Oxidative Coupling of Arenes to Biaryl Compounds

Pd-catalyzed aerobic oxidative coupling of arenes provides efficient access to biaryl compounds. The reaction exhibits near-ideal atom economy with water as the sole by-product however, it typically suffers from low regioselectivity and the blaryl products are often susceptible to further oxidation to afford oligomers. 

Oxidative coupling of other arenes (e.g., toluene, benzene, methyl benzoate) has also been investigated. The activity of Pd catalysts is enhanced by various additives, including P-diketones [36], Zr [37], Mo02(acac)2 [38], Zr /Co /Mn [39], HPMoV-type heteropolyacids (HPA) [40], and triflic acid [41]. Acetic acid is a common solvent for these reactions. It was disclosed recently that supported nanoparticle Au catalysts can be applied as catalysts in reactions of this type [42]. 

Chemistry and Catalysis Applications of Potential Industrial Interest 

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