2,5-Dihydroxyterephthalic Acid Accelerated Cu(NO3)2.3H2O-Catalyzed Homocoupling Reaction of Arylboronic Acids

A catalyst system derived from commercially available Cu(NO3)2.3H2O and 2,5- dihydroxyterephthalic acid is applied to the homocoupling reaction of arylboronic acids. This transformation provides a convenient approach to symmetrical biaryls with good to excellent yields (39%- 95%), and exhibits good functional group compatibility. Furthermore, biaryl can be prepared in gram quantities in good yield.