Visible‐Light‐Induced Metal‐Free Allylic Oxidation Utilizing a Coupled Photocatalytic System of g‐C3N4 and N‐Hydroxy Compounds

Graphitic carbon nitride (g-C3N4) and N-hydroxy compounds can function as a non-metal photocatalytic system to activate O2 for the selective allylic oxidation under mild conditions, avoiding the employment of any metal derivative or organic oxidizing agents. Interestingly, the novel photocatalytic system affords a remarkably high selectivity towards the formation of aldehydes, especially in the oxidation of toluene. By combining the unique nature of g-C3N4 (surface basicity, semiconductor features, high stability) and the remarkable catalytic oxidation reactivity of nitroxyl radicals, this photocatalytic system opens up a mild and efficent access for CH bond activation.