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. [ABSTRACT FROM AUTHOR]