Iron porphyrin catalysed light driven C-H bond amination and alkene aziridination with organic azides

Visible light driven nitrene transfer and insertion reactions of organic azides are an attractive strategy for the design of C-N bond formation reactions under mild reaction conditions, the challenge being lack of selectivity as a free nitrene reactive intermediate is usually involved. Herein is described an iron(iii) porphyrin catalysed sp³ C-H amination and alkene aziridination with selectivity by using organic azides as the nitrogen source under blue LED light (469 nm) irradiation. The photochemical reactions display chemo- and regio-selectivity and are effective for the late-stage functionalization of natural and bioactive compounds with complexity. Mechanistic studies revealed that iron porphyrin plays a dual role as a photosensitizer and as a catalyst giving rise to a reactive iron-nitrene intermediate for subsequent C-N bond formation.