| abstract |
The invention concerns a method of preparing polycyclic aromatic compounds by crosslinking aromatic boron acids with aromatic halogen compounds or perfluoroalkyl sulphonates in the presence of metallic palladium, optionally on a carrier, as catalyst. The method is characterized in that the crosslinking is carried out in the presence of a ligand and a base. The method disclosed enables the yield of polycyclic aromatic compounds to be increased significantly compared with methods in which no ligand is used, i.e. it ensures optimum yields in the pd(O)-catalysed crosslinking of aromatic boron acids with aromatic halogen compounds. |