- A synthetic double (bicyclic hexyl phosphine ) alkane method of the
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The invention discloses a method for synthesizing bis(dicyclohexylphosphine)alkane, belonging to the field of organic synthesis. The method comprises the following steps: (1) under water-free oxygen-free conditions, carrying out amino protection on the initial raw material dicyclohexyl chlorophosphine to obtain dicyclohexyl diethylamino phosphine; and (2) reacting the dicyclohexyl diethylamino phosphine with diethyl cadmium to obtain an di(dicyclohexylphosphine)cadmium intermediate, and reacting with dichloroalkane to synthesize the bis(dicyclohexylphosphine)alkane compound. The method has the advantages of mild reaction conditions and high yield, is easy to operate, lowers the production cost, and is easier for industrial production.
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Paragraph 0006; 0014-0015
(2017/04/03)
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- ETHYLENE TETRAMERIZATION CATALYST SYSTEMS AND METHOD FOR PREPARING 1-OCTENE USING THE SAME
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Disclosed herein is a method of preparing 1-octene at high activity and high selectivity while stably maintaining reaction activity by tetramerizing ethylene using a chromium-based catalyst system comprising a transition metal or a transition metal precursor, a cocatalyst, and a P—C—C—P backbone structure ligand represented by (R1)(R2)P—(R5)CHCH(R6)—P(R3)(R4).
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Page/Page column 11
(2010/06/16)
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- Sterically crowded diphosphinomethane ligands: Molecular structures, UV-photoelectron spectroscopy and a convenient general synthesis of tBu2PCH2PtBu2 and related species
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A series of highly crowded symmetric and unsymmetric diphosphinomethanes R2PCH2PR′2, important ligands in transition metal chemistry and catalysis, namely tBu2PCH2ptBu2 (dtbpm, 11), Cy2PCH2PCy2 (dcpm, 2), tBu2PCH2PCy2 (ctbpm, 3), tBu2PCH2PiPr2 (iptbpm, 4) and tBu2PCH2PPh2 (ptbpm, 5), has been prepared in high yields, using a general and convenient route, which is described in detail for 1. Other than 4, which is a colourless liquid, these compounds are crystalline solids at room temperature. Their molecular structures have been determined by single crystal X-ray diffraction, along with that of the higher homologue of 1, tBu2CH2CH2tBu 2 (dtbpe, 6). The solid-state structures of the dioxide of 1, tBu2P(O)CH2P(O)tBu2 (7), and of two phosphonium cations derived from 1, protonated [tBu2P(H)CH2PtBu2] + (8+) and the chlorophosphonium ion [tBu2P(Cl)CH2PtBu2] + (9+), are also described and show a distinct structural influence of the tetracoordinate P centres. The gas phase UV-photoelectron spectra of the diphosphines 1-6 have been measured. Their first two ionisation potentials are found to be nearly degenerate and all are in the low energy range from 7.5 to 7.8 eV. Comparison with related mono- and bidentate phosphines demonstrates that 1-6 are excellent σ-donors towards metals, in accord with their known coordination chemistry. Molecular geometries and electronic structures of the diphosphine systems have been studied by quantum chemical calculations and are compared to experiment. Unlike standard semiempirical methods (AM1, PM3, MNDO), which give rather poor minimum structures and seem inadequate for such sterically crowded systems, ab initio calculations (RHF/6-31G**) predict molecular geometries with reasonable accuracy and reflect the observed trends in experimental ionisation potentials.
- Eisentraeger, Frank,Goethlich, Alexander,Gruber, Irene,Heiss, Helmut,Kiener, Christoph A.,Krueger, Carl,Notheis, J. Ulrich,Rominger, Frank,Scherhag, Gunter,Schultz, Madeleine,Straub, Bernd F.,Volland, Martin A. O.,Hofmann, Peter
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p. 540 - 550
(2007/10/03)
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- A new synthetic route to ligands of the general composition R2PCH2ER′2 (E = P, As) and some rhodium complexes derived thereof
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Symmetrical and unsymmetrical bis(phosphino)methanes R2PCH2PR′2 (8-16) as well as the arsino(phosphino) analogues R′2AsCH2PR2 (21-25) with bulky alkyl, cycloalkyl or aryl groups R and R′ were prepared from the stannylated phosphines R2PCH2SnR″3 (3-5, 6, 7) Via metalation with MeLi or PhLi in the presence of tetramethylethylenediamine and subsequent treatment with R′2PCl or R′2AsCl, respectively. Compound 25 [R′ = Cy, R = (R)-menthyl] is the first arsino(phosphino)methane which has been structurally characterized. The bis(phosphino)methanes R2PCH2PR2 (R = Pri 17, Cy 18) and R2PCH2PR′2 (12, 19, 20) were also obtained by thermal reaction of R2PCH2SnPh3 and the corresponding chlorophosphine R2PCl or R′2PCl in the absence of solvent. The bis(cyclooctene) derivative [RhCl(C8H14)2]2 26 reacted with excess Pri2PCH2PPri2 to give [Rh(κ2P,P′-Pri2PCH 2PPri2)2]Cl 27, while treatment of 26 with Ph2PCH2PPri2 yielded the chloro-bridged dimer [RhCl(κ2P,P′-Ph2PCH2PPr i2)]2 28. The reaction of the cationic species [Rh(C8H14)2(OCMe2) 2]PF6 29 with Cy2PCH2PPri2 in benzene or toluene afforded the half-sandwich-type complexes [(η6-C6H6)Rh(κ 2,P′-Cy2PCH2PPri 2)]PF6 30, [(η6-C6H5CH3)Rh(κ 2P,P′-Cy2PCH2PPri 2)]PF6 31, of which the latter was characterized by X-ray crystallography.
- Wolf, Justin,Manger, Matthias,Schmidt, Ulrich,Fries, Guido,Barth, Dietmar,Weberndoerfer, Birgit,Vicic, David A.,Jones, William D.,Werner, Helmut
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p. 1867 - 1875
(2007/10/03)
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- Process for the hydrogenation of aryl phosphines and products obtained therefrom
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A process for making a cycloalkyl phosphine comprising hydrogenating an aryl phosphine in the presence of an effective amount of an aryloxide of a metal selected from the group consisting of niobium and tantalum is disclosed. Cycloalkyl phosphine products of this process, useful as ligands in a complex of a transition metal which acts as a catalyst in the formation of stereoisomers, are also set forth. Furthermore, niobium or tantalum organometallic compounds, generated in this process, useful in the catalytic hydrogenation of aryl phosphines and arene-containing polymers, is also described.
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- Regio- and Stereo-selectivity in the Hydrogenation of Aryl Phosphines by Niobium Aryloxide Compounds
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The sequential hydrogenation of the three aryl rings in PPh3 by the catalyst system /3BunLi occurs with relative rates of 39:28:1; NMR analysis of the PhPCy2 obtained from and shows a predominantly all cis hydrogenation of both aryl rings has occurred.
- Potyen, Mark C.,Rothwell, Ian P.
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p. 849 - 852
(2007/10/02)
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- Catalytic Hydrogenation of Aryl Phosphines by Niobium Aryloxide Compounds: High Yield and Efficient Synthesis of Cyclohexyl Phosphine Ligands
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The tris(4-methylbenzyl) compound Nb(OC6H3Ph2-2,6)2(CH2H4-4Me)3 1 (OC6H3Ph2-2,6 = 2,6-diphenylphenoxide) acts as a catalyst precursor for the hydrogenation of a variety of aryl phosphine ligands.
- Yu, Joyce S.,Rothwell, Ian P.
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p. 632 - 633
(2007/10/02)
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