title: Synthesis of polychlorinated biphenyls (PCBs) using the Suzuki-coupling.
abstract: An improved synthesis of polychlorinated biphenyls (PCBs) utilizing a palladium-catalyzed cross-coupling reaction (Suzuki-coupling) is described. The coupling of (chlorinated) aryl boronic acids 1-3 with bromochlorobenzenes 4 using the standard conditions of the Suzuki-coupling gave the desired PCB congeners 5-7 in good to excellent yields. The self-coupling product of the aryl boronic acids is the major impurity of this reaction. 3,4,5-trichlorophenyl derivatives such as 10 can be synthesized by coupling of an aryl boronic acid with the corresponding bromochloroaniline 8. The approach offers the advantage of high selectivity and good yields compared to conventional methods such as the Cadogan reaction and allows the use of less toxic starting materials.
authors.affiliation: Graduate Center for Toxicology, Chandler Medical Center, University of Kentucky, Lexington 40536-0305, USA.
authors.forename: H J
authors.initials: HJ
authors.lastname: Lehmler
authors.forename: L W
authors.initials: LW
authors.lastname: Robertson
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry; D004785:Environmental Pollutants / Q000138:chemical synthesis*; D010165:Palladium / Q000737:chemistry; D011078:Polychlorinated Biphenyls / Q000138:chemical synthesis*
chemical_list: D001555:Benzene Derivatives; D004785:Environmental Pollutants; D010165:Palladium; D011078:Polychlorinated Biphenyls