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

N-heterocyclic olefins (NHOs), IPrCH2(1) and SIPrCH2 (2) (IPrCH2 = {N(2,6-iPr(2)C(6)H(3))CH}(2)CCH2 and SIPrCH2 = {N(2,6-iPr(2)C(6)H(3))CH2}(2)CCH2), 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 center dot 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.