Dehydrogenative Aromatization of Pyrrolidines through Photoredox/Cobaloxime Catalysis

Abstract Direct dehydrogenative aromatization of pyrrolidines represents an atom-economical strategy for pyrrole synthesis. Herein, we report a synergistic photoredox/cobaloxime catalytic strategy that exploits hydrogen atom transfer (HAT)-mediated radical generation to enable efficient dehydrogenative aromatization of pyrrolidines. Unlike conventional sequential single-electron transfer (SET) oxidation, the HAT-mediated process suppresses competing oxidative pathways, thereby substantially expanding the substrate scope. As a result, a broad range of pyrrolidines undergo efficient dehydrogenative aromatization with excellent chemoselectivity. Furthermore, the successful implementation of a recyclable mpg-CN photocatalyst demonstrates the practicality of this protocol.