Asymmetric Arylation of Diazoesters with Anisoles Enabled by Cooperative Gold and Phosphoric Acid Catalysis.

An enantioselective insertion of a carbene into the Csp 2 -H bond of anisole derivatives has been accomplished using an achiral gold complex and a chiral phosphoric acid as the catalytic system, providing a novel protocol for the synthesis of chiral α,α-diaryl acetates. Density functional theory calculations reveal the reactivity and the origin of the enantioselectivity of this reaction.