Thermische Isomerisierung eines Silenketazins zum Diazasilacyclopenten: Experimentelle und theoretische Untersuchungen: Thermal Isomerisation of a Sileneketazine to a Diazasilacyclopentene: Experimental and Theoretical Studies

Lithium-tert-butylmethylhydrazonide II, Me 3 C(Me)C=N-NHLi, reacts with F 2 Si[N(CHMe 2 ) 2 ] 2 to give Me 3 C(Me)C=N-NH-SiF[N(CHMe 2 ) 2 ] 2 1. The lithium salt of 1, Me 3 C(Me)C=N- N(Li)SiF[N(CHMe 2 ) 2 ] 2 , 1a, prepared in the reaction of 1 with n-C 4 H 9 Li, is substituted with F 2 BN(SiMe 3 ) 2 forming Me 3 C(Me)C=N-NBFN(SiMe 3 ) 2 SiF[N(CHMe 2 ) 2 ] 2 , 2. Experiments to synthesise the silaketazine, Me 3 C(Me)C=N-N=Si[N(CHMe 2 ) 2 ], III, via LiF-elimination from 1a lead to the intramolecular formation of an N-functional 1,2-diaza-3-silacyclopentene, H 2 C-C(CMe 3 )=N- NHSi[N(CHMe 2 ) 2 ] 2 , 3, which is a structural isomer of III. The NH unit of 3 can be lithiated with n-C 4 H 9 Li. The lithium salt reacts with F 2 BN(SiMe 3 ) 2 forming the substituted ring compound 4. The rearrangement of the silaketazine III to the ring compound 3 is described by density functional calculations predicting a three-step reaction mechanism correlated with the experimental data. The structures of 3 and 4 are discussed in detail. Thermische Isomerisierung eines Silenketazins zum Diazasilacyclopenten: Experimentelle und theoretische Untersuchungen