Unveiling Potent Photooxidation Behavior of Catalytic Photoreductants

We describe a photocatalytic system that reveals latent photooxidant behavior from one of the most reducing conventional photoredox catalysts, N-phenylphenothiazine (PTH). This aerobic photochemical reaction engages difficult to oxidize feedstocks, such as benzene, in C(sp²)–N coupling reactions through direct oxidation. Mechanistic studies are consistent with activation of PTH via photooxidation and that Lewis acid co-catalysts scavenge inhibitors formed upon catalyst activation.