- Surface acidity and catalytic activity of aged SO24 /SnO2 catalyst supported with WO3
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New solid acid was prepared by loading of aged 15 wt.% SO24 /SnO2 catalyst with 15 and 35 wt.% WO3. The catalysts were calcined at 400 and 650°C. The surface areas of the catalysts were determined by the data of N2 adsorption at -196°C. The surface acidity was measured potentiometricaly using n-butylamine solution in acetonitrile. The types of acidic sites were determined by FT-IR spectra of adsorbed pyridine. The catalytic activities of the catalysts were tested toward esterification of propionic acid (PA) with nbutanol (B). The SBET values of the ISS were decreased with an increase in the calcination temperature, whereas, the SBET of the loaded catalysts was maximum at 400°C. The results reveal that the used catalysts possess very strong acid sites and contain both Br?nsted and Lewis acidic sites. The acid strength, total surface acidity and the conversion of PA were maxima for 400°C products. The effect of the reaction parameters was also studied, and shows that the PA conversion was increased with an increase in the reaction temperature and the catalyst weight. The reactant molar ratio shows a maximum conversion at PA:B = 1:2. The kinetics study indicates that the catalytic esterification of PA with B obey first order kinetics equation.
- Alaya, M. Nasouh,Rabah, Marwa A.
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- Aluminum phosphate-based solid acid catalysts: Facile synthesis, characterization and their application in the esterification of propanoic acid with n-butanol
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Novel solid acid catalysts synthesized from aluminum phosphate were prepared via a precipitation method and a subsequent sulfating treatment. Their catalytic performances for the esterification of propanoic acid with n-butanol were investigated. The as-prepared catalysts were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption–desorption, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption of ammonia (NH3-TPD), infrared spectroscopy of adsorbed pyridine, and other techniques. Experimental results of esterification reactions indicated that the calcination temperature can significantly affect the catalytic performances and the catalyst calcined at 500?°C (SO42?/AlPO4-500) exhibited the highest activity. The effects of different reaction conditions including reaction time, reaction temperature, catalyst amount and alcohol/acid molar ratio were studied in detail. The maximum propanoic acid conversion of 91% was achieved under optimum reaction conditions. Furthermore, the as-prepared SO42?/AlPO4-500 catalysts were tested for their reusability in repeated reaction cycles and could be effectively regenerated by a simple reactivation method.
- Liu, Boliang,Jiang, Pingping,Zhang, Pingbo,Zhao, Hui,Huang, Jie
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- Metallacarboranes in Catalysis. 7. Kinetics and Mechanism of Acrylate Ester Hydrogenation Catalyzed by closo-Rhodacarboranes
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In a search for reactions catalyzed by rhodacarborane clusters, the species I, , II, , III, , and IV, , were examined as catalyst precursors in the hydrogenation of 1-butyl acrylate (C) in THF solution at 40.8 deg C.Only catalyst precursors I and III gave results that were free of complications and suitable for detailed kinetic analyses.Both I and III reversibly hydridometalate C to produce the chelated closo adducts VI and VII, respectively, and an equivalent quantity of PPh3.The slow attainment of equilibria in these hydrometalation reactions accounts for the appearance of a lengthy induction period at the outset of C hydrogenations which employed either I or III as catalyst precursor.The rate law for C hydrogenation using I or III was elucidated and found to be identical in form with that previously observed using closo- or exo-nido-rhodacarboranes in 3-metyl-3-phenylbutene-1 (A) hydrogenation.As in the case of A, it was shown by deuterium labeling that C hydrogenation did not involve the hydride ligand at the RhH vertex of either I of III.The BH vertices of these same species were similarly shown to not be involved.Reduction of C with D2 using I as the catalyst source gave a moderate amount of D scrambling into recovered C and produced 1-butyl propionate-d0-d4.The above results led to a proposed catalytic cycle that culminates in the slow, but probably not rate-limiting, elimination of 1-butyl propionate from a reversibly formed exo-nido alkyl hydride intermediate.These kinetic characteristics may have their origin in the weak electron donor properties of the chelated - ligands that are attached to Rh(1+) or Rh(3+) in exo-nido intermediates by a pair of B-H-Rh three-center bonds.
- Behnken, Paul E.,Busby, David C.,Delaney, Mark S.,King III, Roswell E.,Kreimendahl, Charles W.,et. al.
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- Immobilization of lipase in cage-type mesoporous organosilicas via covalent bonding and crosslinking
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Lipase from Thermomyces lanuginosus (TLL) was immobilized in cage-type mesoporous materials via two different protocols, viz. covalent bonding and cross-linking. The comparison between the biocatalysts generated by the two methods on both pure silica mesocellular siliceous foam (MCF) and cage-type large pore mesoporous organosilicas (PMOs) disclosed that cross-linking results in the immobilization of a larger amount of TLL and reduced diffusion problems compared to covalent bonding. Benzene-bridged PMOs positively influence the activity of immobilized lipase due to the hydrophobic properties of the surface. Furthermore, a transesterification reaction in organic solvent was carried out to verify the biocatalytic performance of differently immobilized lipase in both batch and fixed-bed reactors. The results further confirm the superiority of the PMO support compared to MCF and also reveal that the different immobilization protocols strongly influence the activity, stability and specificity of immobilized TLL. Moreover, two commercial available immobilize formed TLL were also used in a fixed-bed reactor under the same condition for comparison.
- Zhou, Zhou,Piepenbreier, Frank,Marthala, V.R. Reddy,Karbacher, Karl,Hartmann, Martin
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- Membrane reactor for acceleration of esterification using a special ionic liquid with reaction and separation and microwave heating
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To improve conversion of n-butanol to the corresponding ester using acetic acid, the ionic liquid 1-allyl-3-butylimidazolium bis(trifluoromethanesulfonyl) imide ([ABIM]TFSI), which does not dissolve in the water by-product, and poly(vinyl alcohol) (PVA) or PVA-TEOS (tetraethoxysilane) hybrid membranes were employed when using evapomeation (EV), along with microwave heating. The effect on the conversion of n-butanol of each individual process variable as well as that of all of the variables used in combination was investigated, and the characteristics of each approach are discussed.
- Uragami, Tadashi,Kishimoto, Junji,Miyata, Takashi
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- Head-to-tail dimerization of acrylates catalyzed by iridium complexes
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Head-to-tail dimerizations of acrylates and vinyl ketone were successfully performed by the use of iridium complexes in good yields. An iridium hydride complex generated in situ from [IrCl(cod)]2 and alcohols in the presence of Na2CO
- Nakagawa, Hideto,Sakaguchi, Satoshi,Ishii, Yasutaka
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- Encapsulation of heteropolyacids within hollow microporous polymer nanospheres for sustainable esterification reaction
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Herein, the Keggin structural phosphotungstic acid (HPW) has been successfully encapsulated within hollow microporous polymer nanospheres (H-MPNs) by a “ship-in-bottle” approach. The H-MPNs are formed by self-assembly induced by hyper-crosslinking of polylactide-b-polystyrene (PLA-b-PS). The obtained catalysts (HPW@H-MPNs) exhibit more sustainable availability than the previously reported HPW-supported catalysts in esterification reaction. This excellent sustainability can be attributed to the stable microporous channels in H-MPNs which are smaller than the molecular size of HPW, thereby effectively preventing the HPW from leaking out. Moreover, such catalysts also perform well in terms of catalytic activity and universality because of the combination of a hollow structure in the interior and permeable pore channels in the shells. This type of polymer carrier and general encapsulation method may provide a new strategy for developing more sustainable catalysts for various chemical reactions.
- He, Zhiwei,Huang, Kun,Song, Chunmei,Wang, Huaqing,Yu, Haitao,Zhang, Li
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- Ambient Hydrogenation and Deuteration of Alkenes Using a Nanostructured Ni-Core–Shell Catalyst
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A general protocol for the selective hydrogenation and deuteration of a variety of alkenes is presented. Key to success for these reactions is the use of a specific nickel-graphitic shell-based core–shell-structured catalyst, which is conveniently prepared by impregnation and subsequent calcination of nickel nitrate on carbon at 450 °C under argon. Applying this nanostructured catalyst, both terminal and internal alkenes, which are of industrial and commercial importance, were selectively hydrogenated and deuterated at ambient conditions (room temperature, using 1 bar hydrogen or 1 bar deuterium), giving access to the corresponding alkanes and deuterium-labeled alkanes in good to excellent yields. The synthetic utility and practicability of this Ni-based hydrogenation protocol is demonstrated by gram-scale reactions as well as efficient catalyst recycling experiments.
- Beller, Matthias,Feng, Lu,Gao, Jie,Jackstell, Ralf,Jagadeesh, Rajenahally V.,Liu, Yuefeng,Ma, Rui
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supporting information
p. 18591 - 18598
(2021/06/28)
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- Amido PNP complexes of iridium: Synthesis and catalytic olefin and alkyne hydrogenation
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In situ lithiation of HN(o-C6H4PPh2)2 (H[1a]) or HN(o-C6H4PiPr2)2 (H[1b]) with nBuLi in THF at ?35°C followed by addition of [Ir(μ-Cl)(COD)]2 (COD = 1,5-cyclooctadiene) in toluene at ?35°C generates 5-coordinate [1a]Ir(η4-COD) (2a) or 4-coordinate [1b]Ir(η2-COD) (2b), respectively. Oxidative addition of N-H in H[1b] to [Ir(μ-Cl)(COD)]2 affords square pyramidal [1b]Ir(H)(Cl) (3b). Metathetical reaction of 3b with LiBHEt3 in the presence of 1 atm of H2 in toluene produces [1b]Ir(H)2 (4b). Both 2a and 4b are active for catalytic hydrogenation of olefins and alkynes under extremely mild conditions.
- Huang, Mei-Hui,Zou, Xue-Ru,Liang, Lan-Chang
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p. 353 - 360
(2019/12/24)
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- Base-free transfer hydrogenation of aryl-ketones, alkyl-ketones and alkenones catalyzed by an IrIIICp* complex bearing a triazenide ligand functionalized with pyrazole
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An IrIIICp* complex (2) bearing a triazenide ligand functionalized with pyrazole was synthesized and fully characterized by spectroscopic methods and the structure confirmed by X-ray diffraction studies. The catalytic activity of 2 and the control complex 3, which lacks of pyrazole in its structure, was evaluated in the reduction of aryl-ketones, alkyl-ketones, α,β-unsaturated and γ,δ-unsaturated ketones. The catalytic system, using either 2 or 3, exhibited good to excellent selectivity when tested with ketones and alkenones at 90 °C in 2-propanol as hydrogen source under base-free conditions. Reactivity of 2 in 2-propanol and NaH gave a neutral metal hydride (4) while in the absence of base gave two major cationic hydrides species (5 and 6).
- Medrano-Castillo, Layla J.,Collazo-Flores, Miguel á.,Camarena-Díaz, Juan P.,Correa-Ayala, Erick,Chávez, Daniel,Grotjahn, Douglas B.,Rheingold, Arnold L.,Miranda-Soto, Valentín,Parra-Hake, Miguel
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- Genome mining reveals new bacterial type I Baeyer-Villiger monooxygenases with (bio)synthetic potential
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Baeyer-Villiger monooxygenases (BVMOs) are oxidorreductases that catalyze the oxidation of ketones in a very selective manner. By genome mining we detected seven putative type I BVMOs in Bradyrhizobium diazoefficiens USDA 110. As we established the phylogenetic relationships among them and with other type I BVMOs, we found out that they belong to different clades of the phylogenetic tree. Thus, we decided to clone and heterologously express five of them. Three of them, each one from a divergent phylogenetic group, were obtained as soluble proteins, allowing us to proceed with their biocatalytic assessment and enzymatic characterization. As to substrate scope and selectivity, we observed a complementary behavior among the three BVMOs. BVMO2 was the more versatile biocatalyst in whole-cell systems while BVMO4 and BVMO5 showed a narrow substrate profile with preference for linear ketones and particular regioselectivity for (±)-cis-bicyclo[3.2.0]hept-2-en-6-one.
- Bianchi, Dario A.,Carabajal, María Ayelén,Ceccoli, Romina D.,Rial, Daniela V.
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- IrIII-Catalyzed direct syntheses of amides and esters using nitriles as acid equivalents: A photochemical pathway
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An unprecedented IrIII[df(CF3)ppy]2(dtbbpy)PF6-catalyzed simple photochemical process for direct addition of amines and alcohols to the relatively less reactive nitrile triple bond is described herein. Various amides and esters are synthesized as the reaction products, with nitriles being the acid equivalents. A mini-library of different types of amides and esters is made using this mild and efficient process, which uses only 1 mol% of photocatalyst under visible light irradiation (λ = 445 nm). The reaction strategy is also efficient for gram-scale synthesis.
- Talukdar, Ranadeep
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supporting information
p. 5303 - 5308
(2020/04/17)
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- A sulfonic acid type double-nuclear ionic liquid in catalytic synthesis of carboxylic acid butyl ester in application and method
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The invention relates to the field of organic synthetic technology, in particular discloses a sulfonic acid type double-nuclear ionic liquid in catalytic synthesis of carboxylic acid butyl ester in application and method, the sulfonic acid type can absorb almost double-nuclear ionic liquid as Wherein m=3 - 4 ,n=3 - 4 ,X- For the HSO4- . The carboxylic acid of the n-butyl synthetic method is the double-nuclear ionic liquid the states the sulfonic acid, carboxylic acid and normal butanol added into the reactor, heating to reflux the reaction is carried out, after the reaction is finished layered, recovery of the lower sulfonic acid type double-nuclear ionic liquid catalyst, the upper layer to obtain the product carboxylic acid is n-butyl. The invention selected ionic liquid environment friendly, easy to recycle, to the carboxylic acid esterification reaction of high catalytic efficiency.
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Paragraph 0028; 0029
(2019/06/13)
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- Novel Old Yellow Enzyme Subclasses
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Many drug candidate molecules contain at least one chiral centre, and consequently, the development of biocatalytic strategies to complement existing metal- and organocatalytic approaches is of high interest. However, time is a critical factor in chemical process development, and thus, the introduction of biocatalytic steps, even if more suitable, is often prevented by the limited availability of off-the-shelf enzyme libraries. To expand the biocatalytic toolbox with additional ene reductases, we screened 19 bacterial strains for double bond reduction activity by using the model substrates cyclohexanone and carvone. Overall, we identified 47 genes coding for putative ene reductases. Remarkably, bioinformatic analysis of all genes and the biochemical characterization of four representative novel ene reductases led us to propose the existence of two new Old Yellow Enzyme subclasses, which we named OYE class III and class IV. Our results demonstrate that although, on a DNA level, each new OYE subclass features a distinct combination of sequence motifs previously known from the classical and the thermophilic-like group, their substrate scope more closely resembles the latter subclass.
- Peters, Christin,Frasson, David,Sievers, Martin,Buller, Rebecca
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p. 1569 - 1577
(2019/05/15)
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- Hydroformylation of unsaturated esters and 2,3-dihydrofuran under solventless conditions at room temperature catalysed by rhodium: N-pyrrolyl phosphine catalysts
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Rhodium complexes of the type HRh(CO)L3 (where L is an N-pyrrolyl phosphine, such as P(NC4H4)3, PPh(NC4H4)2, or PPh2(NC4H4)) were applied in the hydroformylation of less reactive unsaturated substrates, namely allyl acetate, butyl acrylate, methyl acrylate, 2,3-dihydrofuran and vinyl acetate. Even at room temperature, these catalysts enabled complete substrate conversion and high chemoselectivity towards the corresponding aldehydes. High conversion of vinyl acetate (88% in 6 h) to the branched aldehyde was obtained with HRh(CO)[P(NC4H4)3]3 at 25 °C. An increase of the turnover frequency, TOF, up to 2000 mol mol-1 h-1 was achieved in this reaction under 20 bar of syngas (H2/CO = 1) at 80 °C. The introduction of chiral phosphines, BINAP or Ph-BPE, to this system resulted in the production of a branched aldehyde with enantioselectivity, ee, up to 44 and 81%, respectively. High activity combined with high enantioselectivity was achieved due to the formation of the mixed rhodium hydrides HRh(CO)[P(NC4H4)3](BINAP) and HRh(CO)[P(NC4H4)3](Ph-BPE), identified by the NMR method.
- Alsalahi,Trzeciak
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p. 16990 - 16999
(2019/11/14)
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- Method for preparing propionate by ester alcohol exchange
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The invention discloses a method for preparing propionate by ester alcohol exchange, and relates to a method for preparing propionate. According to the invention, the method for synthesizing propionate by ester alcohol exchange of methyl propionate and various alcohols (including monohydric alcohols such as ethanol, propanol, butanol, tert-butanol, isopropanol, cyclohexanol, allyl alcohol and thelike, dihydric alcohols such as 1,3-propylene glycol and the like, glycerol and the like) is adopted, and methyl propionate and the alcohols are used as raw materials to carry out a reaction under catalysis of alkaline ionic liquid, soluble strong alkali or solid alkali to prepare higher propionate and methanol. According to the method, the synthetic route is short, and the reaction product is taken out through azeotropic extraction of the methyl propionate and methanol, so that the reaction is more thorough, and the target product is directly obtained by one step. The product obtained by thereaction only contains propionate and methanol, the whole reaction process is concise and efficient and is free of pollution, no byproducts are generated, and great significance is achieved for large-scale and low-cost production of propionate.
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Paragraph 0038-0039
(2019/07/04)
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- Method for synthesizing propionate through ester-ester exchange path
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The invention provides a method for synthesizing propionate through an ester-ester exchange path and relates to a method for synthesizing the propionate. According to the method, reaction raw materials include, but are not limited to ethyl formate, propyl formate, butyl formate, ethyl acetate, propyl acetate, butyl acetate and the like; the method for synthesizing the propionate through an ester exchange one-step method is adopted. A catalyst comprises alkaline materials including ionic liquid, soluble strong base, solid base and the like respectively; the catalyst has the advantages of high catalysis efficiency and no pollution. By taking methyl propionate and ethyl acetate reaction as an example, KOH is used as the catalyst, the mol ratio of the raw materials is 1 to 1, the reaction temperature is 60 DEG C and the reaction time is 5 min; the conversion ratios of the methyl propionate and the ethyl acetate can reach 70 percent or more; products comprise ethyl propionate and the methylacetate. The whole reaction path has the characteristics of short synthetic route, simple technological flow and high yield and the catalyst is stable, does not become inactive and can be repeatedlyutilized.
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Paragraph 0030-0031
(2019/04/04)
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- Magnetically recoverable AlFe/Te nanocomposite as a new catalyst for the facile esterification reaction under neat conditions
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In this work, a new Fe3O4/AlFe/Te nanocomposite was synthesized by a one-step sol–gel method. The Fe3O4 magnetic nanoparticles (MNPs) were prepared and then mixed with aluminum telluride (Al2Te3) in an alkali medium to produce the desired catalyst. After characterization of the Fe3O4/AlFe/Te nanocomposite by SEM, TEM, EDS, XRD, and ICP analyses, it was used in the esterification reaction. This heterogeneous catalyst showed high catalytic activity in the esterification of commercially available carboxylic acids with various alcohols to produce the desired esters at high conversions under neat conditions. The Fe3O4/AlFe/Te nanocomposites were separated from the reaction mixture via an external magnet and re-used 8 times without significant loss of catalytic activity.
- Alavi, Seyed Jamal,Sadeghian, Hamid,Seyedi, Seyed Mohammad,Eshghi, Hossein,Salimi, Alireza
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- Rapid “Mix-and-Stir” Preparation of Well-Defined Palladium on Carbon Catalysts for Efficient Practical Use
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A facile direct deposition approach for the preparation of recyclable Pd/C catalysts simply by stirring a solution of tris(dibenzylideneacetone)dipalladium(0) with a suitable carbon material was evaluated. An extraordinarily rapid catalyst preparation procedure (0 centers onto the highly accessible surface area and the avoidance of ill-defined PdII/Pd0 states.
- Yakukhnov, Sergey A.,Pentsak, Evgeniy O.,Galkin, Konstantin I.,Mironenko, Roman M.,Drozdov, Vladimir A.,Likholobov, Vladimir A.,Ananikov, Valentine P.
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p. 1869 - 1873
(2018/04/30)
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- Cross-Dehydrogenating Coupling of Aldehydes with Amines/R-OTBS Ethers by Visible-Light Photoredox Catalysis: Synthesis of Amides, Esters, and Ureas
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A straightforward synthesis of amides, ureas, and esters is reported by visible-light cross-dehydrogenating coupling (CDC) of aldehydes (or amine carbaldehydes) and amines/R-OTBS ethers by photoredox catalysis. The reaction is found to be general and high yielding. A plausible mechanistic pathway has been proposed for these transformations and is supported by appropriate controlled experiments.
- Pandey, Ganesh,Koley, Suvajit,Talukdar, Ranadeep,Sahani, Pramod Kumar
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supporting information
p. 5861 - 5865
(2018/09/21)
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- SEPARATION OF ORGANIC ACIDS FROM MIXTURES CONTAINING AMMONIUM SALTS OF ORGANIC ACIDS
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The invention relates to a process for separation of organic acids from mixture of ammonium salts of one or more organic acids and other compounds via an integrated process. The process involves suspending mixture of ammonium salts of one or more organic acids and other compounds in dry hydrocarbon solvent/s or mixtures thereof; wherein the selected hydrocarbon solvent/s or mixtures thereof have boiling point more than 100° C. and forms an azeotrope with water. The reaction mixture thus obtained is dehydrated azeotropically followed by esterification of basic salt of the organic acids by addition of alcohol in presence of metal or metal salt; thereafter the individual esters formed are separated by distillation and hydrolysed to obtain corresponding organic acids having more than 98% purity.
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Paragraph 0065; 0066; 0073; 0074
(2018/06/30)
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- Selective Hydrodeoxygenation of Alkyl Lactates to Alkyl Propionates with Fe-based Bimetallic Supported Catalysts
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Hydrodeoxygenation (HDO) of methyl lactate (ML) to methyl propionate (MP) was performed with various base-metal supported catalysts. A high yield of 77 % MP was obtained with bimetallic Fe–Ni/ZrO2 in methanol at 220 °C and 50 bar H2. A synergistic effect of Ni increased the yield of MP significantly when using Fe–Ni/ZrO2 instead of Fe/ZrO2 alone. Moreover, the ZrO2 support contributed to improve the yield as a phase transition of ZrO2 from tetragonal to monoclinic occurred after metal doping giving rise to fine dispersion of the Fe and Ni on the ZrO2, resulting in a higher catalytic activity of the material. Interestingly, it was observed that Fe–Ni/ZrO2 also effectively catalyzed methanol reforming to produce H2 in situ, followed by HDO of ML, yielding 60 % MP at 220 °C with 50 bar N2 instead of H2. Fe–Ni/ZrO2 also catalyzed HDO of other short-chain alkyl lactates to the corresponding alkyl propionates in high yields around 70 %. No loss of activity of Fe–Ni/ZrO2 occurred in five consecutive reaction runs demonstrating the high durability of the catalyst system.
- Khokarale, Santosh Govind,He, Jian,Schill, Leonhard,Yang, Song,Riisager, Anders,Saravanamurugan, Shunmugavel
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p. 681 - 687
(2018/02/13)
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- Cathodic reductive couplings and hydrogenations of alkenes and alkynes catalyzed by the B12 model complex
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The reductive coupling and hydrogenation of alkenes were catalyzed by the B12 model complex, heptamethyl cobyrinate perchlorate (1), in the presence of acid during electrolysis at??0.7?V vs. Ag/AgCl in acetonitrile. Conjugated alkenes showed a good reactivity during electrolysis to form reduced products. The product distributions were dependent on the substituents at the C[dbnd]C bond of the alkenes. ESR spin-trapping experiments using 5,5-dimethylpyrroline N-oxide (DMPO) revealed that the cobalt-hydrogen complex (Co–H complex) should be formed during the electrolysis and it functioned as an intermediate for the alkene reduction. The electrolysis was also applied to an alkyne, such as phenylacetylene, to form 2,3-diphenylbutane (racemic and meso) and ethylbenzene via styrene as reductive coupling and hydrogenated products, respectively.
- Shimakoshi, Hisashi,Luo, Zhongli,Tomita, Kazuya,Hisaeda, Yoshio
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- REACTIONS OF STANNYL CATIONS
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The present invention relates to a method of reducing, cleaving and/or coupling at least one C=O, C-O, C=C or C=N bond of a compound, using a reagent comprising a stannyl cation.
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Page/Page column 21
(2018/01/17)
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- PROCESS FOR HYDROGENOLYSIS OF ALPHA-HYDROXY ESTERS OR ACIDS USING A HETEROGENEOUS CATALYST
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The present invention relates to a method for hydrogenolysis of alpha-hydroxy esters or acids, comprising reacting the alpha-hydroxy ester or acid in the presence of a heterogeneous catalyst. The present invention also relates to a method for producing propionic acid ester, and the use of any of the methods for the production of propionic acid esters, such as alkyl propionate.
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Page/Page column 26
(2017/01/31)
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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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- Deep eutectic solvent choline chloride·2CrCl3·6H2O: An efficient catalyst for esterification of formic and acetic acid at room temperature
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A highly efficient and selective method for esterification of formic and acetic acid with alcohols has been achieved at room temperature, with the choline chloride (ChCl)/chromium(iii) chloride hexahydrate (CrCl3·6H2O) deep eutectic solvent as a catalyst. High yields and good selectivities of organic esters are obtained using DES [ChCl][CrCl3·6H2O]2 with the molar ratio 5:1 (carboxylic acids:alcohols) at room temperature in 24 h. The ease of recovery and reusability of DES with high catalytic activity makes this method efficient and practical.
- Cao, Jin,Qi, Bin,Liu, Jun,Shang, Yuhan,Liu, Huiwen,Wang, Wenjing,Lv, Jia,Chen, Zhiyan,Zhang, Haibo,Zhou, Xiaohai
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p. 21612 - 21616
(2016/03/08)
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- Versatile Catalytic Hydrogenation Using A Simple Tin(IV) Lewis Acid
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Despite the rapid development of frustrated Lewis pair (FLP) chemistry over the last ten years, its application in catalytic hydrogenations remains dependent on a narrow family of structurally similar early main-group Lewis acids (LAs), inevitably placing limitations on reactivity, sensitivity and substrate scope. Herein we describe the FLP-mediated H2activation and catalytic hydrogenation activity of the alternative LA iPr3SnOTf, which acts as a surrogate for the trialkylstannylium ion iPr3Sn+, and is rapidly and easily prepared from simple, inexpensive starting materials. This highly thermally robust LA is found to be competent in the hydrogenation of a number of different unsaturated functional groups (which is unique to date for main-group FLP LAs not based on boron), and also displays a remarkable tolerance to moisture.
- Scott, Daniel J.,Phillips, Nicholas A.,Sapsford, Joshua S.,Deacy, Arron C.,Fuchter, Matthew J.,Ashley, Andrew E.
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supporting information
p. 14738 - 14742
(2016/11/23)
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- Continuous flow Fischer esterifications harnessing vibrational-coupled thin film fluidics
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Rapid Fischer esterification reactions occur under solventless, continuous flow conditions in dynamic thin films. This methodology uses limited catalyst, require no additional heat input and occurs within the confinements of an inexpensive vortex fluidic device (VFD). The associated mechanoenergy is primarily delivered from two types of vibration, which are manifested in sharp increases in the yield of the reactions. These vibrations promote the existence of Faraday waves that alter the instantaneous shear rates of the reactants within the rotating tube. Tuning the rotational speed of the device allows harmonic vibrations to be utilized in the synthesis of alkyl-based esters within both a high and low contact angle NMR tube. This journal is
- Britton, Joshua,Dalziel, Stuart B.,Raston, Colin L.
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p. 1655 - 1660
(2015/02/02)
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- Carboxyl activation of 2-mercapto-4,6-dimethylpyrimidine through n-acyl-4,6-dimethylpyrimidine-2-thione: A chemical and spectrophotometric investigation
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2-Mercapto-4,6-dimethylpyrimidine, as effective carboxyl activating group, has been successfully proved by converting it into respective acyl derivatives and the subsequent conversion to the amides and esters respectively using amines, amino alcohols and alcohols. The aminolysis and esterification were monitored chemically and spectrophotometrically. This paved way to establish that the above mercaptopyrimidine derivative is an efficient carboxyl activating group applicable in solid phase peptide synthesis.
- Rajan
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p. 287 - 291
(2015/01/30)
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- Esterification of carboxylic acids with alkyl halides using imidazolium based dicationic ionic liquids containing bis-trifluoromethane sulfonimide anions at room temperature
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Task-specific room temperature ionic liquids (RTILs) composed of symmetrical N-methylimidazolium rings linked with a short oligo (ethylene glycol) chain (cationic part) and bis-trifluoromethane sulfonimide (NTf2, anionic part) were successfully synthesized, and their physicochemical properties were determined by various modern analytical techniques. The catalytic activity of the synthesized RTILs was evaluated in the esterification reaction of acids with alkyl halides in solvent-free conditions at room temperature. From the screening test, all the synthesized RTILs showed a high yield with significant selectivity for respective esters in a very short reaction time. Especially, 0.1 equimolar of RTIL-1 ([tetraEG(mim)2][NTf2]2) was found to be, the most efficient and reusable catalyst for this reaction. As a result, 100% conversion and up to a 94% yield of the respective ester product was obtained in a 30 min reaction time. This might be due to their synergetic effect of Lewis acidity, wide liquid range, and high miscibility compared to the other homogeneous and heterogeneous catalysts. Beside this, RTIL was easily separated from the reaction mixture and reused several times without any significant loss of catalytic activity and structural property. The present dicationic ionic liquids (ILs) under a solvent-free catalytic system were found to be kinetically fast, naturally benign, and achieved good yields for esterification of carboxylic acids with alkyl halides.
- Jadhav, Arvind H.,Lee, Kyuyoung,Koo, Sangho,Seo, Jeong Gil
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p. 26197 - 26208
(2015/10/20)
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- Comparison of the performance of commercial immobilized lipases in the synthesis of different flavor esters
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In this work, it is compared the performance of three commercial lipase preparations (Novozym 435, Lipozyme TL-IM, and Lipozyme RM-IM) in the synthesis of flavor esters obtained by esterification of acetic, propionic, and butyric acids using ethanol, isopropyl alcohol, butanol, or pentanol. A comprehensive comparison was performed verifying activities of these three enzyme preparations versus the different couples of substrates, checking the obtained yields. In general, the longer the acid chain, the higher the reaction yields. Novozym 435 was the most efficient enzyme in most cases, and only Lipozyme RM-IM offered better results than Novozym 435 in the production of ethyl butyrate. Reactions with butyric acid showed the highest conversion rates using all biocatalysts. Using optimal substrates, the reactions catalyzed by the three enzymes were optimized using the response surface methodology, and the catalytic performance of the biocatalysts in repeated batches was assessed. After optimization, yields higher than 90% were obtained for all three enzymes, but Lipozyme TL-IM needed four-times more biocatalyst content than the other two preparations. Novozym 435 kept over 80% of its activity when reused in 9 successive batches, whereas Lipozyme RM-IM can be reused 5 times and Lipozyme TL-IM only 3 times. In general, Novozym 435 showed to be more suitable for these reactions than the other two enzyme preparations.
- Martins, Andrea B.,Da Silva, Alexandre M.,Schein, Mirela F.,Garcia-Galan, Cristina,Zachia Ayub, Marco A.,Fernandez-Lafuente, Roberto,Rodrigues, Rafael C.
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- Graphite oxide as an efficient solid reagent for esterification reactions
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Esterification of organic acids with alcohols under mild conditions in high yields using graphite oxide, a readily available and inexpensive material, as an effective reagent is described.
- Mirza-Aghayan, Maryam,Rahimifard, Mahshid,Boukherroub, Rabah
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p. 859 - 864
(2014/12/10)
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- Synthesis of carboxylic acid esters in the presence of micro- and mesoporous aluminosilicates
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The catalytic properties of zeolites HY, HBeta, and HZSM-12 and of mesoporous amorphous aluminosilicate in liquid-phase esterification of aliphatic (monobasic C1-C18, dibasic C6, C10) and aromatic (benzoic, trimellitic, phthalic) carboxylic acids with butanol were studied. Zeolite HBeta appeared to be the most active catalyst. Procedures were developed for preparing esters in the presence of zeolitic catalyst HBeta, ensuring 100% selectivity of ester formation at 90-98% conversion of the acid.
- Grigor'Eva,Suleimanova,Agliullin,Kutepov
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p. 773 - 779
(2015/01/30)
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- Tuning the wettability of mesoporous silica for enhancing the catalysis efficiency of aqueous reactions
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A series of mesoporous silica-based catalysts with finely-tuned surface wettability have been synthesized, of which the catalysis efficiency towards aqueous hydrogenations is highly dependent on their surface wettability and can be five times higher than that of the commercial Pd/C catalyst. This journal is the Partner Organisations 2014.
- Fu, Luman,Li, Shuru,Han, Zhongyuan,Liu, Huifang,Yang, Hengquan
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supporting information
p. 10045 - 10048
(2014/08/18)
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- Metal-free hydrogenation catalyzed by an air-stable borane: Use of solvent as a frustrated Lewis base
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In recent years 'frustrated Lewis pairs' (FLPs) have been shown to be effective metal-free catalysts for the hydrogenation of many unsaturated substrates. Even so, limited functional-group tolerance restricts the range of solvents in which FLP-mediated reactions can be performed, with all FLP-mediated hydrogenations reported to date carried out in non-donor hydrocarbon or chlorinated solvents. Herein we report that the bulky Lewis acids B(C6Cl5)x(C6F5)3-x (x=0-3) are capable of heterolytic H2 activation in the strong-donor solvent THF, in the absence of any additional Lewis base. This allows metal-free catalytic hydrogenations to be performed in donor solvent media under mild conditions; these systems are particularly effective for the hydrogenation of weakly basic substrates, including the first examples of metal-free catalytic hydrogenation of furan heterocycles. The air-stability of the most effective borane, B(C6Cl5)(C6F5)2, makes this a practically simple reaction method.
- Scott, Daniel J.,Fuchter, Matthew J.,Ashley, Andrew E.
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supporting information
p. 10218 - 10222
(2015/03/31)
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- Formation of a Pt12 cluster by single-atom control that leads to enhanced reactivity: Hydrogenation of unreactive olefins
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A platinum subnanocluster catalyst composed of 12 atoms was synthesized using a phenylazomethine dendrimer, which can assemble twelve PtCl4 units by stepwise complexation, followed by reduction to Pt0. Unreactive olefins that were not activated by conventional 2 nm Pt nanoparticles were successfully hydrogenated by the subnanocluster. EWG=electron-withdrawing group. Copyright
- Takahashi, Masaki,Imaoka, Takane,Hongo, Yushi,Yamamoto, Kimihisa
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p. 7419 - 7421
(2013/07/26)
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- Rhodium catalyzed hydroformylation with formaldehyde and an external H 2-source
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The efficiency of the syngas-free rhodium catalyzed hydroformylation of olefins with formaldehyde can be significantly improved by the addition of hydrogen gas or formic acid.
- Uhlemann, Marcus,Doerfelt, Stephan,B?rner, Armin
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p. 2209 - 2211
(2013/05/09)
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- A substrate-driven approach to determine reactivities of α,β-unsaturated carboxylic esters towards asymmetric bioreduction
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The degree of C=C bond activation in the asymmetric bioreduction of α,β-unsaturated carboxylic esters by ene-reductases was studied, and general recommendations to render these "borderline-substrates" more reactive towards enzymatic reduction are proposed. The concept of "supported substrate activation" was developed. In general, an additional α-halogenated substituent proved to be beneficial for enzymatic activity, whereas β-alkyl or β-aryl substituents were detrimental for the reactivity of nonhalogenated substrates, and α-cyano groups showed little effect. The alcohol moiety of the ester functionality was found to have a strong influence on the reaction rate. Overall, activities were determined by both steric and electronic effects. Biotransformation: The asymmetric bioreduction of α,β-unsaturated carboxylic esters by ene-reductases could be tuned by varying the degree of C=C bond activation (see scheme). An additional α-halogenated substituent proved to be beneficial for enzymatic activity, whereas β-alkyl or β-aryl substituents were detrimental for the reactivity of nonhalogenated substrates. Copyright
- Tasnádi, Gábor,Winkler, Christoph K.,Clay, Dorina,Sultana, Nargis,Fabian, Walter M. F.,Hall, Mélanie,Ditrich, Klaus,Faber, Kurt
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experimental part
p. 10362 - 10367
(2012/10/08)
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- Artificial metalloenzymes via encapsulation of hydrophobic transition-metal catalysts in surface-crosslinked micelles (SCMs)
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Encapsulation of a hydrophobic rhodium catalyst in crosslinked micelles allowed nonpolar substrates to react in water with unusual selectivity. This journal is The Royal Society of Chemistry 2012.
- Zhang, Shiyong,Zhao, Yan
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supporting information
p. 9998 - 10000
(2012/11/07)
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- Determination of steric effect on the esterification of different alcohols with propanoic acid over cation-exchange resin catalyst Dowex 50Wx4
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This paper describes the application of LFER in the form of Taft correlation to understand the mechanism of the esterification of propanoic acid with different alcohols over heterogeneous catalyst, Dowex 50Wx4. The rate constant (k1) in the rate equation decreases with change of alcohols in the order methanol, ethanol, n-propyl, n-butyl, n-pentyl, iso-butyl, iso-propyl and sec-butyl (2-buthanol). The reaction of propanoic acid with alcohols fits the Taft equation, log k1.kCH3 = 1.0061 Es K 0.0012, which implies that the steric effect of the substituent governs that reaction and the mechanism is similar between the different alcohols. The experimental results were modelled according to a simple second-order model. It was found that the equilibrium constant of this reaction does not depend on the structure of the organic alcohols, and has for 333 K the value 4.04. by Oldenbourg Wissenschaftsverlag, Munchen.
- Erdem, Beyhan,Cebe, Mustafa
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experimental part
p. 125 - 136
(2011/04/24)
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- A uniform bimetallic rhodium/iron nanoparticle catalyst for the hydrogenation of olefins and nitroarenes
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Mix and more than match: Relative to the catalytic activity of pure Rh nanoparticles in a dendrimer cage, Rh/Fe bimetallic nanoparticles in dendrimers have improved catalytic activity towards the hydrogenation of olefins, and unlike Wilkinson catalyst could catalyze nitroarene hydrogenation (see scheme, G4=4th generation dendrimer).
- Nakamula, Ikuse,Yamanoi, Yoshinori,Imaoka, Takane,Yamamoto, Kimihisa,Nishihara, Hiroshi
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experimental part
p. 5830 - 5833
(2011/08/02)
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- Esterification of carboxylate-based ionic liquids with alkyl halides
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A facile reaction of 1-ethyl-3-methylimidazolium acetate ([EMIm]Ac) with dichloromethane at room temperature was observed with esters among the products. This esterification can be exploited for mild solvent-free esterification with a range of other carboxylate-based ionic liquids and alkyl halides. The Royal Society of Chemistry.
- Zhao, Bin,Greiner, Lasse,Leitner, Walter
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scheme or table
p. 2973 - 2975
(2011/04/24)
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- Reusable and efficient polystyrene-supported acidic ionic liquid catalyst for esterifications
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Polystyrene (PS)-supported 1-(propyl-3-sulfonate) imidazolium hydrosulfate acidic ionic liquid (PS-CH2-[SO3H-pIM][HSO4]) catalyst was prepared by supporting the ionic liquid onto highly cross-linked chloromethylated polystyrene (PS-CH2Cl). FT-IR, SEM and TG-DSC were employed to characterize the structure and property of the catalyst. Results suggested that acidic ionic liquid was supported onto the surface of PS-CH 2Cl by covalent bond. The original rough surface of PS-CH 2Cl was covered with acidic ionic liquid, forming a compact and thin surface layer, and its size had no obvious change. Moreover, the PS-CH 2-[SO3H-pIM][HSO4] catalyst showed a better thermal stability than that of PS-CH2Cl support. It also exhibited high catalytic activity for a series of esterifications. After the catalyst was reused for 13 times in the synthesis of n-butyl acetate, the yield only decreased 7.3%. A reaction mechanism of esterification over this new catalyst was proposed as well.
- Xu, Zhenjin,Wan, Hui,Miao, Jinmei,Han, Mingjuan,Yang, Cao,Guan, Guofeng
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experimental part
p. 152 - 157
(2011/01/05)
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- Keggin-type mono lacunary silicotungstate supported onto zirconia: Synthesis, characterization, and esterification reaction
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A solid acid catalyst comprising of lacunary silicotungstate and zirconia was synthesized and characterized by physicochemical techniques. Surface morphologies of support and catalyst were studied by scanning electron microscopy. Catalytic properties were evaluated for the esterification of n-butanol with acetic acid. Esterifications of sec-butanol and isobutanol with acetic acid as well as the esterification of n-butanol with different acids such as formic acid and propionic acid were carried out under optimized conditions. Catalytic activities for calcined as well as recycled catalysts were also evaluated for the esterification under optimized condition.
- Pathan, Soyeb,Patel, Anjali
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experimental part
p. 4041 - 4049
(2011/09/20)
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- Pd-MCM-48: A novel recyclable heterogeneous catalyst for chemo- and regioselective hydrogenation of olefins and coupling reactions
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A novel, heterogeneous Pd-MCM-48 catalyst has been developed by encapsulating palladium nanoparticles into the cubic phase of mesoporous MCM-48 matrix at room temperature. The catalyst demonstrated excellent chemo- and regioselectivity for the hydrogenation of olefins at room temperature within 30-80 min. The turnover frequency for the hydrogenation is very high (4400 h-1). Interestingly, selectivity of the catalyst was significantly influenced by the mode of addition of palladium precursor. Moreover, the catalyst was also very effective for the coupling reactions with the formation of carbon-carbon and carbon-nitrogen bonds under ligand-free and aerobic conditions.
- Banerjee, Subhash,Balasanthiran, Vagulejan,Koodali, Ranjit T.,Sereda, Grigoriy A.
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experimental part
p. 4316 - 4321
(2010/11/04)
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- Transesterification via Baeyer-Villiger oxidation utilizing potassium peroxydisulfate (K2S2O8) in acidic media
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Baeyer-Villiger oxidation of ketones with potassium peroxydisulfate (K 2S2O8) and sulfuric acid generates the anticipated esters or lactones. These products are transformed into new esters (or hydroxy esters) in the presence of alcohols via transesterification under Baeyer-Villiger reaction conditions in one pot. Springer-Verlag 2010.
- Zarrabi,Mahmoodi,Marvi
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experimental part
p. 889 - 891
(2011/06/27)
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- Kinetics of catalytic esterification of propionic acid with different alcohols over amberlyst 15
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The kinetics of the esterification reaction between propionic acid and methanol, ethanol, and 1-butanol over the ion exchange resin, Amberlyst 15, was investigated. Experiments were conducted using a fixed-bed plug flow reactor over the temperature range of 298-328 K. Acid to alcohol molar ratios of 3:1, 1:1, and 1:3 were employed. For each esterification system, the equilibrium conversion of propionic acid was found to increase with increasing reaction temperature. Several kinetic models were tested to correlate the collected data under kinetically controlled conditions; the pseudo-homogeneous (P-H), Eley-Rideal (E-R), Langmuir-Hinshelwood (L-H), and Poepken (P-P) models. In all cases, the activity coefficients were estimated using the UNIFAC model to account for the nonideal thermodynamic behavior of the reactants and products. The P-P model was found to best represent the kinetic data of the investigated esterification systems with a total average error of less than 3%. The increase of alcohol chain length had a negative impact on the conversion of propionic acid due to steric hindrance. The activation energy of the esterification reaction is influenced by the chain length of the alcohol used. The adsorption equilibrium constants estimated by the P-P model and the solubility parameters reported by AICHE DIPPER followed the same trend; ester acid alcohol water.
- Ali, Sami H.
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experimental part
p. 432 - 448
(2009/10/10)
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- Enhanced Pd-catalyzed hydrogenation of olefins within polymeric microreactors under organic/aqueous biphasic conditions
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A microreactor of a water-soluble hollow polymeric microsphere with Pd nanoparticles immobilized in the wall was proposed for the hydrogenation of olefins under organic and aqueous biphasic conditions. It was found that the microreactor was stable and was used in practical application for continuous hydrogenation of olefins on a technical scale without deactivation in activity. It was composed of three parts, such as the outer corona of polyacrylamide (PAM), the cross-linked and hydrophobic wall of poly[styrene-co-2-(acetoacetoxy) -ethylmethacrylate] (PS-co-PAEMA), and 3.9 mm Pd nanoparticles. Hollow microspheres were constructed using several procedures of seed polymerization along with removal of the seed for the synthesis of the microreactor. It was observed that the microreactor dispersed easily in aqueous phase due to the presence of the hydrophilic PAM corona. The hydrogenation of CA with H 2 was also evaluated to investigate hydrogenation of olefins within the microreactor.
- Lan, Yang,Zhang, Minchao,Zhang, Wangqing,Yang, Li
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scheme or table
p. 3670 - 3673
(2009/12/05)
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- Highly regioselective and rapid hydroformylation of alkyl acrylates catalyzed by a rhodium complex with a tetraphosphorus ligand
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Alkyl acrylates have been hydroformylated to the linear aldehydes with high regioselectivity (linear/branch > 99/1) and extraordinarily high average turnover frequencies (up to 5400 h-1) by using a rhodium complex with a tetraphosphorus ligand.
- Yu, Shichao,Chie, Yu-Ming,Zhang, Xumu
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experimental part
p. 537 - 540
(2009/11/30)
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- Zirconia supported undecatungstophosphate: Synthesis and characterization of a bifunctional catalyst
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The synthesized supported undecatungstophosphate has been proven to be successful for acid catalyzed as well as oxidation reactions, especially, in obtaining 98.5% conversion of styrene and 100% selectivity for benzaldehyde.
- Shringarpure, Pragati,Patel, Anjali
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scheme or table
p. 3953 - 3955
(2009/02/03)
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- 3-Butyl-1-methylimidazolinium borohydride ([bmim][BH4])-a novel reducing agent for the selective reduction of carbon-carbon double bonds in activated conjugated alkenes
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A novel ionic reducing reagent, 3-butyl-1-methylimidazolium borohydride ([bmim][BH4]), was synthesized and successfully used for the selective reduction of carbon-carbon double bonds in conjugated alkenes as well as the α,β-carbon-carbon double bonds in highly activated α,β,γ,δ-unsaturated alkenes. The reagent can be regenerated and reused several times without losing its activity.
- Wang, Jiayi,Song, Gonghua,Peng, Yanqing,Zhu, Yidong
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supporting information; experimental part
p. 6518 - 6520
(2009/04/06)
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