Cu(I)-catalyzed α-alkylation of ketones with styrene derivatives

α-Alkylation of ketones with styrene derivatives was developed using a mesitylcopper–dppp complex as a soft Brønsted base catalyst. No waste derived from the alkylating reagent was produced in this catalytic alkylation reaction. The bisphosphine ligand structure, as well as the reaction solvent, had profound effects on catalyst activity. The reaction proceeded under mild conditions from a range of ketones and styrene derivatives. The present catalysis is especially useful for the selective mono-alkylation of ketones.