15376-83-7Relevant academic research and scientific papers
Monometallic Ni0 and Heterobimetallic Ni0/AuI Complexes of Tripodal Phosphine Ligands: Characterization in Solution and in the Solid State and Catalysis
Cluff, Kyle J.,Bhuvanesh, Nattamai,Blümel, Janet
, p. 10138 - 10148 (2015/07/07)
The tridentate chelate nickel complexes [(CO)Ni{(PPh2CH2)3CMe}] (2), [(CO)Ni{(PPh2CH2CH2)3SiMe}] (6), and [Ph3PNi{(PPh2CH2CH2)3SiMe}] (7), as well as the bidentate complex [(CO)2Ni{(PPh2CH2)2CMeCH2PPh2}] (3) and the heterobimetallic complex [(CO)2Ni{(PPh2CH2)2CMeCH2Ph2PAuCl}] (4), have been synthesized and fully characterized in solution. All 1H and 13C NMR signal assignments are based on 2D-NMR methods. Single crystal X-ray structures have been obtained for all complexes. Their 31P CP/MAS (cross polarization with magic angle spinning) NMR spectra have been recorded and the isotropic lines identified. The signals were assigned with the help of their chemical shift anisotropy (CSA) data. All complexes have been tested regarding their catalytic activity for the cyclotrimerization of phenylacetylene. Whereas complexes 2-4 display low catalytic activity, complex 7 leads to quantitative conversion of the substrate within four hours and is highly selective throughout the catalytic reaction.
Reaction of C(NMe2)4 with Ni(CO)4 - syntheses and structures of [C(NMe2)3][(CO)3NiC(O)NMe2], [C(NMe2)3]2[Ni5(CO)12], and[C(
Petz
, p. 2274 - 2280 (2008/10/08)
The reaction of C(NMe2)4 with Ni(CO)4 in THF produces the carbamoyl complex [C(NMe2)3][(CO)3NiC(O)-NMe2] (1); side products are the purple cluster compound [C(NMe2)su
Oxidative Addition of Esters of Formic Acid and β-Lactones to Ni(0)-Complexes Involving Cleavage of the C-O Bond
Yamamoto, Takakazu,Ishizu, Junichi,Yamamoto, Akio
, p. 623 - 624 (2007/10/02)
Reactions of esters of formic acid, HCOOR (R = C2H5, CH2C6H5), with Ni(0)-complexes (mixtures of bis(1,5-cyclooctadiene)nickel (Ni(cod)2) and tertiary phosphines (PR'3)), lead to decarbonylation of HCOOR to afford (Ni(CO)n(PR''3)4-n and ROH.Vinyl formate gives a mixture of CH3CHO, Ni(CO)n(PR'3)4-n, C2H4, and CO2 on interaction with the Ni(0)-complexes. β-Lactones liberate CO2 on treatment with the Ni(0)-complexes.Oxidative addition of the reactants to Ni involving cleavage of the C-O bond(s) accounts for the formation of the products.
Reactions of nickel, palladium, and platinum complexes with carbonyl sulfide
Gaffney, Thomas R.,Ibers, James A.
, p. 2860 - 2864 (2008/10/08)
The complexes ML3 (M = Ni, Pd, Pt; L = PPh3, P(p-C6H4CH3)3) react with carbonyl sulfide to afford M(CO)L3, M(CO)2L2, M(η2-COS)L2, and M(COS2)L2 complexes, depending upon M, L, and reaction conditions. These reactions are contrasted with those involving CS2 in place of COS. A mechanism for the reductive disproportionation of COS by Pt(PPh3)4 involving a metal-sulfide intermediate is proposed. The dioxygen complexes Pt(O2)L2 and Pd(O2)L2 react with carbonyl sulfide to afford metal thiocarbonates, Pt(CO2S)L2 and Pd(CO2S)L2, in which the thiocarbonate ligand is asymmetrically bound to the metal.
Insertion of Carbon Monoxide into Nickel-Alkyl Bonds of Monoalkyl- and Dialkylnickel(II) Complexes, NiR(Y)L2 and NiR2L2. Preparation of Ni(COR)(Y)L2 from NiR(Y)L2 and Selective Formation of Ketone, Diketone, and Aldehyde from NiR2L2
Yamamoto, Takakazu,Kohara, Teiji,Yamamoto, Akio
, p. 2161 - 2168 (2007/10/02)
Reactions of monoalkylnickel(II) complexes, NiR(Y)L2 (R=CH3, C2H5; Y=Cl, suc(succinimido), pht(phthalimido), OC6H4-p-CN; L=1/2 bpy (2,2'-bipyridine), PEt3 (triethylphosphine)), with CO afford monoacylnickel(II) complexes, Ni(COR)(Y)L2, which are characterized by elemental analysis and spectroscopies (IR and NMR).Reactions of the acylnickel(II) complexes with alcohols and aniline give the corresponding esters and amides, respectively.Exposure of Ni(COR)(Y)L2 to dry air leads to oxidation of RCO to a RCOO ligand giving a complex formulated as NI(OCOR)(Y)L2.Reactions of dimethylnickel(II) complexes, Ni(CH3)2L2 (L=1/2 bpy, PEt3, 1/2dpe (1,2-bis(diphenylphosphino)ethane, 1/2 dpp (1,3-bis(diphenylphosphino)propane), with carbon monoxide afford acetone and/or 2,3-butanedione in medium to high yields, the acetone/2,3-butanedione ratio varying with the ligand L, reaction temperature, and additives such as maleic anhydride and triphenylphosphine.Generally the acetone/2,3-butanedione ratio decreases with increase in thermal stabilities of Ni(CH3)2L2.Ni(C2H5)2(bpy) and Ni(n-C3H7)2(bpy) give 3-pentanone and 4-heptanone, respectively, on treating them with CO, whereas Ni(C2H5)2(dpe) produces C2H5CHO and C2H4.
Oxidative Addition of Aryl Carboxylates to Ni(0) Complexes Involving Cleavage of the Acyl-O Bond
Yamamoto, Takakazu,Ishizu, Junichi,Kohara, Teiji,Komiya, Sanshiro,Yamamoto, Akio
, p. 3758 - 3764 (2007/10/02)
Reactions of aryl carboxylates RCOO-p-C6H4X (R=CH3, C2H5, n-C3H7; X=H, CH3, OCH3, CN) with bis(1,5-cyclooctadiene)nickel, Ni(cod)2, in the presence of phosphine ligands yield olefin (R(-H)), p-XC6H4OH, and nickel carbonyl complex(es) when the R group has a β hydrogen, whereas CH4, C2H6, nichel carbonyl complex(es), and nickel phenoxide are formed when the R group is CH3.The formation of the products is accounted for by assuming oxidative addition of the ester to nickel involving the cleavage of the acyl-O bond of RCOO-p-C6H4X followed by decarbonylation of the acylnickel complex and decomposition of the alkylnickel complex: RCOO-p-C6H4X + NiLn -> RCONiLnOC6H4X -> RNiLnOC6H4X + CO.The intermediate alkyl(phenoxo)nickel-type complex NiCH3(OC6H5) was in fact isolated in the reaction of phenyl acetate with Ni(cod)2 in the presence of 2,2'-bipyridine.The rate of the reaction is first order with respect to the concentration of the zerovalent nickel complex and the pseudo-first-order rate constant increases with with the increase in the basicity of the phosphine ligand added and with the increase of the electron-withdrawing ability of X.On the basis of these results a mechanism involving a nucleophilic attack at the carbonyl carbon by nickel is proposed.The activation parameters for the reaction of C2H5COOC6H5 with the mixture of Ni(cod)2 and PPh3 are ΔH=21+/-2 kcal/mol, ΔS=-8.8+/-2.9 eu.
