109-21-7Relevant articles and documents
Highly efficient self-esterification of aliphatic alcohols using supported gold nanoparticles under mild conditions
Wang, Fan,Xiao, Qi,Han, Pengfei,Sarina, Sarina,Zhu, Huaiyong
, p. 61 - 69 (2016)
Long aliphatic esters were prepared by the one-step catalytic self-esterification of primary alcohols using molecular oxygen as a green oxidant and supported gold nanoparticles (Au NPs) as catalyst. This heterogeneous catalyst achieved high activity and selectivity in a wide range of less reactive straight-chain alcohols (C4-C12) at atmospheric pressure O2 and near ambient temperature (45?°C). Under optimised conditions, the catalyst with Au loading of 3?wt% achieved the highest catalytic activity and selectivity. The AuNP catalysts are efficient and readily recyclable. The finding of this study may inspire further studies on new efficient catalytic systems for a wide range of organic syntheses using supported AuNP catalysts.
Lipase-catalyzed reactions in ionic liquids.
Madeira Lau,van Rantwijk,Seddon,Sheldon
, p. 4189 - 4191 (2000)
[reaction:see text] Candida antarctica lipase was shown to catalyze alcoholysis, ammoniolysis, and perhydrolysis reactions using the ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate or hexafluorophosphate as reaction media. Reaction rates were generally comparable with, or better than, those observed in organic media.
A quantitative comparison between conventional and bio-derived solvents from citrus waste in esterification and amidation kinetic studies
Clark, James H.,MacQuarrie, Duncan J.,Sherwood, James
, p. 90 - 93 (2012)
(R)-(+)-Limonene, which is available in large quantities from citrus waste, and its close derivative p-cymene are shown herein to be viable yet sustainable solvents for amidation and esterification reactions.
Use of salt hydrates to buffer optimal water level during lipase catalysed in synthesis in organic media: A practical procedure for organic chemists
Kvittingen, Lise,Sjursnes, Birte,Anthonsen, Thorleif,Halling, Peter
, p. 2793 - 2802 (1992)
Enzyme catalyzed reactions in mainly organic media depend very much on the amount of water in the system. We have shown that addition of appropriate solid salt hydrates to the reaction mixture is a simple and convenient method to obtain optimal water level conditions throughout the reaction. As a model reaction the esterification of butanoic acid with butanol catalysed by lipase from Candida rugosa was chosen. Variations in the amount of enzyme, in the solvent and in the concentration of reactants were made.
Genome Mining of Oxidation Modules in trans-Acyltransferase Polyketide Synthases Reveals a Culturable Source for Lobatamides
Ueoka, Reiko,Meoded, Roy A.,Gran-Scheuch, Alejandro,Bhushan, Agneya,Fraaije, Marco W.,Piel, J?rn
, p. 7761 - 7765 (2020)
Bacterial trans-acyltransferase polyketide synthases (trans-AT PKSs) are multimodular megaenzymes that biosynthesize many bioactive natural products. They contain a remarkable range of domains and module types that introduce different substituents into growing polyketide chains. As one such modification, we recently reported Baeyer–Villiger-type oxygen insertion into nascent polyketide backbones, thereby generating malonyl thioester intermediates. In this work, genome mining focusing on architecturally diverse oxidation modules in trans-AT PKSs led us to the culturable plant symbiont Gynuella sunshinyii, which harbors two distinct modules in one orphan PKS. The PKS product was revealed to be lobatamide A, a potent cytotoxin previously only known from a marine tunicate. Biochemical studies show that one module generates glycolyl thioester intermediates, while the other is proposed to be involved in oxime formation. The data suggest varied roles of oxygenation modules in the biosynthesis of polyketide scaffolds and support the importance of trans-AT PKSs in the specialized metabolism of symbiotic bacteria.
Dunbar
, p. 244 (1938)
Saegusa et al.
, p. 1960,1961 (1967)
Crystal structure, thermal decomposition mechanism and catalytic performance of hexaaquaaluminum methanesulfonate
Wang, Rui,Li, Rongrong,Jiang, Heng,Gong, Hong,Bi, Yanfeng
, p. 1327 - 1338 (2017)
Hexaaquaaluminum methanesulfonate crystals, [Al(H2O)6][CH3SO3]3 were synthesized by a hydrothermal reaction of Al(OH)3 with methanesulfonic acid. Single-crystal diffraction determination revealed that Al3+ was coordinated by six water molecules in octahedral geometry, while the CH3SO3 – anion connected with Al3+ through coordinated water molecules by hydrogen bonds. The six-coordinate environment of Al was also determined by 27Al MAS NMR measurement. Thermogravimetric analysis and Fourier transform infrared spectroscopy showed that the decomposition intermediate at 265–365?°C was Al2(μ-OH)(CH3SO3)5 and the final product was amorphous Al2O3 residue with about 0.8 wt% SO3 at 520–800?°C. A pure phase of [Al(H2O)6][CH3SO3]3 was confirmed by powder X-ray diffraction analysis. Esterification of n-butyric acid with n-butanol and ketalization of cyclohexanone with glycol catalyzed by [Al(H2O)6][CH3SO3]3 and Al2(μ-OH)(CH3SO3)5, respectively, proceeded in 100% yield by continuously removing the produced water. In the case of tetrahydropyranylation of n-butanol at room temperature in dichloromethane, the catalytic activity of [Al(H2O)6][CH3SO3]3 was much lower than that of Al2(μ-OH)(CH3SO3)5. Furthermore, both [Al(H2O)6][CH3SO3]3 precursor and Al2(μ-OH)(CH3SO3)5 catalysts could be recycled.
Homoleptic lanthanide amides as homogeneous catalyst for the Tishchenko reaction
Berberich, Helga,Roesky, Peter W.
, p. 1569 - 1571 (1998)
Known for about 25 years, the bis(trimethylsilyl)amides of Group 3 metals and lanthanides, M[N(SiMe3)2]3, are well suited as highly efficient catalysts for the dimerization of aldehydes [Tishchenko reaction, Eq. (1)].
Self-Condensation of n-Butyraldehyde over Solid Base Catalysts
Tsuji, Hideto,Yagi, Fuyuki,Hattori, Hideshi,Kita, Hideaki
, p. 759 - 770 (1994)
The catalytic properties of various solid bases for self-condensation of n-butyraldehyde in liquid phase were studied to elucidation the factors governing the activity and selectivity.For alkaline earth oxide catalysts and γ-alumina catalyst, aldol condensation ocurred, followed by Tishchenko-type cross-esterification of n-butyraldehyde with the dimer produced by the aldol condensation to form trimeric glycol ester.Alkali ion-modified alumina catalysts exhibited a high selectivity for the aldol condensation dimer, the trimeric glycol ester being formed little.Both basic and acidic sites on the surfaces of the alkaline earth oxides and γ-alumina were assumed to contribute to Tishchenko-type cross-esterification.The suppression of Tischenko-type cross-esterification.The suppression of Tischenko-type cross-esterification for alkali ion-modified alumina catalysts is due to the absence of acidic sites on the surfaces.The catalytic performances of alumina-supported magnesium oxide exhibited lower activity but higher selectivity to trimeric glycol ester than MgO.This catalytic feature was caused by the lower basicity and higher acidity on the surface of alumina-supported magnesium oxide as compared with MgO.The activity of alkali ion-exchanged zeolites was lowest among the catalysts examined in this study.The modification of zeolites with excess alkali ions improved the activity.
Facile Ester Synthesis on Ag-Modified Nanoporous Au: Oxidative Coupling of Ethanol and 1-Butanol Under UHV Conditions
Stowers, Kara J.,Madix, Robert J.,Biener, Monika M.,Biener, Juergen,Friend, Cynthia M.
, p. 1217 - 1223 (2015)
A dilute Ag alloy of nanoporous Au (npAu) has been shown to self-couple methanol with 100 % selectivity and high conversion under catalytic flow conditions. However, because prior studies in flow reactors showed difficulty in self-coupling ethanol and 1-butanol over npAu in flow reactors, the inherent capability on npAu for self-coupling of ethanol and 1-butanol was examined under ultrahigh vacuum conditions on identical npAu catalysts. This study shows that the oxygen-covered Ag-modified npAu does efficiently effect the self-coupling of ethanol and 1-butanol under UHV conditions. The coupling is initiated by adsorbed atomic oxygen formed from O2 dissociation via a chemisorbed molecular state. The amount of ester formed increases with the degree of oxygen precoverage at the expense of aldehyde production. Repeated annealing of the catalyst above 550 K for temperature programmed reaction changes the ligament and pore sizes, affecting the product distribution, but high reactivity is sustained over many heating cycles. (Figure Presented).
SELENOESTERS IN ORGANIC SYNTHESIS. 1. CONVERSION OF MIXED CARBOXYLIC ACID ESTERS TO SELENOESTERS
Sviridov, A. F.,Ermolenko, M. S.,Yashunskii, D. V.,Kochetkov, N. K.
, p. 1509 - 1513 (1985)
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Organoaluminum cations for carbonyl activation
Kannan, Ramkumar,Chambenahalli, Raju,Kumar, Sandeep,Krishna, Athul,Andrews, Alex P.,Jemmis, Eluvathingal D.,Venugopal, Ajay
, p. 14629 - 14632 (2019)
In search of stable, yet reactive aluminum Lewis acids, we have isolated an organoaluminum cation, [(Me2NC6H4)2Al(C4H8O)2]+, coordinated with two labile tetrahydrofuran ligands. Its catalytic performance in aldehyde dimerization reveals turn-over frequencies reaching up to 6000 h-1, exceeding that of the reported main group catalysts. The cation is further demonstrated to catalyze hydroelementation of ketones. Mechanistic investigations reveal that aldehyde dimerization and ketone hydrosilylation occur through carbonyl activation.
Deuterium kinetic isotopic study for hydrogenolysis of ethyl butyrate
Gnanamani, Muthu Kumaran,Jacobs, Gary,Keogh, Robert A.,Davis, Burtron H.
, p. 27 - 35 (2011)
The hydrogenation of ethyl butyrate, n-butyric acid, and n-butyraldehyde to their corresponding alcohol(s) has been studied over a γ-Al 2O3-supported cobalt catalyst using a high-pressure fixed-bed reactor in the temperature range of 473-493 K. H2-D 2-H2 switching experiments show that ethyl butyrate and n-butyric acid follow an inverse kinetic isotope effect (KIE) (i.e. r H/rD = 0.50-0.54), whereas n-butyraldehyde did not display any KIE (i.e. rH/rD = 0.98). DRIFTS experiments were performed over the support and catalyst to monitor the surface species formed during the adsorption of ethyl butyrate and n-butyric acid at atmospheric pressure and the desired temperature. Butanoate and butanoyl species are the stable surface intermediates formed during hydrogenation of ethyl butyrate. Hydrogenation of butanoate to a partially hydrogenated intermediate is likely involved in the rate-determining step of ethyl butyrate and butyric acid hydrogenation.
Ruthenium PNN(O) Complexes: Cooperative Reactivity and Application as Catalysts for Acceptorless Dehydrogenative Coupling Reactions
De Boer, Sandra Y.,Korstanje, Ties J.,La Rooij, Stefan R.,Kox, Rogier,Reek, Joost N. H.,Van Der Vlugt, Jarl Ivar
, p. 1541 - 1549 (2017)
The novel tridentate PNNOH pincer ligand LH features a reactive 2-hydroxypyridine functionality as well as a bipyridyl-methylphosphine skeleton for meridional coordination. This proton-responsive ligand coordinates in a straightforward manner to RuCl(CO)(H)(PPh3)3 to generate complex 1. The methoxy-protected analogue LMe was also coordinated to Ru(II) for comparison. Both species have been crystallographically characterized. Site-selective deprotonation of the 2-hydroxypyridine functionality to give 1′ was achieved using both mild (DBU) and strong bases (KOtBu and KHMDS), with no sign of involvement of the phosphinomethyl side arm that was previously established as the reactive fragment. Complex 1′ is catalytically active in the dehydrogenation of formic acid to generate CO-free hydrogen in three consecutive runs as well as for the dehydrogenative coupling of alcohols, giving high conversions to different esters and outperforming structurally related PNN ligands lacking the NOH fragment. DFT calculations suggest more favorable release of H2 through reversible reactivity of the hydroxypyridine functionality relative to the phosphinomethyl side arm.
Acceptorless dehydrogenative coupling of alcohols catalysed by ruthenium PNP complexes: Influence of catalyst structure and of hydrogen mass transfer
Zhang, Lei,Raffa, Guillaume,Nguyen, Duc Hanh,Swesi, Youssef,Corbel-Demailly, Louis,Capet, Frédéric,Trivelli, Xavier,Desset, Simon,Paul, Sébastien,Paul, Jean-Fran?ois,Fongarland, Pascal,Dumeignil, Franck,Gauvin, Régis M.
, p. 331 - 343 (2016)
Base-free catalytic acceptorless dehydrogenative homo-coupling of alcohols to esters under neat conditions was investigated using a combined organometallic synthesis and kinetic modelling approach. The considered bifunctional ruthenium aliphatic PNP complexes are very active, affording TONs up to 15,000. Notably, gas mass transfer issues were identified, which allowed us to rationalize previous observations. Indeed, the reaction kinetics are limited by the rate of transfer from the liquid phase to the gas phase of the hydrogen co-produced in the reaction. Mechanistically speaking, this relates to the interconverting couple amido monohydride/amino bishydride. Overcoming this by switching into the chemical regime leads to an initial turnover frequency increase from about 2000 up to 6100?h?1. This has a significant impact when considering assessment of novel or reported catalytic systems in this type of reaction, as overlooking of these engineering aspects can be misleading.
Tuning acidity in zirconium-based metal organic frameworks catalysts for enhanced production of butyl butyrate
Jrad, Asmaa,Abu Tarboush, Belal J.,Hmadeh, Mohamad,Ahmad, Mohammad
, p. 31 - 41 (2019)
Three isostructural zirconium-based metal organic frameworks (MOFs), UiO-66, UiO-66(COOH)2 and UiO-66(NH2) were synthesized, fully characterized and efficiently used as active and recyclable catalysts for the esterification reaction of butyric acid to produce a green fuel additive, butyl butyrate. The catalytic activities of the used structures were comparable, and mostly better, than other heterogeneous acid catalyst reported in the literature. Moreover, 90% conversion was achieved by employing the most acidic member, UiO-66(COOH)2, which is close to the 95% conversion obtained by the conventional liquid catalyst H2SO4. Using the synthesized MOFs, large variations in the conversion to butyl butyrate were obtained which was the base of a detailed investigation on the origin of their catalytic activities. The analysis of the TGA results helped estimate the number of structural defects in each studied MOF. Interestingly, it was concluded that, for the MOFs with different organic linkers, the catalytic activity was not directly related to the number of defects. Further analysis was done to investigate the alternative parameters that could be behind this difference in catalytic activity, and the parameters included but were not limited to the surface area of the MOFs, their particle size, the linkers’ active sites, and their accessibility through effective mass transfer. Although a combination of these factors were found to contribute to the superior catalytic activity of UiO-66(COOH)2, however, its exceptional conversion was mainly attributed to the effect of the additional active acid functional groups grafted onto its organic linker, along with its smaller particle size which allowed for better mass transfer and accessibility of the active site Furthermore, two kinetic models were successfully developed and used to determine the different kinetic parameters of the esterification reaction and to study their dependence on the different characteristics of the MOFs. With this knowledge, catalytic activity of MOFs can be engineered from a laboratory prototype and optimized by tuning the functional groups of the organic linkers to serve as effective catalysts for the production of fine chemicals such as biofuels.
An antimony(V) substituted Keggin heteropolyacid, H4PSbMo 11O40: Why is its catalytic activity in oxidation reactions so different from that of H4PVMo11O 40?
Goldberg, Hila,Kumar, Devesh,Sastry, G. Narahari,Leitus, Gregory,Neumann, Ronny
, p. 152 - 157 (2012)
An antimony(V) containing α-Keggin type acidic polyoxometalate, H4PSbMo11O40, was prepared by reacting NaMoO4, H3PO4 and Sb2O3 in the presence of aqua regia to appraise its reactivity compared to the well known vanadate analog, H4PVMo11O40. Characterization was by X-ray diffraction, MALDI-TOF MS, IR, UV-vis and 31P NMR spectroscopy. Catalytic redox reactions, such as oxidative dehydrogenation using O2 and N2O as terminal oxidants were studied and showed very different reactivity of H4PSbMo 11O40 versus H4PVMo11O40. It was found by DFT calculations that in contrast to analogous H 4PVMo11O40 where vanadium centered catalysis is observed, in H4PSbMo11O40 catalysis is molybdenum and not antimony centered.
Biocatalytic synthesis of new copolymers from 3-hydroxybutyric acid and a carbohydrate lactone
Kakasi-Zsurka, Sandor,Todea, Anamaria,But, Andrada,Paul, Cristina,Boeriu, Carmen G.,Davidescu, Corneliu,Nagy, Lajos,Kuki, Akos,Keki, Sandor,Peter, Francisc
, p. 22 - 28 (2011)
Lipase-catalyzed reaction of 3-hydroxybutyric acid with d-glucono-δ-lactone at 5:1 molar ratio and 80°C yielded a mixture of moderate molecular weight linear and cyclic oligomers. The most efficient biocatalyst, Candida antarctica B lipase (Novozyme 435), allowed the synthesis of new oligomeric compounds with ring-opened gluconolactone units included in the oligomeric chain, without previous derivatization of the sugar, or activation of the acid monomer. The reaction medium nature had an important influence on the product composition. Although the main copolymer amount was synthesized in tert-butanol/dimethylsulfoxide medium, the highest polymerization degrees, up to 9 for the copolymer, and 10 for the 3-hydroxybutyric acid homopolymer co-product, were achieved in solventless conditions.
Efficient dimeric esterification of alcohols with NBS in water using l-proline as catalyst
Liu, Xiuhong,Wu, Jun,Shang, Zhicai
, p. 75 - 83 (2012)
The L-proline-catalyzed oxidation of aliphatic primary alcohols with N-bromosuccimide (NBS) in water at room temperature to afford the corresponding dimeric esters in good to excellent yields was described. This pathway of dimeric esterification was proved to be very simple and environmentally friendly.
Buffer-mediated activation of Candida antarctica lipase B dissolved in hydroxyl-functionalized ionic liquids
Ou, Guangnan,Yang, Jing,He, Biyan,Yuan, Youzhu
, p. 66 - 70 (2011)
Ionic-liquid buffer having phosphate anion was synthesized for the development of buffered enzymatic ionic liquid systems. Both the conformation and transesterification activity of Candida antarctica lipase B (CALB) dissolved in the hydroxyl-functionalized ionic liquids were buffer dependent. Intrinsic fluorescence studies indicated that the CALB possessed a more compact conformation in the medium consisted of ionic liquid buffer having phosphate anion and hydroxyl-functionalized ionic liquids like 1-(1-hydroxyethyl)-3- methyl-imidazolium tetrafluoroborate and 1-(1-hydroxyethyl)-3-methyl-imidazolium nitrate. High activity and outstanding stability could be obtained with the CALB enzyme in the buffered ionic liquids for the transesterification.
One-step solvent-free aerobic oxidation of aliphatic alcohols to esters using a tandem Sc-Ru?MOF catalyst
Feng, Tingkai,Li, Conger,Li, Tao,Zhang, Songwei
, p. 1474 - 1480 (2022/03/08)
Esters are an important class of chemicals in industry. Traditionally, ester production is a multi-step process involving the use of corrosive acids or acid derivatives (e.g. acid chloride, anhydride, etc.). Therefore, the development of a green synthetic protocol is highly desirable. This work reports the development of a metal-organic framework (MOF) supported tandem catalyst that can achieve direct alcohol to ester conversion (DAEC) using oxygen as the sole oxidizing agent under strictly solvent-free conditions. By incorporating Ru nanoparticles (NPs) along with a homogeneous Lewis acid catalyst, scandium triflate, into the nanocavities of a Zr MOF, MOF-808, the compound catalyst, Sc-Ru?MOF-808, can achieve aliphatic alcohol conversion up to 92% with ester selectivity up to 91%. A mechanistic study reveals a unique “via acetal” pathway in which the alcohol is first oxidized on Ru NPs and rapidly converted to an acetal on Sc(iii) sites. Then, the acetal slowly decomposes to release an aldehyde in a controlled manner for subsequent oxidation and esterification to the ester product. To the best of our knowledge, this is the first example of DAEC of aliphatic alcohols under solvent-free conditions with high conversion and ester selectivity.
Dual utility of a single diphosphine-ruthenium complex: A precursor for new complexes and, a pre-catalyst for transfer-hydrogenation and Oppenauer oxidation
Mukherjee, Aparajita,Bhattacharya, Samaresh
, p. 15617 - 15631 (2021/05/19)
The diphosphine-ruthenium complex, [Ru(dppbz)(CO)2Cl2] (dppbz = 1,2-bis(diphenylphosphino)benzene), where the two carbonyls are mutually cis and the two chlorides are trans, has been found to serve as an efficient precursor for the synthesis of new complexes. In [Ru(dppbz)(CO)2Cl2] one of the two carbonyls undergoes facile displacement by neutral monodentate ligands (L) to afford complexes of the type [Ru(dppbz)(CO)(L)Cl2] (L = acetonitrile, 4-picoline and dimethyl sulfoxide). Both the carbonyls in [Ru(dppbz)(CO)2Cl2] are displaced on reaction with another equivalent of dppbz to afford [Ru(dppbz)2Cl2]. The two carbonyls and the two chlorides in [Ru(dppbz)(CO)2Cl2] could be displaced together by chelating mono-anionic bidentate ligands, viz. anions derived from 8-hydroxyquinoline (Hq) and 2-picolinic acid (Hpic) via loss of a proton, to afford the mixed-tris complexes [Ru(dppbz)(q)2] and [Ru(dppbz)(pic)2], respectively. The molecular structures of four selected complexes, viz. [Ru(dppbz)(CO)(dmso)Cl2], [Ru(dppbz)2Cl2], [Ru(dppbz)(q)2] and [Ru(dppbz)(pic)2], have been determined by X-ray crystallography. In dichloromethane solution, all the complexes show intense absorptions in the visible and ultraviolet regions. Cyclic voltammetry on the complexes shows redox responses within 0.71 to -1.24 V vs. SCE. [Ru(dppbz)(CO)2Cl2] has been found to serve as an excellent pre-catalyst for catalytic transfer-hydrogenation and Oppenauer oxidation.