title: Cross-coupling of diarylborinic acids and anhydrides with arylhalides catalyzed by a phosphite/N-heterocyclic carbene co-supported palladium catalyst system.
abstract: A highly efficient cross-coupling of diarylborinic acids and anhydrides with aryl chlorides and bromides has been effected by using a palladium catalyst system co-supported by a strong σ-donor N-heterocyclic carbene (NHC), N,N'-bis(2,6-diisopropylphenyl) imidazol-2-ylidene, and a strong π-acceptor phosphite, triphenylphosphite, in tert-BuOH in the present of K(3)PO(4)·3H(2)O. Unsymmetrical biaryls with a variety of functional groups could be obtained in good to excellent yields using as low as 0.01, 0.2-0.5, and 1 mol % palladium loadings for aryl bromides and activated and deactivated aryl chlorides, respectively, under mild conditions. A ligand synergy between the σ-donor NHC and the π-acceptor phosphite in the Pd/NHC/P(OPh)(3) catalytic system has been proposed to be responsible for the high efficacy to arylchlorides in the cross-coupling. A scalable and economical process has therefore been developed for synthesis of Sartan biphenyl from the Pd/NHC/P(OPh)(3) catalyzed cross-coupling of di(4-methylphenyl)borinic acid with 2-chlorobenzonitrile.
authors.affiliation: Department of Fine Chemicals, East China University of Science & Technology, 130 Meilong Rd., Shanghai, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Chen
authors.forename: Haihua
authors.initials: H
authors.lastname: Ke
authors.forename: Yao
authors.initials: Y
authors.lastname: Chen
authors.forename: Changwei
authors.initials: C
authors.lastname: Guan
authors.forename: Gang
authors.initials: G
authors.lastname: Zou
mesh_terms: D000812:Anhydrides / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000138:chemical synthesis / Q000737:chemistry; D001889:Borinic Acids / Q000737:chemistry*; D002384:Catalysis; D006571:Heterocyclic Compounds / Q000737:chemistry*; D006846:Hydrocarbons, Halogenated / Q000737:chemistry*; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry; D010165:Palladium / Q000737:chemistry; D017905:Phosphites / Q000737:chemistry*
chemical_list: D000812:Anhydrides; D001713:Biphenyl Compounds; D001889:Borinic Acids; D006571:Heterocyclic Compounds; D006846:Hydrocarbons, Halogenated; D008697:Methane; D009942:Organometallic Compounds; D010165:Palladium; D017905:Phosphites; C030011:carbene; C010574:biphenyl