Enantioselective Aerobic Oxidative C(sp3)–H Olefination of Amines via Cooperative Photoredox and Asymmetric Catalysis

A cooperative photoredox and asymmetric catalysis for the enantioselective aerobic oxidative C­(sp3)–H olefination of tetrahydro-β-carbolines (THCs) is reported. This method, which is also effective for tetrahydroisoquinolines (THIQs), features a triple-catalyst strategy, involving a dicyanopyrazine-derived chromophore (DPZ) as the metal-free photoredox catalyst, a chiral Lewis base catalyst, and an inorganic salt cocatalyst. The current protocol provides straightforward access to a series of valuable α-substituted THCs and THIQs in high yields with excellent regio- and enantioselectivities (up to 95% ee).