Light‐Promoted Chlorine‐Radical‐Mediated Oxidation of Benzylic C(sp3)−H Bonds utilizing Air as Oxidant

Abstract A photocatalyzed metal‐free method for benzylic C(sp 3 )−H bond oxidation has been developed. Achieved under the mild conditions, a variety of methylarenes and benzyl derivatives could be converted into corresponding carboxylic acids and ketones, and isolated yields of 31–98% are obtained. The mechanistic investigations showed that chlorine radical could be generated via the direct single electron transfer (SET) between chloride anion and excited heteroarene under light irradiation, which could be used as hydrogen atom transfer agent to facilitate benzylic C(sp 3 )−H bond oxygenation. The merits of this catalytic system could be further demonstrated by the degradation of plastic to form benzoic acids. magnified image