13945-76-1Relevant academic research and scientific papers
Dehydrative Esterification of Carboxylic Acids with Alcohols Catalyzed by Polymer-Supported Sulfonic Acids in Water
Manabe, Kei,Kobayashi, Shu
, p. 270 - 273 (2002)
Dehydrative esterification of carboxylic acids with alcohols in water was efficiently catalyzed by hydrophobic polystyrene-supported sulfonic acids as recoverable and reusable catalysts. In these reactions, esters were obtained in high yields without using any dehydrating agents or apparatus. The sulfonic acid contents of the catalysts and the presence of long alkyl chains on the benzene rings of polystyrene significantly affected the catalytic activity.
Effect of ionic liquids, organic solvents and supercritical CO2 pretreatment on the conformation and catalytic properties of Candida rugosa lipase
Liu, Yun,Chen, Dawei,Yan, Yunjun
, p. 123 - 127 (2013)
The objective of this work is to assess the structure and activity of Candida rugosa lipase (CRL) pretreated with seventeen ionic liquids (ILs), five organic solvents and super-critical carbon dioxide (SC-CO2). The results revealed that anion selection of ILs showed generally much greater effects on CRL esterification activity than cation choice, and CRL pretreated by ILs with strong water miscible properties showed very low esterification activity. The highest CRL activity treated with ILs [Hmim][PF6] was obtained with the value of 45078.0 U/g-protein. Furthermore, the CRL activities pretreated with five conventional organic solvents were also examined and the values increased with the log P decrease of organic solvents when log P was lower than 2.0. Finally, the CRL activities were respectively 1.2- and 1.3-fold higher over the untreated ones after pretreatment with sub- and super-critical CO2 under the pressures of 6 MPa and 15 MPa at 40 °C for 20 min. Further analyses via FT-IR demonstrated that the high activity of CRL pretreated with ILs, organic solvents and SC-CO2 was probably caused by the changes of CRL secondary structure. In conclusion, the results in this work will be helpful for us to choose the suitable reaction medium in CRL biocatalysis and biotransformation reactions.
Sugar ester-modified lipase for the esterification of fatty acids and long-chain alcohols
Basheer, Sobhi,Nakajima, Mitsutoshi,Cogan, Uri
, p. 1475 - 1479 (1996)
The esterification reaction of a long-chain fatty acid and a fatty alcohol with a surfactant-modified lipase in a microaqueous n-hexane system was studied. Various lipases from different sources were first modified with a surfactant of the sugar ester type to improve their dispersibility in apolar organic solvents. This enzyme modification technique converted inactive crude lipases to highly active biocatalysts for the esterification of long-chain fatty acids and fatty alcohols in a microaqueous n-hexane system. The hydrophilic-lipophilic balance value and chainlength of the fatty acid residue of the fatty acid sugar ester, used for modifying the lipases, significantly influenced the amount of precipitated lipase that was dissolved in the aqueous solution, the protein content of the lipase-surfactant complex and its esterification activity.
Facile aerobic photooxidation of alcohols in the presence of catalytic lithium bromide
Itoh, Akichika,Hashimoto, Shouei,Masaki, Yukio
, p. 2639 - 2640 (2005)
Alcohols were found to be oxidized to the corresponding carboxylic acids in the presence of catalytic lithium bromide under photoirradiation. Georg Thieme Verlag Stuttgart.
Efficient greener methodology for the preparation of bio-based phase change materials from lipids
Y?ld?r?m, Ayhan,K?raylar, Kaan
, p. 407 - 413 (2020)
In the present work, a new, highly efficient and simple strategy has been developed for the synthesis of long chain esters from fatty acids and fatty alcohols as phase change materials. Equivalent amounts of the selected starting compounds were taken to the esterification reaction at 110 °C in a solventless medium. In order to catalyze the esterification reaction, non-hygroscopic triphenylphosphine-sulfur trioxide adduct was used (0.83 mmol%) which is an easily accessible compound. The relevant reaction was completed in a very short time (2 h) and under optimized esterification conditions, excellent conversion were reached. The targeted mono ester compounds (15 examples) were obtained in good to excellent yields even after a simple crystallization step (72-99%). Additionally, a catalyst reuse investigation and study covering the scale-up production of stearyl stearate was also carried out. The triphenylphosphine-sulfur trioxide catalyzed solvent free process can compete with existing processes and proved to be a cheaper, practical and environmentally-friendly method for the esterification of fatty acids and alcohols.
Solvothermal synthesis of FeCo nanoparticles for magneto-controllable biocatalysis
Hou, Jianxuan,Kuang, Yun,Shen, Huaqing,Cao, Hui,Luo, Liang,Liu, Junfeng,Wan, Pengbo,Chen, Biqiang,Sun, Xiaoming,Tan, Tianwei
, p. 11136 - 11141 (2014)
A facile and simple one-step solvothermal method has been developed to synthesize FeCo nanoparticles with well-controlled composition, desired morphology and high saturation magnetization, which exhibit component-dependent magnetic behaviors: the increase of Fe content leads to the increase of saturation magnetization and the decrease of coercivity. Furthermore, due to the availability of a coarse surface for the stable adsorption of targeted cargo, the high saturation magnetization for efficient control and directional separation from a reaction mixture by an external magnetic field, the as-prepared magnetic FeCo nanoparticles could work as a fuel-free magneto-controllable carrier to load biocatalytically-active cargo lipase for magneto-controllable and recyclable biocatalytic synthesis of lauryl laurate under an external magnetic field. By alternate positioning of the FeCo carrier with loaded cargo in and out of the substrate solution, the biocatalysis for esterification from lauric acid and lauryl alcohol to lauryl laurate could be switched between "On" and "Off" states.
Kinetics of the formation of symmetrical wax esters from the corresponding alcohols with the use of hydrobromic acid and hydrogen peroxide
Kulkarni,Sawant
, p. 719 - 723 (2001)
The primary aliphatic alcohols n-octanol, n-decanol, and n-dodecanol have been converted to their corresponding symmetrical esters by using HBr and H2O2 in the absence of a solvent. The reaction was carried out at 30, 40, and 50°C and at mole ratios of alcohol to HBr of 1:0.1, 1:0.2, 1:0.3, and 1:0.5. The rate of the reaction was found to increase with increase in the reaction temperature and concentration of HBr. The maximal conversion of n-octanol was 72% at 40°C and a mole ratio of n-octanol to HBr of 1:0.5. The kinetics of the reaction have been established, and the reaction was found to be first-order with respect to alcohol and bromine concentration in the organic phase, and second-order with respect to both. The second-order rate constants for n-octanol, n-decanol, and n-dodecanol are 27.08, 32.58, and 37.42 mL mol-1 min-1, respectively, at 40°C. The activation energy for the esterification reaction of n-octanol was found to be 16 32 kcal mol-1.
Synthesis of Unsymmetrical N-Heterocyclic Carbene-Nitrogen-Phosphine Chelated Ruthenium(II) Complexes and Their Reactivity in Acceptorless Dehydrogenative Coupling of Alcohols to Esters
He, Xiaochun,Li, Yaqiu,Fu, Haiyan,Zheng, Xueli,Chen, Hua,Li, Ruixiang,Yu, Xiaojun
, p. 1750 - 1760 (2019/04/17)
Two novel ruthenium complexes RuH(CO)Cl(PPh3)(κ2-CP) (1) and [fac-RuH(CO)(PPh3)(κ3-CNP)]Cl (2) bearing unsymmetrical N-heterocyclic carbene-nitrogen-phosphine (CNP) were synthesized and characterized with 1H NMR, 31P NMR, and HRMS. The structure of complex 2 was further confirmed by single-crystal X-ray diffraction. An anion exchange experiment proved that complex 2 could transform into complex 1 in solution. The two complexes exhibited a highly catalytic performance in acceptorless dehydrogenative coupling of alcohols to esters, and the excellent isolated yields of esters were given in a catalyst loading of 1% for para- and meta-substituted benzyl alcohols and long-chain primary alcohols. Although some ortho-substituted benzyl alcohols displayed a relatively low reactivity due to the steric hindrance and the coordination of electron donor with the ruthenium center, the good product yields were still obtained by prolonging the reaction time. Especially, this system successfully realized the dehydrogenative cross-coupling to esters between two different primary alcohols.
Mechanistic study of the selective hydrogenation of carboxylic acid derivatives over supported rhenium catalysts
Toyao, Takashi,Ting, Kah Wei,Siddiki, S. M. A. Hakim,Touchy, Abeda S.,Onodera, Wataru,Maeno, Zen,Ariga-Miwa, Hiroko,Kanda, Yasuharu,Asakura, Kiyotaka,Shimizu, Ken-ichi
, p. 5413 - 5424 (2019/10/29)
The structure and performance of TiO2-supported Re (Re/TiO2) catalysts for selective hydrogenation of carboxylic acid derivatives have been investigated. Re/TiO2 promotes selective hydrogenation reactions of carboxylic acids and esters that form the corresponding alcohols, and of amides that generate the corresponding amines. These processes are not accompanied by reduction of aromatic moieties. A Re loading amount of 5 wt% and a catalyst pretreatment with H2 at 500 °C were identified as being optimal to obtain the highest catalytic activity for the hydrogenation processes. The results of studies using various characterization methods, including X-ray diffraction (XRD), X-ray absorption fine structure (XAFS), X-ray photoelectron spectroscopy (XPS), and scanning transmission electron microscopy (STEM), indicate that the Re species responsible for the catalytic hydrogenation processes have sub-nanometer to a few nanometer sizes and average oxidation states higher than 0 and below +4. The presence of either a carboxylic acid and/or its corresponding alcohol is critical for preventing the Re/TiO2 catalyst from promoting production of dearomatized byproducts. Although Re/TiO2 is intrinsically capable of hydrogenating aromatic rings, carboxylic acids, alcohols, amides, and amines strongly adsorb on the Re species, which leads to suppression of this process. Moreover, the developed catalytic system was applied to selective hydrogenation of triglycerides that form the corresponding alcohols.
PRODUCTION METHOD OF ESTER COMPOUND
-
Paragraph 0030; 0033, (2019/10/01)
PROBLEM TO BE SOLVED: To produce an ester compound at a high conversion even under mild reaction conditions. SOLUTION: A production method of an ester compound includes a reaction step for reacting a carboxylic acid of 8-22 carbons and an alcohol of 8-22 carbons at a temperature of 50-100°C in an ionic liquid composed of a phosphonium cation or an imidazolium cation and a trifluoromethanesulfonic acid anion or a bis (trifluoromethanesulfonyl) imide anion to obtain an ester compound in a liquid phase different from an ionic liquid phase. SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT
