title: Synthesis, Characterization, and Catalytic Activity of Ni(II) Alkyl Complexes Supported by Pyrrole-Diphosphine Ligands.
abstract: The organometallic Ni(II) chemistry of the pyrrole-based pincer ligands, (P2RPyr)-(P2RPyr = 2,5-(R2PCH2)2C4H2N, R = Ph or Cy) is reported. Reactions of Grignard reagents with [NiCl(P2RPyr)] afford a variety of alkyl and aryl complexes (methyl, ethyl, benzyl, phenyl, and allyl) that all display square planar geometries about nickel. The hydride complex, [NiH(P2CyPyr)], can also prepared either through treatment of [NiCl(P2CyPyr)] with LiHBEt3, or by reaction of H(P2RPyr) with [Ni(COD)2] (COD = 1,4-cyclooctadiene). Reactions of the methyl and hydride complexes with CO and CO2, respectively, evince clean migratory insertion chemistry of the Ni-C and Ni-H bonds. Both the alkyl and chloride complexes are active catalysts for the Kumada coupling of aryl chlorides and aryl or alkyl Grignard reagents at room temperature. The solid-state structures of several of the complexes are reported.
authors.affiliation: Department of Chemistry, University of Texas at San Antonio, San Antonio, TX 78249.
authors.forename: Gopaladasu T
authors.initials: GT
authors.lastname: Venkanna
authors.affiliation: Department of Chemistry, University of Texas at San Antonio, San Antonio, TX 78249.
authors.forename: Swetha
authors.initials: S
authors.lastname: Tammineni
authors.affiliation: Department of Chemistry, University of Texas at San Antonio, San Antonio, TX 78249.
authors.forename: Hadi D
authors.initials: HD
authors.lastname: Arman
authors.affiliation: Department of Chemistry, University of Texas at San Antonio, San Antonio, TX 78249.
authors.forename: Zachary J
authors.initials: ZJ
authors.lastname: Tonzetich