105-46-4Relevant articles and documents
A green protocol for chemoselective O-acylation in the presence of zinc oxide as a heterogeneous, reusable and eco-friendly catalyst
Tamaddon, Fatemeh,Amrollahi, Mohammad Ali,Sharafat, Leily
, p. 7841 - 7844 (2005)
The solvent-free acylation of alcohols and phenols with acyl chlorides using ZnO as a catalyst is described. The remarkable selectivity under mild and neutral conditions, and recyclability of the catalyst, are advantages.
Continuous flow Fischer esterifications harnessing vibrational-coupled thin film fluidics
Britton, Joshua,Dalziel, Stuart B.,Raston, Colin L.
, p. 1655 - 1660 (2015)
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
Enantiomeric two-fold interpenetrated 3D zinc(ii) coordination networks as a catalytic platform: significant difference between water within the cage and trace water in transesterification
Choi, Eunkyung,Ryu, Minjoo,Lee, Haeri,Jung, Ok-Sang
, p. 4595 - 4601 (2017)
Self-assembly of Zn(ClO4)2 with 1,1,2,2-tetramethyl-1,2-di(pyridin-3-yl)disilane (L) as a bidentate N-donor gives rise to 3D coordination networks, [Zn(μ-OH)(L)]3(ClO4)3·5H2O (1·5H2O), of unique, 103-a srs net topology. An important feature is that two enantiomeric 3D frameworks, 41- and 43-[Zn(μ-OH)(L)]3(ClO4)3·5H2O, are interpenetrated to form a racemic two-fold 3D network with cages occupied by two water molecules. Another structural characteristic is a C3-symmetric planar Zn3(μ-OH)3 6-membered ring with tetrahedral Zn(ii) ions. The steric hindrance of substrates and trace water effects on transesterification catalysis using the network have been scrutinized. The coordination network acts as a remarkable heterogeneous transesterification catalytic system that shows both the significant steric effects of substrate alcohols and momentous water effects. The substrate activity is in the order ethanol > n-propanol > n-butanol > iso-propanol > 2-butanol > tert-butanol. For the reaction system, solvate water molecules within the cages of the interpenetrated 3D frameworks do not decrease the transesterification activity, whereas the trace water molecules in the substrate alcohols act as obvious obstacles to the reaction.
(S)-2-pentyl (R)-3-hydroxyhexanoate, a banana volatile and its olfactory recognition by the common fruit fly, Drosophila melanogaster
Mowat, Jeffrey,Gries, Regine,Khaskin, Grigori,Gries, Gerhard,Britton, Robert
, p. 772 - 776 (2009)
The volatile organic compounds emitted from ripening bananas that elicit an antennal response from the common fruit fly, Drosophila melanogaster, were analyzed by a combination of gas chromatographic-electroantennographic detection, mass spectrometry, and 1H NMR spectroscopy. These analyses revealed that the headspace of ripening bananas contains a number of EAD-active components including the new ester (S)-2-pentyl (R)-3-hydroxyhexanoate, the structural assignment of which was confirmed by chemical synthesis.
Baeyer-Villiger oxidation of ketones with hydrogen peroxide catalyzed by Sn-palygorskite
Lei, Ziqiang,Zhang, Qinghua,Luo, Jujie,He, Xiaoyan
, p. 3505 - 3508 (2005)
Palygorskite-supported Sn complexes were prepared by a simple procedure. Cyclic ketones and acyclic ketones were oxidized by hydrogen peroxide in a reaction catalyzed by palygorskite-supported Sn complexes, affording corresponding lactones or esters with selectivity for the product of 90-100%. The catalysts can be recycled for several times without significant decline in catalytic activity.
A method for the acetylation of alcohols catalyzed by heteropolyoxometallates
Alizadeh, Mohammad H.,Kermani, Toktam,Tayebee, Reza
, p. 165 - 170 (2007)
Esterifications of acetic acid with some linear, secondary, tertiary, and benzylic alcohols mediated by catalytic amounts of Keggin, Wells-Dawson, and Preyssler type heteropolyacids were carried out under reflux at mild reaction conditions with good to excellent yields. Among the examined catalysts, H 3PW12O40 and H14NaP 5W30O110 revealed better results than other heteropolyacids. This work was performed with the aim of simplifying the esterification process by omitting any solvents and mineral acid catalysts. Easy work-up, low cost, and acidic waste reduction, which are all important features from the environmental and economical points of view, are distinct aspects of this protocol. Heteropolyacid catalysts could be separated after a simple work-up and reused for several times.
Vanadyl sulfate (VOSO4.3H2O). An efficient catalyst for acylation of alcohols and phenols under solvent free condition
Oskooie, Hossein A.,Baghernezhad, Bita,Heravi, Majid M.,Beheshtiha
, p. 713 - 715 (2008)
Alcohols and phenols were efficiently acylated with acetic anhydride in the presence of vanadyl sulfate (VOSO4.3H2O) at room temperature in high yields.
Acid-catalyzed oxidation of levulinate derivatives to succinates under mild conditions
Wang, Yuran,Vogelgsang, Ferdinand,Román-Leshkov, Yuriy
, p. 916 - 920 (2015)
Levulinate derivatives are an attractive platform for the production of renewable chemicals. Here we report on the oxidation of methyl levulinate into dimethyl succinate with peroxides under mild conditions using Br?nsted and Lewis acid catalysts. Selectivities to succinate and acetate derivatives of approximately 60 and 40 %, respectively, were obtained with strong Br?nsted acids in methanol. Although the molecular structure (i.e., carbon-chain length and branching around the C=O group) and the oxidant type affect the product distribution, solvent choice has the strongest impact on changing the location of oxygen insertion into the carbon backbone. Specifically, switching the solvent from methanol to heptane resulted in a decrease in the succinate/acetate ratio from 1.6 to 0.3. In contrast to Br?nsted acids, we demonstrate that the nature of the metal cation is responsible for changing the reaction selectivity of water-tolerant Lewis acidic triflate salts.
Synthesis, characterization, and crystal structure of several novel acidic ionic liquids based on the corresponding 1-alkylbenzimidazole with tetrafluoroboric acid
Chen, Shuan-Hu,Yang, Fen-Rong,Wang, Ming-Tian,Wang, Na-Ni
, p. 1391 - 1396 (2010)
A series of acidic task-specific ionic liquids 1-R2-2-R 1benzimidazolium tetrafluoroborate (R1 = Me, R2 = Me, Et, Pr-n, Bu-n, Pen-n) were prepared by simple acid-base neutralization of the corresponding 1-alkylbenzimidazole and tetrafluoroboric acid. The compounds were characterized by FTIR spectra, elemental analysis, 1HNMR spectra and thermogravimetric analysis. These new ionic liquids are nonvolatile, and have potential use as alternatives to conventional organic solvents due to their solubility and thermal stability. These novel tetrafluoroborate salts show good catalytic activity to esterification of carboxylic acids with alcohols under mild reaction conditions, which could maintain good catalytic performance after recycling at least six times. Furthermore, a crystal of one compound, [H-bmBim]BF4, was prepared, with the crystal structure determined by X-ray diffraction analysis. The molecular structure is formed by weak π-π interactions and intermolecular hydrogen bonds between the benzimidazole rings, yielding a three-dimensional net-like supramolecule.
Carboxylic acids to butyl esters over dealuminated-realuminated beta zeolites for removing organic acids from bio-oils
Li, Jianhua,Liu, Haiyan,An, Tingting,Yue, Yuanyuan,Bao, Xiaojun
, p. 33714 - 33725 (2017)
This article describes a novel method to dealuminate and realuminate H-beta zeolites as catalysts for removing organic acids from bio-oils via their esterification reactions with alcohols. Modified H-beta zeolites were prepared by leaching with solutions of oxalic acid, dl-malic acid, and dl-tartaric acid that have different numbers of hydroxyl groups. The results showed that, while all three organic acids can dealuminate the parent H-beta zeolite, with Al(vi)a atoms and Al(iv)c ones being preferentially removed, they show quite different realumination abilities, with tartaric acid with two hydroxyl groups having the highest realumination ability. The concomitance of dealumination and realumination and their dependence on the hydroxyl group numbers of the organic acids provide the possibility of finely tuning the Al and acidity distributions of the resulting zeolites. Among the three acid treated H-beta zeolites, the one obtained from malic acid leaching exhibited the best performance in catalyzing the esterification reaction between acetic acid and sec-butyl alcohol, attributed to its suitable quantity and density of medium and strong Br?nsted acid sites and enhanced aluminum gradient. The catalytic results obtained in a fixed-bed microreactor revealed that the malic acid leached H-beta exhibited dramatically enhanced catalytic performance compared to the commercial ion-exchange resin Amberlyst 15, demonstrating great potential for industrial application.
