Enantioselective Arylation of Benzylic C-H Bonds by Copper-Catalyzed Radical Relay.

A novel enantioselective copper-catalyzed arylation of benzylic C-H bonds, using alkylarenes as a limiting reagent, has been developed. A chiral bisoxazoline ligand bearing an acetate ester moiety plays a key role in both the reactivity and enantioselectivity of the reaction. The reaction provides efficient access to various chiral 1,1-diarylalkanes in good yields with good to excellent enantioselectivities, and displays excellent functional-group tolerance.