9-Borabicyclo[3.3.l]nonane-induced Friedel-Crafts benzylation of arenes with benzyl fluorides

Friedel-Crafts benzylation of arenes with benzyl fluorides using 9-borabicyclo[3.3.l]nonane (9-BBN) as a mediator has been developed. This provides a simple and cheap route to the activation of C-F bonds to synthesize 1,1-diarylmethanes in good to excellent yields (up to 98%) under mild conditions. Functional group tolerance and the mechanism are considered. 9-Borabicyclo[3.3.l]nonane dimer (9-BBN) mediates the Friedel-Crafts benzylation of arenes with benzyl fluorides, affording a series of 1,1-diarylmethanes under mild conditions.