- ZWITTERIONIC CATALYSTS FOR (TRANS)ESTERIFICATION: APPLICATION IN FLUOROINDOLE-DERIVATIVES AND BIODIESEL SYNTHESIS
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An amide/iminium zwitterion catalyst has a catalyst pocket size that promotes transesterification and dehydrative esterification. The amide/iminium zwitterions are easily prepared by reacting aziridines with aminopyridines. The reaction can be applied a wide variety of esterification processes including the large-scale synthesis of biodiesel. The amide/iminium zwitterions allow the avoidance of strongly basic or acidic condition and avoidance of metal contamination in the products. Reactions are carried out at ambient or only modestly elevated temperatures. The amide/iminium zwitterion catalyst is easily recycled and reactions proceed in high to quantitative yields.
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Paragraph 0010; 0026
(2021/01/29)
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- Directing Selectivity to Aldehydes, Alcohols, or Esters with Diphobane Ligands in Pd-Catalyzed Alkene Carbonylations
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Phenylene-bridged diphobane ligands with different substituents (CF3, H, OMe, (OMe)2, tBu) have been synthesized and applied as ligands in palladium-catalyzed carbonylation reactions of various alkenes. The performance of these ligands in terms of selectivity in hydroformylation versus alkoxycarbonylation has been studied using 1-hexene, 1-octene, and methyl pentenoates as substrates, and the results have been compared with the ethylene-bridged diphobane ligand (BCOPE). Hydroformylation of 1-octene in the protic solvent 2-ethyl hexanol results in a competition between hydroformylation and alkoxycarbonylation, whereby the phenylene-bridged ligands, in particular, the trifluoromethylphenylene-bridged diphobane L1 with an electron-withdrawing substituent, lead to ester products via alkoxycarbonylation, whereas BCOPE gives predominantly alcohol products (n-nonanol and isomers) via reductive hydroformylation. The preference of BCOPE for reductive hydroformylation is also seen in the hydroformylation of 1-hexene in diglyme as the solvent, producing heptanol as the major product, whereas phenylene-bridged ligands show much lower activities in this case. The phenylene-bridged ligands show excellent performance in the methoxycarbonylation of 1-octene to methyl nonanoate, significantly better than BCOPE, the opposite trend seen in hydroformylation activity with these ligands. Studies on the hydroformylation of functionalized alkenes such as 4-methyl pentenoate with phenylene-bridged ligands versus BCOPE showed that also in this case, BCOPE directs product selectivity toward alcohols, while phenylene-bridge diphobane L2 favors aldehyde formation. In addition to ligand effects, product selectivities are also determined by the nature and the amount of the acid cocatalyst used, which can affect substrate and aldehyde hydrogenation as well as double bond isomerization.
- Aitipamula, Srinivasulu,Britovsek, George J. P.,Nobbs, James D.,Tay, Dillon W. P.,Van Meurs, Martin
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p. 1914 - 1925
(2021/06/28)
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- Eco-Friendly Natural Clay: Montmorillonite Modified with Nickel or Ruthenium as an Effective Catalyst in Gamma-Valerolactone Synthesis
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Ni/Ru metals supported on cheap and available support montmorillonite K10 were used for the selective hydrogenation of levulinic acid to γ-valerolactone. Different loadings of the metals were applied by the impregnation method, and detailed characterization was performed (UV–VIS, XRD, TPR, TPD, particle size distribution, SEM, XRF). Metals’ homogeneous distribution on the surface was confirmed. The selectivity to the desired product was almost independent on the used material. A detailed study of the influence of solvents on the studied reaction was also performed—protic alcohol-based solvents caused the formation of levulinic and valeric acid esters in the reaction mixture. The selectivity was influenced mainly by the alcohol structure (the highest selectivity obtained using isopropyl alcohol and sec-butanol). Mainly the solvent’s donor number (except ethanol) influenced the reaction rate. The prepared catalysts are promising, available, and cheap materials for the studied reaction. Solvent may significantly influence the yield of γ-valerolactone. Graphic Abstract: [Figure not available: see fulltext.].
- ?erveny, Libor,Trejbal, Ji?í,Vaňková, Michaela,Vrbková, Eva,Vysko?ilová, Eli?ka
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- Method for preparing carboxylic ester compounds by oxidizing and breaking carbon-carbon bonds of secondary alcohol compounds
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The invention discloses a method for preparing carboxylic ester compounds by oxidizing and breaking carbon-carbon bonds of secondary alcohol compounds. The method comprises the following steps: adding a secondary alcohol compound, an additive and a nitrogen-doped mesoporous carbon loaded monatomic catalyst into a fatty primary alcohol solvent, putting into a pressure container, sealing, introducing oxygen source gas with a certain pressure, controlling the pressure of the oxygen source gas to be 0.1-1 MPa and the reaction temperature to be 80-150 DEG C, and obtaining a product after the reaction to be the carboxylic ester compound. The nitrogen-doped mesoporous carbon-loaded monatomic catalyst adopted by the invention is high in activity, the highest separation yield of the carboxylic ester compound as a reaction product reaches 99%, the method is wide in application range, the reaction conditions are easy to control, the catalyst can be recycled, the post-treatment is simple, and the method is suitable for industrial production.
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Paragraph 0082-0083; 0092
(2021/06/02)
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- Soluble asphaltene oxide: A homogeneous carbocatalyst that promotes synthetic transformations
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Carbocatalysts, materials which are predominantly composed of carbon and catalyze the synthesis of organic or inorganic compounds, are promising alternatives to metal-based analogues. Even though current carbocatalysts have been successfully employed in a broad range of synthetic transformations, they suffer from a number of drawbacks in part due to their heterogeneous nature. For example, the insolubility of prototypical carbocatalysts, such as graphene oxide (GO), may restrict access to catalytically-active sites in a manner that limits performance and/or challenges optimization. Herein we describe the preparation and utilization of soluble asphaltene oxide (sAO), which is a novel material that is composed of oxidized polycyclic aromatic hydrocarbons and is soluble in a wide range of organic solvents as well as in aqueous media. sAO promotes an array of synthetically useful transformations, including esterifications, cyclizations, multicomponent reactions, and cationic polymerizations. In many cases, sAO was found to exhibit higher catalytic activities than its heterogeneous analogues and was repeatedly and conveniently recycled, features that were attributed to its ability to form homogeneous phases.
- Bielawski, Christopher W.,Jung, Hyosic
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p. 15598 - 15603
(2020/05/05)
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- Iron-catalysed 1,2-aryl migration of tertiary azides
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1,2-Aryl migration of α,α-diaryl tertiary azides was achieved by using the catalytic system of FeCl2/N-heterocyclic carbene (NHC) SIPr·HCl. The reaction generated aniline products in good yields after one-pot reduction of the migration-resultant imines.
- Wei, Kaijie,Yang, Tonghao,Chen, Qing,Liang, Siyu,Yu, Wei
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supporting information
p. 11685 - 11688
(2020/10/19)
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- Ruthenium-catalyzed hydrogenation of CO2as a route to methyl esters for use as biofuels or fine chemicals
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A novel robust diphosphine-ruthenium(ii) complex has been developed that can efficiently catalyze both the hydrogenation of CO2 to methanol and its in situ condensation with carboxylic acids to form methyl esters; a TON of up to 3260 is achievable for the CO2 to methanol step. Both aromatic and aliphatic carboxylic acids can be transformed to their corresponding methyl esters with high conversion and selectivity (17 aliphatic and 18 aromatic examples). On the basis of a series of experiments, a mechanism has been proposed to account for the various steps involved in the catalytic pathway. More importantly, this approach provides a promising route for using CO2 as a C1 source for the production of biofuels, fine chemicals and methanol.
- Li, Yong,Liu, Qingbin,Ma, Yanping,Solan, Gregory A.,Sun, Wen-Hua,Wang, Zheng,Zhang, Qiuyue,Zhao, Ziwei,Zhong, Yanxia
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p. 6766 - 6774
(2020/08/25)
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- Method for preparing organic carboxylic ester through combined catalysis of aryl bidentate phosphine ligand
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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.
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Paragraph 0043
(2020/05/29)
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- One-pot direct conversion of levulinic acid into high-yield valeric acid over a highly stable bimetallic Nb-Cu/Zr-doped porous silica catalyst
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The direct conversion of levulinic acid (LA) to valeric biofuel is highly promising for the development of biorefineries. Herein, LA is converted into valeric acid (VA) via one-pot direct cascade conversion over non-noble metal-based Nb-doped Cu on Zr-doped porous silica (Nb-Cu/ZPS). Under mild reaction conditions (150 °C and 3.0 MPa H2 for 4 h), LA was completely converted into VA in high yield (99.8%) in aqueous medium with a high turnover frequency of 0.038 h-1. The Lewis acid sites of ZPS enhanced the adsorption of LA on the catalyst surface, and both the Lewis and Br?nsted acidity associated with Nb2O5 and the metallic Cu0 sites promoted catalysis of the cascade hydrogenation, ring cyclization, ring-opening, and hydrogenation reactions to produce VA from LA. The bimetallic Nb-Cu/ZPS catalyst was also effective for the conversion of VA into various valeric esters in C1-C5 alcohol media. The presence of Nb2O5 effectively suppressed metal leaching and coke formation, which are serious issues in the liquid-phase conversion of highly acidic LA during the reaction. The catalyst could be used for up to five consecutive cycles with marginal loss of activity, even without catalyst re-activation.
- Karanwal, Neha,Verma, Deepak,Butolia, Paresh,Kim, Seung Min,Kim, Jaehoon
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supporting information
p. 766 - 787
(2020/02/25)
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- Aldehyde effect and ligand discovery in Ru-catalyzed dehydrogenative cross-coupling of alcohols to esters
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The presence of different aldehydes is found to have a significant influence on the catalytic performance when using PN(H)P type ligands for dehydrogenation of alcohols. Accordingly, hybrid multi-dentate ligands were discovered based on an oxygen-transfer alkylation of PNP ligands by aldehydes. The relevant Ru-PNN(PO) system provided the desired unsymmetrical esters in good yields via acceptorless dehydrogenation of alcohols. Hydrogen bonding interactions between the phosphine oxide moieties and alcohol substrates likely assisted the observed high chemoselectivity.
- Jiang, Xiaolin,Zhang, Jiahui,Zhao, Dongmei,Li, Yuehui
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p. 2797 - 2800
(2019/03/27)
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- Method for preparing carboxylic ester by alcohol direct oxidation esterification method
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The invention discloses a method for preparing a carboxylic ester by an alcohol direct oxidation esterification method. The method comprises the following steps: taking an aromatic alcohol compound ora saturated linear aliphatic alcohol as a reaction substrate, taking an Au-Co composite particle carrier as a catalyst, adding a low catalytic amount of alkali, reacting for 0.5-15 h in a methanol solvent at the temperature of 25-150 DEG C in air or oxygen or a mixed atmosphere of the air or the oxygen, and performing aftertreatment to obtain a target product carboxylic ester. According to the preparation method disclosed by the invention, the process steps are reduced, conditions are mild, catalyst consumption is less, atom economy is high, the method is simple to operate, the application range of the substrate is wide, and industrial practicability is achieved.
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Paragraph 0070; 0071
(2019/06/30)
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- Structure determination of fatty acid ester biofuels via in situ cryocrystallisation and single crystal X-ray diffraction
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In situ cryocrystallisation in combination with a zone-melting technique enabled the crystal structure determination of a homologous series of low-melting n-alkyl methyl esters Cn-1H2n+1CO2CH3, from methyl pentanoate (n = 5) to methyl tridecanoate (n = 13), by single crystal X-ray diffraction. Two isostructural groups were identified: the odd-numbered triclinic members (C9,11,13) and the even-numbered orthorhombic members (C8,10,12). All observed structural trends, similarities and differences in intermolecular contacts, including the odd-even effect observable in melting point behaviour and unit cell parameters, were easily visualised and described by 2D fingerprint plots generated from the calculated Hirshfeld surfaces, in combination with atom-atom Coulomb-London-Pauli (AA-CLP) lattice energy calculations.
- Prathapa, Siriyara Jagannatha,Slabbert, Cara,Fernandes, Manuel A.,Lemmerer, Andreas
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- Amide/Iminium Zwitterionic Catalysts for (Trans)esterification: Application in Biodiesel Synthesis
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A class of zwitterionic organocatalysts based on an amide anion/iminium cation charge pair has been developed. The zwitterions are easily prepared by reacting aziridines with aminopyridines. They are catalytically applicable to transesterifications and dehydrative esterifications. Mechanistic studies reveal that the amide anion and iminium cation work synergistically in activating the reaction partners, with the iminium cationic moiety interacting with the carbonyl substrates through nonclassical hydrogen bonding. The reaction can be applied to large-scale synthesis of biodiesel under mild conditions.
- Lam, Ying-Pong,Ng, Wing-Hin,Tan, Fei,Tse, Ying-Lung Steve,Wang, Xinyan,Yeung, Ying-Yeung
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p. 8083 - 8092
(2019/08/26)
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- A biocatalytic method for the chemoselective aerobic oxidation of aldehydes to carboxylic acids
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Herein, we present a study on the oxidation of aldehydes to carboxylic acids using three recombinant aldehyde dehydrogenases (ALDHs). The ALDHs were used in purified form with a nicotinamide oxidase (NOx), which recycles the catalytic NAD+ at the expense of dioxygen (air at atmospheric pressure). The reaction was studied also with lyophilised whole cell as well as resting cell biocatalysts for more convenient practical application. The optimised biocatalytic oxidation runs in phosphate buffer at pH 8.5 and at 40 °C. From a set of sixty-one aliphatic, aryl-Aliphatic, benzylic, hetero-Aromatic and bicyclic aldehydes, fifty were converted with elevated yield (up to >99%). The exceptions were a few ortho-substituted benzaldehydes, bicyclic heteroaromatic aldehydes and 2-phenylpropanal. In all cases, the expected carboxylic acid was shown to be the only product (>99% chemoselectivity). Other oxidisable functionalities within the same molecule (e.g. hydroxyl, alkene, and heteroaromatic nitrogen or sulphur atoms) remained untouched. The reaction was scaled for the oxidation of 5-(hydroxymethyl)furfural (2 g), a bio-based starting material, to afford 5-(hydroxymethyl)furoic acid in 61% isolated yield. The new biocatalytic method avoids the use of toxic or unsafe oxidants, strong acids or bases, or undesired solvents. It shows applicability across a wide range of substrates, and retains perfect chemoselectivity. Alternative oxidisable groups were not converted, and other classical side-reactions (e.g. halogenation of unsaturated functionalities, Dakin-Type oxidation) did not occur. In comparison to other established enzymatic methods such as the use of oxidases (where the concomitant oxidation of alcohols and aldehydes is common), ALDHs offer greatly improved selectivity.
- Knaus, Tanja,Tseliou, Vasilis,Humphreys, Luke D.,Scrutton, Nigel S.,Mutti, Francesco G.
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supporting information
p. 3931 - 3943
(2018/09/11)
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- Methylation of Aliphatic and Aromatic Carboxylic Acids with Dimethyl Carbonate under the Influence of Manganese and Iron Carbonyls
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The synthesis of methyl esters has been carried out via the reaction of aliphatic and aromatic carboxylic acids with dimethyl carbonate in the presence of manganese and iron carbonyls. The optimal ratio of catalyst and reagents and other conditions for the synthesis of methyl esters of carboxylic acids with high yield have been found.
- Khusnutdinov,Shchadneva,Mayakova, Yu. Yu.
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- Preparation of valeric acid and valerate esters from biomass-derived levulinic acid using metal triflates + Pd/C
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Recently, great attention has been paid to the study of the conversion of biomass-derived compounds to value-Added chemicals. Levulinic acid (LA) is a versatile and valuable chemical and its various applications have been described. The selective conversion of biomass-derived LA to produce valeric acid and valerate esters was successfully performed in the presence of H2, in which metal triflates and Pd/C were used as the catalysts. Under optimal conditions, a 99% conversion of LA and a 92% selectivity of valeric acid was obtained with Hf(OTf)4 and Pd/C as the catalysts at a relatively low temperature of 150 °C. Moreover, the metal center of the catalyst, the solvent, the reaction temperature and other reaction conditions were studied. In addition, the results of the recycling experiment exhibited that the catalysts continued to have a satisfactory activity after being reused 5 times.
- Zhou, Jian,Zhu, Rui,Deng, Jin,Fu, Yao
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p. 3974 - 3980
(2018/09/11)
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- One-pot oxidative bromination – Esterification of aldehydes to 2-bromoesters using cerium (IV) ammonium nitrate and lithium bromide
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A two-step, one-pot reaction of aldehydes with the CAN/LiBr oxidation system under solvent-free conditions followed by the addition of methanol affords methyl α-bromocarboxylates. The oxidation of aldehydes with methanol using this system gives only methyl esters. A facile method, which does not require special equipment, was developed for the synthesis of 2-bromoesters from aliphatic aldehydes with carbon chain lengths of 5–10 atoms.
- Nikishin, Gennady I.,Kapustina, Nadezhda I.,Sokova, Lyubov L.,Bityukov, Oleg V.,Terent'ev, Alexander O.
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supporting information
p. 352 - 354
(2017/01/03)
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- Thermoalkalophilic lipase from an extremely halophilic bacterial strain Bacillus atrophaeus FSHM2: Purification, biochemical characterization and application
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The present study was designed to isolate and identify an extremely halophilic lipase-producing bacterial strain, purify and characterize the related enzyme and evaluate its application for ethyl and methyl valerate synthesis. Among four halophilic isolates, the lipolytic ability of one isolate (identified as Bacillus atrophaeus FSHM2) was confirmed. The enzyme (designated as BaL) was purified using three sequential steps of ethanol precipitation and dialysis, Q-Sepharose XL anion-exchange chromatography and SP Sepharose cation-exchange chromatography with a final yield of 9.9% and a purification factor of 31.8. The purified BaL (Mw~85 kDa) was most active at 70 °C and pH 9 in the presence of 4?M NaCl and retained 58.7% of its initial activity after 150 min of incubation at 80 °C. The enzyme was inhibited by Cd2+ (35.6 ± 1.7%) but activated by Ca2+ (132.4 ± 2.2%). Evaluation of BaL's stability in the presence of organic solvents showed that xylene (25%) enhanced the relative activity of the enzyme to 334.2 ± 0.6% after 1 h of incubation. The results of esterification studies using the purified BaL revealed that maximum ethyl valerate (88.5%) and methyl valerate (67.5%) synthesis occurred in the organic solvent medium (xylene) after 48 h of incubation at 50 °C.
- Ameri, Atefeh,Shakibaie, Mojtaba,Faramarzi, Mohammad Ali,Ameri, Alieh,Amirpour-Rostami, Sahar,Rahimi, Hamid Reza,Forootanfar, Hamid
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p. 151 - 160
(2017/06/09)
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- Efficient Palladium-Catalyzed Alkoxycarbonylation of Bulk Industrial Olefins Using Ferrocenyl Phosphine Ligands
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The development of ligands plays a key role and provides important innovations in homogeneous catalysis. In this context, we report a novel class of ferrocenyl phosphines for the alkoxycarbonylation of industrially important alkenes. A basic feature of our ligands is the combination of sterically hindered and amphoteric moieties on the P atoms, which leads to improved activity and productivity for alkoxycarbonylation reactions compared to the current industrial state-of-the-art ligand 1,2-bis((di-tert-butylphosphino)methyl)benzene). Advantageously, palladium catalysts with these novel ligands also enable such transformations without additional acid under milder reaction conditions. The practicability of the optimized ligand was demonstrated by preparation on >10 g scale and its use in palladium-catalyzed carbonylations on kilogram scale.
- Dong, Kaiwu,Sang, Rui,Fang, Xianjie,Franke, Robert,Spannenberg, Anke,Neumann, Helfried,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 5267 - 5271
(2017/04/27)
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- Methylation of mono- and dicarboxylic acids with dimethyl carbonate catalyzed with binder-free zeolite NaY
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Synthesis of methyl mono- and dicarboxylates was developed consisting in treating the corresponding acids with dimethyl carbonate in the presence of a heterogenic catalyst, crystalline aluminosilicate whose mechanically strong granules to 90–95% were built of crystal aggregates of zeolite Y with modulus of about 5.0 in the Na-form. Optimum catalyst and reagents ratio and the reaction conditions were found for the preparation in high yields of methyl esters of mono- and dicarboxylic acids.
- Khusnutdinov,Shchadneva,Mayakova, Yu. Yu.,Konovalova, Yu. S.,Khazipova,Kutepov
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p. 163 - 168
(2017/04/24)
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- Highly efficient transformation of Γ-valerolactone to valerate esters over structure-controlled copper/zirconia catalysts prepared via a reduction-oxidation route
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Design and development of novel and efficient catalysts are crucial but challenging for the catalytic conversion of biomass and derivatives to fuels and chemicals. In this paper, a novel separate nucleation and aging steps assistant reduction-oxidation strategy was developed to synthesis CuO/ZrO2 complex precursor with homogeneously distributed Cu and Zr components, which can be used as an ideal precursor for the synthesis of highly dispersed Cu/ZrO2 catalyst. Characterization results revealed that homogeneous dispersion of CuO, high surface area of ZrO2 support with controlled porous structure, and strong interaction between CuO and ZrO2 in CuO/ZrO2 precursor could lead to the enhanced Cu dispersion and the formation of Cu+ active centers. The synthesized Cu/ZrO2 catalysts exhibited excellent catalytic performance (85.4% conversion of GVL and 98.0% selectivity of pentyl valerate) in the catalytic transformation of GVL to valerate esters, more efficient than that of Cu/ZrO2-CP and Cu/ZrO2-CH catalysts prepared via co-precipitation and chemisorption hydrolysis methods, respectively. The superior catalytic performance was mainly attributed to both the cooperation of Cu0 and Cu+ species and the highly dispersed surface Cu0, thereby improving the adsorption and polarization of C[dbnd]O bond in GVL and the following dissociation of H2 to produce active hydrogen for the hydrogenation step during the catalytic transformation of GVL. Moreover, such copper-based catalysts exhibited potential applications in the exploitation and utilization of biomass resources with significantly enhanced efficiency.
- Liu, Shanshan,Fan, Guoli,Yang, Lan,Li, Feng
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p. 180 - 188
(2017/07/10)
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- A levulinic acid by the method of preparation valeric acid and pentanoate (by machine translation)
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The present invention provides a process for preparing valeric acid and by levulinic acid formylvalerate ester, to levulinic acid as a starting material, the hydrogenation catalyst and trifluoromethanesulfonic acid metal salt as a catalyst, the hydrogen atmosphere catalytic hydrogenolysis reaction, to obtain the valeric acid, continue to valeric acid as the raw material, trifluoromethanesulfonic acid metal salt as catalyst, adding alcohol compound to carry out the esterification reaction, to obtain pentanoate. The invention described in the laevulinic acid preparation valeric acid and formylvalerate ester, it has simple process, mild reaction conditions, high product yield, easy to be purified, environment-friendly and the like, and is suitable for large-scale industrial production. (by machine translation)
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Paragraph 0052-0054; 0073-0075
(2017/08/30)
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- Highly efficient metal salt catalyst for the esterification of biomass derived levulinic acid under microwave irradiation
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The esterification of levulinic acid (LA) to alkyl levulinates has been investigated in the presence of various metal salt catalysts under microwave irradiation. The reaction obtained 99.4% yield of methyl levulinate (ML) in the presence of Al2(SO4)3 catalyst in methanol solution under microwave conditions. The optimized reaction conditions were 110 °C and 10 minutes with a 20 mol% catalyst loading. Alcohols with longer carbon chains showed lower reactivities in the microwave electromagnetic field due to their poorer abilities to absorb and transmit microwave energy. Moreover, microwave irradiation provided a significantly higher reaction rate compared to conventional oil bath heating. LA aqueous solution was also converted to ML with high yields. The Al2(SO4)3 catalyst was successfully applied to the esterification of other biomass derived organic acids to their corresponding esters in high yields. Finally, the catalyst was recycled 5 times without much decrease in activity.
- Huang, Yao-Bing,Yang, Tao,Cai, Bo,Chang, Xin,Pan, Hui
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p. 2106 - 2111
(2016/01/20)
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- Synthesis, Chemistry, and Photochemistry of Methylcyanobutadiyne in the Context of Space Science
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An alternative preparation of methylcyanobutadiyne (MeC5N), a molecule present in the interstellar medium, was established in order to circumvent tedious steps from previous methods. The possibility of forming methylcyanoacetylene and MeC5N by gas-phase photolysis was evaluated from relevant acetylene derivatives in the context of space science. The reactivity of MeC5N toward simple nucleophiles was investigated. The exclusive formation of E adducts was observed, together with a solvent dependence for the regioselectivity of the addition.
- Kerisit, Nicolas,Rouxel, Cédric,Colombel-Rouen, Sophie,Toupet, Lo?c,Guillemin, Jean-Claude,Trolez, Yann
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p. 3560 - 3567
(2016/05/24)
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- One-Carbon Homologation of Primary Alcohols to Carboxylic Acids, Esters, and Amides via Mitsunobu Reactions with MAC Reagents
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A method is reported for the one-carbon homologation of an alcohol to the extended carboxylic acid, ester, or amide. The process involves the Mitsunobu reaction with an alkoxymalononitrile, followed by unmasking in the presence of a suitable nucleophile. The homologation and unmasking can even be performed in a one-pot process in high yield.
- Kagawa, Natsuko,Nibbs, Antoinette E.,Rawal, Viresh H.
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supporting information
p. 2363 - 2366
(2016/06/09)
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- Primary alkanols: oxidative homocondensation in water and cross-condensation in methanol
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Water was used as a reaction medium and a reagent in oxidation of primary alkanols to dimeric esters and alkanoic acids using either molecular bromine or a hydrogen peroxide—hydrobromic acid mixture as the oxidants. The similar reaction in methanol produced methyl alkanoates.
- Nikishin,Sokova,Terent′ev,Kapustina
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p. 2845 - 2850
(2016/09/28)
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- Bile acid hydrazides: Gelation, structural, physical and spectroscopic properties
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Synthesis and gelation properties of a series of novel bile acid hydrazides are presented. These compounds are found to undergo self-assembly leading to organogelation in certain organic solvents. Compound 1 was found to be the most "effective" gelator in this series. The properties of this gel have been thoroughly investigated by conventional methods typical for molecular gel studies. Sol-gel transition temperature (Tg) of chloroform gels of compounds 1 and 3 was found to increase with increase in the chain length. Sol-gel transition was probed using the isothermal time test and results show that there is instantaneous increase in both the moduli after shear melting, which suggests that the kinetics of formation of the network was very fast. IR and NMR studies revealed hydrogen bonding between amidic carbonyl in the side chain and hydroxyl groups of cholic acid.
- Pore, Vandana S.,Agalave, Sandip G.,Pharande, Shrikant G.,Patil, Prashant A.,Kotmale, Amol S.
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supporting information
p. 453 - 460
(2015/02/05)
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- Acid-catalyzed oxidation of levulinate derivatives to succinates under mild conditions
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Levulinate derivatives are an attractive platform for the production of renewable chemicals. Here we report on the oxidation of methyl levulinate into dimethyl succinate with peroxides under mild conditions using Br?nsted and Lewis acid catalysts. Selectivities to succinate and acetate derivatives of approximately 60 and 40 %, respectively, were obtained with strong Br?nsted acids in methanol. Although the molecular structure (i.e., carbon-chain length and branching around the C=O group) and the oxidant type affect the product distribution, solvent choice has the strongest impact on changing the location of oxygen insertion into the carbon backbone. Specifically, switching the solvent from methanol to heptane resulted in a decrease in the succinate/acetate ratio from 1.6 to 0.3. In contrast to Br?nsted acids, we demonstrate that the nature of the metal cation is responsible for changing the reaction selectivity of water-tolerant Lewis acidic triflate salts.
- Wang, Yuran,Vogelgsang, Ferdinand,Román-Leshkov, Yuriy
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p. 916 - 920
(2015/03/18)
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- Methyl 4-methoxypentanoate: A novel and potential downstream chemical of biomass derived gamma-valerolactone
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Lignocellulosic derived gamma-valerolactone was effectively converted into methyl 4-methoxypentanoate, a potential liquid biofuel, solvent and fragrance, by the catalysis of a hydrogen exchanged ultra-stable Y zeolite (HUSY) and insoluble carbonates such as CaCO3. The catalytic competing generation process between methyl 4-methoxypentanoate and pentenoate esters was also analysed.
- Li, Zheng,Jiang, Yetao,Tang, Xing,Zuo, Miao,Zeng, Xianhai,Sun, Yong,Lin, Lu
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p. 8297 - 8300
(2015/03/05)
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- Silver nanoparticles embedded over mesoporous organic polymer as highly efficient and reusable nanocatalyst for the reduction of nitroarenes and aerobic oxidative esterification of alcohols
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Silver nanoparticles (Ag-NPs) have been finely dispersed at the mesoporous organic polymer via post-synthetic chemical grafting over mesoporous poly-triallylamine (MPTA-1). The resulting Ag-MPTA-1 nanomaterial has been characterized by elemental analysis, powder x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), UV-vis diffuse reflectance spectroscopy (DRS), thermogravimetric analysis (TGA), EPR spectroscopy and AAS elemental analysis. The Ag-MPTA-1 acts as an efficient heterogeneous nanocatalyst in the reduction of substituted nitrobenzenes via transfer hydrogenation. The material also showed excellent catalytic activity in one-step catalytic oxidative esterification of primary alcohols using molecular oxygen as a green oxidant. The catalyst is air-stable, inexpensive, easy to prepare and reused several times without significant decrease in activity and selectivity.
- Salam, Noor,Banerjee, Biplab,Roy, Anupam Singha,Mondal, Paramita,Roy, Susmita,Bhaumik, Asim,Islam, Sk. Manirul
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p. 184 - 194
(2014/05/06)
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- MONOMER, POLYMER, RESIST COMPOSITION, AND PATTERNING PROCESS
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A polymer comprising recurring units derived from a (meth)acrylate monomer of tertiary ester type having branched alkyl on alicycle is used to form a resist composition. When subjected to exposure, PEB and organic solvent development, the resist composition is improved in dissolution contrast.
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- METHOD OF MANUFACTURE OF OCTANEDIOIC ACID, PRECURSORS, AND DERIVATIVES
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A method for the manufacture of 1,8-octanedioic acid comprises: reacting gamma-valerolactone with an alcohol in the presence of an acid or a base catalyst to provide an alkyl pentenoate, converting the alkyl pentenoate in the presence of a metathesis initiator to provide the dialkyl octenedioate, reacting the dialkyl octenedioate with hydrogen in the presence of a hydrogenation catalyst to provide a dialkyl 1,8-octanedioate and hydrolyzing the dialkyl 1,8-octanedioate to provide the 1,8-octanedioic acid.
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Paragraph 0086; 0087; 0088
(2014/10/04)
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- Selective hydrogenation of levulinic acid to valeric acid and valeric biofuels by a Pt/HMFI catalyst
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We describe one-pot high-yield catalytic pathways for the conversion of levulinic acid (LA) to valeric acid (VA) or valeric acid esters (so-called valeric biofuels) under relatively mild conditions (2 or 8 bar H2, 200 °C). A thorough screening study reveals that a HMFI zeolite-supported Pt metal cluster (Pt/HMFI) with an average cluster size of 1.9 nm shows the highest yield of VA (99%) under solvent-free conditions. The use of ethanol or methanol as solvent changes the selectivity, resulting in 81-84% yields of ethyl valerate (EV) or methyl valerate (MV). Pt/HMFI is also effective for selective formation of valeric acid esters from γVL in alcohols under H2. Kinetics, in situ infrared (IR), and acidity-activity relationship studies show a cooperative mechanism of Pt and Bronsted acid sites of HMFI. VA formation from LA can be driven by Pt-catalyzed hydrogenation of LA to γVL, which undergoes proton-assisted ring-opening by HMFI, followed by Pt-catalyzed hydrogenation. Valeric ester formation from LA is driven by esterification of LA to levulinic ester, which is hydrogenated by Pt. the Partner Organisations 2014.
- Kon, Kenichi,Onodera, Wataru,Shimizu, Ken-Ichi
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p. 3227 - 3234
(2014/08/18)
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- Methoxycarbonylation of olefins catalyzed by palladium(II) complexes containing naphthyl(diphenyl)phosphine ligands
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Palladium(II) complexes containing phosphine donor ligands derived from naphthyl(diphenyl)phosphine were synthesized and characterized by NMR and elemental analysis. The complexes were studied as catalyst precursors in the methoxycarbonylation reaction of several aromatic and aliphatic olefins under mild conditions. The catalysts reported high chemoselectivities (over 96%) and regioselectivities between 44% and 93% for different olefins. The best results were obtained over a styrene substrate with 97% of conversion after 6 h of reaction, with high regioselectivity (93%). Kinetic studies permitted the determination of the rate law (v-‰=-‰k [substrate] 1.21±0.02 [catalyst]0.94±0.11 [acid] 0.52±0.03 [MeOH]0.53±0.05 [CO] 0.65±0.03) for methoxycarbonylation of styrene.
- Zolezzi, Santiago,Moya, Sergio A.,Valdebenito, Gonzalo,Abarca, Gabriel,Parada, Jose,Aguirre, Pedro
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p. 364 - 371
(2014/05/06)
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- PIFA-mediated esterification reaction of alkynes with alcohols via oxidative cleavage of carbon triple bonds
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A metal-free esterification of alkynes via C≡C triple bond cleavage has been developed. In the presence of phenyliodine bis(trifluoroacetate), a diverse range of alkyne and alcohol substrates undergoes triple bond cleavage to produce carboxylic ester motifs in moderate to good yields. The transformation is proposed to proceed via hydroxyethanones and ethanediones as intermediates on the basis of mechanistic studies and exhibits a broad substrate scope and good functional group tolerance.
- Jiang, Qing,Zhao, An,Xu, Bin,Jia, Jing,Liu, Xin,Guo, Cancheng
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p. 2709 - 2715
(2014/04/17)
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- VO(acac)2: An efficient catalyst for the oxidation of aldehydes to the corresponding acids in the presence of aqueous H2O2
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VO(acac)2 catalyzes the oxidation of aldehydes (aromatic, aliphatic, and heterocyclic) to the corresponding acids efficiently and selectively in the presence of H2O2 as an oxidant. This method possesses functional-group compatibility, easy workup procedure, and shorter reaction time. The reaction is highly dependent on the solvent used. Performance of titania-supported VO(acac)2 in the oxidation of aldehyde was also investigated. Georg Thieme Verlag Stuttgart . New York.
- Talukdar, Dhrubajyoti,Sharma, Kiran,Bharadwaj, Saitanya K.,Thakur, Ashim Jyoti
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p. 963 - 966
(2013/06/27)
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- METHOD FOR CONTINUOUSLY PREPARING CARBOXYLIC ACID ESTER
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A method for continuously preparing a carboxylic acid ester is disclosed. In the method of the present invention, a vertical reactor is filled with a solid catalyst, a carboxylic acid and an alcohol are introduced into a lower part of the vertical reactor, esterification is performed to form an esterized mixture, the esterized mixture is output from an upper part of the vertical reactor, and distillation is performed to isolate the carboxylic acid ester. The method of the present invention is simple, easily controlled and environmental friendly, and has significantly high conversion rate and selectivity.
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Paragraph 0024; 0026
(2013/11/19)
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- Conversion of levulinate into succinate through catalytic oxidative carbon-carbon bond cleavage with dioxygen
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Grand Cleft Oxo: Levulinate, available from biomass, is oxidized into succinate through manganese(III)-catalyzed selective cleavage of C-C bonds with molecular oxygen. In addition to levulinate, a wide range of aliphatic methyl ketones also undergo oxidative C-C bond cleavage at the carbonyl group. This procedure offers a route to valuable dicarboxylic acids from biomass resources by nonfermentive approaches. Copyright
- Liu, Junxia,Du, Zhongtian,Lu, Tianliang,Xu, Jie
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p. 2255 - 2258
(2014/01/06)
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- Catalytic conversion of biomass-derived levulinic acid to valerate esters as oxygenated fuels using supported ruthenium catalysts
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The development of the catalytic conversion of biomass-based platform molecules into oxygenated fuel molecules is of great significance in order to reduce the dependence on fossil resources and to solve environmental problems. Alkyl valerate esters were proven to have the potential to be renewable additives of gasoline and diesel. In this work, we studied the hydrogenation of levulinic acid (LA) to valerate esters over supported Ru catalysts, and found that the acidity was an important factor for the catalyst performance. A bifunctional catalyst Ru/SBA-SO3H was developed as an active catalyst, and a highest yield of 94% to ethyl valerate (EV) was achieved. The catalyst was characterized by nitrogen adsorption/desorption methods, X-ray power diffraction (XRD), transmission electron spectroscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The effects of reaction conditions were comprehensively investigated and probable reaction pathways were proposed and verified. The conversion of LA to various alkyl valerate esters can also be catalyzed by the bifunctional catalyst. In addition, supported Cu and Ni catalysts were also screened under similar reaction conditions as Ru-based catalysts, and the combination of Ni/SBA-15 and SBA-SO3H exhibited activity for the conversion of LA to EV.
- Pan, Tao,Deng, Jin,Xu, Qing,Xu, Yang,Guo, Qing-Xiang,Fu, Yao
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p. 2967 - 2974
(2013/10/08)
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- Rhodium-catalyzed hydrogenation of olefins in γ-valerolactone-based ionic liquids
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γ-Valerolactone-based ionic liquids were successfully used as the catalyst phase for [Rh(cod)2][BF4]/RP(C6H 4-m-SO3Na)2 (R = Me, Pr, Bu, Cp) catalyzed hydrogenation of different olefins. Compared to broadly used ionic liquids e.g. 1-butyl-3-methylimidazolium chloride [bmim][Cl], the turnover frequencies were significantly higher and the reaction was selective for the CC double bonds in the presence of carbonyl, cyano, and phenyl groups. The catalyst was recycled for ten consecutive runs under regular or biphasic conditions without loss of activity. The vapour pressure and viscosity of γ-valerolactone-based ionic liquids were determined as well.
- Stradi, Andrea,Molnar, Mark,Ovari, Mihaly,Dibo, Gabor,Richter, Frank U.,Mika, Laszlo T.
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p. 1857 - 1862
(2013/09/24)
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- A flexible Pinner preparation of orthoesters: The model case of trimethylorthobenzoate
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In the absence of additional solvents, a novel procedure was implemented for the synthesis of trimethylorthoesters through the Pinner reaction. At 5 °C, the reaction of both aliphatic and aromatic nitriles (RCN; R = Et, Bu, Ph) with a moderate excess of MeOH and gaseous HCl gave the corresponding imidate hydrochlorides [RC(NH)OR′·HCl] in excellent yields (>90%). At 25-65 °C, the methanolysis of alkyl imidate salts provided trimethylortho-propionate and valerate, while only traces of trimethylorthobenzoate (TMOB) were observed. However, the aromatic hydrochloride could be readily converted into the hydrogenphosphate salt [PhC(NH) OR′·H3PO4] which, in turn, underwent a selective (>80%) reaction with MeOH to produce TMOB in a 62% isolated yield. This allowed for an unprecedented Pinner-type synthesis of TMOB starting from benzonitrile, rather than from the highly toxic trichloromethylbenzene. Overall, remarkable improvements in safety and process intensification were achieved.
- Noe, Marco,Perosa, Alvise,Selva, Maurizio
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p. 2252 - 2260
(2013/09/24)
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- PROCESS TO PRODUCE ALKENOIC ACID ESTERS FROM LACTONES
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This invention relates to a process for the preparation of alkenoic acid esters comprising contacting a lactone with an alcohol and an acidic catalyst in the gas phase, characterised in that the process is carried out in the presence of at least 0.26 wt. % water, relative to the amount of the lactone. The process may result in a good production yield and selectivity with respect to the production of alkenoic acid esters and may also result in less formation of dialkylethers. The improved yield advantageously allows energy conservation.
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Paragraph 0035; 0036
(2013/04/10)
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- Clean preparation of methyl esters in one-step oxidative esterification of primary alcohols catalyzed by supported gold nanoparticles
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Methyl esters were prepared by the clean, one-step catalytic esterification of primary alcohols using molecular oxygen as a green oxidant and a newly developed SiO2-supported gold nanoparticle catalyst. The catalyst was highly active and selective in a broad range of pressure and temperature. At 3 atm O2 and 130 °C benzyl alcohol was converted to methyl benzoate with 100% conversion and 100% selectivity in 4 h of reaction. This catalytic process is much "greener" than the conventional reaction routes because it avoids the use of stoichiometric environmentally unfriendly oxidants, usually required for alcohol oxidation, and the use of strong acids or excess of reactants or constant removal of products required to shift the equilibrium to the desired esterification product. The Royal Society of Chemistry 2009.
- Oliveira, Rafael L.,Kiyohara, Pedro K.,Rossi, Liane M.
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experimental part
p. 1366 - 1370
(2010/05/17)
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- Polarity of the acid chain of esters and transesterification activity of acid catalysts
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The effect of polarity of the esters on the transesterification reaction rate has been investigated. The effect was studied in homogeneous and heterogeneous catalysts. The polarity of different ethyl alkanoate esters was varied by (i) increasing the number of carbon atoms in the acid alkyl chain of the esters and (ii) introducing Br and hydroxy substituents at the end of the acid chain of ethyl hexanoate. Polarity was determined through the λmax of the UV-Vis spectrum of the betaine dye dissolved in the investigated esters (ET(30) scale). The transesterification reaction was carried out with methanol and by using sulfuric acid and a Dowex DR2030 sulfonic resin as homogeneous and heterogeneous catalysts, respectively. It was observed that, in addition to steric hindrance, the polarity of the ester chain has an effect on the reaction rate of the heterogeneous acid catalysts. It is proposed that the positive or negative effect of the polarity is due to repulsive or attractive interactions of the ester chain with the polar groups of the resin and/or with the methanol molecules present in the pores. A very positive effect is found in heterogeneous acid catalysis if H-bonds can stabilize the active intermediate participating in the rate determining step. The attractive or repulsive interactions are absent in the homogeneous case.
- Alonso, D. Martin,Granados, M. Lopez,Mariscal,Douhal
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scheme or table
p. 18 - 26
(2009/06/17)
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- CRYSTALLINE FORM A OF IBANDRONIC ACID AND PROCESS FOR THE PREPARATION
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The present invention relates crystalline Form A of Ibandronic acid having Formula (I) and a process for the preparation thereof.
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Page/Page column 26
(2008/06/13)
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- High-throughput kinetic study of hydrogenation over palladium nanoparticles: Combination of reaction and analysis
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The hydrogenation of 1-acetylcyclohexene, cyclohex-2-enone, nitrobenzene, and trans-methylpent-3-enoate catalyzed by highly active palladium nanoparticles was studied by high-throughput on-column reaction gas chromatography. In these experiments, catalysis and separation of educts and products is integrated by the use of a catalytically active gas chromatographic stationary phase, which allows reaction rate measurements to be efficiently performed by employing reactant libraries. Palladium nanoparticles embedded in a stabilizing polysiloxane matrix serve as catalyst and selective chromatographic stationary phase for these multiphase reactions (gas-liquid-solid) and are coated in fused-silica capillaries (inner diameter 250 μm) as a thin film of thickness 250 nm. The palladium nanoparticles were prepared by reduction of palladium acetate with hydridomethylsiloxane-dimethylsiloxane copolymer and self-catalyzed hydrosilylation with methylvinylsiloxane-dimethylsiloxane copolymer to obtain a stabilizing matrix. Diphenylsiloxane-dimethylsiloxane copolymer (GE SE 52) was added to improve film stability over a wide range of compositions. Herein, we show by systematic TEM investigations that the size and morphology (crystalline or amorphous) of the nanoparticles strongly depends on the ratio of the stabilizing polysiloxanes, the conditions to immobilize the stationary phase on the surface of the fused-silica capillary, and the loading of the palladium precursor. Furthermore, hydrogenations were performed with these catalytically active stationary phases between 60 and 100°C at various contact times to determine the temperature-dependent reaction rate constants and to obtain activation parameters and diffusion coefficients.
- Trapp, Oliver,Weber, Sven K.,Bauch, Sabrina,Baecker, Tobias,Hofstadt, Werner,Spliethoff, Bernd
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experimental part
p. 4657 - 4666
(2009/05/07)
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- Catalytic synthesis of oxygenate from alcohol
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The present invention discloses a method for catalytic synthesis of oxygenate from alcohol. At first, a feeding material comprising at least one alcohol is provided. Next, a copper-containing catalyst is provided and the catalyst further comprises at least one metal element selected from the group consisting of the following: zinc, magnesium, and aluminum elements. Following that, a catalytic reaction of the feeding material over the copper-containing catalyst is carried out to synthesize at least one oxygenate.
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Page/Page column 4-8
(2008/06/13)
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- High-throughput screening of catalysts by combining reaction and analysis
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(Figure Presented) Drudgery minimized, efficiency maximized: By combining catalysis and separation in microcapillaries greater than 2 cm in length, it is possible to efficiently determine the reaction kinetics for entire libraries of substrates. This was demonstrated for hydrogenations over highly active Pd nanoparticles and ring-closing metatheses over the Grubbs 2nd generation catalyst. R: reagents, P: products.
- Trapp, Oliver,Weber, Sven K.,Bauch, Sabrina,Hofstadt, Werner
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p. 7307 - 7310
(2008/09/18)
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- ZrOCl2·8H2O: An efficient, cheap and reusable catalyst for the esterification of acrylic acid and other carboxylic acids with equimolar amounts of alcohols
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Esterifications of carboxylic acids with equimolar amount of alcohols could be efficiently catalyzed by ZrOCl2·8H2O. Acrylate esters were obtained in good yields under solvent-free conditions at ambient temperature. The esterification of other carboxylic acids with alcohols also proceeded at ambient temperature or at 50°C to afford esters in high yields. If the esterification was performed in toluene under azeotropic reflux conditions to remove water, both the catalytic activity of ZrOCl 2·8H2O and the rate of esterification could be increased greatly. Furthermore, in the present catalytic system, the esters could be easily separated from the reaction mixtures and the catalyst could be easily recovered and reused.
- Sun, Hong-Bin,Hua, Ruimao,Yin, Yingwu
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p. 263 - 271
(2007/10/03)
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