Selective α-oxidation of amides via visible-light-driven iron catalysis.

Hydroxyl radicals (˙OH) as one of the highly reactive species can react unselectively with a wide range of chemicals. The ˙OH radicals are typically generated under harsh conditions. Herein, we report hydroxyl radical-induced selective N -α C(sp 3 )-H bond oxidation of amides under greener and mild conditions via an Fe(NO 3 ) 3 ·9H 2 O catalyst inner sphere pathway upon irradiation with a 30 W blue LED light strip ( λ = 455 nm) using NaBrO 3 as the oxidant. This protocol exhibited high chemoselectivity and excellent functional group tolerance. A preliminary mechanism investigation demonstrated that the iron catalyst afforded hydroxyl radicals via the visible-light-induced homolysis (VLIH) of iron complexes followed by a hydrogen atom transfer (HAT) process to realize this transformation.