C−N and C−C Bond Formation in Annulation and Aromatization through Metal‐Catalyzed Photoredox C−H Functionalization

Abstract

AbstractThe construction of heterocyclic nucleus by enabling photoredox C−H functionalization is an efficient, resurgence, and astonishing evolution for many different scientific disciplines. Recent research has shown interest in photolytically activated radical species, which involve the generation of an annulative or aromatic nucleus by triggering C−H bond cleavage. Single‐electron‐transfer (SET) events between substrates and a metal photocatalyst are eye‐catching synthesis under visible light irradiation. The approach functions without the need for substrate preactivation by employing reductive or oxidative quenching cycles to initiate SET. When a single electron is added at a deficiency, causes electron circulation, which results in cascade radical cyclization. They are found to be a prevalent, powerful, and reliable technique for the modern synthesis of valuable molecular entities. In current review photoredox catalyzed distinct radical generation strategies and transformations acting through a proton coupled electron transfer (PCET), C−H functionalization to form carbon‐carbon and carbon‐nitrogen atom bond are discussed.