Facile access to silyl-functionalized N-heterocyclic olefins with HSiCl3

Abstract

N-heterocyclic olefins (NHOs), IPrCH₂ (1) and SIPrCH₂ (2) (IPrCH₂ = {N(2,6-iPr₂C₆H₃)CH}₂CCH₂ and SIPrCH₂ = {N(2,6-iPr₂C₆H₃)CH₂}₂CCH₂), react with HSiCl₃ and afford IPrCH(SiHCl₂) (3) and SIPrCH(SiHCl₂) (4), respectively. Compounds 3 and 4 have been isolated in almost quantitative yield. Interestingly, treatment of the silylene IPr·SiCl₂ with 1 also affords 3, where silylene insertion into a C–H bond is observed. Computational analysis shows a high energy barrier for silylene insertion, therefore a protonation–deprotonation mechanism is more likely.