Photo-induced selective N-N bond construction via harnessing nitrene release and transfer

Nitrogen incorporation is fundamental in organic synthesis for functional materials, pharmaceuticals, and agrochemicals. While C–N bond formation has gained great progress, N-N bond construction remains challenging: existing methods rely on prefunctionalized precursors, and direct coupling is hindered by narrow substrate scope and poor reactivity control. Although transition-metal-catalyzed nitrene strategies exhibit high efficacy for intermolecular N–H insertion, nitrene-mediated N–N coupling under metal-free conditions has rarely been explored. Herein, we report a broadly applicable sulfilimine-based approach for selective N–N coupling. By leveraging sulfilimines as nitrene precursors, we achieve controlled release of highly reactive nitrene intermediates, enabling intermolecular N-N coupling with amines. This strategy provides an alternative pathway for nitrene-mediated N-H insertion reaction over conventional methods, providing a streamlined route for constructing complex N–N-containing architectures. Transition-metal-catalyzed nitrene strategies exhibit high efficacy for intermolecular N–H insertion, but nitrene-mediated N–N coupling under metal-free conditions has rarely been explored. Herein, the authors report the selective N–N coupling using sulfilimines as nitrene precursors.