A photochemical strategy for aromatic nitrogen ortho-isomerization

Anilines are essential functional groups in bioactive molecules. Their aromatic substitution pattern governs key physicochemical properties and thus biological activity. Accessing anilines with identical substituents but at alternative aromatic positions is highly desirable, but remains synthetically challenging. Herein, we report a synthetic strategy enabling the ortho-isomerization of aromatic nitrogen substituents. This approach leverages the visible light-mediated decomposition of aryl azides in the presence of a tailored thiophenol reagent to generate ortho-aminothiophenols. This transformation proceeds via nitrene generation and insertion, relocating the nitrogen group to its ortho position while installing the sulfur moiety at the ipso site. Subsequent oxidative cyclization yields a cyclic sulfonium intermediate, which can be cleaved or exploited as linchpins for divergent functionalization.