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1. |
Pyrazolato and related anions. Part VI. Vibrational and electronic spectra of salts of 1,2,4‐triazole and 3‐bromo‐1,2,4‐triazole |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 98,
Issue 7‐8,
1979,
Page 425-431
R. van Houten,
J. G. Vos,
W. L. Groeneveld,
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摘要:
AbstractSalts of 1,2,4‐triazole and 3‐bromo‐1,2,4‐triazole with Cd, Zn, Co, Ni, Cu and Ag are reported. The compounds have been identified and characterized by chemical analyses, vibrational and electronic absorption spectra. Different coordination possibilities are discussed in view of the observed vibrational spectra. For the salts of 1,2,4‐triazole, 1,2‐bidentate or tridentate coordinations are observed. In the salts of 3‐bromo‐1,2,4‐triazole, bidentate and tridentate coordina
ISSN:0165-0513
DOI:10.1002/recl.19790980702
出版商:WILEY‐VCH Verlag
年代:1979
数据来源: WILEY
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2. |
Ab initiocalculations on thermodynamic and kinetic aspects of the isomerization process of some acyclic unsaturated C5H6hydrocarbons |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 98,
Issue 7‐8,
1979,
Page 432-437
A. B. A. van Den Berg,
D. H. W. den Boer,
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摘要:
AbstractAb initiocalculations of the thermodynamic stability order of six acyclic unsaturated hydrocarbons are presented. The results are in reasonable agreement with the experimentally observed order in the equilibrium mixture of isomers resulting from the base‐catalyzed isomerizations. The charge distribution and molecular electrostatic potential of two postulated intermediate carbanions involved in these isomerizations are also calculated in order to explain their initial product ratios which have been observed to differ from the thermodynamical order. These properties fail to reproduce the observed kinetic behaviour. Inclusion of polarization does not improve essentially these results. An estimate of the activation entropy on the basis of the shape of the potentials permits of an interpretation in agreement with the observed reactivit
ISSN:0165-0513
DOI:10.1002/recl.19790980703
出版商:WILEY‐VCH Verlag
年代:1979
数据来源: WILEY
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3. |
Cyclic Organolead Compounds II. Synthesis and characterization of several plumbole derivatives |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 98,
Issue 7‐8,
1979,
Page 437-440
D. C. van Beelen,
J. Wolters,
A. van der Gen,
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摘要:
AbstractThe synthesis of several plumbole derivatives is reported. Monocyclic compounds may be prepared by the reaction of organoaihthio compounds with diorganolead dibromides. Spirocyclic compounds may be formed from the reaction of dilithio compounds with lead(II) chloride. The compounds are characterized by1H NMR and IR spectroscopy.
ISSN:0165-0513
DOI:10.1002/recl.19790980704
出版商:WILEY‐VCH Verlag
年代:1979
数据来源: WILEY
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4. |
Reactions of carbon nucleophiles with 4‐phenyl‐ and 4‐tert‐butyl‐5‐halogenopyrimidines. On the occurrence of anSRN1 mechanism |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 98,
Issue 7‐8,
1979,
Page 441-444
E. A. Oostveen,
H. C. van der Plas,
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摘要:
AbstractReaction of 5‐X‐4‐phenylpyrimidine (X =Br, Cl) with the enolate anions of acetone and acetophenone in liquid ammonia yields 5‐acetonyl‐ and 5‐phenacyl‐4‐phenylpyrimidine, respectively. It is shown that these reactions proceedviaanSRN1 mechanism. Reaction of 5‐X‐4‐phenylpyrimidine (X =Br, Cl) with the enolate anion of pinacolone gives besidesSRN1 substitution, addition of the anion to the N(1)‐C(6)‐azomethine bond. On treatment of 5‐X‐4‐tert‐butylpyrimidine with the enolate anions of acetone, acetophenone or pinacolone, substitution products are formed in very low yields. Addition of potassium to the liquid ammonia or irradiation with near ultraviolet light, however, increases the yields of 5‐substituted 4‐tert‐b
ISSN:0165-0513
DOI:10.1002/recl.19790980705
出版商:WILEY‐VCH Verlag
年代:1979
数据来源: WILEY
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5. |
Anomalous effects in measurements of rotational barriers in formamidinium ions. Influence of solvent, counter‐ion and concentration |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 98,
Issue 7‐8,
1979,
Page 445-447
R. J. F. M. Staps,
J. W. Scheeren,
F. W. Pijpers,
R. J. F. Nivard,
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摘要:
AbstractChemical exchange studies on the tetramethylformamidinium ion lead to anomalous values for the Arrhenius parameters of internal rotation when apolar solvents, high concentrations and nucleophilic anions are used. The deviations cannot be ascribed to ion‐pairing, and might be due to covalent bondin
ISSN:0165-0513
DOI:10.1002/recl.19790980706
出版商:WILEY‐VCH Verlag
年代:1979
数据来源: WILEY
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6. |
The synthesis of bis(4‐methyl‐3‐pentenyl)thiophenes |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 98,
Issue 7‐8,
1979,
Page 448-451
Cornelus G. M. Janssen,
Anton A. Macco,
Henk M. Buck,
Erik F. Godefroi,
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摘要:
AbstractAll possible isomers of title compounds5a‐8ahave been prepared. All the routes presented have involved Wittig olefination of dicarbaldehydes5c‐8c. Synthetic aspects as regards the relevant intermediates are discus
ISSN:0165-0513
DOI:10.1002/recl.19790980707
出版商:WILEY‐VCH Verlag
年代:1979
数据来源: WILEY
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7. |
Photoreactions ofo‐vinyltriphenylethylenes II. Photochemistry of 1,1‐diphenyl‐2‐(o‐vinylphenyl)‐ and 1,1‐diphenyl‐2‐(o‐propenylphenyl)ethylene |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 98,
Issue 7‐8,
1979,
Page 452-459
M. Sindler‐Kulyk,
W. H. Laarhoven,
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摘要:
AbstractIrradiation of 1,1‐diphenyl‐2‐(o‐vinylphenyl)ethylene (3) leads stereoselectively toendo‐4,5‐diphenylbenzobicyclo[3.1.0]hex‐2‐ene (6). The analogous reaction of the homologous (o‐propenylphenyl)ethylene derivative (4) seems to be less stereoselective, as products 10 and 11 could be isolated. In both cases a photodehydrocyclisation product (7 and 12, respectively) is also found. Possible mechanisms for the photocyclisation reactions are discussed, and the photochemical behaviour of 3 and 4 is compared with that of othero‐vinylstilbenes, prev
ISSN:0165-0513
DOI:10.1002/recl.19790980708
出版商:WILEY‐VCH Verlag
年代:1979
数据来源: WILEY
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8. |
The photosensitized oxidation of the 19‐norsteroids: 17α‐19‐norpregn‐5‐en‐20‐yne‐3β,17‐diol, 3β‐chloro‐17α‐19‐norpregn‐5‐en‐20‐yn‐17‐ol and 17α‐19‐norpregn‐5‐en‐20‐yn‐17‐ol |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 98,
Issue 7‐8,
1979,
Page 459-461
J. A. M. Peters,
N. P. van Vliet,
F. J. Zeelen,
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摘要:
AbstractPhotosensitized oxygenation of 19‐norsteroids with a 5–6 double bond proceeds with high stereoselectivity to give, after reduction of the initially formed hydroperoxides, 5α‐hydroxy 6‐enes as the major products. Higher amounts of 6β‐hydroxy 4‐enes, the minor products, are formed than in the case of cholesterol. These results are in agreement with the “ene” mechanism proposed bySchenckandNickonand not with the peroxirane mechanism propose
ISSN:0165-0513
DOI:10.1002/recl.19790980709
出版商:WILEY‐VCH Verlag
年代:1979
数据来源: WILEY
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9. |
Reactions d'insertion du phénylphosphinidène dans diverses liaisons germanium‐hétéroélément |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 98,
Issue 7‐8,
1979,
Page 461-466
J. Escudié,
C. Couret,
J. Satgé,
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摘要:
AbstractPhenylphosphinidene inserts into Ge‐Y bonds (Y = H, C, N, O, P) with formation of germylphosphines with astructure. However some adducts (Y = N, O, P) undergo a thermal redistribution reaction giving particularly bis(trialkylgermyl)phosphines. Insertion reactions of phenylphosphinidene into Si‐P or Ge‐P bonds of 2‐sila or 2‐germaphospholanes lead to a new class of cyclic metalla‐IVb‐diphosphines, the 3‐sila‐ or 3‐germa
ISSN:0165-0513
DOI:10.1002/recl.19790980710
出版商:WILEY‐VCH Verlag
年代:1979
数据来源: WILEY
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10. |
Stereoselective synthesis of (+)‐pilocarpine, an imidazole alkaloid used in ophthalmology (Imidazole Chemistry, Part VII) |
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Recueil des Travaux Chimiques des Pays‐Bas,
Volume 98,
Issue 7‐8,
1979,
Page 467-468
A. Noordam,
L. Maat,
H. C. Beyerman,
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摘要:
AbstractThe synthesis of a mixture of (+)‐pilocarpine and (+)‐isopilocarpine from L‐histidine is described. Their separation is
ISSN:0165-0513
DOI:10.1002/recl.19790980711
出版商:WILEY‐VCH Verlag
年代:1979
数据来源: WILEY
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