Enantioselective Alkoxycarbonyl-Lactonization of Alkenes via the Merger of Photoredox and Copper Catalysis.

The synthesis of ester derivatives represents one of the most significant and fundamental tasks in modern organic chemistry, and numerous methods have been developed in both academic and industrial contexts. Among these, alkoxycarbonyl radical-mediated functionalization strategies have emerged as a highly efficient and versatile tool for the synthesis of these compounds. Despite the significant advancements in recent years, the radical-induced enantioselective alkoxycarbonylation reaction remains largely unexplored. Herein, a highly enantioselective alkoxycarbonyl-lactonization of alkenes is reported through a photoredox/copper dual-catalyzed alkoxycarbonyl radical addition/cyclization reaction. With this approach, a diverse array of ester-substituted chiral γ-butyrolactones bearing a quaternary stereocenter can be readily obtained in high yields and with excellent enantioselectivities under mild reaction conditions. This versatile method shows good substrate tolerance for primary, secondary, and tertiary alcohol derivatives while maintaining exceptional stereochemical control.