Cyclization of Carbonyl Electrophiles via Dual HAT/Photoredox‐Catalyzed Reductive Radical‐Polar Crossover

Photocatalytic reductive radical‐polar crossover is a versatile platform for achieving carbon–carbon bond formations under mild conditions and is complementary to traditional radical reactivity. Herein, we report a study on the reactivity of esters and ketones under this platform to produce cyclic ketone and alcohol products, respectively. The process is amenable to a variety of functionalized systems, and mechanistic experiments suggest intermediacy of both a benzylic radical and anion arising from photocatalytic reduction.