Transition-Metal-Free α-Vinylation of Enolizable Ketones with ß-Bromostyrenes.

An α-vinylation of enolizable ketones has been developed by using ß-bromostyrenes and a KO tBu/NMP system. ß,γ-Unsaturated ketones of E configuration were obtained in excellent yield and selectivity. Further synthetic possibilities are highlighted by one-pot functionalization via trapping of intermediate dienolates with alkyl, allyl, benzyl, and propargyl halides to generate quaternary centers. The reported transformation is believed to involve phenylacetylene and propargylic alcohol derivatives.