摘要:

1972 787The I ,4=lnsertion Reactions of I ,I -Bis( perhalogenomethyl)-2,2-dicyano-ethylenes to Produce KeteniminesBy E. W. Abel," J. P. Crow, and J. N. Wingfield. Department of Inorganic Chemistry, The University, BristolBS8 I T SThetwo olefins (CFB)&=C(CN), and (CF,) (CF,CI)C=C(CN), undergo reactionwith awidevarietyof organometalliccompounds by a 1,4-addition. The products are ketenimines, and in this way a good range of ketenimino-derivatives of silicon, germanium, tin, and boron have been synthesised. The spectral properties and chemicalreactions of these metal and metalloid ketenimines are reported.THE study of the addition reactions of cyano-olefins toorganometallic compounds is of particular interestbecause of the variety of reactions reported. Thuscyanoethylene undergoes addition 1 simply across theolefin double-bond as illustrated in equation (1) ; and incontrast tetracyanoethylene is reported in certaincases to add simply across the cyano-group, as illustratedin equation (2).In the case of l-phenyl-2,2-dicyano-ethylene, however, both the olefin and the cyanide areutilised to bring about a lJ4-addition as illustrated inequation (3).SnEt3II1 1 CH2=CH-C=N + Et3SSn.NMe2 - Me2N.CHrCH-CrNgroup shows the protons as a septet (JF-= = 1.5 Hz)confirming the presence of the (CF,),(MeS)C group in theproduct. Similar spectroscopic properties were notedfor all the products reported in Table 1. In additionto these reactions 1, l-bis (trifluoromethyl) -2,2-dicyano-ethylene underwent analogous reactions with dimethyl-amino t nmet h y lsilane , dimet hy larsino t rimet h y lsilan e ,tris(methylthio)borane, and tris(dimethylamino)borane,but in each case the reaction was so violent that pureproducts could not be isolated.From the spectra ofthe impure materials, however, it would appear the1,4-addition reactions occurred in these compounds also.In the case of organometallic bases with more thanone reactive bond, it is possible to add the reactiveolefins to each of these bonds as illustrated in equations(5) and (6). Nevertheless, it is possible to utilise onlyN7 (NEC)2C=CtCN12+ Me3Sn*NMe2 - Me3Sn.N=C-C=C(CN)2INMe2,N=C=C (CNK [cF3I2.SMe\EtZN CN N=C=C(CNI*C(CFJ2*SMPE t p ( SMe12+Z (CF312 C=C t CN 1,- Et2Sn (51YhPhCH=C(CN12 + E$Pb.NEt, - CH-C=C=N*PbEtj 131I IN=C=C(CN I*C (CF3);NMe2/\We have found the two perhalogenocyano-olefins1 ,l-bis(trifluoromethyl)-2,2-dicyanoethylene and 1-trifluor omethyl-1 -chlorodifluorome t hyl-2 ,2-dicy ano-ethylene to be exceedingly reactive with an extensiveB(NMe213+ 3(CF3)2C=C(CN 12- B-N=C=C ICN 1.C(CF312.NMe2 (6)N=C=C (CN l-C(CF312*NMo2/Me\N=C=C(CN ).C(CF,);SMerange of organometallic compounds, especially organo-metallic bases.A typical reaction occurs with methyl-thiotrimet hylsilane.Me2S i ( SMe),+ ( C F3$ C=C ( CN l2 -Me2Si (71Evidence for the 1,4-addition and ketenimino-structureof the product is solely spectroscopic. The i.r. spectrumof the addition compound contains a strong band at2210 cm-l which is characteristic4 of a conjugatednitrile, such a band would be absent if the addition hadtaken place 1,2 across the olefin.An even strongerband in the i.r. spectrum at 2140 cm-l is characteristicof alkyl and metal substituted ketenimines. The U.V.spectrum contains an absorption at 229 nm (E =7 x lo3), which is believed characteristic of theC=C=N chromophore. The n.m.r. spectrum of the MeST. A. George and M. F. Lappert, J . Orgartometallic Chem.,W. P. Neumann and K. Kuhlein, Tetrahedron Letters, 1966,W. J. Middleton, J . Org. Chem., 1965, 30, 1402.1968, 14, 328.3423.one of the available reactive bonds, by using exactlystoicheiometric quantities of reagents as illustrated inequation (7). Here the two different methylthio-groupsaxe clearly differentiated in the n.m.r.spectrum.Although allyl- and methallyl-trimethyltins gave theexpected 1 ,klinear insertion product analogous to thosereported above, cyclopentadienyltrimethylsilane gave a1 : 1 compound with l,l-bis(trifluoromethyl)-2,2-dicyano-ethylene which had none of the characteristics of aketenimine. From the 19F n.m.r. spectrum it is apparentthat the olefin has undergone a Diels-Alder type ofaddition to the cyclopentadienyl ring, and a mixture ofisomers results. The problem of these isomers isespecially complex, as in addition to the usual syn andanti possibilities, a number of other isomers are formed4 L. J. Bellamy, ' The Infrared Spectra of Complex Mole-5 W. Beck, H. S. Smedal, and H. Kohler, 2. anorg.Chem.,6 R. Diikstra and H. J. Backer, Rec. Tvav. chirn., 1954, 73,cules,' Methuen, London, 2nd edn., p. 264.1967, 354, 69.575788 J.C.S. Daltondue to the prototropic isomerisations in trimethylsilyl-cyclopentadiene itself, resulting in 1,2- and 5-substitutedisomers of this omp pound.^*^The ketenimino-metalloid derivatives listed in Table 1fluorines have been calculated from the ABX, spectraby a previously reported m e t h ~ d , ~ and are noted inTables 2 and 3.The reported ketenimines of boron and silicon areTABLE 1Interaction of organometallic compounds with (CF,),C:C(CN), and (CF,) (CF,Cl)C:C(CN), to formorganometallic ketenimidesAnalysisRequired (%)Me,Si-SMe + (CF,),C=C(CN), Me,SiNCC(CN)C(CF,) ,SMe 35.6 3.5 35.9 3.6Found (yo)Reactants Product 7 C H C HMe,Si*SMe + (CF,) (CF,CI)C=C(CN), Me,SiNCC(CN)C(CF,) (CF,Cl) ShSe 34.0 3.3 34.2 3.4Me,Si.SPh + (CF,),C=C(CN), Me,SiNCC(CN) C(CF,) ,SPh 46.6 3.5 45.5 3.5Me,Si(SMe), + (CF,),C=C(CN), Me,Si(SMe)NCC(CN)C (CF,I ,SMe 32-8 3.1 32-8 3.3Me,SiH + (CF,)(CF,Cl)C=C(CN), Me,SiNCC(CN) C(CF,) (CF,Cl) H 34-9 3.0 35.4 3.3Me,Si*NHPh + (CF,),C=C(CN), Me,SiNCC(CN) C( CF,) ,NHPh 47.5 4-2 47.5 4.0Me,SiH + (CF,),C=C(CN), Me,SiNCC(CN)C(CF,),H :Me,Sn*SMe + (CF,) , e C (CN) , Me,SnNCC(CN)C(CF,) ,SMe 5 28.3 3-1 28.3 2.8Me,Sn-SMe + (CF,)(CF,Cl)C=C(CN), Me,SnNCC(CN)C(CF,) (CF,Cl)SMe b 27-0 2.8 27.2 2.7Et,Sn(SMe), + 2(CF,),C=C(CN), Et2Sn[NCC(CN)C(CF3) ,SMe], e 31.1 2.0 30.9 2.3Me,Sn*AsMe, + (CF,),C=C(CN), Me,SnNCC(CN)C(CF,) ,AsMe, d 26.6 3.2 27.4 3.1Me,SnC,H, + (CF,),C=C(CN), Me,SnNCC(CN)C(CF,) ,C3H5 34.3 3-3 34.4 3.3Me,Sn*C,H, + (CF,),C=C(CN), Me,SnNCC(CN) C(CF,) ,C,H7 * 36.0 3.8 36-3 3.7Ph,BCl + (CF,) ,C;=C (CN) , Ph,BNCC(CN)C(CF,) ,C1 52.3 3.0 52.2 2.4Bun,Ge*NMe, + (CF,) ,C=C(CN), Bun,GeNCC(CN) C(CF,) ,NMe, 48.4 7.1 48.0 6.6B(NMe2)3 f ~(CF,)ZC=C(CN)~ B[NCC(CN)C(CF,) ,NMe,] , 36-9 2.5 36.7 2.3Me,Si(a-C,H,) + (CF,),C=C(CN), Me,Si(x-C,H,) (CF,) ,C=C(CN) , 3 47.4 4.4 47.7 4-0(Me3Si)2S + (CF3)2CFC(CN)2 (Me,Si),S(CF,),C=C(CN), * 36.6 3.4 36.7 4- 1@ M.P.145-147". M.P. 127-128". ' M.P. 143". * M.P. 120". ' M.P. 91".* Not ketenimide, possibly a charge-transfer complex. All yieIds were virtually quantitative. $ Spectroscopic character-isation only. § Diels-Alder adduct, not ketenimide.are either involatile, colourless viscous liquids or whitesolids.All were sufficiently soluble in deuteriochloro-form to allow n.m.r. measurements, which were all inaccord with the proposed structures for these productsand are reported in Table 2.Of particular interest are the l9F n.m.r. spectra of theaddition products from 1 -trifluoromethyl- 1 -chloro-difluoromethyl-2,2-dicyanoethylene. As illustrated inCLF2F ,CNMe S I-SMe t (CF3) [CF,CL 1 C=C (CN 1, - CFj-G- CNc+ 181SMeN-SiMe,equation (8) addition of this olefin invariably results inthe generation of an asymmetric carbon atom. In turnreadily attacked by both water and alcohol at thenitrogen-metalloid bond. The ketenimines formed inSMeCL(1)such reactions undergo instant rearrangement to theisomeric dinitriles as illustrated in equations (9) and (10).A number of the dicyanoalkanes prepared by suchhydrolyses and alcoholyses are characterised in TableF C CN>C-CL-H5c W'N 'CN(91NS: NF(CF,I,C-C=C=N-SiMe, + H20 - M%Si.OH + [CF 1 C-C=C=NH -CI 3 2 tNHPh NHPhF3C, /CN - F3C-c-c-~ (101 NS; NC[(CF3)2C-bC=N-l,B + 3 E t O H -1Et0I3B -tSMe MeS ' 'CNthis renders the two fluorine atoms of the chlorodifluoro-methyl group non-equivalent as illustrated in (I).Thusthe 19F spectra of these compounds have a complexABX, pattern for the fluorine atoms of the CF&l group.The values of JAB and SaB for these non-equivalentC. S. Kraihanzel and M. L. Losee, J . Amer. Clzem. SOC..A. J . Ashe 111, J . Amer.Clzem. SOC., 1970, 92, 1233.1968, 90, 4701.3. The use of heavy water or a deuterio-alcohol allowsplacement of a deuterium atom upon the dicyano-carbonatom of the alkane.If the original addition to the olefin is carried out withtrimethylsilane, hydrolysis of the addition product givesthe alkane, which overall represents a convenientE. W. Abel, M. A. Cooper, R. J. Goodfellow, and A. J. Rest,Tram. Faraday SOC., 1969, 19671972 789TABLE 2N.m.r. spectra of organometallic ketenimides formed by 1 : 4-cyano-olefin insertionsCompoundMe,SiNCC(CN) C(CF,) ,SMeMe,SiNCC (CN) C (CF,) (CF,Cl) SMeMe,SiNCC (CN) C (CF,) ,SPhMe,SiNCC(CN) C(CF,) (CF,Cl)SPhMe,SiNCC(CN)C(CF,) ,NMe,Me,SiNCC(CN)C(CF,),NHPhhiIe,SiNCC(CN)C(CF,),AsMe,hle,SiNCC(CN)C(CF,) ,HMe,SiNCC(CN) C( CF,) (CF,Cl)HMe,Si(SMe) NCC(CN) C(CF,) ,SMehle,Si[NCC( CN) C(CF,) ,SMe],Me,SnNCC(CN) C(CF,) ,SMeMe,SnNCC( CN)C(CF,) (CF,Cl) SMeEt,Sn[NCC( CN) C( CF,) ,SMe],Bun,GeNCC(CN)C(CF,) ,NMe,Me,SnNCC(CN) C(CF,) ,AsMe,Me,SnNCC(CN)C(CF,),C,H,Me,SnNCC(CN)C(CF,),CH,C(CH,)=CH,(Me,Si) ,S.( CF,) ,C=C( CN) ,PhB[NCC(CN)C(CF,) ,SMe] aPh,BNCC(CN)C(CF,) ,SMePh,BNCC( CN) C(CF,) ,C1Me,Si(x-C,H,) *(CF,) ,C=C(CN) , *1BF (Upfield from CFCl,)CF, 67.97 CF, 65.2 CF, 52-1{JAB = 164 Hz{ J A ~ = 134 HzSAB = 1.64 p.p.m.CF, 67-0t CF, 64.2 CF, 51.2SAB = 0.41 p.p.m.CF, 66-9CF, 72.0t CF, 66.8CF, 67-9CF, 67-8CF, 68.3CF, 65-4CF, 67-2CF, 66.8CF, 62.6CF, 70.0CF, 69.9CF, 64.5JF-H = 8 HZAB = 172 HZSAB = 3.16 p.p.m.CF, 52.0SCH, 7.61 heptetSCH, 7-52 hextetF-H = 1.5 HZF-H = 1.4 HZSi(CH,), 9-55 (singlet) {Si(CH,), 9.57 (singlet) {Si(CH,), 9.66 (singlet) ; SPh 2-1-2-8Si(CH,), 9.62 (singlet) ; SPh 2-1-26Si(CH,), 9.57 (singlet) ; N(CH,), 7.39Si(CH,), 9.78 (singlet) ; NH 5.6 (broad)multiplet(multiplet)(broad){ NPh 2.3-3.5 (broad)Si(CH,), 9-50; 'As(CH3), 8.50CH 6.7 (heptet) Si(CH,), 9.8 { F-H = 7 H ZSi (CH,) , 9.56 ; CH 5 9-6.65 multipletSi(CH,), 9-32; Si-SCH, 7.57(CF,),CSCH, 7.32 (heptet) ; JF-H = 1 HzSi(CH,), 9.17; SCH, 7.56; JF-H = 1 HzSn(CH,), 9-39; Jsa 117-c-a.68.5 HzJsn 1 1 9 - ~ - ~ 71.5 Hz; SCH, 7.69 (multi-Sn(CH,), 9.37; Jsn 1 1 7 - ~ - ~ 72 Hz;iP WJs,, 1 1 9 - ~ - ~ 74 Hz; SCH, 7.64 (multi- { P WNMe, 7.36 (heptet) ; JF-H = 1.5 HzBun 8.53-9.16 (multiplet)Sn(CH,), 9-45; Jan 1117-c-~ 68.5;As(CH,), 8-68Sn(CH,), 9.4; Jsn 1 1 7 - ~ - ~ 72.5 Hz;SnCH, 7.45 (doublet) ; -CH=CH, 3-8-5.2(multiplet)Sn(CH,), 9.4; C-CH, 8.09; SnCH, 7.5;e C H , 6.02Si(CH,), 9-6S(CH,) 7.75; Ph 2.64S(CH,) 7.92; P h 2-72Si(CH,), 10.3 (+ small peak at 9-75)Ring protons 3.62, 6.04, 6-47IJ8n 119-c-~ 71.6 HZJsn 1 1 9 - e ~ 74.5 HZPh 2.0-2.8* Diels-*4lder product, not a ketenimide. t FA and FB are the non-equivalent fluorine atoms.TABLE 3Substituted ethanes formed by hydrolysis and subsequent rearrangement of organometallic ketenimidesProduct(CF,) ,CHCH( CN) ,(CF,) (CF,Cl)CHCH(CN),(CF,) ,C( SMe) CH (CN) ,(CF,) (CF,Cl)C(SMe)CH(CN),[:2{ @$$)G%':r!k (CN) ,(CF,),C(NHPh)CH(CN), C(CF,) (CF,Cl)C=C( CN) dAnalysisFound (7') Calc.(yo)C H C H33.5 1-6 33.3 0.931.3 2.3 31.0 0.931.9 1.6 32.1 1.530.0 1.4 30.2 1.444-1 1.9 44.3 1.942.5 1.8 42.3 1.846.6 2.6 46.9 2.331.2 31.2leF (Upfield from CFCl,)CF, 65.5CF, 64.1CF, 52.1CF, 67.6CF, 63-4CF, 50.8CF, 64.2CF, 62.2CF, 49.1CF, 65.0CF, 61.1CF, 53.3JF-F = 10 HZ{ Doublet J F-H= 7 HZ{ JAB 184 HZ'€3 (4(CN),CH 5.29 (doublet) ; JH-H = 3 Hz(CN),CH 4.92 (doublet) ; JH-H = 4 Hz(CF,) (CF,Cl)CH 5.35-5.95 (multiplet)S(CH,) 7.48 (heptet); J F - ~ = 1.5 HzCH 5.52S(CH,) 7-45 (hextet); JF-H = 1.4 HzCH 5.21SPh 2-15-2-55; CH 5.64SPh 2.1-2.5; CH 5.58CH 5.0 (broad) ; N-Ph 2-6-3-6M.p. 29-31". b B.p. 68/0-15 mm. 31.p. 104-106".d B.p. 133-135" (this new olefin is characterised for conveniencehere)790 J.C.S. Daltonhydrogenation of the original dicyano-alkene. The use EXPERIMENTALof heavy water Or a deuterio-alcohol brings about ineffect the overall stereospecific addition of HD to theoriginal olefin, as illustrated in equation (1 1)-All reactions, as a matter of course, were conducted underdry nitrogen, and solvents were dried before use. Then.m.r. spectra were run on Perkin-Elmer R10 and VarianCF3 CNI IH O:F3 ,Cr'd EtOD I I(11 1 Me3SiH + [CF3l2c=CIcN l2 -f CF3-$-C - CF3-C-C-CN 3- MejSi OEt"c\N-SiMe3The involatile nature of the ketenimines reportedherein is very likely due to the association of the secondnitrile group with the metal or metalloid atom of anothermolecule, giving rise to chains as illustrated in (11).Such chains appear to break down in solution, and themolecular weight of certain of the ketenimines aredependent upon solution concentration.The interestingpossibility of resonance in such chains is illustratedin (11).HC 3 \ NCY H3C ,CH3 H3C\ 7 3SN--S~ - N P c = c - C ; ~ ~ N ~ ~ - N ~ ~ - C ~ N ~ ~ - ~ ~I I I I ICH3 CH3 /C\ CH3F3c/i'scH, F3c I scHsCF3 CF3In contrast to the addition compounds of silicon andboron, which are easily hydrolysed as mentioned above,all the tin ketenimines axe stable to water. This isanalogous to the hydrolytic stability already reportedfor nitrogen co-ordinated, polymeric five-co-ordinate tincompounds.10Adv. Organometallic Chem..1965, 3, 397.(If1lo J. G. A. Luijten, F. Rijkens, and G. J. M. van der Kerk,HA100 spectrometers, either as neat liquids or as deuterio-chloroform solutions. U.V. spectra were obtained on aUnican SP 800 spectrometer. 1 , l-Bis(trifluoromethyl)-2,2-dicyanoethylene was prepared by the method of Middlet~n,~and the new olefin l-trifluoromethyl-l-difluoromethyl-2,Z-dicyanoethylene was prepared by an analogous methoddescribed below. All other reagents were prepared byliterature methods.Prefiaration of 1- Tyipuoyomethyl- l-dipuorochloromethyl-2,2-dicyanoethylene.-Malononitrile (20 g), monochloropenta-fluoroacetone (58 g), and zinc chloride ( 5 g ) were sealed in aheavy-walled glass tube and heated a t 80' for 50 h. Phos-phorus pentoxide (10 g) was added to the resulting solution,and after being set aside (5 h) volatiles were pumped into acold trap (-180'). Subsequent distillation of the con-densate yielded the required olefin (35%) as characterised inTable 3.Reactions of Polyhalogenocyano-olefins to Produce Keten-imides (Table 1) .-The polyhalogenocyano-olefin was addeddropwise to the other reactant in the exact stoicheiometricquantity required. Where the reaction was particularlyviolent, cyclohexane was used as a solvent. After removalof volatiles (25'/0.001 mm), the product was either aviscous non-volatile oil or a white solid. Yields werevirtually quantitative .The authors are grateful for support from the U.S. AirForce Office of Scientific Research through its EuropeanResearch Office, the Allied Chemical Company and MidlandSilicones Ltd.[1/1068 Received, 25th June, 1971

ISSN:1477-9226    

DOI:10.1039/DT9720000787

出版商:RSC    

年代:1972

数据来源: RSC