- Bulky diarylammonium arenesulfonates as mild and extremely active dehydrative ester condensation catalysts
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More environmentally benign alternatives to current chemical processes, especially large-scale, fundamental reactions like ester condensations, are highly desirable for many reactions. Bulky diarylammonium pentafluorobenzenesulfonates and tosylates serve as extremely active dehydration catalysts for the ester condensation reaction of carboxylic acids with equimolar amounts of sterically demanding alcohols and acid-sensitive alcohols. Typically, the esterification reaction is performed in heptane by heating at 80°C in the presence of 1 mol% of the catalyst without removing water. Esterification with primary alcohols proceeds without solvents even at room temperature. Furthermore, 4-(N-mesitylamino)polystyrene resin-bound pentafluorobenzenesulfonate can be recycled more than 10 times without a loss of activity.
- Sakakura, Akira,Nakagawa, Shoko,Ishihara, Kazuaki
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- Bulky diarylammonium arenesulfonates as selective esterification catalysts
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More environmentally benign alternatives to current chemical processes, especially large-scale, fundamental reactions such as ester condensations, are highly desirable for many reactions. Bulky diarylammonium pentafluorobenzenesulfonates and tosylates serve as extremely active dehydration catalysts for the ester condensation reaction of carboxylic acids with equimolar amounts of sterically demanding alcohols and acid-sensitive alcohols. Typically, the esterification reaction is performed in heptane by heating at 80 °C in the presence of 1 mol % of the catalyst without removing water. Esterification with primary alcohols proceeds without solvents even at room temperature. Furthermore, 4-(N-mesitylamino)polystyrene resin-bound pentafluorobenzenesulfonate can be recycled more than 10 times without activity loss. Copyright
- Ishihara, Kazuaki,Nakagawa, Shoko,Sakakura, Akira
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- SO3H and NH2+ functional carbon-based solid acid catalyzed transesterification and biodiesel production
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A SO3H and NH2+ functional carbon-based solid acid was used as a highly active heterogeneous catalyst for the transesterification of various carboxylic methyl esters with alcohols under mild conditions. It also showed high catalytic performance for transesterification of triolein with methanol or isopropanol. Furthermore, it was able to catalyze simultaneous esterification and transesterification of rice oil and butter respectively, the yields of biodiesel obtained were up to 94%, and the catalyst could be easily recovered and reused more than ten times without loss of activity, which indicated the carbon-based solid acid was a potential catalyst for the biodiesel industry.
- Cai, Liangzhen,Meng, Decai,Zhan, Shaoqi,Yang, Xiaoxia,Liu, Taoping,Pu, Huiming,Tao, Xiaochun
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- Direct ester condensation from a 1:1 mixture of carboxylic acids and alcohols catalyzed by hafnium(IV) or zirconium(IV) salts
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To promote atom efficiency in synthesis and to avoid the generation of environmental waste, the use of stoichiometric amounts of condensing reagents or excess substrates should be avoided. In esterification, excess amounts of either carboxylic acids or alcohols are normally needed. We found that the direct condensation of equimolar amounts of carboxylic acids and alcohols could be achieved using hafnium(IV) or zirconium(IV) salts. These metal salts are highly effective as catalysts for the selective esterification of primary alcohols with carboxylic acids in the presence of secondary alcohols or aromatic alcohols. The present methods can be applied to direct polyesterification and may be suitable for large-scale operations.
- Ishihara, Kazuaki,Nakayama, Masaya,Ohara, Suguru,Yamamoto, Hisashi
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- N-alkyl-4-boronopyridinium halides versus boric acid as catalysts for the esterification of α-hydroxycarboxylic acids
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(Chemical Equation Presented) Boric acid is a highly effective catalyst for the dehydrative esterification reaction between equimolar mixtures of α-hydroxycarboxylic acids and alcohols. In contrast, N-methyl-4- boronopyridinium iodide (2a) is a more effective catalyst than boric acid for the similar esterification in excess alcohol. A heterogeneous catalyst, such as N-polystyrene-bound 4-boronopyridinium chloride, is also an effective catalyst and can be recovered by filtration.
- Maki, Toshikatsu,Ishihara, Kazuaki,Yamamoto, Hisashi
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- 2,2,6,6-Tetramethylpiperidinium triflate (TMPT): a highly selective and self-separated catalyst for esterification
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An eco-friendly and readily accessible 2,2,6,6-tetramethylpiperidinium triflate was found as highly-selective and self-separated catalyst for esterification under solvent-free condition. The X-ray crystallography revealed that it formed a ‘hydrophobic wall’ which could effectively eliminate the generated water from the reactive sites. Moreover, it could precipitate from the reaction system with excellent recovery ratio (>99%) and be reused for ten times without any significant loss of activity.
- Gao, Lan,Liu, Taoping,Tao, Xiaochun,Huang, Yongmin
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- Ruthenium pincer complex-catalyzed heterocycle compatible alkoxycarbonylation of alkyl iodides: Substrate keeps the catalyst active
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The electron pair of the heteroatom in heterocycles will coordinate with metal catalysts and decrease or even inhibit their catalytic activity consequently. In this work, a pincer ruthenium-catalyzed heterocycle compatible alkoxycarbonylation of alkyl iodides has been developed. Benefitting from the pincer ligand, a variety of heterocycles, such as thiophenes, morpholine, unprotected indoles, pyrrole, pyridine, pyrimidine, furan, thiazole, pyrazole, benzothiadiazole, and triazole, are compatible here. This journal is
- Ai, Han-Jun,Wu, Xiao-Feng,Yuan, Yang
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p. 2481 - 2486
(2022/03/08)
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- The carbon material functionalized with NH2+ and SO3H groups catalyzed esterification with high activity and selectivity
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A novel carbon-based solid acid was conveniently prepared by heating a mixture of d-glucose, p-toluenesulfonic acid and diphenylammonium tosylate. Its structure was measured by XRD, FT-IR, XPS, 13C MAS NMR and EA to illustrate that the carbon material has been functionalized with NH2+ and SO3H groups and has a strong "hydrophobic effect". It can be used to catalyze the esterification reaction of carboxylic acids with equimolar amounts of sterically demanding and acid-sensitive alcohols with high reactivity (yield up to 90%) and selectivity (up to 95%) in heptane at 80 °C. It could be easily recovered and reused more than ten times without loss of activity.
- Zhan, Shaoqi,Tao, Xiaochun,Cai, Liangzhen,Liu, Xiaohui,Liu, Taoping
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supporting information
p. 4649 - 4653
(2015/02/19)
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- Esterification catalysis by pyridinium p -toluenesulfonate revisited - Modification with a lipid chain for improved activities and selectivities
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The lipid analogs of pyridinium p-toluenesulfonate (PPTS) were examined for catalysis of the condensation of an equimolar mixture of carboxylic acids and alcohols under mild conditions without removal of water. Although PPTS is a poor catalyst, the introduction of a lipid chain and nitro group significantly improved the activity of PPTS and led to selectivity at suppressing the elimination side reactions of alcohols. 2-Oleamido-5-nitro-pyridinium p-toluenesulfonate (6) is a lead catalyst that promoted various esterification reactions with yields up to 99%.
- Wang, Wei,Liu, Huimin,Xu, Shaoyi,Gao, Yong
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p. 2906 - 2912
(2013/09/02)
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- N-Butyl-2,4-dinitro-anilinium p-toluenesulfonate as a highly active and selective esterification catalyst
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N-Butyl-2,4-dinitro-anilinium p-toluenesulfonate (1) was found to be a very active esterification catalyst that promotes condensation of equal mole amount of carboxylic acids and alcohols under mild conditions. This catalyst is also highly selective towards carboxylic acid and alcohol substrates at ambient temperature.
- Sattenapally, Narsimha,Wang, Wei,Liu, Huimin,Gao, Yong
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supporting information
p. 6665 - 6668
(2013/11/19)
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- Protic acid immobilized on solid support as an extremely efficient recyclable catalyst system for a direct and atom economical esterification of carboxylic acids with alcohols
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(Chemical Equation Presented) A convenient and clean procedure of esterification is reported by direct condensation of equimolar amounts of carboxylic acids with alcohols catalyzed by an easy to prepare catalyst system of perchloric acid immobilized on silica gel (HClO4-SiO2). The direct condensation of aryl, heteroaryl, styryl, aryl alkyl, alkyl, cycloalkyl, and long-chain aliphatic carboxylic acids with primary/secondary alkyl/cycloalkyl, allyl, propargyl, and long-chain aliphatic alcohols has been achieved to afford the corresponding esters in excellent yields. Chiral alcohol and N-t-Boc protected chiral amino acid also resulted in ester formation with the representative carboxylic acid or alcohol without competitive N-t-Boc deprotection and detrimental effect on the optical purity of the product demonstrating the mildness and chemoselectivity of the procedure. The esters of long-chain (>C10) acids and alcohols are obtained in high yields. The catalyst is recovered and recycled without significant loss of activity. The industrial application of the esterification process is demonstrated by the synthesis of prodrugs of ibuprofen and a few commercial flavoring agents. Other protic acids such as H2SO4, HBr, TfOH, HBF4, and TFA that were adsorbed on silica gel were less effective compared to HClO4-SiO2 following the order HClO4-SiO 2 ? H2SO4-SiO2 > HBr-SiO 2 > TfOH-SiO2 ? HBF4-SiO2 ≈ TFA-SiO2. When HClO4 was immobilized on other solid supports the catalytic efficiency followed the order HClO4-SiO 2 > HClO4-K10 > HClO4-Al 2O3 (neutral) > HClO4-Al2O 3 (acidic) > HClO4-Al2O3 (basic).
- Chakraborti, Asit K.,Singh, Bavneet,Chankeshwara, Sunay V.,Patel, Alpesh R.
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supporting information; experimental part
p. 5967 - 5974
(2009/12/24)
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- METHOD FOR PRODUCING ESTER AND ESTERIFICATION CATALYST
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A process for producing an ester includes the step of allowing a carboxylic acid to react with an alcohol, wherein an ammonium sulfonate is used as an esterification catalyst, the ammonium sulfonate being composed of an ammonium cation having a basic skeleton represented by formula (1) (wherein n represents 1 or 2) in which hydrogen atoms in the benzene rings and hydrogen atoms bonded to bridge carbon may be substituted), and a sulfonic acid anion represented by RSO 3 - (wherein R represents an arene, a perfluoroalkane having 1 to 8 carbon atoms, or a bulky alkane).
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Page/Page column 8; 21
(2008/06/13)
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- Use of water-in-oil microemulsions and gelatin-containing microemulsion-based gels for lipase-catalysed ester synthesis in organic solvents
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Chromobacterium viscosum (CV) lipase and lipoprotein lipase ex Pseudomonas have been solubilised in AOT water-in-oil microemulsions at two different R-values, and used to catalyse the lactonisation of 16-hydroxyhexadecanoic acid at 40 deg C.CV lipase has also been immobilised in gelatin-containing microemulsion-based gels (MBGs) with retention of catalytic activity.These lipase-containing MBGs prove to be novel solid-phase catalysts for use in apolar organic solvents.MBGs do not dissolve in their parent nor, oil, when pelletted, do they self-associate in the organicsolvent in which they are placed in contact.CV lipase-containing MBGs have been used to synthesise on a preparative scale, a variety of different esters under mild conditions and both regio- and stereoselective syntheses have been demonstrated.Lipase-containing MBGs have also been shown to effectively catalyse esterifications at temperatures as low as -20 deg C.
- Rees, G D,Jenta, T R J,Nascimento, M G,Catauro, M,Robinson, B H,et al.
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