Photochemical, electrochemical and electrophotochemical C-N bond-forming cross-coupling reactions.

Nitrogen-containing molecules are foundational to modern synthesis, spanning a wide range of pharmaceuticals, agrochemicals, life science and functional materials. Recent advances in photochemical and electrochemical methods have begun to redefine how C-N bonds can be constructed, expanding beyond traditional thermally driven metal-catalysed cross-couplings to encompass radical, hybrid, and fully metal-free pathways. These strategies can offer precise control over redox events, access to otherwise inaccessible intermediates and greater modularity in reaction design, thereby enabling transformations that are operationally simple, scalable and increasingly sustainable. In this Review, we systematically summarize photochemical, electrochemical and electrophotochemical C-N cross-coupling reactions, spanning mechanistic principles, catalytic paradigms, reaction classes and synthetic applications. We highlight convergent trends across these fields, analyse their distinct advantages and provide a forward-looking perspective on their potential and future development.