14126-37-5Relevant articles and documents
Catalysis of Cross-Coupling and Homocoupling Reactions of Aryl Halides Utilizing Ni(0), Ni(I), and Ni(II) Precursors; Ni(0) Compounds as the Probable Catalytic Species but Ni(I) Compounds as Intermediates and Products
Manzoor, Adeela,Wienefeld, Patrick,Baird, Michael C.,Budzelaar, Peter H.M.
, p. 3508 - 3519 (2017/10/03)
Both Ni(0) and Ni(I) compounds are believed to exhibit cross-coupling catalytic properties under various conditions, and the compounds Ni(PPh3)4 and NiCl(PPh3)3 are compared as catalysts for representative Suzuki-Miyaura and Heck-Mizoroki cross-coupling reactions. The Ni(0) compound exhibits catalytic activities, for cross-coupling of chloro and bromoanisole with phenylboronic acid and of bromobenzene with styrene, yielding results which are comparable with those of many palladium-based catalysts, but our findings with NiCl(PPh3)3 are at this point unclear. It seems to convert to catalytically active Ni(0) species under Suzuki-Miyaura reaction conditions and is ineffective for Heck-Mizoroki cross-coupling. The paramagnetic Ni(I) compounds NiX(PPh3)3 (X = Cl, Br, I) are characterized for the first time by 1H NMR spectroscopy and are found to exhibit broad meta and para resonances at δ 9-11 and 3-4, respectively, and very broad ortho resonances at δ 46; these resonances are very useful for detecting Ni(I) species in solution. The chemical shifts of NiCl(PPh3)3 vary with the concentration of free PPh3, with which it exchanges, and are also temperature-dependent, consistent with Curie law behavior. The compound trans-NiPhCl(PPh3)2, the product of oxidative addition of chlorobenzene to Ni(PPh3)4 and a putative intermediate in cross-coupling reactions of chlorobenzene, is found during the course of this investigation to exhibit entirely unanticipated thermal lability in solution in the absence of free PPh3. It readily decomposes to biphenyl and NiCl(PPh3)2 in a reaction relevant to the long-known but little-understood nickel-catalyzed conversion of aryl halides to biaryls. Ni(I) and biphenyl formation is initiated by PPh3 dissociation from trans-NiPhCl(PPh3)2 and formation of a dinuclear intermediate, a process which is now better defined using DFT methodologies.
Specific features of nickel-catalyzed synthesis of poly(butyl (meth)acrylates)
Grishin,Valetova,Il'Ichev
, p. 1965 - 1969 (2012/03/12)
The activity of the catalytic system NiBr2(PPh3) 2/Zn/PhI in polymerization of butyl acrylate and butyl methacrylate and in copolymerization of butyl methacrylate with styrene was examined.
LINEAR PYRIDAZINE AND PYRROLE COMPOUNDS, METHOD FOR OBTAINING THEM AND APPLICATIONS
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Page/Page column 32, (2010/02/16)
The present invention relates to linear pyridazine compounds, and more particularly to those of these compounds which are oligopyridazine compounds, to processes for obtaining them, to their uses, and also to their reduction to pyrroles and to the uses of the pyrrole, pyridazinylpyrrole and oligopyrrole compounds obtained. The invention relates in particular to the uses as medicaments, in particular for treating pathologies such as cancer, bacterial infections or parasitic infections, and also the applications in the materials, environmental, electronics and optics field.
Synthesis of 2-(N-arylimino-κN-methyl)pyrrolide-κN complexes of nickel
Pérez-Puente, Pilar,de Jesús, Ernesto,Flores, Juan C.,Gómez-Sal, Pilar
, p. 3902 - 3906 (2009/04/06)
2-(N-aryliminomethyl)pyrrole precursors (2,6-R2-C6H3-N{double bond, long}CH-2-C4H3NH) (R = Me, IH; R = iPr, IIH) were prepared and transformed into their corresponding sodium salts (Na+I- and Na+II-) by treatment with NaH. Both salts readily react with [NiBr2(DME)] (DME = 1,2-dimethoxyethane) to give the respective bis{2-(N-arylimino-κN-methyl)pyrrolide-κN}nickel(II) complexes (1, 2) in almost quantitative yields. The oxidative addition of IH to [Ni(COD)2] (COD = 1,5-cyclooctadiene) results in the formation of 3, which is a mono(iminomethylpyrrolide)-η3-(cyclic-allyl)-type organonickel(II) complex. The crystal structure of compound 1 has been established by X-ray diffraction studies.
Ethylene polymerization and oligomerization catalyzed by bulky β-diketiminato Ni(II) and β-diimine Ni(II) complexes/methylaluminoxane systems
Zhang, Junkai,Ke, Zhuofeng,Bao, Feng,Long, Jieming,Gao, Haiyang,Zhu, Fangming,Wu, Qing
, p. 31 - 39 (2008/10/09)
β-Diketiminato complexes Ni{(N(Ar)C(Me))2CH}Br (9), Ni{(N(Ar)C(Me))2CH} Pph3Br (10) and β-diimine complexes Ni{(N(Ar)C(Me))2CH2}Br2 (5) (Ar = 2,6-iPr2C6H3 (a), 2,6-Me2C6H3 (b)) were used as catalyst precursors for ethylene polymerization in the presence of methylaluminoxane (MAO). High molecular weight ethylene polymers as well as short chain oligomers (C4-C8) were simultaneously produced from the catalysis reactions. Ethylene polymers obtained by using these β-N-N Ni(II)/MAO catalyst systems are mainly methyl branched. Small amounts of even number branches were also observed in the 13C NMR spectra of the obtained ethylene polymers, which are believed generating from the incorporation of simultaneously produced α-olefins. Except methyl branch and the branches derived from the incorporation of α-olefin oligomers, the formation of other branch types via the chain walking process is not favored in β-diketiminato Ni(II) systems.
Thermochemistry of adducts of some bivalent transition metal bromides with triphenylphosphine
Dunstan, Pedro Oliver
, p. 100 - 105 (2008/10/09)
The compounds [MBrm(L)n] (where M is Mn(II), Fe(II), Co(II), Ni(II), Cu(I) or Zn(II); L = triphenyphosphine (tpp); m = 1 or 2; n = 1.5, 2 or 3) were synthesized and characterized by melting points, elemental analysis, thermal analysis and electronic and IR spectroscopy. The enthalpies of dissolution of the adducts, metal(II) bromides and triphenylphosphine in methanol or in a solution of 10% (v/v) triethanolamine, 40% (v/v) acetonitrile and 50% (v/v) methanol were measured and by using thermochemical cycles, the following thermochemical parameters for the adducts, have been determined: the standard enthalpies for the Lewis acid/base reaction (ΔrH θ), the standard enthalpies of formation (Δ fHθ), the standard enthalpies of decomposition (ΔDHθ), the lattice standard enthalpies (ΔMHθ) and the standard enthalpies of the Lewis acid/base reaction in the gaseous phase (ΔrH θ(g)). The mean bond dissociation enthalpies of the metal(II)-phosphorus bonds (D?(M-P)) have been estimated.
EPR spectra from EPR-silent species: high-frequency and high-field EPR spectroscopy of pseudotetrahedral complexes of nickel(II).
Krzystek,Park, Ju-Hyun,Meisel, Mark W,Hitchman, Michael A,Stratemeier, Horst,Brunel, Louis-Claude,Telser, Joshua
, p. 4478 - 4487 (2008/10/08)
High-frequency and high-field electron paramagnetic resonance (HFEPR) spectroscopy (using frequencies of approximately 90-550 GHz and fields up to approximately 15 T) has been used to probe the non-Kramers, S = 1, Ni(2+) ion in a series of pseudotetrahedral complexes of general formula NiL(2)X(2), where L = PPh(3) (Ph = phenyl) and X = Cl, Br, and I. Analysis based on full-matrix solutions to the spin Hamiltonian for an S = 1 system gave zero-field splitting parameters: D = +13.20(5) cm(-1), /E/ = 1.85(5) cm(-1), g(x) = g(y) = g(z) = 2.20(5) for Ni(PPh(3))(2)Cl(2). These values are in good agreement with those obtained by powder magnetic susceptibility and field-dependent magnetization measurements and with earlier, single-crystal magnetic susceptibility measurements. For Ni(PPh(3))(2)Br(2), HFEPR suggested /D/ = 4.5(5) cm(-1), /E/ = 1.5(5) cm(-1), g(x) = g(y) = 2.2(1), and g(z) = 2.0(1), which are in agreement with concurrent magnetic measurements, but do not agree with previous single-crystal work. The previous studies were performed on a minor crystal form, while the present study was performed on the major form, and apparently the electronic parameters differ greatly between the two. HFEPR of Ni(PPh(3))(2)I(2) was unsuccessful; however, magnetic susceptibility measurements indicated /D/ = 27.9(1) cm(-1), /E/ = 4.7(1), g(x) = 1.95(5), g(y) = 2.00(5), and g(z) = 2.11(5). This magnitude of the zero-field splitting ( approximately 840 GHz) is too large for successful detection of resonances, even for current HFEPR spectrometers. The electronic structure of these complexes is discussed in terms of their molecular structure and previous electronic absorption spectroscopic studies. This analysis, which involved fitting of experimental data to ligand-field parameters, shows that the halo ligands act as strong pi-donors, while the triphenylphosphane ligands are pi-acceptors.
On the interaction of a nickel(0) complex with mono- and di-bromo derivatives of cyclopropane. Novel η3-allylnickel complexes
Peganova, T. A.,Isaeva, L. S.,Petrovskii, P. V.,Kravtsov, D. N.
, p. 397 - 403 (2007/10/02)
The interaction of (η2-ethylene)bis(triphenylphosphine)nickel(0) with 1-bromo-2-methyl-2-phenyl- and 1,1,-dibromo-2-methyl-2-phenyl-cyclopropane has been studied.These reactions were expected to proceed with opening of the three-membered ring a
Homogeneous Isomerization of 1-Butene Catalyzed by -NaBH4 Systems (M=Co, Ni, X=Halides, SCN, PR3=PPhnEt3-n) - Acceleration by Phosphine Addition and Stereoselectivity
Kanai, Hiroyoshi,Sakai, Shigeyoshi,Sakatani, Takenobu
, p. 1589 - 1594 (2007/10/02)
The stoichiometric or a little excess amount of NaBH4 was treated with (M=Co, Ni, X=halides, SCN, PR3=PPhnEt3-n) in THF-1,2-dimethoxyethane to form monohydride species which were active for isomerization of 1-butene.The reaction was accelerated by excess PPh3 in -NaBH4 systems.Other catalytic systems have optimum ratios of excess phosphine to metal for getting maximum activities.Thiocyanate-metal complexes are the most active in each Co- and Ni-catalyst system.Cis-selectivity depends on the cone angle of PR3, the size of anion ligands, and the congested structure of the complexes.
INTERACTION OF A ZEROVALENT NICKEL COMPLEX WITH ORGANOMERCURIALS
Isaeva, L. S.,Morozova, L. N.,Bashilov, V. V.,Petrovskii, P. V.,Sokolov, V. I.,Reutov, O. A.
, p. 253 - 256 (2007/10/02)
The oxidative addition of ArHgX (Ar=Ph, X=Cl; Ar=C6F5, X=Br) to the nickel complex (Ph3P)4Ni resulting in formation of ?-aryl derivatives of bivalent nickel, (Ph3P)2Ni(Ar)X, has been performed.It was found that the reaction between (Ph3P)4Ni and (C6F5)2Hg yields the bimetallic compound (Ph3P)2Ni(C6F5)HgC6F5.Similarly, the reaction between 3Hg and (Ph3P)4Ni gives (Ph3P)2NiHgGe(C6F5)3, containing a Ge-Ni-Hg-Ge chain.A five-membered metallocycle with a N -> Ni chelate bond was obtained from the reaction of (Ph3P)4Ni with 8-(α-bromomercuriethyl)quinoline.
