Photocatalyst‐Free Cyclization Through Electron Donor–Acceptor Complexes: Efficient Access to Cyclic Phosphinamides

Herein, we report a novel formate‐promotedstrategy for the synthesis of cyclic phosphinamides. This photocatalytic method operates without conventional photocatalysts or metal catalysts,instead exploiting in situ‐generated electron donor–acceptor (EDA) complexes between formate salts (or Et 3 N) and aryl halides to efficiently access diverse phosphinamide scaffolds. The reaction is characterized by operational simplicity, mild conditions, high efficiency, and broad functional group tolerance. Its utility is further demonstrated through the one‐pot synthesis of valuable phosphate esters and successful extension to sulfonamide derivatives. Notably, the process does not require nitrogen‐atom protection, streamlining the synthesis and affording products in high yield, which underscores the generality and practicality of this approach for N ‐heterocycle construction.