Nickel(II) complexes containing a pyrrole-diphosphine pincer ligand.

A new pincer ligand, (P(2)(Ph)Pyr)(-), based on the anion of 2,5-bis[(diphenylphosphino)methyl]pyrrole has been prepared in four steps from pyrrole. The ligand undergoes oxidation to diphosphine oxide under ambient conditions and was therefore isolated as its borane adduct, H(P(2)(Ph)Pyr)·2BH(3) (2). Delivery of the ligand to nickel(II) was accomplished by the direct reaction of NiCl(2) with 2 in the presence of Et(2)NH to afford [NiCl(P(2)(Ph)Pyr)]. Salt metathesis reactions of the chloro complex afford new compounds including [Ni(CH(3))(P(2)(Ph)Pyr)] and [Ni(NCCH(3))(P(2)(Ph)Pyr)](OTf). In all cases, the ligand gives rise to diamagnetic square-planar complexes, which have been fully characterized in solution and the solid state. All complexes examined display an irreversible oxidation to nickel(III) according to cyclic voltammetry. Reduction of the chloro complex in dichloromethane results in an electrocatalytic process, whereas reduction in tetrahydrofuran leads to the irreversible formation of a nickel(I) species.

[1]  L. Gade,et al.  A readily accessible PNP pincer ligand with a pyrrole backbone and its Ni(I/II) chemistry. , 2012, Dalton transactions.

[2]  D. Ghorai,et al.  Mononuclear, helical binuclear palladium and lithium complexes bearing a new pyrrole-based NNN-pincer ligand: fluxional property. , 2012, Dalton transactions.

[3]  E. Reijerse,et al.  Closed-shell and open-shell square-planar iridium nitrido complexes. , 2012, Nature chemistry.

[4]  A. Goldman,et al.  Alkane metathesis by tandem alkane-dehydrogenation-olefin-metathesis catalysis and related chemistry. , 2012, Accounts of chemical research.

[5]  Rakesh Ganguly,et al.  A new type of phosphaferrocene–pyrrole–phosphaferrocene P-N-P pincer ligand , 2012 .

[6]  Paul G. Hayes,et al.  Ring-opening polymerisation of rac-lactide mediated by cationic zinc complexes featuring P-stereogenic bisphosphinimine ligands. , 2012, Dalton transactions.

[7]  J. Kerr,et al.  Metal complexes of Co, Ni and Cu with the pincer ligand HN(CH2CH2P(i)Pr2)2: preparation, characterization and electrochemistry. , 2011, Dalton transactions.

[8]  Xile Hu.  Nickel-catalyzed cross coupling of non-activated alkyl halides: a mechanistic perspective , 2011 .

[9]  G. van Koten,et al.  The monoanionic pincer-metal platform: a scaffold for meeting challenges in catalysis and materials research. , 2011, Dalton transactions.

[10]  M. Pink,et al.  Selectivity of attack on a Si–C(sp3) sigma bond coordinated to NiII , 2011 .

[11]  D. Milstein,et al.  Metal-ligand cooperation by aromatization-dearomatization: a new paradigm in bond activation and "green" catalysis. , 2011, Accounts of chemical research.

[12]  M. Baik,et al.  Room temperature dehydrogenation of ethane to ethylene. , 2011, Journal of the American Chemical Society.

[13]  M. Pink,et al.  Evaluating the reducing power of 3-coordinate T-shaped NiI ☆ , 2011 .

[14]  B. Foxman,et al.  Reactivity of a Pd(I)-Pd(I) dimer with O2: monohapto Pd superoxide and dipalladium peroxide in equilibrium. , 2011, Journal of the American Chemical Society.

[15]  M. Pink,et al.  Three-coordinate NiII: tracing the origin of an unusual, facile Si-C(sp3) bond cleavage in [(tBu2PCH2SiMe2)2N]Ni+. , 2011, Journal of the American Chemical Society.

[16]  Z. Hou,et al.  Highly Cis-1,4-Selective Living Polymerization of 1,3-Conjugated Dienes and Copolymerization with ε-Caprolactone by Bis(phosphino)carbazolide Rare-Earth-Metal Complexes , 2011 .

[17]  Y. Miyake,et al.  A molybdenum complex bearing PNP-type pincer ligands leads to the catalytic reduction of dinitrogen into ammonia. , 2011, Nature chemistry.

[18]  S. Brooker,et al.  Copper(II) and palladium(II) complexes of a terdentate pyrrolidine diester ligand , 2011 .

[19]  A. Spek,et al.  Construction of a monoanionic S,N,S-pincer ligand with a pyrrole core by sequential [1,2] phospho-Fries rearrangement. Characterization of palladium and silver coordination complexes. , 2010, Dalton transactions.

[20]  K. G. Caulton,et al.  Mechanism of heterolysis of H2 by an unsaturated d8 nickel center: via tetravalent nickel? , 2010, Journal of the American Chemical Society.

[21]  Chia‐Her Lin,et al.  A new type of asymmetric tridentate pyrrolyl-linked pincer ligand and its aluminum dihydride complexes. , 2010, Inorganic chemistry.

[22]  Joseph A. Wright,et al.  Synthesis of neutral and zwitterionic phosphinomethylpyrrolato complexes of nickel , 2009 .

[23]  J. Reek,et al.  Neutral tridentate PNP ligands and their hybrid analogues: versatile non-innocent scaffolds for homogeneous catalysis. , 2009, Angewandte Chemie.

[24]  Bradley M. Wile,et al.  Reduction chemistry of aryl- and alkyl-substituted bis(imino)pyridine iron dihalide compounds: molecular and electronic structures of [(PDI)2Fe] derivatives. , 2009, Inorganic chemistry.

[25]  D. Spasyuk,et al.  Regioselective Hydroamination of Acrylonitrile Catalyzed by Cationic Pincer Complexes of Nickel(II) , 2009 .

[26]  J. C. Flores,et al.  Synthesis of 2-(N-arylimino-κN-methyl)pyrrolide-κN complexes of nickel , 2008 .

[27]  M. Pink,et al.  [Ni{N(SiMe2CH2PtBu2)2}]+: direct observation of transannular Si-C(sp3) bond coordination. , 2008, Angewandte Chemie.

[28]  M. Chipara,et al.  A dinuclear Ni(I) system having a diradical Ni2N2 diamond core resting state: synthetic, structural, spectroscopic elucidation, and reductive bond splitting reactions. , 2008, Inorganic chemistry.

[29]  D. Zargarian,et al.  Preparation and Reactivities of PCP-Type Pincer Complexes of Nickel. Impact of Different Ligand Skeletons and Phosphine Substituents , 2008 .

[30]  Philip A. Gale,et al.  Structural diversity in the first metal complexes of 2,5-dicarboxamidopyrroles and 2,5-dicarbothioamidopyrroles. , 2008, Dalton transactions.

[31]  M. Pink,et al.  Influence of the d-Electron Count on CO binding by three-coordinate [(tBu2PCH2SiMe2)2N]Fe, -Co, and -Ni. , 2008, Inorganic chemistry.

[32]  C. Senanayake,et al.  Reduction of tertiary phosphine oxides with DIBAL-H. , 2008, The Journal of organic chemistry.

[33]  G. Sheldrick.  A short history of SHELX. , 2008, Acta crystallographica. Section A, Foundations of crystallography.

[34]  Carmine Capacchione,et al.  Synthesis, Structure and Dynamics of a C2‐symmetrical Bis(oxazolinylmethylene)pyrrolinato‐Zinc Complex , 2007 .

[35]  D. Mindiola,et al.  Addition of ammonia, water, and dihydrogen across a single Pd-Pd bond. , 2007, Journal of the American Chemical Society.

[36]  M. Bröring,et al.  Palladium complexes of sterically hindered meridonal tridentate NNN ligands , 2007 .

[37]  Hongjun Fan,et al.  Intermolecular C−H Bond Activation Reactions Promoted by Transient Titanium Alkylidynes. Synthesis, Reactivity, Kinetic, and Theoretical Studies of the Ti⋮C Linkage , 2007 .

[38]  M. Reshetova,et al.  Pincer ligands based on α-amino acids: I. Synthesis of polydentate ligands from pyrrole-2,5-dicarbaldehyde , 2007 .

[39]  Brad C. Bailey,et al.  Snapshots of an alkylidyne for nitride triple-bond metathesis. , 2007, Journal of the American Chemical Society.

[40]  Lan‐Chang Liang.  Metal complexes of chelating diarylamido phosphine ligands , 2006 .

[41]  Takakazu Yamamoto,et al.  Synthesis and Structural Features of a Series of κ3SNS Pincer Complexes of Group 10 Metals σ-Bonded to Centered Pyrrolate Unit , 2006 .

[42]  B. Foxman,et al.  Carbon-halide oxidative addition and carbon-carbon reductive elimination at a (PNP)Rh center. , 2006, Journal of the American Chemical Society.

[43]  S. Parkin,et al.  Halobenzenes and Ir(I): kinetic C-H oxidative addition and thermodynamic C-Hal oxidative addition. , 2005, Journal of the American Chemical Society.

[44]  K. Mashima,et al.  Uniqueness and Versatility of Iminopyrrolyl Ligands for Transition Metal Complexes , 2005 .

[45]  M. Baik,et al.  A facile approach to a d4 RuN: moiety. , 2005, Journal of the American Chemical Society.

[46]  J. Andrieu,et al.  A P-chirogenic β-aminophosphine synthesis by diastereoselective reaction of the α-metallated PAMP–borane complex with benzaldimine , 2004 .

[47]  S. Brooker,et al.  Syntheses, structures and tautomers of 2,5-disubstituted pyrroles , 2003 .

[48]  David Milstein,et al.  Cyclometalated phosphine-based pincer complexes: mechanistic insight in catalysis, coordination, and bond activation. , 2003, Chemical reviews.

[49]  L. Gade,et al.  Double bonds in motion: bis(oxazolinylmethyl)pyrroles and their metal-induced planarization to a new class of rigid chiral C2-symmetric complexes. , 2003, Chemistry.

[50]  L. Gade,et al.  Synthesis and coordination chemistry of the first C2-chiral bisoxazine ligand. , 2003, Inorganic chemistry.

[51]  K. K. Hii,et al.  Examining the effect of hemilabile donor groups in non-C2 symmetrical terdentate ligands , 2002 .

[52]  L. Gade,et al.  A Bis(oxazolinyl)pyrrole as a New Monoanionic Tridentate Supporting Ligand: Synthesis of a Highly Active Palladium Catalyst for Suzuki-Type C−C Coupling , 2001 .

[53]  T. Miura,et al.  Stereospecific reduction of phosphine oxides to phosphines by the use of a methylation reagent and lithium aluminum hydride. , 2001, Organic letters.

[54]  S. Peng,et al.  Synthesis and structure characterization of 2-(dimethylaminomethyl)pyrrolate and 2,5-bis(dimethylaminomethyl)pyrrolate zirconium complexes , 2000 .

[55]  M. Thornton-Pett,et al.  Synthesis and reactivity of sterically hindered iminopyrrolato complexes of zirconium, iron, cobalt and nickel , 2000 .

[56]  M. R. Dubois,et al.  The activation of η5-pyrrole complexes toward nucleophilic attack , 1998 .

[57]  A. Blackman.  Reactions of Coordinated Ligands , 1994 .

[58]  H. Adams,et al.  Copper(II) complexes of pyrrole-containing Schiff-base macrocycles: crystal and molecular structures of a mononuclear macrocyclic complex, and of pyrrole-2,5-dicarbaldehyde , 1986 .

[59]  T. Imamoto,et al.  FACILE REDUCTION OF ORGANIC HALIDES AND PHOSPHINE OXIDES WITH LiAlH4–CeCl3 , 1985 .

[60]  Kazuhiko Sato,et al.  Phosphine oxides and lithium aluminum hydride-sodium borohydride-cerium(III) chloride: synthesis and reactions of phosphine-boranes , 1985 .

[61]  M. D. Fryzuk,et al.  Tridentate amidophosphine derivatives of the nickel triad: synthesis, characterization, and reactivity of nickel(II), palladium(II), and platinum(II) amide complexes , 1982 .