- Janus dendritic phosphines: Synthesis and application in Suzuki coupling reactions
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A new kind of codendrimer consisting of a Frechet-type dendron and a Tomalia-type PAMAM dendron has been synthesized via a liquid-phase approach, which could easily be purified using a simple precipitation method without the need for chromatographic separ
- Liu, Ji,Feng, Yu,He, Yanmei,Yang, Nianfa,Fan, Qing-Hua
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- Synthesis and characterisation of a range of Fe, Co, Ru and Rh triphos complexes and investigations into the catalytic hydrogenation of levulinic acid
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The coordination chemistry of the N-triphos ligand (NP3Ph, 1b) has been investigated with a range of Fe, Co and Rh precursors and found to form either tridentate or bidentate complexes. Reaction of NP3Ph with [Rh(COD)(CH3CN)2]BF4 resulted in the formation of the tridentate complex [Rh(COD)(κ3-NP3Ph)]BF4 (3) in the solid state, however, in solution a bidentate complex predominates in more polar solvents. Reaction of NP3Ph with Fe carbonyl precursors revealed the formation of the bidentate complexes [Fe(CO)3(κ1,κ2-NP3Ph)Fe(CO)4] (4) and [Fe(CO)3(κ2-NP3Ph)] (5), while reaction with FeBr2 resulted in the paramagnetic bidentate complex [Fe(Br)2(κ2-NP3Ph)] (6). Reaction of NP3Ph with CoCl2 gave a dimeric Co species [(κ2-NP3Ph)CoCl(κ1,κ2-NP3Ph)CoCl3] (7), while Zn powder reduction of NP3Ph Co halides resulted in the formation of the tridentate complexes of the type: [Co(X)(κ3-NP3Ph)]. The related triphos Ru complex, [Ru(CO3)(CO)(κ3-CP3Ph)] (2), has also been isolated and characterised. Preliminary catalytic hydrogenation of levulinic acid (LA) was conducted with 2 and 3. The Ru complex was found to be catalytically active, giving high conversions of LA to form gamma-vvvalerolactone (GVL) and 1,4-pentanediol (1,4-PDO), while 3 was found to be catalytically inactive. In situ catalytic testing with 1b and Fe(BF4)2.6H2O resulted in low conversions of LA while a combination of 1b and Co(BF4)2.6H2O gave high conversions to GVL.
- Omoruyi, Uwaila,Page, Samuel J.,Apps, Samantha L.,White, Andrew J.P.,Long, Nicholas J.,Miller, Philip W.
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- Selective Ruthenium-Catalyzed Transformation of Carbon Dioxide: An Alternative Approach toward Formaldehyde
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Formaldehyde is an important precursor to numerous industrial processes and is produced in multimillion ton scale every year by catalytic oxidation of methanol in an energetically unfavorable and atom-inefficient industrial process. In this work, we present a highly selective one-step synthesis of a formaldehyde derivative starting from carbon dioxide and hydrogen gas utilizing a homogeneous ruthenium catalyst. Here, formaldehyde is obtained as dimethoxymethane, its dimethyl acetal, by selective reduction of carbon dioxide at moderate temperatures (90 °C) and partial pressures (90 bar H2/20 bar CO2) in the presence of methanol. Besides the desired product, only methyl formate is formed, which can be transformed to dimethoxymethane in a consecutive catalytic step. By comprehensive screening of the catalytic system, maximum turnover numbers of 786 for dimethoxymethane and 1290 for methyl formate were achieved with remarkable selectivities of over 90% for dimethoxymethane.
- Siebert, Max,Seibicke, Max,Siegle, Alexander F.,Kr?h, Sabrina,Trapp, Oliver
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supporting information
p. 334 - 341
(2019/01/16)
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- Monophosphine substituted bridged azapropane bridged iron hydrogenase model compound and synthesis method and application thereof
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The invention discloses a monophosphine substituted bridged azapropane bridged iron hydrogenase model compound and a synthesis method and application thereof. The chemical formula of the model compound is Fe2[micro-SCH2]2NCH2PPh2] (CO) 5, and the structur
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Paragraph 0008; 0035
(2019/04/30)
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- Aminoferrocene-containing bisphosphine ligand Fe-Fe hydrogenase model and synthesis method and application thereof
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The invention discloses an aminoferrocene-containing bisphosphine ligand Fe-Fe hydrogenase model and a synthesis method and application thereof. The chemical formula of the model is (micro-pdt)Fe2(CO)4[FcN[CH2P(Ph)2]2, and the structural formula is shown
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Paragraph 0030
(2019/06/27)
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- Base-Free Hydrogenation of Carbon Dioxide to Methyl Formate with a Molecular Ruthenium-Phosphine Catalyst
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Herein, a molecular ruthenium-phosphine catalyst system for the effective base-free methyl formate production from carbon dioxide is described. In detail, the novel [Ru(N-triphosCy)(tmm)] complex, bearing sterically demanding cyclohexyl groups in the triphos-ligand structure, enabled in combination with the Lewis acid Al(OTf)3 the selective transformation of carbon dioxide to methyl formate with unprecedented activity. From a mechanistic perspective, in the initial step formic acid is formed, undergoing a consecutive Lewis acid promoted esterification with methanol to methyl formate. This selective transformation with carbon dioxide paves the way to versatile processes for important C1 building blocks.
- Westhues, Niklas,Belleflamme, Maurice,Klankermayer, Jürgen
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p. 5269 - 5274
(2019/07/12)
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- Selective Cu(I) complex with phosphine-peptide (SarGly) conjugate contra breast cancer: Synthesis, spectroscopic characterization and insight into cytotoxic action
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The main disadvantage of conventional anticancer chemotherapy is the inability to deliver the correct amount of drug directly to cancer. Those molecular delivering systems are very important to destroy cancer cells selectively. Herein we report synthesis
- Komarnicka, Urszula K.,Kozie?, Sandra,Starosta, Rados?aw,Kyzio?, Agnieszka
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p. 162 - 175
(2018/06/26)
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- Branched-Selective Hydroformylation of Nonactivated Olefins Using an N-Triphos/Rh Catalyst
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We report a catalytic system comprised of nitrogen-centered di- or triphosphine ligands in conjunction with rhodium that is capable of delivering branched aldehydes from terminal olefin substrates which commonly give more linear aldehydes than branched. The incorporation of an apical nitrogen atom into the ligand backbone dramatically improves the reaction rate. Mechanistic and labeling studies suggest the unusual selectivity is due to the irreversible trapping of the Rh-alkyl species along the branched pathway, in comparison to the more reversible linear pathway. A precatalytic equilibrium mixture of rhodium species was observed by high-pressure in situ NMR spectroscopy, suggesting this equilibrium is the catalytic resting state.
- Phanopoulos, Andreas,Nozaki, Kyoko
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p. 5799 - 5809
(2018/05/29)
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- Synthesis, characterization, photoluminescence and electrochemical properties of Pt(II) and Ag(I) complexes of tetradentate aminomethylphosphine ligands and antiproliferative activities on HT-29 human colon cancer
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Novel N1,N1,N4,N4-tetrakis((diphenylphosphino)methyl)benzene-1,4-diamine (L1), N1,N1,N5,N5-tetrakis((diphenylphosphino) methyl)naphthalene-1,5-diamine (L2) and 4,4′-me
- Uru?, Serhan,?ncesu, Mahmut,K??ker, Seda,Kurt, Akif Hakan,Ceyhan, G?khan
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- Synthesis, characterization, and reactivity of ruthenium hydride complexes of N-centered triphosphine ligands
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The reactivity of the novel tridentate phosphine ligand N(CH 2PCyp2)3 (N-triphosCyp, 2; Cyp = cyclopentyl) with various ruthenium complexes was investigated and compared that of to the less sterically bulky and less electron donating phenyl derivative N(CH2PPh2)3 (N-triphosPh, 1). One of these complexes was subsequently investigated for reactivity toward levulinic acid, a potentially important biorenewable feedstock. Reaction of ligands 1 and 2 with the precursors [Ru(COD)(methylallyl)2] (COD = 1,5-cycloocatadiene) and [RuH2(PPh3)4] gave the tridentate coordination complexes [Ru(tmm){N(CH2PR2) 3-δ3P}] (R = Ph (3), Cyp (4); tmm = trimethylenemethane) and [RuH2(PPh3){N(CH 2PR2)3-δ3P}] (R = Ph (5), Cyp (6)), respectively. Ligands 1 and 2 displayed different reactivities with [Ru3(CO)12]. Ligand 1 gave the tridentate dicarbonyl complex [Ru(CO)2{N(CH2PPh2)3- δ3P}] (7), while 2 gave the bidentate, tricarbonyl [Ru(CO) 3{N(CH2PCyp2)3-δ2P} ] (8). This was attributed to the greater electron-donating characteristics of 2, requiring further stabilization on coordination to the electron-rich Ru(0) center by more CO ligands. Complex 7 was activated via oxidation using AgOTf and O2, giving the Ru(II) complexes [Ru(CO)2(OTf){N(CH 2PPh2)3-δ3P}](OTf) (9) and [Ru(CO3)(CO){N(CH2PPh2)3- δ3P}] (11), respectively. Hydrogenation of these complexes under hydrogen pressures of 3-15 bar gave the monohydride and dihydride complexes [RuH(CO)2{N(CH2PPh2) 3-δ3P}] (10) and [RuH2(CO){N(CH 2PPh2)3-δ3P}] (12), respectively. Complex 12 was found to be unreactive toward levulinic acid (LA) unless activated by reaction with NH4PF6 in acetonitrile, forming [RuH(CO)(MeCN){N(CH2PPh2)3- δ3P}](PF6) (13), which reacted cleanly with LA to form [Ru(CO){N(CH2PPh2)3-δ3P} {CH3CO(CH2)2CO2H- δ2O}](PF6) (14). Complexes 3, 5, 7, 8, 11, and 12 were characterized by single-crystal X-ray crystallography.
- Phanopoulos, Andreas,Brown, Neil J.,White, Andrew J. P.,Long, Nicholas J.,Miller, Philip W.
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p. 3742 - 3752
(2014/05/06)
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- An easily prepared tetraphosphine and its use in the palladium-catalyzed Suzuki-Miyaura coupling of aryl chlorides
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An air-stable tetraphosphine N,N,N′,N′- tetra(diphenylphosphinomethyl)-benzene-1,3-diamine (L3) was easily prepared in two steps from triphenylphosphine, which in combination with [Pd(η3-C3H5)Cl]2 affords an efficient catalyst for Suzuki-Miyaura coupling of activated chloroarenes. Even at high temperature of 130 C, this catalyst exhibits good stability and longevity, and could allow a high turnover number of 680,000 to be reached. Graphical Abstract: [Figure not available: see fulltext.].
- Wang, Kun,Wang, Wei,Luo, Heng,Zheng, Xueli,Fu, Haiyan,Chen, Hua,Li, Ruixiang
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p. 1214 - 1219
(2014/01/06)
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- Catalysts on functionalized polymer chips (PC) as recyclable entities
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We describe surface-modified sintered polyethylene sheets as a suitable carrier system for various catalysts. The material shows high rigidity and no swelling properties and allows for easy removal and reuse of the supported catalysts. The application was demonstrated for Pd-, Rh-, and Ru-catalysts in Suzuki couplings, hydroformylation, and olefin metathesis, respectively. Georg Thieme Verlag Stuttgart.
- Koc, Fikret,Michalek, Florian,Rumi, Luigi,Bannwarth, Willi,Haag, Rainer
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p. 3362 - 3372
(2007/10/03)
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- Synthesis of Bis(phosphinomethyl)amines via Bis(hydroxymethyl)phosphonium Salts. Isolation of 9,9-Bis(hydroxymethyl)-9-phosphoniabicyclononane Hydrogensulfate and Chloride Salts, and the Crystal Structures of (1+)Cl(1-) and <(C6H11)2P
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Phosphines of the type PR2H reacted readily with formaldehyde in the presence of acid to afford high yields of bis(hydroxymethyl)phosphonium salts (1+)X(1-), (1+)X(1-), , and (X = Cl or HSO4).Treatment of the mixed
- Fawcett, John,Hoye, Peter A. T.,Kemmitt, Raymond D. W.,Law, David J.,Russell, David R.
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p. 2563 - 2568
(2007/10/02)
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