Alkali-Metal-Catalyzed Cross-Dehydrogenative Couplings of Hydrosilanes with Amines
Abstract
We report the N−H/H−Si cross-dehydrogenative coupling (CDC) of hydrosilanes and amines with high conversion (>90 %) and chemoselectivity for the production of silazanes, using group 1 metal hexamethyldisilazides [MN(SiMe3)2] (M=Li, Na, K) as precatalysts under mild conditions. [KN(SiMe3)2] showed higher activity than the congeneric lithium and sodium salts. The catalyzed CDC reaction displays a broad substrate scope. Phenylsilane and diphenylsilane react with a number of amines under ambient conditions; more elevated temperature is required for triphenylsilane to undergo CDC reactions. The intermediate lithium complex [(THF)2Li-{N(SiHPh2)(Dipp)}] (1) has been isolated and characterized in an attempt to identify the operative reaction mechanism.