One-Pot, Telescoped Alkenylation of Amides via Stable Tetrahedral Intermediates as Lithium Enolate Precursors

A mild and efficient telescoped procedure for the stereoselective alkenylation of simple, non-activated amides using LiCH2SiMe3 and carbonyl compounds as surrogates of alkenyllithium reagents is reported. Our methodology relies on the formation of stable tetrahedral intermediates, which, upon collapse into highly reactive lithium enolates in a solvent-dependent fashion, allows for the assembly of α,β-unsaturated ketones in a single synthetic operation with high stereoselectivity.