Palladium-Catalyzed Coupling Reaction of Aromatic Compounds

Abstract

The oxidative coupling reaction of aromatic compounds proceeds catalytically with palladium salt under oxygen pressure. Yields and isomer distributions are attributed to the reaction variables such as temperature, additives, and the nature of the substituent on a benzene ring. Naphthalene was converted mainly into 1-substituted products and o-xylene into 4-substituted products. The coupling of diphenyl ether afforded diphenylene oxide with coupling dimers. An intramolecular two stage dehydrogenation process is proposed.