Selective benzylic C-H electrochemical oxygenation under ambient air promoted by an Fe-N-C electrocatalyst.

Selective benzylic C-H electrochemical oxygenation is achieved using ambient air via a cathode-loaded Fe-N-C electrocatalyst, in which Fe sites serve as the primary catalytically active species. This protocol provides a range of aromatic aldehydes and ketones in up to 96% isolated yields with broad functional group tolerance. Mechanistic studies reveal that the reaction proceeds through a superoxide radical anion (O2˙-) generated at the cathode and a benzylic radical intermediate generated at the anode. Notably, this cathodic ORR-coupled anodic oxidation strategy is free from external chemical oxidants and uses ethanol as a green solvent, highlighting its advantages in sustainable electrochemical C-H functionalization.