N‑Hydroxyphthalimide-Mediated Electrochemical Iodination of Methylarenes and Comparison to Electron-Transfer-Initiated C–H Functionalization

An electrochemical method has been developed for selective benzylic iodination of methylarenes. The reactions feature the first use of N-hydroxy­phthalimide as an electrochemical mediator for C–H oxidation to nonoxygenated products. The method provides the basis for direct (in situ) or sequential benzylation of diverse nucleophiles using methylarenes as the alkylating agent. The hydrogen-atom transfer mechanism for C–H iodination allows C–H oxidation to proceed with minimal dependence on the substrate electronic properties and at electrode potentials 0.5–1.2 V lower than that of direct electrochemical C–H oxidation.