Photoredox Nickel‐Catalyzed Dehydrogenative Alkoxycarbonylation of Benzylic C─H Bonds

ABSTRACT Radical‐mediated transition‐metal‐catalyzed C─H carbonylation represents a direct and powerful approach for the synthesis of carbonyl compounds; however, the stoichiometric oxidants typically required for hydrogen atom abstraction hamper the extensive application of these protocols and raise environmental concerns. In this study, we report a photoredox Ni‐catalyzed acceptorless dehydrogenative alkoxycarbonylation of alkylarenes with releasing hydrogen gas (H 2 ) as the sole byproduct. A variety of benzylic carboxylates, benzofuranones, and lactones with different frameworks were obtained with high selectivity through intermolecular and intramolecular alkoxycarbonylation. The reaction is distinguished by broad functional‐group compatibility with radical‐quenching phenolic hydroxyl group applicable. Notably, the use of biphosphine ligand promotes the reductive elimination of acylnickel(II) intermediate with alcohols while suppressing undesired single‐electron oxidative addition with benzylic radical.