7, J 7.9 and 5.3 Hz), [2.09, 2.03] (H-9), [2.23, 2.05] (H-10), 4.81 (dd, H-11, J 8.9 and 3.5 Hz), [1.99] (H-13), [1.55] (H-14), 1.42 (dddd, H-14, J 14.1, 9.5, 4.8 and 4.3 Hz), [1.68] (H-15), 0.89 (d, H-16, J 7.0 Hz), 0.91 (d, H-17, J 7.0 Hz), 1.69 (br.s, H-18), 1.57 (br. s, H-19), 1.50 (br. s, H-20), 3.92 and 3.89 (PhCH2N, AB-system, JAB 13.7 Hz), 7.60 (d, 2H, PhCH2N, J 7.2 Hz), 7.22 (m, 2H, PhCH2N), 7.20 (m, 1H, PhCH2N), 10.21 (s, =NOH), 10.1 and 8.6 (2br.s, NH2 +), 1.94 (s, MeCN). 13C NMR, d: 47.08 (C-1, 1JC–H 127.0 Hz), 141.13 (C-2, 1JC–H 149.1 Hz), 126.29 (C-3, 1JC–H 157.3 Hz), 65.85 (C-4), 155.97 (C-5), 24.70 (C-6, 1JC–H 129.5 Hz, 2,3JC–H 3.5 Hz), 118.72 (C-7, 1JC–H 153.8 Hz), 133.07 (C-8 or C-12), 38.25 (C-9, 1JC–H 125.0 Hz), 23.66 (C-10, 1JC–H 129.0 and 124.5 Hz), 124.93 (C-11, 1JC–H 150.8 Hz), 131.12 (C-12 or C-8), 36.32 (C-13, 1JC–H 125.0 Hz), 26.50 (C-14, 1JC-H 125.9 Hz), 32.18 (C-15, 1JC–H 125.5 Hz), 20.05 (C-16, 1JC–H 124.4 Hz, 2,3JC–H 5×5.1 Hz), 19.83 (C-17, 1JC–H 124.8 Hz, 2,3JC–H 5×4.4 Hz), 23.35 (C-18, 1JC–H 129.7 Hz), 15.33 (C-19, 1JC–H 125.2 Hz, 2,3JC–H 8.0, 3.9 and 3.9 Hz), 14.85 (C-20, 1JC–H 125.2 Hz, 2,3JC–H 8.5, 5.2 and 3.2 Hz), 47.60 (t, PhCH2N, 1JC–H 143.5 Hz), 131.01 (d, PhCH2N, 1JC–H 158.8 Hz, 2,3JC–H 6.4 and 6.4 Hz), 128.51 (d, PhCH2N, 1JC–H 160.4 Hz, 2,3JC–H 7.6 Hz), 128.75 (d, PhCH2N, 1JC–H 160.6 Hz, 2,3JC–H 7.6 and 7.6 Hz), 136.64 (s, PhCH2N), 1.57 (q, MeCN, 1JC–H 135.9 Hz), 116.09 (s, MeCN, 2,3JC–H 10.2 Hz).IR (KBr, n/cm–1): 1575 (dN–H), 1455 (nC=CAr), 977 (nN–O).MS, m/z (%): 408.31425 (M+, 4), 392 (30), 391 (M+ – OH, 98), 317 (15), 303 (17), 286 (13), 284 (15), 260 (11), 258 (12), 228 (12), 160 (21), 148 (8), 107 (21), 106 (47), 95 (8), 92 (10), 91 (100), 81 (14), 79 (15), 69 (10), 67 (11), 55 (12), 41 (18), 36 (11), 32 (11). Found (%): C, 72.2; H, 9.1; Cl, 7.5; N, 7.1. Calc. for C27H41ClN2O· ·0.5CH3CN (%): C, 72.23; H, 9.20; Cl, 7.61; N, 7.52.¶ (3E,7E,11S,12E)-11-Isopropyl-4,8-dimethyl-14-oxopentadeca-3,7,12- trienenitrile 7. Viscous yellowish oil, [a]14 580 –10 (c 1.0, CHCl3). NMR data (0.73 mmol cm–3 in CDCl3, 30 °C). 1H NMR, d: 2.93 (dq, H-2, J 7.0 and 0.7 Hz), 5.05 (ttq, H-3, J 7.0, 1.3 and 1.3 Hz), [1.95] (H-5), [1.98] (H-6), 4.94 (tq, H-7, J 6.7 and 1.2 Hz), [1.82, 1.73] (H-9), [1.52] (H-10), 1.30 (dtd, H-10, J 13.5, 9.6 and 5.3 Hz), [1.84] (H-11), 6.49 (dd, H-12, J 15.9 and 9.6 Hz), 5.89 (d, H-13, J 15.9 Hz), 2.14 (s, H-15), 1.56 (br.s, H-16), 1.46 (d, H-17, J 1.2 Hz), [1.60] (H-18), 0.80 (d, H-19, J 6.7 Hz), 0.75 (d, H-20, J 6.7 Hz). 13C NMR, d: 118.04 (C-1), 15.70 (C-2), 111.49 (C-3), 134.83 (C-4), 38.70 (C-5), 25.57 (C-6), 123.35 (C-7), 141.60 (C-8), 37.00 (C-9), 29.29 (C-10), 48.40 (C-11), 150.20 (C-12), 131.90 (C-13), 197.79 (C-14), 26.49 (C-15), 15.89 (C-16), 15.52 (C-17), 31.21 (C-18), 20.20 (C-19), 18.76 (C-20).IR (CCl4, n/cm–1): 2245 (nCºN), 1690, 1675, 1630 (nC=O, nC=C), 1250, 980 (dCH=CH). UV [EtOH, lmax/nm (lg e)]: 227 (3.83). MS, m/z (%): 301.24041 (M+, 7), 286 (2), 258 (14), 243 (4), 216 (2), 207 (4), 189 (8), 163 (7), 149 (15), 139 (23), 126 (14), 123 (12), 121 (16), 109 (21), 107 (22), 97 (35), 95 (28), 93 (24), 81 (53), 79 (16), 71 (38), 69 (24), 68 (15), 67 (27), 55 (28), 53 (12), 43 (100), 41 (28).Figure 1 Molecular structure of the most stable conformation of compound 4. The characteristic dihedral angles and calculated and experimental spin–spin coupling constants are as follows: H1–C1–C2–H2 +158°, 3Jcalc. 10.3 Hz (3Jexp. 9.3 Hz); H1–C1–C14–H14a –160°, 3Jcalc. 11.5 Hz (3Jexp. 9.3 Hz); H1–C1–C14–H14b –49°, 3Jcalc. 2.3 Hz (3Jexp. 4.3 Hz); H6a–C6– C7–H7 +63°, 3Jcalc. 3.4 Hz (3Jexp. 3.0 Hz); H6b–C6–C7–H7 +163°, 3Jcalc. 10.8 Hz, (3Jexp. 10.8 Hz); H1–C1–C15–H15 +65°, 3Jcalc. 3.4 Hz (3Jexp. 4.4 Hz). 1 2 3 4 6 7 9 14 15 18Mendeleev Communications Electronic Version, Issue 2, 2000 (pp. 83–124) compounds 4–6 (DdH = 0.05–0.3 ppm), as compared to known amino oximes with six-membered carbocycles (0.7–1.4 ppm),8 indicates that there is another type of orientation of the methylene group adjacent to the oxime moiety. Such a disposition is possible in the case of a synclinal position of protons of the methylene group and the oxime moiety. The methyl C-18 group is antiperiplanar to H-2 [nuclear Overhauser effect (3H18�H2)].Conformational anaylsis by molecular mechanics (MM2) and quantum-chemical semiempirical calculations (MNDO, PM3) show that there are at least six stable low-energy conformations (DDHf 0 = 0.0, 1.7, 3.4, 3.5, 3.6 and 5.4 kcal mol–1), which differ in the orientation of endocyclic carbon–carbon double bonds. The calculated couplings 3JH–C(sp2)–C(sp3)–H (obtained by a known equation9) for the least strained conformation of morpholino derivative 4 are in good agreement with the experimental values (Figure 1).This work was supported by the Russian Foundation for Basic Research (grant no. 96-15-97017) and INTAS (granto. 97-0217). References 1 (a) A. J. Haagen-Smit, T. H. Wang and N. T. Mirov, J. Am. Pharm.Assoc., 1951, 40, 557; (b) W. G. Dauben, W. E. Thiessen and P. R. Resnick, J. Am. Chem. Soc., 1962, 84, 2015; (c) H. Kobayashi and S. Akiyoshi, Bull. Chem. Soc. Jpn., 1962, 35, 1044. 2 (a) A. J. Wienheimer, C. W. J. Chang and J. A. Matson, Fortschr. Chem. Org. Naturst., 1979, 36, 285; (b) I. Wahlberg and A.-M. Eklund, Fortschr. Chem. Org. Naturst., 1992, 59, 141. 3 A. V. Tkachev, Ross.Khim. Zh., 1998, 42, 42 (in Russian). 4 A. V. Tkachev, A. V. Rukavishnikov, A. M. Chibirjaev and L. B. Volodarsky, Synth. Commun., 1990, 20, 2123. 5 (a) A. V. Vorob’ev, G. E. Salnikov, M. M. Shakirov and V. A. Raldugin, Khim Prir. Soedin., 1991, 455 [Chem. Nat. Compd. (Engl. Transl.), 1991, 396]; (b) C. Muller, L. Ma and P. Bigler, J. Mol. Struct. (Teochem.), 1994, 308, 25. 6 M. G. B. Drew, D. H. Templeton and A. Zalkin, Acta Crystallogr., 1969, 25B, 261. 7 Epoxidation by per acids: (a) V. A. Raldugin, L. Ya. Korotkih, A. I. Rezvukhin and V. A. Pentegova, Khim. Prir. Soedin., 1977, 525 [Chem. Nat. Compd. (Engl. Transl.), 1977, 439]; (b) V. A. Raldugin, N. I. Yaroshenko and Yu. V. Gatilov, Khim. Prir. Soedin., 1981, 174 [Chem. Nat. Compd. (Engl. Transl.), 1981, 133]; photooxidation: (c) V. A. Raldugin, V. L. Salenko, N. I. Yaroshenko, V. G. Storozhenko, A. I. Rezvukhin and V. A. Pentegova, Khim. Prir. Soedin., 1981, 60 [Chem. Nat. Compd. (Engl. Transl.), 1981, 54]; oxidation by SeO2: (d) V. A. Raldugin, L. Ya. Korotkih, N. I. Yaroshenko and V. A. Pentegova, Khim. Prir. Soedin., 1978, 410 [Chem. Nat. Compd. (Engl. Transl.), 1978, 348]; (e) A. V. Vorob’ev, M. M. Shakirov and V. A. Raldugin, Sib. Khim. Zh., 1991, 6, 83 (in Russian). 8 A. V. Tkachev, A. Yu. Denisov, A. V. Rukavishnikov, A. M. Chibirjaev, Yu. V. Gatilov and I. Yu. Bagrjanskaja, Aust. J. Chem., 1992, 45, 1077. 9 E. W. Garbish, Jr., J. Am. Chem. Soc., 1964, 86, 5561. Received: 1st December 1999; Com. 99/1566
ISSN:0959-9436
出版商:RSC
年代:2000
数据来源: RSC
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Synthesis of chiral fused pyrimidines from (+)-3-carene- and limonene-derived isomeric β-enaminones |
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Mendeleev Communications,
Volume 10,
Issue 3,
2000,
Page 112-114
Sergey A. Popov,
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摘要:
Mendeleev Communications Electronic Version, Issue 2, 2000 (pp. 83–124) Synthesis of chiral fused pyrimidines from (+)-3-carene- and limonene-derived isomeric -enaminones Sergey A. Popova and Alexey V. Tkachev*b a Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russian Federation b N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russian Federation. Fax: +7 3832 34 4752; e-mail: atkachev@nioch.nsc.ru 10.1070/MC2000v010n03ABEH001199 New heterocyclic compounds, pyrimidines annelated with modified terpenic frames, were synthesised from positional isomers of b-enaminones derived from limonene and (+)-3-carene.Chiral fused heterocycles (mainly pyrazoles and pyridines) were reported to be useful for the preparation of optically active complexes, chiral auxiliaries1,2 or resolving agents.3 Chiral heterocycles containing pyrimidine moiety are less studied although fused pyrimidines are promising chiral auxiliaries and biologically active compounds.4 We report the preparation of new chiral fused pyrimidines with terpene-based carbon frames from readily accessible enaminones 1 and 25 and new enaminones 9 and 10 prepared from diketones 4 and 7.3,6 Cyclic b-hydroxymethylene ketones, including camphor derivatives, can be used in reactions with guanidine affording fused 2-aminopyrimidine derivatives.7 We failed to apply this method to the synthesis of pyrimidines from acetylcyclopentanone analogues 4 and 7.The refluxing of a mixture of diketones 4 or 7 and guanidine or amidines (benzamidine, acetamidine) as free bases or as their carbonates in methanol or n-butanol gave only traces of pyrimidine-type compounds.Treatment of acyclic b-enaminones with cyanamide in aqueous solutions on heating was reported to be a facile method for preparation of 2-aminopyrimidines.8 Enaminone 1, derived from (+)-3-carene, is inert towards cyanamide under the conditions specified.8 The inertness of compound 1 is stipulated by hindrance of an enamine fragment with one of the methyls of the cyclopropane moiety.3 On the other hand, we found that compound 1 can be transformed into 2-aminopyrimidine 5 under more severe conditions.For example, the reaction of compound 1 with cyanamide in benzene in the presence of an equimolar amount of p-toluensulfonic acid under the distillation of water afforded 2-aminopyrimidine 5 in a good yield (82%)† (Scheme 1).Analogous limonene-derived enaminone 2, which is more reactive than compound 1, reacted with cyanamide in hot aqueous † The procedure. A mixture of CNNH2 (40.0 mmol, 1.68 g) and enaminone 1 (20.0 mmol, 3.30 g) was added in one portion to a hot solution of anhydrous p-TsOH (20 mmol) in dry C6H6 (80 ml) with stirring.The reaction mixture was vigorously stirred under azeotropic distillation of water for 20–30 min and then cooled to room temperature. The resulting solution was washed with 1 M aq. H2SO4 (2×20 ml), and the aqueous phase was neutralised with aq. NH3 (30 ml) and extracted with CHCl3 (4×25 ml).The organic phase was dried with anhydrous Na2SO4, the solvent was distilled off and the residue was chromatographed on a short silica gel column (CHCl3) to give the crude product, which was then crystallised from EtOH–MeCN. (1aR,6aR)-1,1,2-Trimethyl-1,1a,6,6a-tetrahydro-3,5-diazacyclopropa- [a]inden-4-ylamine 5. CNNH2 and enaminone 1 in the presence of p-TsOH afforded 82% of pyrimidine 5; reaction of enaminone 9 with aqueous CNNH2 afforded 90% of pyrimidine 5.Pale yellow crystals, mp 181–183 °C (EtOH–MeCN), [a]20 +31 (c 1.21, EtOH). 1H NMR (CDCl3, 200 MHz) d: 5.31 (br. s, 2H, NH2), 2.92 (dd, 1H, H-5b, J 18.7 and 7.4 Hz), 2.54 (ddd, 1H, H-5a, J 18.7, 1.4 and 1.0 Hz), 2.21 (s, 3H, H-1), 1.94 (dd, 1H, H-7, J 6.9 and 1.4 Hz), 1.37 (ddd, 1H, H-6, J 7.4, 6.9 and 1.0 Hz), 1.06 (s, 3H, H-9), 0.56 (s, 3H, H-10). 13C NMR (CDCl3, 50 MHz) d: 176.27 (s, C-4), 162.05 (s, C-2), 161.73 (s, C-3), 123.18 (s, C-11), 33.52 (t, C-5), 31.22 (d, C-7), 26.32 (q, C-9), 25.39 (d, C-6), 21.53 (s, C-8), 21.15 (q, C-1), 13.70 (q, C-10).IR (CHCl3, n/cm–1): 3530, 3425, 3300, 3180, 1600, 1570, 1475, 1380, 1295, 860, 820. UV [EtOH, lmax/nm (e)]: 241 (15380), 312 (4590).MS, m/z (%): 189.1262 (M+, 43), 174 (100), 147 (7), 146 (9), 133 (41), 118 (8), 106 (6), 91 (13), 77 (6), 65 (5). solutions (the procedure was analogous to that described in ref. 8) for 5–6 h to give corresponding 2-aminopyrimidine derivative 8 in good yield (85%).‡ The synthesis of 2-(1-aminoethylidene)cyclopentanone-type enaminoketones is well documented: reaction of 2-acetylcyclopentanone with NH3 in EtOH is known to proceed regioselectively to give 2-(1-aminoethylidene)cyclopentanone in a very good yield.9 Our effort to apply this method to diketones 4 and 7 was unsuccessful.Under the recommended conditions, the formation of stable ammonium salts of the enols of diketones was initially observed. The prolonged treatment of the diketones with NH3 in EtOH resulted in poor yields of the enaminones.w-Ketoesters, products of retro-condensation of b-diketones, were the main reaction products (20–35%) accompanied by a number of unidentified by-products. When diketones 4 and 7 were treated with a 1- to 4-molar excess of NH4OAc in C6H6 under reflux (as described in ref. 10) aminoethylidene derivatives 9§ and 10¶ were obtained in very good yields.We found that compounds 9 and 10 are much more reactive than enaminones 1 and 2 (Table 1). Thus, the treatment of enaminones 9 and 10 with aqueous CNNH2 on heating for 1 h (according to ref. 8) resulted in aminopyrimidines 5 and 8 in ‡ (±)-6-Isopropenyl-4-methyl-6,7-dihydro-5H-cyclopentapyrimidin-2-ylamine 8. The reaction of enaminone 2 or enaminone 10 afforded 85% or 95% of pyrimidine 8, respectively.Pale yellow crystals, mp 138–139 °C (MeCN–EtOH). 1HNMR (CDCl3, 200 MHz) d: 5.51 (br. s, 2H, NH2), 4.69 (br. s, 1H, H-10), 4.66 (br. s, 1H, H-10), 3.1–2.4 (m, 5H, H-5, H-6 and H-7), 2.14 (s, 3H, H-1), 1.66 (br. s, 3H, H-9). 13C NMR (CDCl3, 50 MHz) d: 173.55 (s, C-4), 162.45 (s, C-11), 161.94 (s, C-2), 146.61 (s, C-8), 121.28 (s, C-3), 109.57 (t, C-10), 43.47 (d, C-6), 38.46 (t, C-5), 32.54 (t, C-7), 21.08 (q, C-1), 20.32 (q, C-10).IR (CHCl3, n/cm–1): 3540, 3425, 3300, 3175, 1600, 1575, 1440, 1380, 940, 890. UV [EtOH, lmax/nm (e)]: 231 (5680), 253 (1010), 301 (2115). MS, m/z (%): 189.1264 (M+, 100), 188 (93), 174 (63), 160 (8), 148 (23), 147 (24), 133 (29), 120 (5), 119 (6), 106 (16), 91 (13), 80 (7), 79 (9), 77 (10), 65 (9), 53 (12), 43 (11), 42 (9), 41 (8), 39 (12).§ (1R,5R)-2-(1-Aminoethylidene)-6,6-dimethylbicyclo[3.1.0]hexan-3-one 9. Yellow crystals, 91% yield, mp 116–118 °C (after vacuum sublimation); [a]19 –116 (c 1.2, CHCl3). 1H NMR (CDCl3, 200 MHz) d: 8.6 (br. s, 1H, NH, W1/2 80 Hz), 5.3 (br. s, 1H, NH, W1/2 80 Hz), 2.38 (dd, 1H, H-5b, J 19.5 and 7.5 Hz), 1.95 (d, 1H, H-5a, J 19.5 Hz), 1.83 (s, 3H, H-1), 1.53 (d, 1H, H-7, J 7.5 Hz), ~0.94 (m, 1H, H-6), 0.93 (s, 3H, H-9), 0.67 (s, 3H, H-10). 13C NMR (CDCl3, 50 MHz) d: 203.89 (s, C-4), 155.89 (s, C-2), 104.63 (s, C-3), 37.69 (t, C-5), 30.04 (d, C-7), 26.32 (q, C-9), 21.34 (s, C-8), 20.90 (d, C-6), 20.19 (q, C-1), 14.08 (q, C-10). IR (CHCl3, n/cm–1): 3500, 3240, 1650, 1600, 1515, 1240, 925, 860. UV [EtOH, lmax/nm (e)]: 334 (12700).MS, m/z (%): 165.1155 (M+, 44), 150 (100), 133 (21), 122 (20), 107(5), 105 (12), 94 (10), 91 (5), 81 (6), 80 (5), 79 (9), 69 (15), 68 (14), 53 (8), 42 (45), 41 (17), 39 (12). b Table 1 Preparation of aminopyrimidines 5 and 8 by treatment of enaminones with cyanamide in aqueous solutions. b-Enaminone Reaction time/h Final product Yield (%) 1 12 5 traces 2 6 8 85 9 1 5 90 10 1 8 95Mendeleev Communications Electronic Version, Issue 3, 2000 (pp. 83–124) excellent yields (90–95%). The main reason of the greater reactivity of isomeric enaminones 9 and 10 as compared to 1 and 2 seems to be the absence of steric hindrance of the attack of a reagent on the enamine moiety. The reaction of enaminones with trimethyl orthoformate in the presence of NH3 was studied in order to prepare 2-unsubstituted pyrimidines.Moderate yields of pyrimidine derivatives 3 and 6 were obtained when enaminones 1, 2, 9 or 10 were treated with (MeO)3CH in MeCN media saturated with NH3 in a bomb at 120 °C for 10–12 h. The other route to the above products included treatment of enaminones 1, 2, 9 or 10 with (MeO)3CH and NH4OAc in C6H6 under the distillation of water.†† The latter method afforded better yields of pyrimidines 3‡‡ and 6.§§ ¶ (±)-2-(1-Aminoethylidene)-4-isopropenylcyclopentanone 10.Yellow crystals, 84% yield, mp 68–70 °C (MeCN). 1H NMR (CDCl3, 200 MHz) d: 8.89 (br. s, 1H, NH, W1/2 60 Hz), 5.75 (br. s, 1H, NH, W1/2 60 Hz), 4.56 (br. s, 2H, H-10), 2.7–2.4 (m, 2H, H-5), 2.3–2.0 (m, 3H, H-6 and H-7), 1.76 (s, 3H, H-1), 1.59 (br.s, 3H, H-9). 13C NMR (CDCl3, 50 MHz) d: 200.88 (s, C-4), 155.75 (s, C-8), 146.92 (s, C-2), 108.96 (t, C-10), 102.22 (s, C-3), 43.12 (t, C-5), 41.05 (d, C-6), 32.19 (t, C-7), 20.29 (q, C- 1), 19.78 (q, C-9). IR (CHCl3, n/cm–1): 3500, 3230, 1640, 1600, 1515, 1230, 915, 870. UV [EtOH, lmax/nm (e)]: 318 (19650). MS, m/z (%): 165.1153 (M+, 75), 150 (12), 137 (13), 123 (34), 122 (29), 108 (15), 69 (100), 68 (13), 54 (9), 43 (11), 42 (27), 41 (14).††(MeO)3CH (5.00 g, 51.5 mmol) and AcONH4 (4.00 g, 51.9 mmol) were added to a solution of enaminone 1, 2, 9 or 10 (1.65 g, 10.0 mmol) in C6H6 (80 ml) with stirring. The reaction mixture was stirred vigorously under the azeotropic distillation of water for 4 h and then cooled to room temperature. Concentrated aq.NH3 (10 ml) and water (50 ml) were added, and the mixture was extracted with C6H6 (2×20 ml). The organic extract was dried with Na2SO4, the solvent was distilled off and the residue was treated with an excess of AcCl (7 mmol) in a mixture of pyridine (7 mmol) and CHCl3 (20 ml). The resulting mixture was stirred for 10 min, washed with water (30 ml) and treated with 1 M aq.H2SO4 (2×20 ml). The acidic extract was neutralised with concentrated aq. NH3 (30 ml) and extracted with CHCl3 (3×25 ml). The combined organic extracts were dried with Na2SO4, the solvent was distilled off and the residue was chromatographed on a short silica gel column (C6H6) to give crude pyrimidine 3 or 6 as yellow oil. Analytical samples were obtained by vacuum sublimation of the crude products.This work was supported by the Russian Foundation for Basic Research (grant nos. 96-03-33222, 96-15-97017 and 98 03-32910), the Competitive Centre on Natural Sciences at the St. Petersburg University (grant no. 95-0-9.4-102) and INTAS (grant no. 97-0217). References 1 C. Kashima, I. Fukuchi, K. Takahashi and A. Hosomi, Tetrahedron, 1996, 52, 10335. 2 M. Gianini and A. von Zelevsky, Synthesis, 1996, 702. 3 S. A. Popov and A. V. Tkachev, Tetrahedron: Asymmetry, 1995, 6, 1013. ‡‡ (1aR,6aR)-1,1,2-Trimethyl-1,1a,6,6a-tetrahydro-3,5-diazacyclopropa- [a]indene 3. The reaction of enaminone 1 with trimethyl orthoformate– ammonium acetate afforded 53% of pyrimidine 3; the reaction of enaminone 9a afforded 58% of compound 3. Yellow oil, [a]20 +50.5 (c 0.48, CHCl3). 1H NMR (CDCl3, 200 MHz) d: 8.62 (s, 1H, H-11), 3.05 (dd, 2H, H-5b, J 19.0 and 7.4 Hz), 2.72 (ddd, 2H, H-5a, J 19.0, 1.6 and 1.3 Hz), 2.38 (s, 3H, H-1), 2.04 (dd, 1H, H-7, J 6.7 and 1.6 Hz), 1.50 (ddd, 1H, H-6, J 7.4, 6.7 and 1.3 Hz), 1.16 (s, 3H, H-9), 0.59 (s, 3H, H-10). 13C NMR (CDCl3, 50 MHz) d: 174.23 (s, C-4), 161.13 (s, C-2), 156.34 (d, C-11), 133.14 (s, C-3), 34.08 (t, C-5), 32.53 (d, C-7), 27.22 (q, C-9), 26.70 (d, C-6), 22.35 (s, C-8), 21.68 (q, C-1), 14.36 (q, C-10).IR (CHCl3, n/cm–1): 1630, 1580, 1560, 1450, 1420, 1390, 1360, 1310, 1140, 1040, 840, 820. UV [EtOH, lmax/nm (e)]: 218 (6150), 276 (3240). MS, m/z (%): 174.1152 (M+, 50), 159 (65), 132 (19), 118 (100), 105 (5), 91 (33), 85 (5), 83 (7), 79 (6), 77 (8), 65 (8), 51 (5), 41 (7), 39 (8).§§ (±)-6-Isopropenyl-4-methyl-6,7-dihydro-5H-cyclopentapyrimidine 6. The reaction of enaminone 2 with trimethyl orthoformate–ammonium acetate afforded 56% of compound 6; the reaction of enaminone 10 afforded 55% of pyrimidine 6. Yellow crystals, mp 32–33 °C (pentane). 1H NMR (CDCl3, 200 MHz) d: 8.68 (s, 1H, H-11), 4.77 (br. s, 1H, H-10), 4.74 (br. s, 1H, H-10), 3.1–2.6 (m, 5H, H-5, H-6 and H-7), 2.32 (s, 3H, H-1), 1.73 (br.s, 3H, H-9). 13C NMR (CDCl3, 50 MHz) d: 172.09 (s, C-4), 161.06 (s, C-2), 157.38 (d, C-8), 146.48 (s, C-11), 131.83 (s, C-3), 110.79 (t, C-10), 44.01 (d, C-6), 39.02 (t, C-7), 33.81 (t, C-5), 21.65 (q, C-1), 21.08 (q, C-9). IR (CHCl3, n/cm–1): 890, 940, 1390, 1440, 1570, 1590, 1650. UV [EtOH, lmax/nm (e)]: 255 (4570), 333 (shoulder, 220).MS, m/z (%): 174.1147 (M+, 75), 173 (100), 159 (52), 158 (5), 145 (11), 132 (25), 118 (31), 104 (12), 91 (44), 79 (9), 77 (11), 65 (10), 53 (9), 52 (9), 51 (9), 39 (13). Scheme 1 The numbering of carbons is inconsistent with IUPAC recommendations and is given only for NMR interpretation purposes. O NH2 H H 1 HCl·H2O O O H H 4 N N H H 3 N N H H 5 NH2 1 2 3 4 5 6 7 8 9 10 11 NH2 O H H 9 NH4OAc AcOH C6H6 (MeO)3CH NH4OAc C6H6 CNNH2, H2O CNNH2, H+, PhH (MeO)3CH NH4OAc C6H6 O NH2 2 HCl·H2O O O 7 N N 6 N N 8 NH2 1 2 3 4 5 6 7 8 9 10 11 NH2 O 10 NH4OAc AcOH C6H6 (MeO)3CH NH4OAc C6H6 CNNH2, H2O CNNH2, H2O (MeO)3CH NH4OAc C6H6Mendeleev Communications Electronic Version, Issue 2, 2000 (pp. 83–124) 4 D. J.Brown, in The Chemistry of Heterocyclic Compounds, eds. E. C. Tailor and A. Weissberger, John Wiley, New York, 1994. 5 A. V. Tkachev and A. V. Rukavishnikov, Mendeleev Commun., 1992, 161. 6 S. A. Popov, A. Yu. Denisov, A. V. Gatilov, I. Yu. Bagryanskaya and A. V. Tkachev, Tetrahedron: Asymmetry, 1994, 5, 479. 7 E. Benary, Chem. Ber., 1930, 63, 2601. 8 A. Alberola, C. Andres, A. G. Ortega, R. Pedrosa and M. Vicente, Synth. Commun., 1987, 17, 1309. 9 J. V. Greenhill, M. Ramli and T. Tomassini, J. Chem. Soc., Perkin Trans. 1, 1975, 588. 10 P. G. Baraldi, D. Simoni and S. Manfredini, Synthesis, 1983, 902. Received: 18th May 1999; Com. 99/1527
ISSN:0959-9436
出版商:RSC
年代:2000
数据来源: RSC
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| 17. |
Effect of substitution on the yield of high-spin nitrenes in the photolysis of 2,6-diazidopyridines |
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Mendeleev Communications,
Volume 10,
Issue 3,
2000,
Page 114-115
Sergei V. Chapyshev,
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摘要:
Mendeleev Communications Electronic Version, Issue 2, 2000 (pp. 83–124) Effect of substitution on the yield of high-spin nitrenes in the photolysis of 2,6-diazidopyridines Sergei V. Chapyshev,*a Richard Waltonb and Paul M. Lahti*b a Institute for Problems of Chemical Physics, Russian Academy of Sciences, 142432 Chernogolovka, Moscow Region, Russian Federation. Fax: +7 096 515 3588; e-mail: chap@icp.ac.ru b Department of Chemistry, University of Massachusetts, Amherst, MA 01003-4510, USA.Fax: +1 413 545 4490; e-mail: lahti@grond.chem.umass.edu 10.1070/MC2000v010n03ABEH001281 The effect of substitution on the yield of high-spin nitrenes in the photolysis of 3-(2,6-diazidopyridin-4-yl)-3-azatricyclo[3.2.1.02,4]- octane derivatives at a cryogenic temperature in inert matrices is described.In recent years, there has been considerable progress in the study of high-spin nitrenes as models for molecular electronic behaviour.1 The attention was focused on the exploration of the effects of geometry and bond connectivity in nitrenes on their spin states and EPR characteristics.2 At the same time, almost nothing is known about the effect of substituents on the yield of high-spin nitrenes in the photolysis of polysubstituted aryl azides. Such azides do not undergo undesirable ring expansions3 upon irradiation and therefore can be considered as the most promising precursors of high-spin nitrenes. This work deals with an EPR study of open-shell products formed by photolysis of diazides 1a–c in a cryogenic marix.The synthesis of diazides 1a–c was described earlier.4 The irradiation of diazide 1a in a degassed frozen 2-methyltetrahydrofuran (MTHF) solution for 5 min with a xenon arc lamp (Pyrex filtered, > 300 nm) at 77 K led to the appearance of an EPR spectrum (Figure 1). By analogy with previously studied pyridylnitrenes,5–7 a strong signal at 6900 G can be assigned to triplet 2-nitrenopyridine 2a with the zero field splitting (zfs) parameters |D/hc| = 1.02 cm–1 and |E/hc| = 0.003 cm–1.The other signals in the spectrum are attributable to quintet dinitrene 4a with the following zfs parameters assigned by an eigenfield8 simulation: S = 2, |D/hc| = 0.257 cm–1 and |E/hc| = 0.052 cm–1. For aromatic m-dinitrenes, the quintet zfs D-value typically is significantly smaller, with a major peak at about 3000 G rather than the peak at about 3300 G, just upfield of a radical peak at g ~ 2.9 The higher D-value for 4a is apparently due to the effect of the pyridine nitrogen on the intramolecular exchange interaction between electrons in two nitrene units.Figures 1(a) and 1(b) show the simulated and experimental EPR spectra, respectively. Diazides 1b,c were irradiated under the same conditions as in the case of 1a.Only a very weak EPR signal of triplet nitrene 2c at about |D/hc| = 1.05 cm–1 was detected from 1c [Figure 1(c)]. The higher D-value for 2c compared to that for 2a is explained by the effect of the two strong electron-withdrawing CN groups. Similar effects were observed earlier for other triplet pyridyl-2- nitrenes.6(b) Interestingly, there is no indication of the quintet dinitrene formation from 2c.This shows that the formation of 4c is inefficient in this case. B3LYP/6-31G* computations† indicate that the ground state of 4c should still be a quintet by about 29 kJ mol–1, so the lack of a quintet spectrum is presumably not due to a change in the ground state spin multiplicity going from 4a to 4c. The EPR spectrum of 1b [Figure 1(d)] represents an intermediate behaviour between that of 1a and 1c, since it contains a broad upfield peak from presumed nitrenes 2b and 3, as well as weak signals at 1047 and 3233 G attributable to quintet dinitrene 4b.The appearance of the upfield peak is similar to an analogous peak observed in the photolysis of 1a. Presumably, only small amounts of the nitrene ortho to the CN group are formed, but enough to give the observed small quintet peak.The results clearly indicate that the progressive introduction of cyano groups into the 3- and 5-positions of 2,6-diazidopyridines disfavours the preparation of high-spin products. This effect most probably results from an enhanced photolability of intermediates 2b,c and 3, which more readily undergo fragmentation‡ of the pyridine ring rather than produce quintet dinitrenes 4b,c.Similar problems have recently been observed on an attempt to prepare high-spin products from cyanuric triazide.11 Obviously, the higher the percentage of nitrogen atoms in the molecules of nitrenes, the lower the stability. At the same time, the high yield of quintet dinitrene 4a from 1a [Figure 1(b)] demonstrates that readily available chlorine-substituted aromatic polyazides can be successfully used for the synthesis of novel magnetic organic materials.This work was supported by the National Science Foundation (grant nos. CHE-951595 and CHE-9740401). References 1 (a) H. Iwamura and S. Murata, Mol. Cryst. Liq. Cryst., 1989, 176, 33; (b) H. Iwamura, N. Nakamura, N.Koga and S. Sasaki, Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A, 1992, 218, 207; (c) P. M. Lahti, M. Minato and C. Ling, Mol. Cryst. Liq. Cryst., 1995, 271, 147 and references therein; (d) T. Ohana, M. Kaise, S. Nimura, O. Kikuchi and A. Yabe, Chem. Lett., 1993, 765. 2 R. S. Kalgutkar and P. M. Lahti, J. Am. Chem. Soc., 1997, 119, 4771 and references therein. 3 (a) O.L. Chapman and J.-P. LeRoux, J. Am. Chem. Soc., 1978, 100, 282; (b) J. C. Hays and R. S. Sheridan, J. Am. Chem. Soc., 1990, 112, 5881; (c) G. B. Schuster and M. S. Platz, Adv. Photochem., 1992, 17, 69. 4 (a) S. V. Chapyshev, Khim. Geterotsikl. Soedin., 1993, 1560 [Chem. Heterocycl. Compd. (Engl. Transl.), 1993, 29, 1426]; (b) S. V. Chapyshev and V. M. Anisimov, Khim. Geterotsikl.Soedin., 1997, 1521 [Chem. Heterocycl. Compd. (Engl. Transl.), 1997, 33, 1315]; (c) S. V. Chapyshev, Mendeleev Commun., 1999, 164. 5 E. Wasserman, Prog. Phys. Org. Chem., 1971, 8, 319. † Computations were carried out using the B3LYP density functional with the 6-31G* basis set, optimising the quintet and triplet states separately with the program Gaussian-98 for Silicon Graphics computer.10 ‡ According to an FTIR study6(c) of the photolysis of 1c in argon at 7 K, this diazide forms nitrene 2c in < 1% yield.This is obviously the reason for the low intensity of the EPR signal of 2c [Figure 1(c)]. N R1 N R2 N3 N3 N R1 N R2 N N3 N Cl N CN N3 N h n 1a–c 2a–c 3 N R1 N R2 N N 4a–c a R1 = R2 = Cl b R1 = Cl, R2 = CN c R1 = R2 = CNMendeleev Communications Electronic Version, Issue 3, 2000 (pp. 83–124) 6 (a) M. Kuzaj, H. Lüerssen and C. Wentrup, Angew. Chem., Int. Ed. Engl., 1986, 25, 480; (b) R. A. Evans, M. Wong and C. Wentrup, J. Am. Chem. Soc., 1996, 118, 4009; (c) S. V. Chapyshev, A. Kuhn, M. Wong and C. Wentrup, J. Am. Chem. Soc., 2000, 122, 1572. 7 S. V. Chapyshev, R. Walton, J. A. Sanborn and P. M. Lahti, J. Am. Chem. Soc., 2000, 122, 1580. 8 (a) G. G. Belford, R. L. Belford and J. F. Burkhalter, J. Magn. Reson., 1973, 11, 251; (b) Y. Teki, T. Takui, H. Yagi, K. Itoh and H. Iwamura, J. Chem. Phys., 1985, 83, 539; (c) Y. Teki, T. Takui and K. Itoh, J. Chem. Phys., 1988, 88, 6134; (d) Y. Teki, I. Fujita, T. Takui, T. Kinoshita and K. Itoh, J. Am. Chem. Soc., 1994, 116, 11499; (e) Y. Teki, Ph. D. Thesis, Osaka City University, Osaka, Japan, 1985; ( f ) K.Sato, Ph. D. Thesis, Osaka City University, Osaka, Japan, 1994. 9 T. A. Fukuzawa, K. Sato, A. S. Ichimura, T. Kinoshita, T. Takui, K. Itoh and P. M. Lahti, Mol. Cryst. Liq. Cryst., Section A, 1996, 278, 253. 10 M. J. Frisch, G. W. Trucks, H. B. Schlegel, P. M. W. Gill, B. G. Johnson, M. A. Robb, J. R. Cheeseman, T. Keith, G. A. Petersson, J.A. Montgomery, K. Raghavachari, M. A. Al-Laham, V. G. Zakrzewski, J. V. Ortiz, J. B. Foresman, J. Cioslowski, B. B. Stefanov, A. Nanayakkara, M. Challacombe, C. Y. Peng, P. Y. Ayala, W. Chen, M. W. Wong, J. L. Andres, E. S. Replogle, R. Gomperts, R. L. Martin, D. J. Fox, J. S. Binkley, D. J. Defrees, J. Baker, J. P. Stewart, M. Head-Gordon, C. Gonzalez and J. A. Pople, Gaussian Inc., Pittsburgh, PA, 1998. 11 T. Nankai, K. Sato, D. Shiomi, T. Takui, K. Itoh, M. Kozaki and K. Okada, Mol. Cryst. Liq. Cryst., 1999, 334, 157. N R Q (a) (b) (c) (d) 0 2000 4000 6000 8000 10000 Field/G N N R Figure 1 (a) Simulated8 EPR spectrum for a randomly oriented system with S = 2, |D/hc| = 0.257 cm–1, |E/hc| = 0.052 cm–1; (b) EPR spectrum from the photolysis of diazide 1a (n0 = 9.562 GHz) at 77 K in a 2-methyltetrahydrofuran glass; (c) EPR spectrum from the photolysis of diazide 1c (n0 = 9.562 GHz) at 77 K in a 2-methyltetrahydrofuran glass; (d) EPR spectrum from the photolysis of diazide 1b (n0 = 9.569 GHz) at 77 K in a 2-methyltetrahydrofuran glass. The arrow indicates the quintet peak in the inset for 3000–3500 G. N is the triplet nitrene peak, Q is the quintet dinitrene peak and R is the radical peak. Received: 11th February 2000; Com. 00/1607
ISSN:0959-9436
出版商:RSC
年代:2000
数据来源: RSC
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| 18. |
Thermal generation of singlet oxygen (1ΔgO2) on ZSM-5 zeolite |
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Mendeleev Communications,
Volume 10,
Issue 3,
2000,
Page 116-117
Alexey N. Romanov,
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摘要:
Mendeleev Communications Electronic Version, Issue 2, 2000 (pp. 83–124) Thermal generation of singlet oxygen (1 gO2) on ZSM-5 zeolite Alexey N. Romanov,* Yury N. Rufov and Vladimir N. Korchak N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow, Russian Federation. E-mail: ran@decsy.ru 10.1070/MC2000v010n03ABEH001187 Thermal generation of equilibrium 1DgO2 in air at moderate temperatures and non-equilibrium thermal desorption of singlet oxygen from Ca–Cs/ZSM-5 zeolite were experimentally detected.The participation of singlet oxygen (1DgO2) in the oxidation of hydrocarbons on heterogeneous catalysts was discussed previously. 1–3 Data on the thermal desorption of 1DgO2 from the Li–Sn–P–O system2 and V2O5 catalysts3 were reported, and indirect evidence of the occurrence of 1DgO2 at the surface of transition metal oxides was also obtained by EPR spectroscopy.1 However, these results are inadequately reproducible, and until the present time there is no direct evidence of the participation of thermally generated 1DgO2 in oxidation reactions (either homogeneous or heterogeneous), although the possibility of the direct thermal excitation of oxygen to a singlet state was considered by Turro.4 Moreover, the thermal generation of 1DgO2 in an equilibrium concentration at moderate temperatures according to the reaction (the reverse of the quenching of singlet oxygen) was not observed (probably, because of the absence of sensitive methods for the detection of 1DgO2).Previously,5 a sensitive chemiluminescence (CL) technique for the determination of extremely low concentrations of singlet oxygen in a gas phase was developed.This technique allowed us to perform continuous measurements of equilibrium 1DgO2 concentrations in air at relatively low temperatures and to examine non-equilibrium thermal desorption of 1DgO2 from zeolites. The generation of singlet oxygen took place in an air flow (pressure of 60 Torr and linear velocity of 1.2 m s–1) passed through a heated zone of a quartz tubular reactor (30 mm in length and 5 mm internal diameter).At the reactor outlet, the gas was rapidly cooled to ambient temperature and then arrived at a CL detector (for experimental detail, see ref. 5). Because the time of singlet oxygen quenching in air is rather long (~1 s at 60 Torr and room temperature), the equilibrium 1DgO2 concentration corresponding to the temperature of the heated zone of the reactor can be measured.In this case, the quenching of 1DgO2 during the time it takes for air to be cooled and transferred to the CL detector is negligible. The equilibrium 1DgO2 concentration is determined by the expression [in the case of C(1DgO2) << C(O2)]6 where C(1DgO2) is the equilibrium 1DgO2 concentration in the gas phase at the temperature T; C(O2) is the ground-state oxygen concentration (total oxygen concentration); g1/g2 is the electronic statistical weight ratio for the singlet and ground triplet states of oxygen, g1/g2 = 2/3 (ref. 6); E is the excitation energy of the oxygen singlet state (the enthalpy of formation of 1DgO2).Indeed, the intensity of the thermal formation of equilibrium 1DgO2 was essentially the same on various catalysts (Ca–Cs/ ZSM-5, the Li–Sn–P–O system and V2O5) and in an empty reactor. Figure 1 demonstrates a typical curve for this process. The energy E calculated from these data using equation (2) is 88.6 kJ mol–1 (±10%), which is consistent with E = 94.2 kJ mol–1, as found from spectroscopy data.1 The corresponding preexponential factor C(O2)(g1/g2) is ~6×1017 molecule cm–3 (the calculated value for air at 60 Torr and room temperature is 3.7×1017 molecule cm–3, the difference may be due to incorrect independent calibration of the CL detector at low 1DgO2 concentrations).If a sufficient ballast volume or a glass filter was placed between the reactor and the CL detector, the signal vanished due to 1DgO2 quenching.The same behaviour was observed in experiments when singlet oxygen was photochemically generated in a glass tube coated with methylene blue (in place of a heated reactor). Taking into account all of the results, we can state with assurance that direct thermal generation of 1DgO2 in equilibrium concentrations took place in our experiments.Note that a simple blank reactor can be used as a reliable standard source for calibration because the temperature dependence of 1DgO2 concentration at the reactor outlet is determined by equation (2). The Li–Sn–P–O and V2O5 catalysts generated 1DgO2 only in equilibrium concentrations in our experiments. Thus, they exhibited no difference from an empty reactor.D O2 O2(1Dg) (1) C(1DgO2) = C(O2)(g1/g2)exp(–E/RT) (2) 3 2 1 0 0 200 400 600 800 22 °C 225 °C 265 °C 290 °C 313 °C oven off C(1DgO2)/10–9 molecule cm–3 t/s Figure 1 Thermal generation of equilibrium 1DgO2 in an empty quartz reactor under conditions of a stepwise increase in the temperature (the detector was calibrated using a photochemical generator of 1DgO2). 4 3 2 1 0 100 200 300 20 60 100 140 180 220 oven off T/°C t/s 0 C(1DgO2)/10–8 molecule cm–3 Figure 2 Non-equilibrium thermal desorption of 1DgO2 from Ca–Cs/ZSM-5 zeolite under conditions of a linear increase in the temperature (the detector was calibrated with thermally generated equilibrium 1DgO2 at the outlet of an empty quartz reactor).Mendeleev Communications Electronic Version, Issue 3, 2000 (pp. 83–124) The non-equilibrium generation of 1DgO2 (i.e., in higher than equilibrium concentrations) was observed only on zeolite samples (ZSM-5 exchanged with alkaline and alkaline-earth cations). Figure 2 demonstrates a typical plot of the thermal desorption of 1DgO2 from Ca–Cs/ZSM-5 zeolite. The sample was prepared from H-ZSM-5 (Si/Al ratio of 80) by continuous ion exchange in a 0.1 M CsNO3 solution and then in a 0.1 M Ca(NO3)2 solution. Next, it was calcined at 650 °C in air for 4 h and exposed to dry air at room temperature for 16 h prior to the use in experiments.It can be seen in Figure 2 that, in addition to the thermal generation of equilibrium 1DgO2, which is detectable at temperatures higher than 140 °C, the curve exhibits a low-temperature peak of non-equilibrium thermal desorption of 1DgO2 (Tmax = = 55 °C). This peak completely disappeared in the subsequent thermal desorption experiments. The capacity of the zeolite for non-equilibrium desorption of 1DgO2 was restored after exposure to air at ambient pressure for 24 h.It is obvious that, in this case, oxygen molecules adsorbed on the zeolite are the source of 1DgO2. The reasons why the concentration of electronically excited 1DgO2 in desorbed oxygen exceeds an equilibrium value are unclear.It is our opinion that the following factors can be responsible for this phenomenon: (i) stabilization of the 1Dg state of an adsorbed O2 molecule as a result of splitting two degenerate pg*- orbitals1 in strong electrostatic fields within zeolite channels (ª1010Vm–1 in ZSM-5)7 and (ii) differences in the activation energies of adsorption (and desorption) for the ground 3Sg and excited 1Dg states of oxygen molecules, e.g., at the surface of MgO, Ea ads(1DgO2) = 0, while Ea ads(3SgO2) > 0 (ref. 8). Anyway, this experimental fact is the first example of the non-equilibrium thermal production of 1DgO2 over heterogeneous catalysts (with the exception of the results,2,3 which were found to be irreproducible).References 1 M. Che and A. J. Tench, Adv. Catal., 1983, 32, 1. 2 J. P. Guillory and C. M. Shiblom, J. Catal., 1978, 54, 24. 3 I. A. Myasnikov, V. Ya. Sukhachev, L. Yu. Kupriyanov and S. A. Zavjalov, in Poluprovodnikovye sensory v fiziko-khimicheskikh issledovaniyakh (Semiconductor Sensors in Physico-Chemical Studies), 1991, Nauka, Moscow, p. 307 (in Russian). 4 N. Turro, Tetrahedron, 1985, 41, 2089. 5 A. N. Romanov and Yu. N. Rufov, Zh. Fiz. Khim., 1998, 72, 2094 (Russ. J. Phys. Chem., 1998, 72, 1908). 6 B. Lewis, G. von Elbe, Phys. Rev., 1932, 41, 678. 7 S. Bernan, J. Mol. Catal., 1988, 45, 225. 8 V. I. Vladimirova, Yu. N. Rufov and O. V. Krylov, Kinet. Katal., 1977, 18, 809 [Kinet. Catal. (Engl. Transl.), 1977, 18, 675]. Received: 8th July 1999; Com. 99/1515
ISSN:0959-9436
出版商:RSC
年代:2000
数据来源: RSC
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| 19. |
The Ritter reaction in the 5-cyano-1,2,4-triazine series |
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Mendeleev Communications,
Volume 10,
Issue 3,
2000,
Page 117-118
Dmitry N. Kozhevnikov,
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摘要:
Mendeleev Communications Electronic Version, Issue 2, 2000 (pp. 83–124) The Ritter reaction in the 5-cyano-1,2,4-triazine series Dmitry N. Kozhevnikov, Tatiana V. Nikitina, Vladimir L. Rusinov* and Oleg N. Chupakhin Urals State Technical University, 620002 Ekaterinburg, Russian Federation. Fax: +7 3432 74 0458; e-mail: rusinov@htf.ustu.ru 10.1070/MC2000v010n03ABEH001255 5-Cyano-1,2,4-triazines enter into the Ritter reaction with secondary and tertiary alcohols to form N-alkylated 1,2,4-triazine-5- carboxamides.The cyano group at a 1,2,4-triazine ring does not undergo reactions accompanied by a nucleophilic attack on the carbon atom of CN (these reactions are typical of nitriles).1–4 At the same time, the reactions of nucleophilic ipso-substitution for the cyano group with alcohols,1 amines,2 CH-active compounds and Grignard reagents3,4 proceed very smoothly.We found that the nitrile group in 5-cyano-1,2,4-triazines 1 can react with carbocations obtained in situ from alcohols under conditions of the Ritter reaction in spite of the electron-withdrawing properties of the heterocyclic ring. Thus, the reaction of 3-aryl-5-cyano-6-phenyl-1,2,4-triazines 1a–c with the secondary alcohol propan-2-ol in 95% sulfuric acid leads to corresponding N-isopropyl-3-aryl-6-phenyl-1,2,4-triazine-5-carboxamides 2 in 45–60% yields.† The reaction with the tertiary alcohol adamantanol proceeds in a similar manner to form N-(adamant-1-yl)-3-aryl-6-phenyl- 1,2,4-triazine-5-carboxamides 3a,b in higher yields (80–85%) (Scheme 1).Unexpectedly, compounds 1a–c do not enter into the Ritter reaction with tert-butanol under the same conditions. Instead, the hydrolysis of the cyano group takes place yielding 3-aryl-6-phenyl-1,2,4-triazine-5-carboxamides 4a–c.However, the treatment of cyano compounds 1 with concentrated H2SO4 at room temperature without tert-butanol does not afford any products. On the other hand, the use of dilute H2SO4 leads to nucleophilic displacement of the cyano group, and 3-aryl-6- phenyl-1,2,4-triazin-5(2H)-ones 5a,b are formed.† The reaction with primary alcohols such as methanol, ethanol and benzyl alcohol does not take place because of the instability of intermediate carbocations.The difference in reactivity between two tertiary alcohols, adamantan-1-ol and tert-butanol, can be explained by the following reasons.The rate of reaction of cyano-1,2,4-triazines 1 and the well-stabilised tert-butyl cation is lower than the rate of formation of tert-butyl sulfate (Me3COSO2OH). The ester reacts with compounds 1 at the nitrile carbon atom to form carboxamides 4 (Scheme 2), similarly to the reaction of aliphatic † Typical reaction procedure: cyano-1,2,4-triazine 1a–c (1 mmol) and a corresponding alcohol were dissolved in 2 ml of 95% sulfuric acid; the mixture was kept for 0.5–2 h at room temperature and then poured into ice water.The crystals of 2–4 were filtered off, washed with water and recrystallised from propan-2-ol. Typical procedure for the synthesis of 3-aryl-6-phenyl-1,2,4-triazine- 5(2H)-ones 5a,b: cyano-1,2,4-triazine 1a,b (1 mmol) was dissolved in 4 ml of 60% sulfuric acid at 40 °C, and the solution was kept for 2 h.The reaction mixture was diluted with water, and the crystals of 5a,b were filtered off and recrystallised from ethanol. nitriles with olefins in sulfuric acid.6 This reaction accompanied by a nucleophilic attack on the cyano carbon is a rare example for 1,2,4-triazine carbonitriles.However, the classical Ritter reaction mechanism seems to be preferable in the reaction of 1 with less stable adamantyl or isopropyl cations. Thus, the presence of a nitrile group in 1,2,4-triazines provides an opportunity to perform various modifications of 1,2,4-triazines by both ipso-substitution and nucleophilic or electrophilic reactions of the cyano group. The structures of the compounds obtained were confirmed by 1H NMR spectroscopy;‡ the melting point of compound 5a is equal to the published value.7 ‡ All the compounds obtained exhibited satisfactory analytical data (maximum differences between the calculated and found data were no more than 0.15% for C, 0.18% for H and 0.24% for N).The 1H NMR spectra were measured on a Bruker WM-250 spectrometer at a frequency of 250.137 MHz, the solvent was [2H6]DMSO.The mass spectra (electron impact ionization) were measured on a Varian MAT-311 spectrometer. For 2a: yield 45%, mp 196–198 °C. 1H NMR, d: 1.12 (d, 6H, 2Me, J 7 Hz), 4.02 (m, 1H, CH), 7.52 (m, 3H), 7.60 (m, 3H), 7.85 (m, 2H), 8.52 (m, 2H), 8.64 (br. d, 1H, NH, J 7 Hz). For 2b: yield 55%, mp 248–249 °C. 1H NMR, d: 1.13 (d, 6H, 2Me, J 7 Hz), 4.03 (m, 1H, CH), 7.54 (m, 3H), 7.62 (d, 2H), 7.91 (m, 2H), 8.54 (d, 2H), 8.66 (br.d, 1H, NH, J 7 Hz). MS, m/z (%): 354 (2), 352 (5) [M+]. For 2c: yield 60%, mp 292–263 °C. 1H NMR, d: 1.12 (d, 6H, 2Me, J 7 Hz), 4.03 (m, 1H, CH), 7.58 (m, 3H), 7.87 (m, 2H), 8.42 (d, 2H), 8.65 (br. d, 1H, NH, J 7 Hz), 8.78 (d, 2H). For 3a: yield 78%, mp 185–188 °C. 1HNMR, d: 1.63 (br.s, 6H, 3CH2), 1.97 (br. s, 6H, 3CH2), 2.03 (br. s, 3H, 3CH), 7.58 (m, 3H), 7.63 (m, 3H), 7.90 (m, 2H), 8.17 (br. s, 1H, NH), 8.49 (m, 2H). MS, m/z (%): 410 (58) [M+]. For 3b: yield 80%, mp 132–135 °C. 1H NMR, d: 1.63 (br. s, 6H, 3CH2), 1.97 (br. s, 6H, 3CH2), 2.03 (br. s, 3H, 3CH), 7.58 (m, 3H), 7.69 (d, 2H), 7.90 (m, 2H), 8.41 (br. s, 1H, NH), 8.50 (d, 2H). MS, m/z (%): 446 (12), 444 (34) [M+].For 4a: yield 50%, mp 227–228 °C. 1H NMR, d: 7.51 (m, 3H), 7.60 (m, 3H), 7.86 (m, 2H), 7.95 (br. s, 1H, NH2), 8.30 (br. s, 1H, NH2), 8.57 (m, 2H). For 4b: yield 55%, mp 235–236 °C. 1H NMR, d: 7.58 (m, 3H), 7.70 (d, 2H), 7.86 (m, 2H), 7.98 (br. s, 1H, NH2), 8.38 (br. s, 1H, NH2), 8.58 (d, 2H). MS, m/z (%): 312 (4), 310 (11) [M+]. N N N Ph O NH2 N N N Ph NC Ar Ar N N N Ph Ar O NH R N NH N Ph O Ar 4a–c 1a–c 2a–c, 3a,b 2 R = Pri 3 R = adamant-1-yl 5a,b H2SO4 (60%) ButOH H2SO4 (95%) ROH H2SO4 (95%) a Ar = Ph b Ar = 4-ClC6H4 c Ar = 4-NO2C6H4 Scheme 1 N N N Ph HN O N N N Ph NC Ar Ar N N N Ph C Ar 4a–c 1a–c 2a–c, 3a,b R = Pri, adamant-1-yl Me3COSO2OH Scheme 2 N R S O O O Me Me Me H2O H2O R+Mendeleev Communications Electronic Version, Issue 3, 2000 (pp. 83–124) This work was supported by the Russian Foundation for Basic Research (grant no. 99-03-32923). References 1 O. N. Chupakhin, V. L. Rusinov, E. N. Ulomsky, D. N. Kozhevnikov and H. Neunhoeffer, Mendeleev Commun., 1997, 66. 2 M. Makosza and P. van Ly, J. Heterocycl. Chem., 1996, 33, 1567. 3 S. Konno, S. Ohba, M. Agata, V. Aizawa, M. Sagi and H. Yamanaka, Heterocycles, 1987, 26, 3259. 4 S. Ohba, S. Konno and H. Yamanaka, Chem. Pharm. Bull., 1991, 39, 486. 5 A. J. Gordon and R. A. Ford, The Chemist’s Companion: A Handbook of Practical Data, Techniques and References, Wiley, New York, 1972. 6 J. J. Ritter, J. Am. Chem. Soc., 1948, 70, 4253. 7 H. Neunhoeffer and V. Bohnisch, Liebigs Ann. Chem., 1976, 153. For 4c: yield 58%, mp 277–280 °C. 1H NMR, d: 7.55 (m, 3H), 7.90 (m, 2H), 8.07 (br. s, 1H, NH2), 8.40 (br. s, 1H, NH2), 8.49 (d, 2H), 8.82 (d, 2H). For 5a: yield 90%, mp 271–273 °C (lit.,7 275 °C). 1HNMR, d: 7.4–7.7 (m, 6H), 8.1–8.3 (m, 4H), 14.2 (br. s, 1H, NH). For 5b: yield 95%, mp > 290 °C. 1HNMR, d: 7.5 (m, 3H), 7.7 (d, 2H), 8.1–8.2 (m, 4H), 14.3 (br. s, 1H, NH). Received: 27th December 1999; Com. 99/1581
ISSN:0959-9436
出版商:RSC
年代:2000
数据来源: RSC
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Synthesis ofo-carborane derivatives containing the tri(ethylene glycol) group |
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Mendeleev Communications,
Volume 10,
Issue 3,
2000,
Page 118-120
Andrej A. Semioshkin,
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摘要:
Mendeleev Communications Electronic Version, Issue 2, 2000 (pp. 83–124) Synthesis of o-carborane derivatives containing the tri(ethylene glycol) group Andrei A. Semioshkin,*a Gennadii M. Ptashits,b Sergey A. Glazun,a Vadim V. Kachala,b Pavel V. Petrovskiia and Vladimir I. Bregadzea a A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 117813 Moscow, Russian Federation.Fax: +7 095 135 5085; e-mail: bre@ineos.ac.ru b Higher Chemical College, Russian Academy of Sciences, 125047 Moscow, Russian Federation. E-mail: dva@nmr1.ioc.ac.ru 10.1070/MC2000v010n03ABEH001214 A general approach to the preparation of carborane derivatives containing the hydrophilic ethylene glycol fragment was developed. The derivatization of the carborane cage C2B10H12 can be performed because two carbon atoms are accessible to organic reactions. Thus, the cage can be incorporated into biologically active moieties.However, the high lipophilicity of the carborane cage often leads to low water solubility of the final compounds. Sufficient solubility in water is very important for potential applications to the boron nuclear capture therapy of cancer.To increase the water solubility, the o-carborane cage can be degraded to the corresponding anionic [nido-7,8-C2B9H11]– species. This method was used to prepare dicarbaundecaborate derivatives of porphyrines,1 thioureas2 and amino acids.3 The water solubility can also be increased by the attachment of hydrophilic substituents. For example, a number of carboranyl carbohydrates have been synthesised recently.4–6 Yamamoto and co-workers7 have developed a method of polyol cascade synthesis, which was used for the preparation of hydrophilically substituted carboranyl amino acids,8–9 amines,9–11 netropsin and distamycin A analogues.12 The aim of this work was to develop the preparation of the poly(ethylene glycol)-containing o-carborane with one CH group free for modification: Compound 2 can be easily converted into iodide 4 in two steps with a total yield of 92%.13 Compound 4 reacted with lithium trimethylsilylacetylenide to give trimethylsilylacetylenide 5 (Scheme 1).† Compound 5 was treated with tetrabutylammonium fluoride to remove the Me3Si group and give novel acetylene 6 in a total yield of 86% (from 4).Note that this method for the preparation of polyglyme acetylenes is novel and very convenient.Previously,19 the synthesis of 4-(2-methoxyethoxy)- but-1-yne by the interaction of propargyl bromide and 2-methoxyethoxymethyl chloride in 74% yield was described.14 Compound 6 reacted with decaborane in acetonitrile to give carborane 7 in a rather good yield (52%). An attempt to prepare 7 by the interaction of a dilithiated carborane with iodide 4 resulted, as expected, in a mixture of 7, the disubstituted derivative and the unsubstituted carborane in the 2:1:1 ratio.The modification of 7 was studied by the example of lithiation followed by carboxylation.‡ Note that carboranyl lithium derivative of 7 was almost insoluble in a THF–hexane mixture, as compared with other carboranyllithium derivatives.This may be explained by the formation of intramolecular complex 9. The formation of similar complexes (like 10 or 11) was also proposed earlier.15,16 † Materials and equipment. Commercial chemicals of reagent grade were used. THF was distilled from Na/benzophenone. Sublimated decaborane was used. Compound 4 was prepared according the described method.13 1H and 13C NMR spectra were recorded on a Bruker AMX-400 spectrometer at 400.13 and 100.33 MHz, respectively. 11B NMR spectra were recorded on a Bruker AC-200 spectrometer at 64.21 MHz. Chemical shifts were measured with respect to external standards (TMS and BF3·Et2O). Mass spectra were measured on a Kratos MS-890 (80 eV) spectrometer. Melting points were measured in sealed capillaries and not corrected. 1-Trimethylsilyl-5,8,11-trioxadodec-1-yne 5. A 1.6 M BuLi solution in hexane (45.6 ml, 0.073 mol) was added to a cooled (–50 °C) solution of trimethylsilylacetylene (10.3 ml, 0.073 mol) in dry THF (50 ml), and the resulting mixture was stirred at –50 °C for 1 h. Next, it was warmed to –20 °C, and a solution of 10 g (0.0365 mol) of iodide 4 was added dropwise. The mixture was stirred at room temperature and then added to 150 ml of a saturated NaCl solution.The mixture was extracted with diethyl ether (5×50 ml), and the ether fractions were combined and dried with Na2SO4. After removing the solvent, the residue was distilled in vacuo to give 8.1 g of compound 5 (90%), bp 61 °C (10–3 Torr). 1H NMR (CDCl3) d: 0.11 (s, 9H, Si–Me), 2.49 (t, 2H, CH2–CºC), 3.35 (s, 3H, OMe), 3.53 and 3.61 (A2B2, 4H, MeO–CH2CH2), 3.56 (t, 2H, CH2CH2–CºC), 3.61 (m, 4H, CH2O–CH2CH2–OCH2).Found (%): C, 58.98; H, 9.77. Calc. for C12H24O3Si (%): C, 58.97, H, 9.90. 5,8,11-Trioxadodec-1-yne 6. A solution of 8 g (0.033 mol) of 5 and of 8 g of Bu4NF·H2O in 50 ml of THF was stirred at room temperature for 18 h. Next, it was added to 150 ml of a saturated NaCl solution.The mixture was extracted with diethyl ether (5×50 ml), and the ether fractions were combined and dried with Na2SO4. The removal of the solvents and distillation in vacuo gave 4.9 g (95.2%) of 6, bp 96–98 °C (3 Torr). 1H NMR (CDCl3) d: 1.9 (t, 1H, HCº, JHCCCH2 2.6 Hz), 2.42 (td, 2H, HC=C–CH2, JHCCCH2 2.6 Hz), 3.3 (s, 3H, OMe), 3.5–3.65 (m, 10H, CH2O). 13C NMR (CDCl3) d: 20.13 (CH2–CºCH), 59.27 (OMe), 68.62 (HCº), 69.63, 69.71, 70.69, 70.91, 72.31 (CH2O), 81.58 (CºCH).Found (%): C, 62.53; H, 9.74. Calc. for C9H16O3 (%): C, 62.77; H, 9.36. ‡ 1-Carboxy-2-(3',6',9'-trioxadecyl)-1,2-dicarba-closo-dodecaborane 8. To a solution of 7 (4.2 g, 0.015 mol) in 50 ml of dry THF cooled to –30 °C 10 ml (0.015 mol) of 1.6 M BuLi in hexane was added, and the resulting mixture was stirred at –30 °C for 1 h.A white precipitate was formed. The mixture was warmed to room temperature and added to an excess of solid CO2. Next, 50 ml of a saturated NaHCO3 solution was added, and the resulting mixture was extracted twice with diethyl ether (40 ml) and twice with hexane (40 ml). The separated aqueous layer was acidified to pH 1–2, and the white precipitate of 8 was filtered off and dried in vacuo to give 4.8 g (94%), mp 127–129 °C. 1H NMR (CDCl3) d: 0.96–3.42 (m, 10H, BH), 2.76 (t, 2H, CH2–Carb.), 3.40 (s, 3H, OMe), 3.5–3.6 (m, 10H, CH2O), 7.69 (s, 1H, COOH). 13C NMR (CDCl3) d: 35.75 (CH2–Carb.), 58.80 (OMe), 69.24, 69.45, 69.61, 69.78, 71.53, (CH2O), 78.46 (CCH2), 161.40 (C=O), C–COOH unresolved. MS, m/z: 334 (M+). Found (%): C, 35.17; H, 7.50.Calc. for C10H26B10O5 (%): C, 35.92; H, 7.84. B10H10 H (OCH2CH2)nOR 1 B10H10 7 O O MeO B10H10 8 O O MeO COOH i, BuLi ii, CO2 B10H10 O O O Me Li 9 B10H10 Me O O Me Li 10 B10H10 O Li 11 OMendeleev Communications Electronic Version, Issue 3, 2000 (pp. 83–124) This work was supported by the Russian Foundation for Basic Research (grant no. 99-03-33073), INTAS and Volkswagen. We are grateful to D.Zverev for the measurement of mass spectra. References 1 M. Miura, D. Gabel, G. Oenbrink and R. E. Fairchild, Tetrahedron Lett., 1990, 31, 2247. 2 H. Ketz, W. Tjarks and D. Gabel, Tetrahedron Lett., 1990, 31, 4003. 3 A. Varadarajan and M. F. Hawthorne, Bioconjugate Chem., 1991, 2, 242. 4 J. L. Maurer, F. Berchier, A. J. Serino, C. B. Knobler and M.F. Hawthorne, J. Org. Chem., 1990, 55, 838. 5 W. Tjarks, K. M. Anisuzzaman, L. Liu, A. H. Soloway, R. Barth, D. J. Perkins and D. M. Adams, J. Med. Chem., 1992, 35, 1628. 6 W. V. Dahlhoff, J. Bruckmann, K. Angermund and C. Kruger, Liebigs Ann. Chem., 1993, 8, 831. 7 H. Nemoto, J. G. Wilson, H. Nakamura and Y. Yamamoto, J. Org. Chem., 1992, 57, 435. 8 J. Malmquist, J. Carlsson, K.E. Markides, P. Pettersson, P. Olsson, K. Sunnerheim-Sjöberg and S. Sjöberg, in Cancer Neutron Capture Therapy, ed. Y. Mishima, Plenum Press, New York, 1996, p. 131. 9 P. Lindstroem, P. Olsson, J. Malmqvist, J. Pettersson, P. Lemmen, S. Sjöberg, A. Olin and J. Carlsson, Anti-Cancer Drugs, 1994, 5, 43. 10 S. Sjöberg, J. Carlsson, P. Lindstroem and J. Malmquist, in Current Topics in the Chemistry of Boron, ed. G.W. Kabalka, The Royal Society of Chemistry, Cambridge, 1994, p. 173. 11 J. Malmquist and S. Sjöberg, Acta Chem. Scand., 1994, 48, 886. 12 Y. Yamamoto, J. Cai, H. Nakamura, N. Sadayori, N. Asao and H. Nemoto, J. Org. Chem., 1995, 60, 3352. 13 L. Jullien, J. Canceill, L. Lacombe and J.-M. Lehn, J. Chem. Soc. Perkin Trans. 2, 1994, 5, 989. 14 D.Guedin-Vuong and Y. Nakatami, Bull. Soc. Chim. Fr., 1986, 2, 245. 15 V. A. Brattsev, G. N. Danilova and P. Lemmen, Abstracts of the 1st European Conference on Boron Chemistry, Barcelona, 1997, p. 45. 16 C. Vinas, R. Benakki, F. Texidor and J. Casobo, Inorg. Chem., 1995, 34, 3844. B10H10 7 O O MeO OH 2 O O MeO OTs 3 O O MeO i ii I 4 O O MeO iii 5 O O MeO SiMe3 6 O O MeO iv v Scheme 1 i, TsCl–pyridine, CH2Cl2; ii, NaI/acetonitrile, reflux, iii, LiCºCTMS, THF; iv, (NBu4)Faq, THF; v, B10H14, acetonitrile, reflux. 1-(3',6',9'-Trioxadecyl)-1,2-dicarba-closo-dodecaborane 7.To a boiling solution of decaborane (4 g, 0.033 mol) in 50 ml of dry acetonitrile 4.6 g (0.033 mol) of 6 in 20 ml of acetonitrile was added, and the mixture was refluxed until the evolution of hydrogen stopped (about 5 h). Next, the mixture was cooled, the solvent was evaporated, and the residue was extracted with hot hexane (4×40 ml). The hexane extracts were combined, and hexane was evaporated; the residue was crystallised from diethyl ether–hexane (1:1) to give 4.2 g (52%) of pure 7, mp 145–147 °C. 1H NMR (CDCl3) d: 1.00–3.44 (m, 10H, B–H), 2.51 (t, 2H, CH2–Carb.), 3.37 (s, 3H, OMe), 3.5–3.7 (m, 10H, CH2O), 4.17 (br. s, 1H, CH–Carb.). 13C NMR (CDCl3) d: 38.22 (CH2–Carb.), 59.96 (CH–Carb.), 61.24 (OMe), 69.34, 70.90, 71.11, 71.39, 72.78 (CH2O), 74.39 [C(Carb.)–CH2]. MS, m/z: 290 (M+). Found (%): C, 36.84; H, 9.36. Calc. for C9H26B10O3 (%): C, 37.22; H, 9.02. Received: 19th October 1999; Com. 99/1542
ISSN:0959-9436
出版商:RSC
年代:2000
数据来源: RSC
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