Enantioselective Access to Chiral γ-Ketoamides via Photoredox Catalyzed Carbamoyl Radical Addition/Asymmetric Protonation

Herein, we report a method for the enantioselective synthesis of β-chiral amides through photoredox-catalyzed carbamoyl radical addition to α,β-unsaturated ketones, followed by enantioselective protonation. The combination of photoredox catalysis with chiral Brønsted acid catalysis enables the generation of carbamoyl radicals under mild conditions and achieves stereocontrol in the protonation step. This dual catalytic system offers a direct and efficient approach to access synthetically valuable β-chiral γ-ketoamides, delivering products with high enantioselectivities and broad functional group tolerance. Mechanistic investigations support a sequential process involving photoinduced radical conjugate addition, single-electron reduction, and enantioselective protonation. This strategy expands the utility of carbamoyl radicals in asymmetric synthesis and contributes to the development of radical-based enantioselective methodologies.