- Synthesis and characterisation of a bulky chelating bis(phosphine) ligand, 1,2-bis(dinbutylphosphino)ethane (DBPE), and its iron metal coordinated complexes, Fe(DBPE)2Cl2 and Fe(DBPE)2(-CC-C6H5)2
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The synthesis of a bulky chelating bis(phosphine) ligand, 1,2-bis(dinbutylphosphino)ethane, nBu2PCH2CH2PnBu2 (1) (Bu = Butyl = C4H9) (DBPE) is reported.This ligand was coordinated to iron by treatment with FeCl2 to yield F
- Lewis, Jack,Khan, Muhammad S.,Kakkar, Ashok K.,Raithby, Paul R.,Fuhrmann, Klaus,Friend, Richard H,
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- Synthesis, Characterization, and Isomerization of trans- and cis- + and Related Complexes
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A number of new diphosphine complexes of cobalt(III), trans- and cis-+, trans- and cis-+, trans- and cis-2+, trans-+, and + have been prepared and characterized, where dmpe, dmpp, dbpe, and dpee denote 1,2-bis(dimethylphosphino)ethane, 1,3-bis(dimethylphosphino)propane, 1,2-bis(dibutylphosphino)ethane, and cis-1,2-bis(diphenylphosphino)ethylene, respectively.The trans isomers of the dihalogeno complexes are stable to aquation, while the cis isomers release one of the halide ions in water fairly rapidly to yield cis-+ which isomerizes to the trans isomer on exposure of ultraviolet light.The cis-+ complexes in methanol or ethanol solution isomerize to the trans isomer, and the rates were followed spectrophotometrically in the temperature range of 39.0-65.0 deg C.The rates have a first-order dependence on the complex concentration.Both the ΔH and ΔS values for the isomerization increase in the order diphosphine=dmpedmppdbpedpee.This order coincides with the increasing order in cone angle of phosphine ligands, and suggests that the difference in rates among the complexes comes from a steric factor.Absorption spectra of all the complexes have been recorded and the results compared with those of the corresponding ethylenediamine complexes.
- Ohishi, Tomoji,Kashiwabara, Kazuo,Fujita, Junnosuke
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- A convenient synthetic protocol to 1,2-bis(dialkylphosphino)-ethanes
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1,2-Bis(dialkylphosphino)ethanes are readily prepared from the parent phosphine oxides, via a novel sodium aluminium hydride/sodium hydride reduction protocol of intermediate chlorophosphonium chlorides. This approach is amenable to multi-gram syntheses, utilises readily available and inexpensive reagents, and benefits from a facile non-aqueous work-up in the final reductive step.
- Doyle, Laurence R.,Heath, Alex,Low, Choon Heng,Ashley, Andrew E.
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p. 603 - 608
(2014/05/20)
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- The first catalytic synthesis of an acrylate from CO2 and an alkene-A rational approach
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For more than three decades the catalytic synthesis of acrylates from the cheap and abundantly available C1 building block carbon dioxide and alkenes has been an unsolved problem in catalysis research, both in academia and industry. Herein, we
- Lejkowski, Michael L.,Lindner, Ronald,Kageyama, Takeharu,Bodizs, Gabriella E.,Plessow, Philipp N.,Mueller, Imke B.,Schaefer, Ansgar,Rominger, Frank,Hofmann, Peter,Futter, Cornelia,Schunk, Stephan A.,Limbach, Michael
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supporting information
p. 14017 - 14025
(2013/01/15)
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- Process for the preparation of substituted aromatic compounds
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A process for the preparation of a substituted aromatic compound in which a chloroaromatic compound and an alkyl-, alkenyl- or aryl-boronic acid ester or anhydride are coupled in the presence of palladium and a lipophilic aliphatic phosphine comprising at least one branched aliphatic group or a lipophilic aliphatic Dis(phosphine). Preferred phosphines include triisopropyl, triisobutyl and tricyclohexylphosphine.
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- Bis(di-tert-butylphosphino)ethane-nickel(0) Complexes
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Ni(cdt) reacts with tBu2PC2H4PtBu2 in pentane at 20 deg C to yield brownish crystals of (tBu2PC2H4PtBu2)Ni(η2-C12H18) (1).The molecular structure of 1, as established by X-ray crystallography, exhibits a trigonal-planar coordination geometry of the nickel center with a η2-bonded cdt ligand.In the crystal 1 exists as two enantiomers, which are determined by the left- or right-handed screw axis of the cdt ligand.The cdt ligand in 1 resists most typical displacement reactions but 1 reacts with CO at -78 deg C to afford the colorless 18e complex (tBu2PC2H4PtBu2)Ni(CO)2 (2).From the reaction of Ni(cod)2 with tBu2PC2H4PtBu2 yellow needles of (tBu2PC2H4PtBu2)Ni(η2-cod) (3) are obtained.Low temperature NMR spectroscopy established that only one diene C=C bond is coordinated to nickel(0).At higher temperatures a rapid exchange of the coordinated and unbound C=C bonds is induced.When solutions of 3 are kept at 20 deg C for several days the dinuclear, almost insoluble yellow complex tBu2PC2H4PtBu2)Ni>2(μ-η2,η2-cod) (4) precipitates.The reaction of Ni(C2H4)3 and tBu2PC2H4PtBu2 affords orange (tBu2PC2H4PtBu2)Ni(C2H4) (5).From Ni(1,5-hexadiene)2 and tBu2PC2H4PtBu2 in 1,5-hexadiene the yellow-greenish complex (tBu2PC2H4PtBu2)Ni(η2-C6H10) (6) is obtained.As for 3, only one diene C=C bond is coordinated to nickel(0), but the structure is fluxional with exchange of the coordinated and unbound C=C bonds (NMR at 20 degC).From a solution of 6 in pentane the dinuclear, diastereomeric compounds rac/meso-tBu2PC2H4PtBu2)Ni>2(μ-η2,η2-C6H10) (7a,b) separate in large yellow crystals.In similar reactions the 1,6-heptadiene complexes (tBu2PC2H4PtBu2)Ni(η2-C7H12) (8) and rac/meso-tBu2PC2H4PtBu2)Ni>2(μ-η2,η2-C7H12) (9a,b) are also obtained.In 6, 7a,b, 8, and 9a,b the open-chain diene ligands can easily be displaced, e.g., by ethene to afford 5.Thus, complexes 6, 7a,b, 8, 9a,b are the most reactive.These complexes react readily (the ethene derivative 5 also reacts but very slowly) with butadiene to yield large yellow cubes of (tBu2PC2H4PtBu2)Ni(η2-C4H6) (10), which is also fluxional.The alkene complexes 5, 6, 7a,b, 8, 9a,b, 10 react with ethyne to yield yellow-brownish crystalline (tBu2PC2H4PtBu2)Ni(C2H2) (11).Key Words: Alkenens, Ethyne, Nickel(0), Phosphane, X-Ray
- Poerschke, Klaus-Richard,Pluta, Christian,Proft, Bernd,Lutz, Frank,Krueger, Carl
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p. 608 - 626
(2007/10/02)
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- Co-dimerization of vinyl aromatics with α-monoolefins
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The invention concerns a process for the co-dimerization of a vinyl aromatic monomer (e.g. styrene) with an α-monoolefin monomer (e.g. ethylene, propylene or 1-butylene), using a catalyst composition comprising palladium, an anion of a strong acid and an aliphatic diphosphine.
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- Intermediates in the Palladium-Catalysed Reactions of 1,3-Dienes, Part 5. Butadiene Complexes of Nickel, Palladium and Platinum
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A series of complexes of Ni, Pd and Pt has been prepared and their structures investigated NMR-spectroscopically.The nickel and palladium complexes, irrespective of the substituents at phosphorus, contain a fluxional η2-bonded butadiene molecule.In the case of platinum the bonding mode is ligand dependent: an η2-arrangement is observed where R is tert-butyl or cyclohexyl while when R is isopropyl the butadiene adopts an η1,η1-arrangement to give a platinacyclopentene derivative. - Keywords: Nickel-organo Complex, Palladium-organo Complex, Platinum-organo Complex, Butadiene Complex
- Benn, R.,Jolly, P. W.,Joswig, T.,Mynott, R.,Schick, K.-P.
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p. 680 - 691
(2007/10/02)
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