- A family of cis-macrocyclic diphosphines: modular, stereoselective synthesis and application in catalytic CO2/ethylene coupling
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A family of cis-macrocyclic diphosphines was prepared in just three steps from white phosphorus and commercial materials using a modular synthetic approach. Alkylation of bicyclic diphosphane 3,4,8,9-tetramethyl-1,6-diphosphabicyclo(4.4.0)deca-3,8-diene, or P2(dmb)2, produced phosphino-phosphonium salts [R-P2(dmb)2]X, where R is methyl, benzyl and isobutyl, in yields of 90-96%. Treatment of these salts with organolithium or Grignard reagents yielded symmetric and unsymmetric macrocyclic diphosphines of the form cis-1-R-6-R′-3,4,8,9-tetramethyl-2,5,7,10-tetrahydro-1,6-DiPhospheCine, or R,R′-DPC, in which R′ is methyl, cyclohexyl, phenyl or mesityl, in yields of 46-94%. Alternatively, symmetric diphosphine Cy2-DPC was synthesized in 74% yield from the dichlorodiphosphine Cl2P2(dmb)2. As a first application, these cis-macrocyclic diphosphines were used as ligands in the nickel-catalyzed synthesis of acrylate from CO2 and ethylene, for which they showed promising catalytic activity.
- Knopf, Ioana,Tofan, Daniel,Beetstra, Dirk,Al-Nezari, Abdulaziz,Al-Bahily, Khalid,Cummins, Christopher C.
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- Cobalt Complexes Supported by cis-Macrocyclic Diphosphines: Synthesis, Reactivity, and Activity toward Coupling Carbon Dioxide and Ethylene
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The coordination chemistry of cis-macrocyclic diphosphines readily accessed from white phosphorus was explored, with a focus on preparing and studying cobalt complexes. cis-1,6-Dicyclohexyl-3,4,8,9-tetramethyl-2,5,7,10-tetrahydro-1,6-DiPhospheCine, or Cy2-DPC (1), was primarily used as a model diphosphine. Cobalt(II) dihalide diphosphine complexes such as (Cy2-DPC)CoX2, X = Cl (2) and I (3), were prepared, and their reactivity toward a variety of reducing agents was studied. We were successful in preparing and structurally characterizing an unusual iodide-bridged cobalt(I) dimer, [(Cy2-DPC)CoI]2 (8). These cobalt complexes were also investigated as potential catalysts for the coupling of carbon dioxide and ethylene to produce acrylate, a valuable polymer precursor. Although not yet catalytic, the first examples of cobalt complexes capable of mediating this transformation are reported. Notably, the well-known commercial complex ClCo(PPh3)3 was also found to be active in mediating acrylate production. As part of our mechanistic investigation, a pseudotetrahedral cobalt methyl acrylate complex, (Cy2-DPC)CoI(CH2CHCOOMe) (10), was prepared and structurally characterized.
- Knopf, Ioana,Courtemanche, Marc-André,Cummins, Christopher C.
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- Catalytic formation of acrylate from carbon dioxide and ethene
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With regard to sustainability, carbon dioxide (CO2) is an attractive C1 building block. However, due to thermodynamic restrictions, reactions incorporating CO2 are relatively limited so far. One of the so-called "dream reactions" in this field is the catalytic oxidative coupling of CO2 and ethene and subsequent β-H elimination to form acrylic acid. This reaction has been studied intensely for decades. However up to this date no suitable catalytic process has been established. Here we show that the catalytic conversion of ethene and CO2 to acrylate is possible in the presence of a homogeneous nickel catalyst in combination with a "hard" Lewis acid. For the first time, catalytic conversion of CO2 and ethene to acrylate with turnover numbers (TON) of up to 21 was demonstrated.
- Hendriksen, Coen,Pidko, Evgeny A.,Yang, Gang,Sch?ffner, Benjamin,Vogt, Dieter
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- NEW CATALYST COMPOUND AND METHOD FOR SYNTHESIZING ACRLYLATE USING THE SAME
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The present invention is to provide a novel catalyst compound which can be used for synthesis of acrylate from ethylene and a method for synthesizing acrylate using the same. A pyridine-chelated imidazo [1,5-a] pyridine N-heterocyclic carbene nickel (II) compound according to the present invention is represented by formulas 1 to 3, and can be used as a catalyst for synthesis of acrylate from ethylene.(AA) Chemical formula 1(BB) Chemical formula 2-1(CC) Chemical formula 3-1COPYRIGHT KIPO 2020
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Paragraph 120-0125
(2020/05/20)
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- METHODS OF PRODUCING ALPHA, BETA-UNSATURATED CARBOXYLIC ACID SALTS FROM ALKANES AND CARBON DIOXIDE
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Methods of producing α,β-unsaturated carboxylic acid salt are described. A method can include reacting an alkene and carbon dioxide with a composition that includes a carboxylation catalyst, an organic base that is solubilized in the composition, and an inorganic base that is not solubilized in the composition, under reaction conditions suitable to produce an inorganic base salt of an α,β-unsaturated carboxylic acid. The organic base can have a first pKa and the inorganic base has a second pKa that is greater than the first pKa.
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Paragraph 0070
(2019/04/11)
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- Formation of carboxylate complexes from the reactions of CO2 with ethylene complexes of molybdenum and tungsten. X-ray and neutron diffraction studies
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Carbon-carbon bond formation by coupling of ethylene with carbon dioxide on the coordination sphere of the metal center in the electron-rich complexes trans-M(C2H4)2(PMe3)4 (M = Mo, 1; M = W, 2) can be effected under mild conditions by reactions of 1 and 2 with CO2. These afford the binuclear hydrido acrylate derivatives [MH(OOCCH=CH2)(C2H4)(PMe3) 2]2 (M = Mo, 3; M = W, 4), which contain bridging μ2-η3,η1-acrylate ligands. Hydrogenation of 3 and 4 in the presence of PMe3 provides the hydrido propionates MoH(η2-OOCCH2CH3)(PMe3) 4 (5) and WH3(η1-OOCCH2CH3) (PMe3)4 (6), but the direct reaction of 1 and 2 with a 1:1 mixture of CO2/H2 yields instead the hydrido carbonate derivatives MH2(η2-CO3)(PMe3)4 (M = Mo, 7; M = W, 8). The hydrido allyl compounds MH(η3-C3H5)(PMe3)4 (M = Mo, 9; M = W, 10), formed by sodium amalgam reduction of MCl4(PMe3)3 under propylene, do not react with CO2 with carbon-carbon bond formation but rather with reductive elimination of propylene and production of the adduct transMo(CO2)2(PMe3)4 and various carbonate complexes. The crystal and molecular structures of 3, 4, and 6 have been determined by X-ray studies, and, in addition, a low-temperature (20 K) neutron diffraction analysis of 4 has been performed. 3 is monoclinic, P21/n, with a = 12.117 (8) A?, b = 15.072 (5) A?, c = 17.700 (5) A?, β = 102.18 (3)°, Z = 4, and R = 0.032, while 6 is monoclinic, P21/c, with a = 12.813 (2) A?, b = 8.903 (3) A?, c = 21.671 (3) A?, β = 88.62 (1)°, Z = 4, and R = 0.048. The crystal of 4 used for the neutron diffraction study is monoclinic, P21/c, with a = 14.23 (1) A?, b = 11.80 (1) A?, c = 20.58 (2) A?, β = 104.94 (6)°, Z = 4, and R = 0.034.
- Alvarez, Rafael,Carmona, Ernesto,Galindo, Agustín,Gutiérrez, Enrique,Marín, José M.,Monge, Angeles,Poveda, Manuel L.,Ruiz, Caridad,Savariault, Jean M.
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p. 2430 - 2439
(2008/10/08)
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