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

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.