- Investigations of cylindrical reaction cavities from ordered phases of alkyl alkanoates and their influence on some Norrish-Yang and photo-fries reactions
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The Norrish-Yang photochemistry of three isomeric p-alkyl alkanophenones (p-propyl nonadecanophenone, p-pentyl heptadecanophenone and p-octyl tetradecanophenone) and the photo-Fries reactions of 2-naphthyl myristate have been investigated in the ordered (layered) phases of three isomeric alkyl alkanoates. Comparisons of photoproduct selectivity for irradiation of one substrate in the isotropic and ordered phases of one host ester provide information concerning the influence of the cylindrically shaped reaction cavities on the relative motions and conformational changes necessary to convert the reactants to products. Comparisons of photoproduct distributions from one substrate in comparable phases of two or more esters provide details concerning the "wall stiffness" and importance of functional group interactions of the reaction cavities. Finally, comparisons using one substrate and two ordered phases of the same ester indicate the role of wall stiffness on photoproduct selectivity. The results show that the course of the photochemical reactions can be controlled effectively within the ordered media and provide an indication of how to design and select ordered media to effect other photochemical transformations selectively.
- Baldvins, Jon E.,Cui, Changxing,Weiss, Richard G.
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- Immobilizing heteropolyacids on zirconia-modified silica as catalysts for oleochemistry transesterification and esterification reactions
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A new method of chemical immobilization of Keggin heteropolyacids (HPAs) was suggested. H3PW12O40, H4SiW12O40, and H3PMo12O40 were immobilized on the silica which was previously grafted with zirconium butoxide. The immobilization method promoted strong interaction HPA-support and yielded 25 wt.% of well-dispersed HPAs, so increasing the density of acid sites. The catalysts were active in the reaction of transesterification of methyl stearate with n-butanol and esterification of oleic acid with trimethylolpropane. We demonstrate that, contrary to the immobilized H3PMo12O40, the H3PW12O40 and H4SiW12O40-based catalysts are stable toward leaching in a non-polar oleic acid medium. A discussion on circumventing the leaching in non-polar versus polar media is proposed in terms of interaction strength HPA-support. The stronger interaction (i.e., better resistance for leaching) between the support and H3PW12O40 (or H4SiW12O40) is referred to the lower difference of electronegativity between Zr and W and the lower polarizability of the bonds Zr-O-W compared to Zr-O-Mo.
- Kuzminska, Maryna,Kovalchuk, Tetyana V.,Backov, Rénal,Gaigneaux, Eric M.
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- Robust acidic pseudo-ionic liquid catalyst with self-separation ability for esterification and acetalization
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The novel acidic pseudo-ionic liquid catalyst with self-separation ability has been synthesized through the quaternization of triphenylphosphine and the acidification with silicotungstic acid. The pseudo-IL showed high activities for the esterification with average conversions over 90%. The pseudo-IL showed even higher activities for acetalization than traditional sulfuric acid. The homogeneous catalytic process benefited the mass transfer efficiency. The pseudo-IL separated from the reaction mixture automatically after reactions, which was superior to other IL catalysts. The high catalytic activities, easy reusability and high stability were the key properties of the novel catalyst, which hold great potential for green chemical processes.
- Shi, Yingxia,Liang, Xuezheng
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p. 1413 - 1421
(2019/05/04)
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- Development and Validation of a Novel Free Fatty Acid Butyl Ester Gas Chromatography Method for the Determination of Free Fatty Acids in Dairy Products
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Accurate quantification of free fatty acids in dairy products is important for both product quality control and legislative purposes. In this study, a novel fatty acid butyl ester method was developed, where extracted free fatty acids are converted to butyl esters prior to gas chromatography with flame ionization detection. The method was comprehensively validated to establish linearity (20-700 mg/L; R2 > 0.9964), limits of detection (5-8 mg/L), limits of quantification (15-20 mg/L), accuracy (1.6-5.4% relative error), interday precision (4.4-5.3% relative standard deviation), and intraday precision (0.9-5.6% relative standard deviation) for each individual free fatty acid. A total of 17 dairy samples were analyzed, covering diverse sample matrices, fat content, and degrees of lipolysis. The method was compared to direct on-column injection and fatty acid methyl ester methods and overcomes limitations associated with these methods, such as either column-phase absorption or deterioration, accurate quantification of short-chain free fatty acids, and underestimation of polyunsaturated free fatty acid.
- Mannion, David T.,Furey, Ambrose,Kilcawley, Kieran N.
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p. 499 - 506
(2019/01/08)
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- Synthesis, structural characterization, and reactivity of (thiolato)bismuth complexes as potential water-tolerant Lewis acid catalysts
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We have synthesized bismuth complexes incorporating polydentate mono-and di-thiolate ligands and examined their utility as water-tolerant Lewis acid catalysts. The reaction of Bi(OAc)3 or Bi(NO3)3·5H2O and the corresponding mono-or di-thiol(ate) yielded the compounds [(SNNS)Bi(OAc)] (4), [(SNNSPr)Bi(OAc)] (5), [(NNS2)Bi(OAc)] (6), [(ONS2)Bi(OAc)] (7), [(ONS2)Bi(NO3)] (8), and [(NNS)2Bi][NO3] (9) [H2(SNNS) = N,N′-dimethyl-N,N′-bis(2-mercaptoethyl)ethylenediamine; H2(SNNSPr) = N,N′-diethyl-N,N′-bis(2-mercaptoethyl)propanediamine; H2(NNS2) = N,N-diethyl-N′,N′-bis(2-mercaptoethyl)ethanediamine; H2(ONS2) = 2-methoxyethyl-bis(2-mercaptoethyl)amine; H(NNS) = N,N-diethyl-N′-(2-mercaptoethyl)ethanediamine]. The solid-state structures of 4-8 show similar distorted pentagonal pyramidal geometries at the bismuth centre with a thiolate sulfur atom in the axial site, whereas 8 shows second structural arrangement with a distorted trigonal bipyramidal geometry at bismuth. The cation of 9 shows two NNS-bonded ligands and a distorted octahedral geometry at bismuth. Two-dimensional NMR studies of 4-8 show geminal 1H coupling in-SCH2CH2N-groups and suggests strong dative Bi-N intramolecular interactions. Bi(NO3)3·5H2O and BiCl3 show high activity toward the esterification of stearic acid, Bi(NO3)3·5H2O, and 4-7 and 9 show high activity toward the transesterification of methyl stearate in butanol, and 7 shows moderate activity as a catalyst for the transesterification of glyceryl trioctanoate in methanol.
- Briand, Glen G.,Decken, Andreas,Shannon, Whitney E.M.M.,Trevors, Eric E.
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p. 561 - 569
(2018/06/07)
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- Synthesis, characterization and reactivity of (dithiolato)indium complexes
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We have synthesized indium complexes incorporating tetradentate dithiolate ligands. The 1:1 reaction of InX3 (X?=?OAc, NO3) and the corresponding dithiol or dithiolate yielded the compounds [(SOOS)In(py)(NO3)] (1), [(SNNS)In(OAc)] (2), [In(μ-SNNS)2(μ-OMe)In][NO3] (3), [(SNNSPr)In(OAc)] (4), [(NNS2)In(OAc)] (5) and [(NNS2)In(NO3)] (6) [H2(SOOS)?=?2,2′-(ethylenedioxy)diethanethiol; H2(SNNS)?=?N,N′-dimethyl-N,N′-bis(2-mercaptoethyl)ethylenediamine; H2(SNNSPr)?=?N,N′-diethyl-N,N′-bis(2-mercaptoethyl)propanediamine; H2(NNS2)?=?N,N-diethyl-N′,N′-bis(2-mercaptoethyl)ethanediamine]. The solid-state structures of 1, 2 and 4–6 are mononuclear and show a tetradentate SOOS/SNNS/NNS2 ligand and a distorted octahedral (1) or trigonal bipyramidal (2, 4–6) coordination geometry at indium. Compound 3 is dinuclear, with the indium centres bridged by a -OMe oxygen atom and a thiolate sulfur atom of chelating tetradentate ligands, respectively. InX3 (X?=?Cl, NO3) were found to be useful Lewis acid catalysts for the aldol reaction of benzaldehyde and 1-(trimethylsiloxy)cyclohexene under ambient conditions, while compounds 1–6 show moderate activity as catalysts for the esterification of stearic acid and transesterification of methyl stearate and glyceryl trioctanoate.
- Anderson, Timothy S.,Briand, Glen G.,Brüning, Ralf,Decken, Andreas,Margeson, Matthew J.,Pickard, Heidi M.,Trevors, Eric E.
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p. 101 - 108
(2017/07/24)
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- A novel poly(p-styrenesulfonic acid) grafted carbon nanotube/graphene oxide architecture with enhanced catalytic performance for the synthesis of benzoate esters and fatty acid alkyl esters
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Considering the issue of low yield in the synthesis of benzoate esters and fatty acid alkyl esters, designing a high catalytic activity composite catalyst is very significant and attractive. In this study, the rational design strategy was used to develop a novel poly(p-styrenesulfonate acid, namely PSSF) grafted multi-walled carbon nanotube composite with graphene oxide nanomaterial (PSSF-mCNTs-GO) using a simple two-step method. FT-IR and Raman spectroscopy, XRD, SEM, TEM, and NH3-TPD were used to characterize the inorganic-organic hybrid material. In particular, the addition of GO remarkably enhanced its catalytic performance in the production of fatty acid alkyl esters (92.16%) and benzoate esters (90.27%), in which the conversion was more than doubled as a result of its strong π-π interaction with the substrate. In addition, PSSF-mCNTs-GO can be separated from the substrate conveniently and still maintained a relatively high catalytic activity even after 6 times recycling, which indicates its rather good reusability. This novel catalyst is promising in the synthesis of biodiesel and benzoate esters.
- Bian, Gang,Jiang, Pingping,Zhang, Weijie,Jiang, Kelei,Hu, Ling,Jian, Zhang,Shen, Yirui,Zhang, Pingbo
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p. 90757 - 90765
(2015/11/16)
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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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- Esterification of free fatty acids (Biodiesel) using nano sulfated-titania as catalyst in solvent-free conditions
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Nano sulfated titania was tested as catalyst for esterification of free fatty acids, specially methanolic and ethanolic esterification of stearic acid (biodiesels). Factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents on ester conversion. This nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. This prepared sulfated titania showed high catalytic activity in direct esterification of fatty acids as well as benzoic acids with various alcohols and phenols under solvent-free conditions. This method is of great value because of its environmentally benign character, easy handling, high yields, convenient operation, and green. FT-IR studies are shown that the catalyst can be reused for acylation without loss of catalytic activity.
- Hosseini-Sarvari, Mona,Sodagar, Esmat
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p. 229 - 238
(2013/05/09)
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- Specific enzyme-catalyzed hydrolysis and synthesis in aqueous and organic medium using biocatalysts with lipase activity from Aspergillus niger MYA 135
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In the present study, the specific hydrolytic activity of three biocatalysts such as the constitutive mycelium-bound lipase, the induced mycelium-bound lipase and the lyophilized induced supernatant from A. niger MYA 135 was evaluated in both aqueous and organic media.A direct correlation between activity in water and n-hexane was not observed for the same hydrolytic reaction. The n-hexane/water activity ratio (RO/A) was applied to characterize the activity in organic medium. The three biocatalysts showed RO/A values higher than 1 for hydrolysis of long-chain fatty acid esters, demonstrating a higher specific hydrolytic activity in organic solvent than in water. A different behavior was observed during hydrolysis of middle-chain fatty acid esters, which was higher in aqueous medium (R O/Adw) observed in a reaction mixture containing propanol and p-nitrophenyl laurate. Finally, both p-nitrophenyl caprate (C10) and p-nitrophenyl laurate (C12) were preferentially methanolized by the lyophilized induced supernatant, being this lipase activity the most specific biocatalyst preparation under transesterification conditions. A selectivity-based analysis of each lipase preparation toward transesterification or hydrolysis in organic medium was evaluated as well. Springer Science+Business Media, LLC 2012.
- Romero, Cintia M.,Pera, Licia M.,Loto, Flavia,Baigori, Mario D.
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p. 1361 - 1368
(2013/01/15)
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- A novel Bronsted acidic heteropolyanion-based polymeric hybrid catalyst for esterification
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A new SO3H-functionalized HPA-based acidic polymeric hybrid was prepared by coupling task-specifically designed SO3H-functionalized polymeric ionic liquid with Keggin-structured heteropolyanion, and characterized by 1H NMR, FT-IR, TG, XRD, BET, Hammett indicator, melting point, and elemental analysis. Its catalytic performance for esterification of alcohols with carboxylic acids was studied under solvent-free conditions. The results demonstrate that the polymeric hybrid is a highly active and selective solid catalyst for various esterifications, and can be easily recovered and steadily reused.
- Leng, Yan,Jiang, Pingping,Wang, Jun
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experimental part
p. 41 - 44
(2012/10/07)
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- Stearic acid gel derived MgTiO3 nanoparticles: A low temperature intermediate phase of Mg2TiO4
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Stearic acid gel is employed to study the phase evolution of MgTiO3 nanoparticles by thermal gravimetric analysis, X-ray diffraction, and Fourier transform infrared. During the preparation of stearic acid gel, tetrabutyl titanate easily absorbed moisture to hydrolyze into Ti(OH)4 firstly, and then reacts with stearic acid and magnesium stearate to form magnesium-titanium oxide network polymer gel, meanwhile n-butanol is generated. When stearic acid gel is calcined in air, a series of oxidation and combustion reactions occur, meanwhile apparent heat is given off. The results show that a metastable intermediate phase Mg2TiO4 is generated at 450 °C and nearly disappeared at 550 °C. Simultaneously, a new solid phase of MgTiO3 appears. The metastable intermediate phase Mg2TiO4 is successfully identified in the current work.
- Li, Dandan,Wang, Liqiu,Xue, Dongfeng
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experimental part
p. 564 - 569
(2010/06/12)
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- Novel H3PW12O40: Catalysed esterification reactions of fatty acids at room temperature for biodiesel production
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The catalytic activity of Bronsted acids on fatty acid (FA) esterification at room temperature has been investigated. Noticeably, the H 3PW12O40 heteropolyacid (HPW) showed a very high activity than other catalysts herein evaluated, i.e. p-toluene sulfonic acid and sulfuric acid. High yields in ethyl esters (ca. 90%) were reached after a 4 h reaction at 25 °C on a HPW catalysed reactions. Despite the fact that HPW catalyst was used in a homogeneous phase, it could be efficiently recovered and reused through out a simple recycling protocol, without any activity loss. The effects of alcohol and the FA nature on yield reaction were also investigated.
- De Godoi Silva, Vinicius Wilker,Laier, Leticia Oliveira,Silva, Marcio Jose Da
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experimental part
p. 207 - 211
(2010/08/03)
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- Esterifications of carboxylic acids and alcohols catalyzed by Al 2(SO4)3 · 18H2O under solvent-free condition
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Esterifications of equimolar mixture of carboxylic acids and alcohols can be effectively catalyzed by Al2(SO4)3 · 18H2O under solvent-free condition. The esterification catalyzed by Al2(SO4)3 · 18H2O is a promising green method thanks to no need of organic solvent, no pollution, no causticity and ease to handle after reaction. This catalyst is of a low toxicity (usually it is used as purifying agent for drinking water), low-cost compound and is easily separated from the reaction mixture by simple filtration. Moreover, the catalyst can be recycled for the further esterification and the conversion does not evidently decrease.
- Gang, Li,Wenhui, Pang
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experimental part
p. 559 - 565
(2011/01/07)
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- Transesterification of various methyl esters under mild conditions catalyzed by tetranuclear zinc cluster
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(Chemical Equation Presented) A new catalytic transesterification promoted by a tetranuclear zinc cluster was developed. The mild reaction conditions enabled the reactions of various functionalized substrates to proceed in good to high yield. A large-scale reaction under solvent-free conditions proceeded with a low E-factor value (0.66), indicating the high environmental and economical advantage of the present catalysis.
- Iwasaki, Takanori,Maegawa, Yusuke,Hayashi, Yukiko,Ohshima, Takashi,Mashima, Kazushi
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p. 5147 - 5150
(2008/09/21)
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- Process for producing fatty acid alkyl ester composition
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An object of the present invention is to solve a problem of separation and recovery of catalysts present in an alkali metal catalytic method currently often used, a problem of excess consumption of a catalyst by a free fatty acid in a raw material, and other problems, and to solve a problem of the presence of a large excess amount of alcohol in a conventional supercritical methanol method, and to provide a method for producing a fatty acid alkyl ester composition in a reaction system containing water and free fatty acid present. The present invention has attained the above-mentioned object by provided a method for producing a fatty acid alkyl ester composition using fats and oils containing a fatty acid glyceride and/or fatty acid, wherein alcohol and/or water is allowed to co-exist with the above-mentioned fats and oils and the reaction is conducted under conditions of a temperature of 100° C. to 370° C. and a pressure of 1 to 100 MPa.
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Page/Page column 7-8
(2008/06/13)
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- Alumina sulfuric acid as a novel heterogeneous system for esterification of carboxylic acids in solvent free conditions
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Neat chlorosulfonic acid reacts with alumina to give alumina sulfuric acid (ASA) in which sulfuric acid is immobilised on the surface of alumina via a covalent bond. Carboxylic acids can be readily converted to their corresponding esters with a combination of ASA and alcohols in solvent free conditions.
- Sharghi, Hashem,Sarvari, Mona Hosseini,Eskandari, Razieh
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p. 488 - 491
(2007/10/03)
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- An eco-friendly method for the synthesis of aryl and alkyl esters of carboxylic acids using acid activated Indian bentonite
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Esterification of various carboxylic acids with phenol and alcohols has been achieved using acid activated Indian bentonite (AAIB) as catalyst. The catalyst is versatile, and the reaction is found to work well for primary, secondary and tertiary alcohols. The yields are very good under specific reaction conditions.
- Vijayakumar,Iyengar, Pushpa,Nagendrappa, Gopalpur,Prakash, B. S. Jai
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p. 922 - 925
(2007/10/03)
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- Silica Chloride: A Versatile Heterogeneous Catalyst for Esterification and Transesterification
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Silica chloride has been found to be an efficient catalyst for esterification of carboxylic acids (aliphatic, aromatic and conjugated) with alcohols (primary, secondary and tertiary) as well as for transesterification of esters (by both alcoholysis and acidolysis).
- Srinivas,Mahender,Das, Biswanath
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p. 2479 - 2482
(2007/10/03)
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- A mild and efficient method for esterification and transesterification catalyzed by iodine
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Iodine, was found to be a practical and useful Lewis acid catalyst for the esterification of carboxylic acids with alcohols. The high catalytic activity of iodine can be used for the transesterification of esters by different alcohols including tertiary alcohols and sterically hindered primary and secondary alcohols. The method presented is especially effective for simultaneous esterification and transesterification reactions.
- Ramalinga,Vijayalakshmi,Kaimal
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p. 879 - 882
(2007/10/03)
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- A CONVENIENT METHOD FOR ENZYMATIC BENZYL-ALKYL TRANSESTERIFICATION UNDER MILD NEUTRAL CONDITIONS
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Lipases from Candida cylindracea and from Pseudomonas fluorescens efficiently catalyse the benzyl to alkyl transesterification in organic solvents under mild conditions in nearly quantitative yields.
- Gutman, Arie L.,Shkolnik, Eleonora,Shapira, Michal
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p. 8775 - 8780
(2007/10/02)
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