Recyclable Cu@C3N4-catalyzed hydroxylation of aryl boronic acids in water under visible-light: Synthesis of phenols under ambient condition and room temperature

A heterogeneous photocatalyst based on copper doped g-C3N4 was developed for the oxidative hydroxylation of aryl boronic acids into phenols under room temperature in the irradiation of blue light (460 nm). The reaction proceeded efficiently in water as a green solvent and air as green oxidant, giving various phenols as products with high yields in short reaction time. Importantly, this heterogeneous catalyst can be used at least for 5 times with reactivities maintained.