Synthesis of Terphenyl Derivatives by Pd-Catalyzed Suzuki-Miyaura Reaction of Dibromobenzene Using 2N2O-Salen as a Ligand in Aqueous Solution

A simple and efficient catalytic system for Na2PdCl4 catalyzing the Suzuki-Miyaura reaction of dibromobenzene and arylboronic acid has been developed by using 2N2O-salen as a ligand in H2O/EtOH (V:V=4:1) at 100 degrees C. Using this method, the reactions of substrates containing sterically demanding ortho substituents (e.g. dibromobenzene and/or arylboronic acids) proceeded efficiently, with the corresponding terphenyl derivatives being produced in moderate to excellent yields. Furthermore, this method offers interesting features for the multi-gram scale synthesis of terphenyl compound.