Long-Range C-H Bond Activation by Rh~(Ⅲ)-Carboxylates

摘要

Traditional C-H bond activation by a concerted metalation-deprotonation (CMD) mechanism involves precoordination of the C-H bond followed by deprotonation from an internal base. Reported herein is a "through-arene" activation of an uncoordinated benzylic C-H bond that is 6 bonds away from a Rh~Ⅲ ion. The mechanism, which was investigated by experimental and DFT studies, proceeds through a dearomatized xylene intermediate. This intermediate was observed spectro-scopically upon addition of a pyridine base to provide a thermodynamic trap.