Direct electrochemical oxidation of alkylarenes to aryl aldehydes and ketones.

A green and sustainable electrochemical protocol for the direct benzylic C(sp3)-H oxidation of alkylarenes to aryl aldehydes and ketones is developed. The protocol employs potassium persulfate as a co-oxidant under constant current electrolysis. It exhibits broad substrate scope, excellent functional group tolerance, and high site-selectivity without over-oxidation. Mechanistic studies, including 18O-labeling experiments, confirm that water serves as the exclusive oxygen atom donor. This operationally simple approach offers an economical alternative for aldehyde and ketone synthesis.