Catalytic Intermolecular Direct Arylation of Perfluorobenzenes

Penta-, tetra-, tri-, and difluorobenzenes undergo direct arylation with a wide range of arylhalides in high yield. Inverse reactivity is observed compared to the common electrophilic aromatic substitution pathway since electron-deficient, C−H acidic arenes react preferentially. Computational studies indicate that C−H bond cleavage occurs via a concerted carbon−palladium and carbon−hydrogen bond cleaving event involving a carbonate or a bromide ligand. The reactions are rapid, require only a slight excess of the perfluoroarene reagent, and utilize commercially available, air-stable catalyst precursors.