Stabilization of Reactive Nitrene by Silylenes without Using a Reducing Metal

Abstract

Herein, we report the stabilization of nitrene reagents as the source of a nitrogen atom to synthesize nitrogen-incorporated R1LSi-N←SiLR2 (1) [L=PhC(NtBu)2; R1=NTMS2, R2=NTMS]. Compound 1 is synthesized by reacting LSi(I)-SiIL with 3.1 equivalents of Me3SiN3 at low temperature to afford a triene-like structural framework. Whereas the reaction of the LSi(I)-SiIL with 2.1 equivalents of Me3SiN3 at room temperature produced silaimine 2 with a central four-membered Si2N2 ring which is accompanied by a silylene LSi and a cleaved silylene fragment. 1 further reacts with AgOTf at room temperature to yield compound 3 which shows coordination of nitrene to silver with the triflate salt. The compounds 1 and 2 were fully characterized by NMR, mass spectrometry, and X-ray crystallographic analysis. The quantum mechanical calculations reveal that compounds 1 and 2 have dicoordinated monovalent N atoms having two active lone pairs of electrons. These lone pairs are stabilized by hyperconjugative interactions.