Synthesis of Chiral β,β-Disubstituted Ketones via CuH-Catalyzed Coupling of Aryl Alkenes and 3-Aryl-2H-azirines.

A CuH-catalyzed coupling of aryl alkenes with 3-aryl-2H-azirines has been developed to synthesize optically active β,β-disubstituted ketones. We propose that this protocol occurs through a sequence in which a chiral alkylcopper complex regioselectively attacks the N-C2 bonds of azirines to generate chiral β-aryl imines, which additionally afford ketones upon hydrolysis. This method provides a novel complementary approach for synthesizing chiral β,β-disubstituted ketones in good yields with high levels of enantioselectivity under mild conditions.