Sulfonamide as Photoinduced Hydrogen-Atom Transfer Catalyst for Regioselective Alkylation of C(sp3)-H Bonds Adjacent to Heteroatoms.

Based on the DFT calculations, the sulfonamide was explored as an efficient hydrogen-atom transfer catalyst for the C(sp3)-H alkylation. The combination of a metal-free photoredox catalyst and a sulfonamide catalyst enables highly regioselective alkylation of the C-H bonds adjacent to heteroatoms, which features broad substrate scope and excellent functional group compatibility. Remarkably, the sulfonamide catalyst was also applicable to the C(sp3)-C(sp3) couplings through the merger of photoredox, nickel, and HAT catalysis.