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

摘要

The generation of (2-PyMe_2Si)_2CHLi was easily acomplished by the deprotonation of (2-PyMe_2Si)_2CH_2 using n-BuLi in Et_2O.The ~1H NMR analysis of (2-PyMe_2Si)_2CHLi in Et_2O-d_(10) revealed the coordination of both pyridyl groups to lithium.Thus generated (2-PyMe_2Si)_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).