Modulating Electron Transfer via Cerium Photocatalysis for Alkoxy Radical‐Mediated Selective Hydroetherification

Abstract

Abstract We present a ligand‐to‐metal charge transfer (LMCT)‐enabled catalytic platform utilizing cerium(IV) benzoate complexes to address the long‐standing challenge of directly coupling free alcohols with electron‐rich alkenes, overcoming inherent polarity mismatches. This approach effectively circumvents the typical selectivity in single‐electron transfer processes, enabling the selective generation of electrophilic alkoxy radicals from free alcohols in the presence of redox‐labile electron‐rich alkenes. The Ce‐benzoate‐based photocatalytic protocol promotes regioselective hydroetherification via both intramolecular cyclization and intermolecular addition pathways, showcasing broad functional group tolerance, operational simplicity, and versatility across a diverse array of alkenes, including silyl enol ethers and enamides/enecarbamates. Detailed mechanistic studies elucidate the structure of the active Ce(IV) benzoate catalyst, highlighting its unique selectivity for alkoxy radical generation, thereby establishing a practical and atom‐economical framework for hydroetherification.