Facile generation of [bis(2-pyridyldimethylsilyl)methyl]lithium and its reaction with carbonyl compounds. New method for the stereoselective synthesis of vinylsilanes

The generation of (2-PyMe2Si)2CHLi was easily accomplished by the deprotonation of (2-PyMe2Si)2CH2 using n-BuLi in Et2O. The 1H NMR analysis of (2-PyMe2Si)2CHLi in Et2O-d10 revealed the coordination of both pyridyl groups to lithium. Thus generated (2-PyMe2Si)2CHLi was found to react with a variety of aldehydes and ketones to give the corresponding vinylsilanes in extremely high yields with complete stereoselectivities (>99% E).