Visible-Light-Driven Photoredox-Catalyzed Reduction of Nitro (Hetero)arenes to (Hetero)aryl Amines and Subsequent C─N Bond-Forming Reactions.

A sustainable and efficient visible-light photoredox catalytic strategy was developed for the selective reduction of nitro(hetero)arenes to the corresponding amino(hetero)arenes, followed by in situ C─N coupling, using a Cu-Ti-gCN composite as non-noble photocatalyst. The reduced products were obtained in good to excellent yields (up to 95%) under mild reaction conditions and exhibits a broad substrate scope, accommodating halogenated, heteroaromatic, and fused nitroarenes. Mechanistic studies, supported by radical-quenching experiments, indicate a multisite proton-coupled electron transfer (MS-PCET) pathway involving key radical intermediates. The application of the method was further extended to reductive cyclization reactions, providing access to biologically relevant N-heterocycles.