Visible Light Induced Rhodium(I)‐Catalyzed C−H Borylation

Abstract

AbstractAn efficient visible light induced rhodium(I)‐catalyzed regioselective borylation of aromatic C−H bonds is reported. The photocatalytic system is based on a single NHC−RhI complex capable of both harvesting visible light and enabling the bond breaking/forming at room temperature. The chelating nature of the NHC‐carboxylate ligand was critical to ensure the stability of the RhI complex and to provide excellent photocatalytic activities. Experimental mechanistic studies evidenced a photooxidative ortho C−H bond addition upon irradiation with blue LEDs, leading to a cyclometalated RhIII‐hydride intermediate.