Photoredox and Vanadate Cocatalyzed Hydrolysis of Aryl Ethers at Ambient Temperature

Abstract

Cleavage of aryl ether C−O bonds is significant for both biomass utilization and synthetic chemistry. However, a general method with high selectivity and atom economy, under mild reaction conditions, is unavailable. Herein, we describe photoredox and vanadate cocatalyzed hydrolysis of aryl ethers to cleave C−O bonds at ambient temperature via a cation radicalaccelerated nucleophilic aromatic substitution enabled by a "hydroxyl shuttle" pathway. Specifically, a vanadate derived from V 2 O 5 in situ hydrolysis serves as a nucleophile to an aryl ether radical cation due to noncovalent interactions. A favorable V•••O interaction in the corresponding Meisenheimer-like intermediate facilitates ether C−O bond cleavage. In situ hydrolysis of the resulting phenyl vanadate enables nucleophilic vanadate catalyst recycling. Cooperation of these processes complete the transfer of hydroxyl groups from water to arene radical cations. This method offers a preferred option for C−O bond cleavage and demonstrates potential application to lignin degradation.