N-H Insertion of Anilines on N-Tosylhydrazones Induced by Visible Light Irradiation

Diazo compounds as well as their precursors represent an interesting category for organic synthesis. Particularly N-tosylhydrazones, have attracted attention for their easy accessibility and diverse reactivity, including carbene transfer reactions. We described a visible light induced N-H insertion reaction of anilines on in-situ generated diazo compounds. Optimal conditions using DBU in toluene yielded desired products efficiently. Mechanistic studies enabled us to trap a carbene intermediate that has a key role in this transformation.