B(C₆F₅)₃-Catalyzed [2+3]-Cyclative o,m-diC-H Functionalization of Phenols

Metal-free catalytic C−H functionalization is highly desired for the construction of C−C bonds. We herein report a highly chemoselective consecutive C−H [2+3]-cyclative functionalization for the simultaneous formation of two C−C bonds with construction of polycyclic phenols catalyzed by commercially available and low-cost B(C₆F₅)₃. This catalytic system tolerates a wide range of substrate scope, providing a series of 2,6,7,8-tetrahydroacenaphthylen-3-ol-type polycyclic compounds efficiently. Several derivatizations of the catalytic products have also been conducted to show the potential application of this method in synthesis of polycyclic compounds.