Photoredox-Cobaloxime Catalysis [4 + 2] Annulation of Enamines with Alkynes for the Synthesis of Naphthylamine Derivatives

Herein, we present a strategy for the visible light-driven oxidative [4 + 2] annulation of enamines with alkynes to synthesize naphthylamine derivatives at room temperature under external-oxidant-free conditions. This protocol avoids the use of high temperatures, multistep reactions, and stoichiometric oxidants in the synthesis of naphthylamines, and it exhibits broad substrate compatibility, with high atom- and step-economy. Furthermore, this transformation also proceeds efficiently under natural sunlight irradiation.