Friedel–Crafts Reaction of Benzyl Fluorides: Selective Activation of CF Bonds as Enabled by Hydrogen Bonding

A Friedel–Crafts benzylation of arenes with benzyl fluorides has been developed. The reaction produces 1,1-diaryl alkanes in good yield under mild conditions without the need for a transition metal or a strong Lewis acid. A mechanism involving activation of the CF bond through hydrogen bonding is proposed. This mode of activation enables the selective reaction of benzylic CF bonds in the presence of other benzylic leaving groups.