Barium-mediated cross-dehydrocoupling of hydrosilanes with amines: a theoretical and experimental approach.

Abstract

Alkaline-earth (most prominently barium) complexes of the type [Ae{N(SiMe3 )2 }2 ⋅(THF)x ] and [{N^N}Ae{N(SiMe3 )2 }⋅(THF)x ] are very active and productive precatalysts (TON=396, TOF up to 3600 h(-1) ; Ca<Sr<Ba) for NH/HSi cross-dehydrocoupling, with excellent chemoselectivity in the reaction of (di)amines with (di)hydrosilanes. Experimental and DFT investigations revealed that the reactions proceed by nucleophilic attack of a metal amide at the incoming silane and subsequent turnover-limiting hydrogen transfer to the metal center.