Bimetallic Photoredox Catalysis: Visible Light-Promoted Aerobic Hydroxylation of Arylboronic Acids with a Dirhodium(II) Catalyst

We report the use of a rhodium­(II) dimer in visible light photoredox catalysis for the aerobic oxidation of arylboronic acids to phenols under mild conditions. Spectroscopic and computational studies indicate that the catalyst Rh2(bpy)2(OAc)4 (1) undergoes metal–metal to ligand charge transfer upon visible light irradiation, which is responsible for catalytic activity. Further reactivity studies demonstrate that 1 is a general photoredox catalyst for diverse oxidation reactions.