Reductant-Free Enantioselective Aza-Reformatsky Reaction Enabled by Synergistic Visible Light Photocatalysis and Lewis Acid Catalysis

Abstract

Classical aza-Reformatsky reaction generally involves excess reductants. Herein, we developed a visible light-induced catalytic asymmetric aza-Reformatsky reaction via a chiral Lewis acid-assisted direct excitation of imines without additional reductants, enabling the carbon–iodine bond cleavage of iododifluoromethyl ketones and the subsequent enantioselective radical coupling. This protocol provided an ingenious access to chiral β-amino ketones containing a gem-difluorine moiety. The mechanistic studies including radical trapping experiment, NMR experiment, electron paramagnetic resonance experiment, cyclic voltammetry experiment and spectroscopic analysis rationalized the reaction process.