Facile generation of α-silyl carbanion of trimethylsilyl group assisted by intramolecular pyridyl group coordination

Novel methodology for the generation of α-silyl carbanion by the deprotonation of trimethylsilyl group with tert-butyllithium or LDA has been developed. This newly developed α-lithiation protocol is based on the intramolecular pyridyl group coordination to stabilize the α-silyl carbanion, together with the inherent silicon α effect. The importance of the use of the 2-pyridyl group in 'pyridyl'- and 'silyl'-directed α- lithiation has been confirmed by the control experiments utilizing phenyltrimethylsilane and (3-pyridyl)trimethylsilane.