Abstract
Pyridine N-oxides have been well established as a class of potent hydrogen-atom-transfer (HAT) catalysts for C-H functionalization of unactivated alkanes and activated C-H substrates. The combination of acridine derivatives and Lewis acids forms in situ-generated photocatalysts that are able to photo-oxidize pyridine N-oxides to generate N-oxide radicals upon irradiation with visible light. Herein, we described a photocatalytic C-H functionalization utilizing acridine-Lewis acid complexes and pyridine N-oxide based HAT catalysts. The readily available and facilely tunable photocatalytic system of acridine-Lewis acid complexes and pyridine N-oxides enables a broad range of substrates with high reactivities (up to 97% yield).