Double-coupling of dibromo arenes with aryltriolborates for synthesis of diaryl-substituted planar frameworks

A new method for simple and practical synthesis of diaryl-substituted arenes using potassium aryltriolborates was developed. Double-cross-coupling of dibromo arenes with aryltriolborates was carried out in the presence of a palladium catalyst, such as Pd(OAc)2, Pd(PPh3)4 or Pd(OAc)2/BIPHEP. The use of CuCl (40 mol %) with a palladium catalyst was found to be highly effective to give diaryl-substituted aromatic compounds in good yields.