A Photochemical Strategy for N-Aryl-ortho-Phenylenediamines Synthesis via Dearomative-Rearomative Coupling of Aryl Azides and Anilines

This paper describes a novel strategy for the synthesis of N-aryl-ortho-phenylenediamines from aryl azides and anilines. The process employs low-energy photoexcitation to generate singlet nitrenes via decomposition of the aryl azide. The nitrene undergoes a dearomative N-insertion that, in the presence of a Lewis acid additive, enables aniline nucleophiles to be incorporated into the 3H-azepine product. Subsequent treatment with the electrophile Boc₂O triggers a 7-to-6 ring contraction that re-aromatizes the system to give N-aryl-ortho-phenylenediamines.