A Photo‐Dual Catalytic Strategy for Azo Compound Synthesis

Azo compounds as a class of privileged molecules continue to attract significant attention in many fields including drug discovery, organic synthesis, and materials science. Despite notable progress in their synthesis, the use of visible light to directly construct azo compounds under photocatalytic conditions from amine precursors remains a challenging endeavour. Herein, we report the first instance of photo‐dual catalytic Cu/photosensitizer (PS) synthesis of symmetric and non‐symmetric azo compounds from readily available amines using renewable light energy input, ambient conditions, and ubiquitous air as a stoichiometric oxidant. This reliable and efficient photo‐driven procedure is scalable and tolerates a variety of functional groups with broad substrate scope and allows for the preparation of azo‐based photoswitches, arylazopyrazoles, and diazocines. The origin of this remarkable reactivity is delineated by in‐depth experimental and computational studies.