Weak Coordination Promoted Regioselective Oxidative Coupling Reaction for 2,2'-Difunctional Biaryl Synthesis in Hexafluoro-2-propanol.

An unprecedented weak coordination promoted dehydrogenative cross-coupling reaction has been developed by palladium catalysis, which provides a convenient access to a wide range of 2,2'-difunctional biaryls from easily accessible substrates. Both HFIP solvent and oxidants serve as the critical factors in this new reaction. A plausible mechanism involving Pd(II)/Pd(IV) is proposed. The reaction demonstrates excellent reactivity, broad functional-group tolerance and high yields.