title: Biaryl synthesis via Pd-catalyzed decarboxylative coupling of aromatic carboxylates with aryl halides.
abstract: A new strategy for the regiospecific construction of unsymmetrical biaryls is presented, in which easily available salts of carboxylic acids are decarboxylated in situ to give arylmetal species that serve as the nucleophilic component in a catalytic cross-coupling reaction with aryl halides. The catalyst system consists of a copper phenanthroline complex that mediates the extrusion of CO2 from aromatic carboxylates to generate arylcopper species, and a palladium complex that catalyzes the cross-coupling of these intermediates with aryl halides. This bimetallic system allows the direct coupling of various aryl, heteroaryl, or vinyl carboxylic acids with aryl or heteroaryl iodides, bromides, or chlorides at 160 degrees C in the presence of a mild base such as potassium carbonate. The present scope and potential economic impact of the reaction are demonstrated by the synthesis of 42 biaryls, some of which are of substantial industrial relevance. Remaining challenges and future perspectives of the new transformation are discussed.
authors: Institut für Organische Chemie, TU Kaiserslautern, Erwin-Schrödinger-Strasse, Building 54, D-67663 Kaiserslautern, Germany. goossen@chemie.uni-ki.de
authors: Lukas J
authors: LJ
authors: Goossen
authors: Nuria
authors: N
authors: Rodríguez
authors: Bettina
authors: B
authors: Melzer
authors: Christophe
authors: C
authors: Linder
authors: Guojun
authors: G
authors: Deng
authors: Laura M
authors: LM
authors: Levy
mesh_terms: D001897:Boronic Acids / Q000737:chemistry; D002264:Carboxylic Acids / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D003432:Cross-Linking Reagents / Q000737:chemistry; D006219:Halogens / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*
chemical_list: D001897:Boronic Acids; D002264:Carboxylic Acids; D003432:Cross-Linking Reagents; D006219:Halogens; D007477:Ions; D010165:Palladium