Visible Light-Driven Deracemization of Cyclic Sulfonamides by Quinuclidine and Chiral Arylthiol Catalysis

A photocatalytic system comprising an achiral tertiary amine and a chiral C₂-symmetric arylthiol was developed for the deracemization of various cyclic sulfonamides. This protocol exhibited high yields, good to excellent enantioselectivity, and broad substrate scope. The resulting products can be readily transformed into diverse diarylmethylamines, presenting a viable alternative to metal-catalyzed asymmetric methods. The reaction pathway involving a relay of non-enantioselective hydrogen-atom abstraction (HAA) and enantioselective hydrogen-atom delivery (HAD).