- Ruthenium complex immobilized on supported ionic-liquid-phase (SILP) for alkoxycarbonylation of olefins with CO2
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In this study, the heterogeneously catalyzed alkoxycarbonylation of olefins with CO2based on a supported ionic-liquid-phase (SILP) strategy is reported for the first time. An [Ru]@SILP catalyst was accessed by immobilization of ruthenium complex on a SILP, wherein imidazolium chloride was chemically integrated at the surface or in the channels of the silica gel support. An active Ru site was generated through reacting Ru3(CO)12with the decorated imidazolium chloride in a proper microenvironment. Different IL films, by varying the functionality of the side chain at the imidazolium cation, were found to strongly affect the porosity, active Ru sites, and CO2adsorption capacity of [Ru]@SILP, thereby considerably influencing its catalytic performance. The optimized [Ru]@SILP-A-2 displayed enhanced catalytic performance and prominent substrate selectivity compared to an independent homogeneous system under identical conditions. These findings provide the basis for a novel design concept for achieving both efficient and stable catalysts in the coupling of CO2with olefins.
- Xia, Shi-Ping,Ding, Guang-Rong,Zhang, Rui,Han, Li-Jun,Xu, Bao-Hua,Zhang, Suo-Jiang
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p. 3073 - 3080
(2021/05/05)
-
- Sterically hindered (pyridyl)benzamidine palladium(II) complexes: Syntheses, structural studies, and applications as catalysts in the methoxycarbonylation of olefins
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Reactions of ligands (E)-N′-(2,6-diisopropylphenyl)-N-(4-methylpyridin-2-yl)benzimidamide (L1), (E)-N′-(2,6-diisopropylphenyl)-N-(6-methylpyridin-2-yl)benzimidamide (L2), (E)-N′-(2,6-dimethylphenyl)-N-(6-methylpyridin-2-yl)benzimidamide (L3), (E)-N′-(2,6-dimethylphenyl)-N-(4-methylpyridin-2-yl)benzimidamide (L4), and (E)-N-(6-methylpyridin-2-yl)-N′-phenylbenzimidamide (L5) with [Pd(NCMe)2Cl2] furnished the corresponding palladium(II) precatalysts (Pd1–Pd5), in good yields. Molecular structures of Pd2 and Pd3 revealed that the ligands coordinate in a N^N bidentate mode to afford square planar compounds. Activation of the palladium(II) complexes with para-tolyl sulfonic acid (PTSA) afforded active catalysts in the methoxycarbonylation of a number of alkene. The resultant catalytic activities were controlled by the both the complex structure and alkene substrate. While aliphatic substrates favored the formation of linear esters (>70%), styrene substrate resulted in the formation of predominantly branched esters of up to 91%.
- Akiri, Saphan O.,Ojwach, Stephen O.
-
-
- Model of selectivity to methyl pelargonate in hydrocarbomethoxylation of 1-octene in the presence of the Pd(PPh3)2Cl2—PPh3—p-toluenesulfonic acid catalytic system
-
The model of selectivity to methyl pelargonate was developed for the hydrocarbomethoxylation of 1-octene catalyzed by the Pd(PPh3)2Cl2—PPh3—p-toluenesulfonic acid system (378 K). The ratio of the rate of methyl pelargonate formation to the sum of the rates of formation of three isomeric esters (reaction products) was accepted as the differential selectivity of the reaction. The model represents a system of equations relating the differential selectivity of the reaction to the CO pressure and concentrations of methanol, PPh3, and p-toluenesulfonic acid. The model adequately depicts the experimental data in a wide range of 1-octene conversions up to 95.5%. The regularities of a change in the reaction selectivity were substantiated using the hydride multiroute mechanism of hydrocarbomethoxylation of 1-octene.
- Batashev, S. A.,Sevostyanova, N. T.
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p. 1561 - 1568
(2020/09/23)
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- A general platinum-catalyzed alkoxycarbonylation of olefins
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Hydroxy- and alkoxycarbonylation reactions constitute important industrial processes in homogeneous catalysis. Nowadays, palladium complexes constitute state-of-the-art catalysts for these transformations. Herein, we report the first efficient platinum-catalysed alkoxycarbonylations of olefins including sterically hindered and functionalized ones. This atom-efficient catalytic transformation provides straightforward access to a variety of valuable esters in good to excellent yields and often with high selectivities. In kinetic experiments the activities of Pd- and Pt-based catalysts were compared. Even at low catalyst loading, Pt shows high catalytic activity.
- Beller, Matthias,Dühren, Ricarda,Franke, Robert,Ge, Yao,Huang, Weiheng,Jackstell, Ralf,Liu, Jiawang,Neumann, Helfried,Schneider, Carolin,Yang, Ji
-
supporting information
p. 5235 - 5238
(2020/07/30)
-
- Palladium(II) complexes of (pyridyl)imine ligands as catalysts for the methoxycarbonylation of olefins
-
Reactions of 2-methoxy-N-((pyridin-2-yl)methylene)ethanamine (L1), 2-((pyridin-2-yl)methyleneamino)ethanol (L2) and 3-methoxy-N-((pyridin-2-yl)methylene)propan-1-amine (L3) ligands with either [PdCl2(COD)] or [PdCl(Me)(COD)] produced the corresponding monometallic complexes [PdCl2(L1)] (1), [PdClMe(L1)] (2), [PdCl2(L2)] (3) and [PdCl2(L3)] (4). The solid state structure of complex 1 confirmed the bidentate coordination mode of L1, giving a distorted square planar geometry. All the complexes (1–4) formed active catalysts for the methoxycarbonylation of higher olefins to give linear and branched esters. The catalytic behavior of complexes 1–4 were influenced by both the complex structure and olefin chain length.
- Zulu, Zethu,Nyamato, George S.,Tshabalala, Thandeka A.,Ojwach, Stephen O.
-
-
- Method for preparing organic carboxylic ester through combined catalysis of aryl bidentate phosphine ligand
-
The invention discloses a method for preparing organic carboxylic ester by combined catalysis of an aryl bidentate phosphine ligand. The method comprises the following steps: under the action of a palladium compound/aryl bidentate phosphine ligand/acidic additive combined catalyst, carrying out a hydrogen esterification reaction on terminal olefin, carbon monoxide and alcohol so as to generate theorganic carboxylic ester with one more carbon than olefin. According to the invention, by adoption of the palladium compound/aryl bidentate phosphine ligand/acidic additive combined catalyst, good catalytic activity and selectivity for the hydrogen esterification reaction of the olefin are achieved, and olefin carbonylation to synthesize organic carboxylic ester can be efficiently catalyzed. Thearyl bidentate phosphine ligand has a rigid skeleton structure of a rigid ligand and the flexibility of a flexible ligand, so the aryl bidentate phosphine ligand has proper flexibility due to the characteristic that the aryl bidentate phosphine ligand is soft and rigid, and a most favorable coordination mode and a stable active structure in space are favorably formed. In addition, the aryl bidentate phosphine ligand has the advantages of high stability, simple and convenient synthesis method and the like; and a novel industrial technology is provided for production of organic carboxylate compounds.
- -
-
Paragraph 0045
(2020/05/29)
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- Palladium catalyzed hydroesterification of substituted alkenes under microwave conditions
-
While several catalyst systems have been utilized in the hydroesterification or methoxycarbonylation of alkenes or equivalent substrates, these reactions are conventionally performed in autoclave reactor systems under high CO pressure (20-70 bar) and thermal heating (70 - 110 oC). In this paper, the first methoxycarbonylation reactions performed in a microwave reactor fitted with a gas-Addition accessory system are reported on and compared to the same reactions performed under conventional heating in an autoclave reactor. Thus 1-octene, styrene, allylbenzene, o-and p-methoxyallylbenzene and β-methylstyrene were subjected to methoxycarbonylation over a palladium acetate-aluminum triflate catalyst system at 12 bar and 95 oC. Results obtained indicated the methoxycarbonylation of these alkenes to be much faster under microwave conditions when compared to conventional heating and improvements in conversion ranged between 3 and 5% for the more reactive substrates (1-octene and styrene) and 6 - 20% for the allylbenzenes and β-methylstyrene.
- Du Plessis, Maretha,Marais, Charlene,Bezuidenhoudt, Barend C. B.
-
supporting information
p. 40 - 48
(2020/09/16)
-
- Structural and theoretical studies of the methoxycarbonylation of higher olefins catalysed by (Pyrazolyl-ethyl)pyridine palladium (II) complexes
-
Reactions of 2-[1-(3,5-dimethylpyrazol-1-yl)ethyl]pyridine (L1) and 2-[1-(3,5-diphenylpyrazol-1-yl)ethyl]pyridine (L2) with the [Pd (COD)Cl2] or [Pd (COD)MeCl] produced palladium (II) complexes [Pd(L1)ClMe] (1), [Pd(L1)Cl2] (C2), [Pd(L2)ClMe] (3), and [Pd(L2)Cl2] (4) in quantitative yields. Solid state structures of complexes 1, 3 and 4 established the formation of mononuclear compounds, containing one bidentate ligand unit per metal atom, to give square planar complexes. All the other spectroscopic characterization data and elemental analyses were consistent with the observed structures. All the palladium (II) complexes 1–4 gave active catalysts in the methoxycarbonylation of 1-octenes. The catalysts demonstrated 100% chemoselectivities towards esters and favored the formation of linear isomers. Reaction conditions such as the type of phosphine derivative, acid promoter, solvent system, time, pressure and temperature have been investigated and shown to affect both the catalytic activity and regio-selectivity of the catalysts. Solid-angle modelling established the comparable steric contributions from the ligands, consistent with the similar regioselectivities of the resultant catalysts.
- Zulu, Siyabonga,Alam, Mohd.G.,Alam, Mohd. G.,Ojwach, Stephen O.,Akerman, Matthew P.
-
-
- Methoxycarbonylation of olefins catalysed by homogeneous palladium(II) complexes of (phenoxy)imine ligands bearing alkoxy silane groups
-
The Schiff base compounds 2-phenyl-2-((3(triethoxysilyl)propyl)imino)ethanol (HL1) and 4-methyl-2-((3(triethoxysilyl)propyl)imino)methyl)phenol (HL2) were synthesized via condensation reactions of a suitable ketone or aldehyde and (3-aminopropyl) triethoxy silane (APTES). Whereas the reactions of HL1 and HL2 with [Pd(OAc)2] afforded the bis(chelated) palladium compounds [Pd(L1)2] (1) and [Pd(L2)2] (2), treatments of HL1 and HL2 with [Pd(NCMe)2Cl2] gave the mono(chelated) complexes [Pd(HL1)2Cl2] (3) and [Pd(HL2)2Cl2] (4) respectively. Structural characterization of the compounds was achieved using NMR and FT-IR spectroscopies, mass spectrometry and micro-analyses. Complexes 1–4 gave active catalysts in the methoxycarbonylation of higher olefins producing linear esters as the major products. The coordination environment around the palladium center of the complexes dictated the relative catalytic activity, where the bis(chelated) analogues 1 and 2 were more active than the mono(chelated) analogues 3 and 4. The nature of the acid promoter, phosphine groups, solvent system, olefin substrate and reactions conditions influenced the catalytic behaviour of the complexes.
- Akiri, Saphan O.,Ojwach, Stephen O.
-
p. 236 - 243
(2019/03/02)
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- Alkoxycarbonylation of olefins with carbon dioxide by a reusable heterobimetallic ruthenium-cobalt catalytic system
-
The heterobimetallic ruthenium-cobalt catalytic system exhibited good catalytic performance and reusability in the reductive alkoxycarbonylation of olefins with carbon dioxide. Compared to the previous system only consisting of ruthenium catalyst, the binary catalyst system effectively reduced the usage of noble metal and ionic liquid additives. The respective contribution of ruthenium and cobalt catalysts in this multiple-step catalytic process was investigated by a series of condition-controlled experiments. The evolution of the ruthenium catalyst and the occurrence of alkene hydrogenation during the reaction was explained by theortical calculations.
- Zhang, Xuehua,Shen, Chaoren,Xia, Chungu,Tian, Xinxin,He, Lin
-
supporting information
p. 5533 - 5539
(2019/01/03)
-
- Palladium-catalyzed selective generation of CO from formic acid for carbonylation of alkenes
-
A general and selective palladium-catalyzed alkoxycarbonylation of all kinds of alkenes with formic acid (HCOOH, FA) is described. Terminal, di-, tri-, and tetra-substituted including functionalized olefins are converted into linear esters with high yields and regioselectivity. Key-to-success is the use of specific palladium catalysts containing ligands with built-in base, e.g., L5. Comparison experiments demonstrate that the active catalyst system not only facilitates isomerization and carbonylation of alkenes but also promotes the selective decomposition of HCOOH to CO under mild conditions.
- Sang, Rui,Kucmierczyk, Peter,Dong, Kaiwu,Franke, Robert,Neumann, Helfried,Jackstell, Ralf,Beller, Matthias
-
supporting information
p. 5217 - 5223
(2018/04/24)
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- MONOPHOSPHINE COMPOUNDS AND PALLADIUM CATALYSTS BASED THEREON FOR THE ALKOXYCARBONYLATION OF ETHYLENICALLY UNSATURATED COMPOUNDS
-
The invention relates to compounds of formula (I) where R1 is selected from —(C1-C12)-alkyl, —(C3-C12)-cycloalkyl, —(C3-C12)-heterocycloalkyl; R2 is selected from —(C3-C12)-heterocycloalkyl, —(C6-C20)-aryl, —(C3-C20)-heteroaryl; R3 is —(C3-C20)-heteroaryl; and R1, R2 and R3 may each independently be substituted by one or more substituents selected from —(C1-C12)-alkyl, —(C3-C12)-cycloalkyl, —(C3-C12)-heterocycloalkyl, —O—(C1-C12)-alkyl, —O—(C1-C12)-alkyl-(C6-C20)-aryl, —O—(C3-C12)-cycloalkyl, —S—(C1-C12)-alkyl, —S—(C3-C12)-cycloalkyl, —COO—(C1-C12)-alkyl, —COO—(C3-C12)-cycloalkyl, —CONH—(C1-C12)-alkyl, —CONH—(C3-C12)-cycloalkyl, —CO—(C1-C12)-alkyl, —COO—(C3-C12)-cycloalkyl, —N—[(C1-C12)-alkyl]2, —(C6-C20)-aryl, —(C6-C20)-aryl-(C1-C12)-alkyl, —(C6-C20)-aryl-O—(C1-C12)-alkyl, —(C3-C20)-heteroaryl, —(C3-C20)-heteroaryl-(C1-C12)-alkyl, —(C3-C20)-heteroaryl-O—(C1-C12)-alkyl, —COOH, —OH, —SO3H, —NH2, halogen. The invention further relates to Pd complexes comprising the compound according to the invention and to the use thereof in alkoxycarbonylation.
- -
-
Paragraph 0176; 0177; 0178; 0179; 0180; 0181
(2017/02/24)
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- Palladium(II) complexes bearing mixed N^N^X (X?=?O and S) tridentate ligands as pre-catalysts for the methoxycarbonylation of selected 1-alkenes
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The methoxycarbonylation of selected 1-alkenes catalyzed by various neutral and cationic palladium(II) complexes, containing mixed N^N^X (X = O and S) tridentate ligands 2-[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]-6-(phenoxymethyl)pyridine (L1), 2-[(3,5-di-tert-butyl-1H-pyrazol-1-yl)methyl]-6-(phenoxymethyl)pyridine (L2), 2-[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]-6-(phenylthiomethyl)pyridine (L3), 2-[(3,5-di-tert-butyl-1H-pyrazol-1-yl)methyl]-6-(phenylthiomethyl)pyridine (L4), has been investigated. Neutral complexes, [(?2-L1)Pd(CH3)(Cl)] (1a), [(?2-L2)Pd(CH3)(Cl)] (2a), [(?2-L3)Pd(CH3)(Cl)] (3a), [(?2-L4)Pd(CH3)(Cl)] (4a), and the salts, [(?3-L3)Pd(CH3)][BAr4F] (3c) and [(?3-L4)Pd(CH3)][BAr4F] (4c), underwent complete decomposition during the reaction to palladium black and showed no catalytic activity. However, the addition of PPh3 to the reaction dramatically increased the catalytic activity. On the other hand, the salts, [(?2-L1)Pd(CH3)(PPh3)][BAr4F] (1b), [(?2-L2)Pd(CH3)(PPh3)][BAr4F] (2b), [(?2-L3)Pd(CH3)(PPh3)][BAr4F] (3b) and [(?2-L4)Pd(CH3)(PPh3)][BAr4F] (4b), showed good conversion of the selected olefins to branched and linear esters without PPh3. Addition of PPh3 to reactions with 1b-4b significantly improved catalytic activity. All decomposition of complexes led to the formation of the known palladium complexes, [Pd(PPh3)2(Cl)(CH3)] and [Pd(PPh3)2Cl2]. The decomposition of all palladium complexes could be followed by NMR studies and [Pd(PPh3)2Cl2] could be isolated from the crude methoxycarbonylation reaction.
- Kumar, Kamlesh,Darkwa, James
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p. 249 - 257
(2017/10/27)
-
- Parameters Influencing Reactivity and Regioselectivity in the Methoxycarbonylation of Arylalkenes
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Previous research showed that the steric bulk, electronic character, and bite angle of the ligand have an influence on both the catalyst activity and regioselectivity of hydroformylation and hydroesterification reactions. However, little is known in this regard about the influence of the steric and electronic environment around the double bond of the substrate. A variety of arylalkenes were therefore subjected to methoxycarbonylation to investigate the steric and electronic effects of substituents on the aromatic ring of the substrate on the regioselectivity and reactivity in the methoxycarbonylation reaction of these substrates with a Pd(II)/Al(OTf)3/Ph3P catalyst system.
- Du Plessis, Maretha,Marais, Charlene,Bezuidenhoudt, Barend C. B.
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p. 557 - 565
(2016/02/14)
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- Toward the development of efficient and stable Pd-catalysts for the methoxycarbonylation of medium chain alkenes
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Methoxycarbonylation provides a one-step synthesis to valuable ester products utilised in both the fine and heavy chemical industry. However, in general, reaction rates for longer chain alkenes are poor which renders industrial implementation economical unviable. In cases where suitable rates are achieved, the requisite reagents are costly and in addition, the catalyst complexes readily decompose at elevated temperatures. This paper describes the use of an alternative ligand structural motif for the efficient methoxycarbonylation of terminal and internal medium chain alkenes to their corresponding esters. Promising results were obtained using a catalyst complex generated in situ from an unsymmetrical diphosphine ligand based on a ferrocene backbone, Pd(OAc)2 and methane sulfonic acid.
- Bredenkamp, Tyler,Holzapfel, Cedric
-
p. 421 - 427
(2016/01/27)
-
- The scope and mechanism of palladium-catalysed Markovnikov alkoxycarbonylation of alkenes
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Hydroesterification reactions represent a fundamental type of carbonylation reaction and constitute one of the most important industrial applications of homogeneous catalysis. Over the past 70 years, numerous catalyst systems have been developed that allow for highly linear-selective (anti-Markovnikov) reactions and are used in industry to produce linear carboxylates starting from olefins. In contrast, a general catalyst system for Markovnikov-selective alkoxycarbonylation of aliphatic olefins remains unknown. In this paper, we show that a specific palladium catalyst system consisting of PdX2/N-phenylpyrrole phosphine (X, halide) catalyses the alkoxycarbonylation of various alkenes to give the branched esters in high selectivity (branched selectivity up to 91%). The observed (and unexpected) selectivity has been rationalized by density functional theory computation that includes a dispersion correction.
- Li, Haoquan,Dong, Kaiwu,Jiao, Haijun,Neumann, Helfried,Jackstell, Ralf,Beller, Matthias
-
p. 1159 - 1166
(2016/11/28)
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- Pd-Catalyzed Regioselective Alkoxycarbonylation of 1-Alkenes Using a Lewis Acid [SnCl2 or Ti(OiPr)4] and a Phosphine
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The phosphine ligand mediated palladium catalyzed alkoxycarbonylation of alkenes was investigated with the objective of attaining good linear selectivity for the ester. The effect of various parameters such as solvents, additives, palladium precursors, CO pressures, and alkenes of various structural complexities were examined. The results revealed the importance of using a Lewis acid such as SnCl2 or Ti(OiPr)4 in combination with a monodentate ligand such CYTOP 292 or P(p-anisyl)3 to enhance the regioselectivity for the linear isomers in the range of 70-96%.
- Amézquita-Valencia, Manuel,Achonduh, George,Alper, Howard
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p. 6419 - 6424
(2015/06/30)
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- An Empirical Study of Phosphine Ligands for the Methoxycarbonylation of Medium-Chain Alkenes
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The methoxycarbonylation reaction provides a route to the synthesis of esters from medium-chain alkenes that may be used as fuel supplements. However, the known productive catalytic systems are expensive and/or unstable at elevated temperatures. Most of the data available on the methoxycarbonylation of alkenes is derived from ethylene and styrene as substrates. To broaden the scope, we conducted a comparative study of a range of phosphine ligands under comparable conditions for the methoxycarbonylation of 1-octene. The results demonstrate that a number of ligand structural motifs facilitate the process effectually. Furthermore, the critical importance of alkene isomerization and the acid/ligand and Pd/ligand ratios are presented.
- Holzapfel, Cedric,Bredenkamp, Tyler
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p. 2598 - 2606
(2015/09/15)
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- Palladium complexes of (benzoimidazol-2-ylmethyl)amine ligands as catalysts for methoxycarbonylation of olefins
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Reactions of N-(1H-benzoimidazol-2-ylmethyl)-2-methoxy aniline (L1) and N-(1H-benzoimidazol-2-ylmethyl)-2-bromo aniline (L2) with either [PdCl2(COD)] or [PdClMe(COD)] afforded the neutral palladium complexes [PdCl2(L1)] (1), [PdClMe(L1)] (2) and [PdClMe(L2] (3), respectively. Treatment of 2 and 3 with one equivalent of PPh3 in the presence of NaBAr4 (Ar = 3,5-(CF3)2C6H3) produced the corresponding cationic species, [PdMe(L1)]BAr4 (4) and [PdMe(L2)]BAr4 (5). All the palladium complexes formed active catalysts in the methoxycarbonylation of alkenes to produce linear and branched esters. The catalytic behaviour was dependent on the catalyst structure, presence of PPh3, acid promoter and alkene chain length.
- Tshabalala, Thandeka A.,Ojwach, Stephen O.,Akerman, Matthew A.
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p. 178 - 184
(2015/06/25)
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- PROCESS FOR PREPARING ESTERS FROM FORMATES AND OLEFINICALLY UNSATURATED COMPOUNDS
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The invention provides a process for preparing esters from formates and olefinically unsaturated compounds with catalysts based on palladium compounds. In addition, the invention discloses a polyphasic reaction mixture and nonyl methyl ester mixtures prepared by the process according to the invention.
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-
Paragraph 0042; 0050; 0060
(2014/10/29)
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- Synthesis of new diphosphine ligands and their application in pd-catalyzed alkoxycarbonylation reactions
-
Carbocyclic and N-heterocyclic analogues of the industrially applied ligand bis(di-tert-butylphosphinomethyl)benzene (1) have been synthesized in moderate to very good yields. The new ligands are based on benzene, tetralin, lutidine, pyrazine, quinoxaline, and maleimide backbones. Electronic and steric variations of the phosphorous donor sites were performed. As a benchmark reaction, the palladium-catalyzed methoxycarbonylation of 1-octene has been tested. Ester yields up to 64 and high linear selectivities up to 92 were achieved. So much potential: Carbocyclic and N-heterocyclic analogues of bis(di-tert- butylphosphinomethyl) benzene (1) have been synthesized in moderate to very good yields. The new ligands demonstrated their catalytic potential in palladium-catalyzed methoxycarbonylation of 1-octene.
- Pews-Davtyan, Anahit,Fang, Xianjie,Jackstell, Ralf,Spannenberg, Anke,Baumann, Wolfgang,Franke, Robert,Beller, Matthias
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p. 1168 - 1174
(2014/04/17)
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- Cobalt-catalyzed photopromoted carbonylation of chloroalkanes in the presence of KI
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The photopromoted carbonylation of chloroalkanes with carbon monoxide catalyzed by cobalt compounds [Co(OAc)2, CoCl2] in the presence of KI was carried out under ambient conditions. The results revealed that the catalytic activity of Co(OAc)2 was higher than that of CoCl2. A basic additive NaOAc was beneficial to the reaction. Interestingly, with NaOAc as an additive, Co(OAc)2 and CoCl2 exhibited similar catalytic activity. Preliminary work showed that the role of iodide ion was initially to form active iodoalkanes via substituting chloride ion in chloroalkanes in situ, and then, the carbonylation of iodoalkanes proceeded under irradiation.
- Jia, Ying Ping,Cui, Ying Na,Yin, Jing Mei,Zhou, Guang Yun,Li, Shen Min,Gao, Da Bin,Wang, Xiang Sheng
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p. 1033 - 1036
(2011/10/05)
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- Lyzed isomerization and hydroformylation of olefins
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The palladium-catalyzed hydroformylation of 1-octene has been studied in the presence of different phosphines and acid cocatalysts. The best results are achieved in the presence of in situ-generated palladium complexes with bidentate phosphines. It is demonstrated that the acid concentration is a crucial factor for obtaining high linear selectivity. A novel optimized catalyst based on an arylheteroarylphosphine has been applied for hydroformylation of different aliphatic and aromatic olefins. Good activity and excellent selectivity towards the linear aldehydes is achieved.
- Jennerjahn, Reiko,Piras, Irene,Jackstell, Ralf,Franke, L Robert,Wiese, Klaus-Diether,Beller, Thias
-
experimental part
p. 6383 - 6388
(2010/01/16)
-
- Radical cyanocarbonylation using alkyl allyl sulfone precursors
-
Acyl cyanides have been prepared by the three-component coupling reactions comprised of alkyl allyl sulfones, carbon monoxide, and p-tolylsulfonyl cyanide under tin-free radical reaction conditions. Georg Thieme Verlag Stuttgart.
- Kim, Sangmo,Cho, Chang Ho,Kim, Sunggak,Uenoyama, Yoshitaka,Ryu, Ilhyong
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p. 3160 - 3162
(2007/10/03)
-
- Palladium-catalyzed hydroesterification of styrene derivatives in the presence of ionic liquids
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The palladium-catalyzed hydroesterification of olefins occurs efficiently in a range of ionic liquid media. Selectivities ranging from 5-7:1 for the linear ester were obtained with styrene in a range of IL solvents. The use of ILs allowed the catalyst to be easily separated from the organic product by either extraction or distillation. The (Ph3P)2PdCl 2 precatalyst could be recovered unchanged from the ionic liquid phase. The IL/catalyst phase could be recycled five times with an average yield of 68%.
- Klingshirn, Marc A.,Rogers, Robin D.,Shaughnessy, Kevin H.
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p. 3620 - 3626
(2007/10/03)
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- Hydroesterification Reactions with Palladium-Complexed PAMAM Dendrimers Immobilized on Silica
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Highly active, recyclable catalytic systems for the hydroesterification reaction of olefins with methanol and carbon monoxide were prepared by complexing various palladium species to generation zero through four PAMAM dendrimers immobilized on silica. The silica-dendrimer-Pd(PPh3) 2 complexes were the most facile recyclable catalysts and could be recycled four to six times by filtration under air. These catalysts show selectivity for the linear reaction product.
- Reynhardt, Jan P. K.,Alper, Howard
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p. 8353 - 8360
(2007/10/03)
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- Hydroesterification of Olefins Catalyzed by Pd(OAc)2 Immobilized on Montmorillonite
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Palladium acetate immobilized on montmorillonite is an efficient catalyst for the hydroesterification of olefins with carbon monoxide and methanol, in the presence of triphenylphosphine and an acid promoter, affording branched chain esters.The reaction is regiospecific for aryl olefins as well as for vinyl benzoate and regioselective for aliphatic olefins.
- Lee, Chul Woo,Alper, Howard
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p. 250 - 252
(2007/10/02)
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- 2,5,6,7-tetranor-4,8-inter-m-phenylene PGI2 derivatives
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Disclosed herein are novel prostaglandin I2 (PGI2) derivatives exhibiting excellent in vivo duration and activities, said derivatives being represented by the general formula: STR1 wherein R1, X, R2 and R3 are as defined herein.
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-
- Photochemical Hydroformylation with Cobalt Catalysts in Methanol
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The photochemical hydroformylation of 1-octene with cobalt/phosphane complexes in methanol leads under mild conditions (80 deg C, 80 bar CO/H2) with >= 90percent selectivity to linear aldehydes.The reaction rate increases with temperature (Ea = 5 - 6 kcal/mol) and synthesis gas pressure, and is nearly independent of the cobalt source, e.g.Co(OAc)2, Co2(CO)8, or Co2(CO)6(PBu3)2.At low pressures hydroesterification is the preferred photoreaction of 1-octene.Isoprene reacts under similar conditions to give unsaturated oxoproducts and linear isoprene dimers.With unmodified octacarbonyldicobalt the hydroformylation of internal olefins is enhanced by UV light, but not the reaction of terminal olefins or dienes.UV irradiation of cobalt acetate under hydroformylation conditions leads to rapid reduction of the Co(II) species, thus decreasing the induction period from ca. 15 h (without irradiation) to ca. 30 min.
- Mirbach, Manfred J.,Topalsavoglou, Nikolaos,Phu, Tuyet Nhu,Mirbach, Marlis F.,Saus, Alfons
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p. 1422 - 1440
(2007/10/02)
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