Nickel(II) complexes with bifunctional phosphine–imidazolium ligands and their catalytic activity in the Kumada–Corriu coupling reaction
作者:Joffrey Wolf、Agnès Labande、Jean-Claude Daran、Rinaldo Poli
DOI:10.1016/j.jorganchem.2005.09.010
日期:2006.1
Zwitterionic Ni(II) complexes of type NiX3(NCN+), (NCN+ = 1-(2-diphenylphosphinoethyl)-3-(2,4,6-trimethylphenyl)imidazolium and X = Cl, 6; Br, 7), have been prepared by addition of NCN+ bromide (1a) or tetrafluoroborate (1b) to NiX2L, and characterised by X-ray crystallography. They have been used as catalytic precursors in the Kumada-Corriu coupling reaction between phenylmagnesium chloride and 4-chloroanisole, yielding high catalytic activities. Stoechiometric deprotonation investigations did not provide clear evidence for the formation of coordinated carbene species. (c) 2005 Elsevier B.V. All rights reserved.
Contribution of heterobifunctional ligands to transition metal-catalysed C--C coupling reactions
作者:Agnes LABANDE、Eric DEYDIER、Eric MANOURY、Jean-Claude DARAN、Catherine AUDIN、Rinaldo POLI
DOI:10.3906/kim-1507-73
日期:——
In this account the authors' latest results in C-C coupling catalysis are reviewed. First, an efficient catalytic system for the Kumada-Tamao-Corriu coupling reaction based on NHC-phosphine (NHC = N-heterocyclic carbene) nickel complexes is presented. Then the use of palladium complexes of chiral ferrocenyl NHC-phosphines in the asymmetric Suzuki-Miyaura coupling reaction is reported. High catalytic activities and moderate enantioselectivities (ee up to 46%) were obtained. Chiral ferrocenyl phosphine-ethers were also tested in the asymmetric Suzuki-Miyaura reaction yielding good activities and moderate enantioselectivities (ee up to 37%). Finally, the original synthesis of a ferrocenyl rhodium(III) complex and its successful use as catalyst for a C-C coupling reaction via C-H activation of 2-phenylpyridine is presented.