Visible-Light-Induced Intramolecular C(sp2)-H Amination and Aziridination of Azidoformates via a Triplet Nitrene Pathway.

Catalytic intramolecular C-H amination and aziridination reactions of o-allylphenyl azidoformates have been achieved under visible-light irradiation, providing a mild, clean, and efficient method for the synthesis of useful benzoxazolones and [5.1.0] bicyclic aziridines. Mechanistic studies suggest that a triplet nitrene acts as the reactive intermediate. The chemoselectivity of the reaction, with alkyl olefin aziridination ≫ electron deficient olefin aziridination ≈ C(sp2)-H amination ≫ C(sp3)-H amination was observed, which may be instructive in the development of an understanding of visible-light-induced triplet nitrene transformation reactions.