Facile Access to the Functionalized N-Donor Stabilized Silylenes PhC(NtBu)2SiX (X = PPh2, NPh2, NCy2, NiPr2, NMe2, N(SiMe3)2, OtBu)

Reactions of silylenes with organic substrates generally lead to silicon(IV) compounds. Ligand substitution at the silicon(II) atom of silylene, without changing the formal +2 oxidation state, is very rare. We report herein a straightforward route to functionalized silylenes LSiX (L = PhC(NtBu)(2) and X = PPh2 (1), NPh2 (2), NCy2(3), NiPr2 (4), NMe2 (5), N(SiMe3)(2) (6), OtBu (7)). Silylenes 1-7 have been prepared in quantitative yield by a modified ligand exchange reaction of PhC(NtBu)(2)SiCl (LSiCl) with the corresponding lithium or potassium salts. Compounds 1-7 were characterized by spectroscopic and spectrometric techniques. Single-crystal X-ray structures of 1, 3, and 4 were determined.