106-70-7Relevant articles and documents
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Pitkaenen,M.T.,Korhonen,I.O.
, p. 529 (1981)
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Heterogeneous catalysis in an oscillatory baffled flow reactor
Eze, Valentine C.,Phan, Anh N.,Pirez, Cyril,Harvey, Adam P.,Lee, Adam F.,Wilson, Karen
, p. 2373 - 2379 (2013)
The first demonstration of heterogeneous catalysis within an oscillatory baffled flow reactor (OBR) is reported, exemplified by the solid acid catalysed esterification of organic acids, an important prototypical reaction for fine chemicals and biofuel synthesis. Suspension of a PrSO3H-SBA-15 catalyst powder is readily achieved within the OBR under an oscillatory flow, facilitating the continuous esterification of hexanoic acid. Excellent semi-quantitative agreement is obtained between OBR and conventional stirred batch reaction kinetics, demonstrating efficient mixing, and highlighting the potential of OBRs for continuous, heterogeneously catalysed liquid phase transformations. Kinetic analysis highlights acid chain length (i.e. steric factors) as a key predictor of activity. Continuous esterification offers improved ester yields compared with batch operation, due to the removal of water by-product from the catalyst, evidencing the versatility of the OBR for heterogeneous flow chemistry and potential role as a new clean catalytic technology. The Royal Society of Chemistry 2013.
The Co-promotion effect of Mo and Nd on the activity and stability of sulfated zirconia-based solid acids in esterification
Jiang, Kanghua,Tong, Dongmei,Tang, Jinqiang,Song, Ruili,Hu, Changwei
, p. 46 - 51 (2010)
SO42-/ZrO2-MoO3 (SZM), SO 42-/ZrO2-Nd2O3 (SZN) and SO42-/ZrO2-MoO3-Nd2O 3 (SZMN) solid acids catalysts were prepared and characterized by XRD, NH3-FTIR, NH3-TPD and TG-DTG. The activities and stabilities of the catalysts for the esterification of fatty acids were investigated. Experimental and characterization results show that the excellent activity and stability of SZMN are attributed to the firm combination of sulfur species with t-ZrO2. The co-addition of Mo and Nd increases the dispersion of t-ZrO2 and stabilizes the structure of small-crystallite t-ZrO2, which is favorable to increasing the acid sites amount, strengthening the acidity, and then enhancing the activity and stability of the catalyst.
Oxidative esterification of aldehydes with urea hydrogen peroxide catalyzed by aluminum chloride hexahydrate
Lee, Sin-Ae,Kim, Yoon Mi,Lee, Jong Chan
, p. 1368 - 1370 (2016)
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Acylated dolabellane-type diterpenes from Nigella sativa seeds with triglyceride metabolism-promoting activity in high glucose-pretreated HepG2 cells
Morikawa, Toshio,Ninomiya, Kiyofumi,Xu, Fengming,Okumura, Naomichi,Matsuda, Hisashi,Muraoka, Osamu,Hayakawa, Takao,Yoshikawa, Masayuki
, p. 198 - 204 (2013)
Two new acylated dolabellane-type diterpenes, nigellamines B3 (9) and D (10), were isolated from Nigella sativa (Ranunculaceae) seeds using column chromatography and preparative HPLC. Their structures were determined based on chemical and physi
Ultralow-Molecular-Weight Stimuli-Responsive and Multifunctional Supramolecular Gels Based on Monomers and Trimers of Hydrazides
Wu, Dehua,Song, Jintong,Qu, Lang,Zhou, Weilan,Wang, Lei,Zhou, Xiangge,Xiang, Haifeng
, p. 3370 - 3378 (2020)
The simpler, the better. A series of simple, neutral and ultralow-molecular-weight (MW: 140–200) hydrazide-derived supramolecular gelators have been designed and synthesized in two straightforward steps. For non-conjugated cyclohexane-derived hydrazides, their monomers can self-assemble to form gels through intermolecular hydrogen bonds and dipole-dipole interactions. Significantly, conjugated phthalhydrazide can self-aggregate into planar and circular trimers through intermolecular hydrogen bonds and then self-assemble to form gels through intermolecular π–π stacking interactions. It is interesting that these simple gelators exhibit unusual properties, such as self-healing, multi-response fluorescence, and visual and selective recognition of chiral (R)/(S)-1,1′-binaphthalene-2,2′-diamine and S2? through much different times of gel re-formation and blue-green color change, respectively. These results underline the importance of supramolecular gels and extend the scope of supramolecular gelators.
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Chukovskaya,E.Ts. et al.
, (1973)
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Knifton
, p. 2885,2887 (1976)
Titanosilicate (TS-1) catalyzed oxidation of aromatic aldehydes to esters
Chavan, Subhash P.,Dantale, Shubhada W.,Govande, Chitra A.,Venkatraman, Meenakshi S.,Praveen, Cherukupally
, p. 267 - 268 (2002)
A facile conversion of aromatic aldehydes to esters using molecular sieves, TS-1, and 30% H2O2 is described.
Polarity of the acid chain of esters and transesterification activity of acid catalysts
Alonso, D. Martin,Granados, M. Lopez,Mariscal,Douhal
, p. 18 - 26 (2009)
The effect of polarity of the esters on the transesterification reaction rate has been investigated. The effect was studied in homogeneous and heterogeneous catalysts. The polarity of different ethyl alkanoate esters was varied by (i) increasing the number of carbon atoms in the acid alkyl chain of the esters and (ii) introducing Br and hydroxy substituents at the end of the acid chain of ethyl hexanoate. Polarity was determined through the λmax of the UV-Vis spectrum of the betaine dye dissolved in the investigated esters (ET(30) scale). The transesterification reaction was carried out with methanol and by using sulfuric acid and a Dowex DR2030 sulfonic resin as homogeneous and heterogeneous catalysts, respectively. It was observed that, in addition to steric hindrance, the polarity of the ester chain has an effect on the reaction rate of the heterogeneous acid catalysts. It is proposed that the positive or negative effect of the polarity is due to repulsive or attractive interactions of the ester chain with the polar groups of the resin and/or with the methanol molecules present in the pores. A very positive effect is found in heterogeneous acid catalysis if H-bonds can stabilize the active intermediate participating in the rate determining step. The attractive or repulsive interactions are absent in the homogeneous case.
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Dhar,M.L. et al.
, p. 842 - 861 (1964)
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Impact of Macroporosity on Catalytic Upgrading of Fast Pyrolysis Bio-Oil by Esterification over Silica Sulfonic Acids
Manayil, Jinesh C.,Osatiashtiani, Amin,Mendoza, Alvaro,Parlett, Christopher M.A.,Isaacs, Mark A.,Durndell, Lee J.,Michailof, Chrysoula,Heracleous, Eleni,Lappas, Angelos,Lee, Adam F.,Wilson, Karen
, p. 3506 - 3511 (2017)
Fast pyrolysis bio-oils possess unfavorable physicochemical properties and poor stability, in large part, owing to the presence of carboxylic acids, which hinders their use as biofuels. Catalytic esterification offers an atom- and energy-efficient route to upgrade pyrolysis bio-oils. Propyl sulfonic acid (PrSO3H) silicas are active for carboxylic acid esterification but suffer mass-transport limitations for bulky substrates. The incorporation of macropores (200 nm) enhances the activity of mesoporous SBA-15 architectures (post-functionalized by hydrothermal saline-promoted grafting) for the esterification of linear carboxylic acids, with the magnitude of the turnover frequency (TOF) enhancement increasing with carboxylic acid chain length from 5 % (C3) to 110 % (C12). Macroporous–mesoporous PrSO3H/SBA-15 also provides a two-fold TOF enhancement over its mesoporous analogue for the esterification of a real, thermal fast-pyrolysis bio-oil derived from woodchips. The total acid number was reduced by 57 %, as determined by GC×GC–time-of-flight mass spectrometry (GC×GC–ToFMS), which indicated ester and ether formation accompanying the loss of acid, phenolic, aldehyde, and ketone components.
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Saus,Krings
, p. 947 (1967)
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A Simple and Cost Effective Synthesis of Chloromethyl Methyl Ether
Linderman, Russell J.,Jaber, Mohammed,Griedel, Brian D.
, p. 6499 - 6500 (1994)
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Pittman et al.
, p. 590,591 (1975)
Chiles,Reeves
, p. 3367,3370 (1979)
Three step auto-tandem catalysed hydroesterification: Access to linear fruity esters from piperylene
Neubert, Peter,Steffen, Matthias,Behr, Arno
, p. 122 - 127 (2015)
A convenient and selective access to saturated hexanoic esters via hydroesterification of piperylene with synthesis gas and methanol is presented. This is the first three step auto-tandem hydroesterification, which is 100% atom economic proceeding under mild conditions. Our optimisations revealed Pd2(dba)3/1,2-dtbpmb as the best catalytic system. Besides, the reaction also tolerates several alcohols, which offers a broad range of fruity esters. In addition, we present insights into the reaction sequence, investigating whether the reaction proceeds via two- or three-step reaction cascade.
PIFA-mediated esterification reaction of alkynes with alcohols via oxidative cleavage of carbon triple bonds
Jiang, Qing,Zhao, An,Xu, Bin,Jia, Jing,Liu, Xin,Guo, Cancheng
, p. 2709 - 2715 (2014)
A metal-free esterification of alkynes via C≡C triple bond cleavage has been developed. In the presence of phenyliodine bis(trifluoroacetate), a diverse range of alkyne and alcohol substrates undergoes triple bond cleavage to produce carboxylic ester motifs in moderate to good yields. The transformation is proposed to proceed via hydroxyethanones and ethanediones as intermediates on the basis of mechanistic studies and exhibits a broad substrate scope and good functional group tolerance.
PCl3-mediated transesterification and aminolysis of tert-butyl esters via acid chloride formation
Wu, Xiaofang,Zhou, Lei,Li, Fangshao,Xiao, Jing
, p. 491 - 497 (2021/01/20)
A PCl3-mediated conversion of tert-butyl esters into esters and amides in one-pot under air is developed. This novel protocol is highlighted by the synthesis of skeletons of bioactive molecules and gram-scale reactions. Mechanistic studies revealed that this transformation involves the formation of an acid chloride in situ, which is followed by reactions with alcohols or amines to afford the desired products.
Fully recyclable Br?nsted acid catalyst systems
Watson, Christopher B.,Kuechle, Adrianna,Bergbreiter, David E.
, p. 1266 - 1273 (2021/02/26)
Homogeneous and heterogeneous sulfonic acid catalysts are some of the most common catalysts used in organic chemistry. This work explores an alternative scheme using a fully recyclable polymeric solvent (a poly-α-olefin (PAO)) and soluble PAO-anchored polyisobutylene (PIB)-bound sulfonic acid catalysts. This PAO solvent is nonvolatile and helps to exclude water by its nonpolar nature which in turn drives reactions without the need for distillation of water, avoiding the need for excess reagents. This highly nonpolar solvent system uses polyisobutylene (PIB) bound sulfonic acid catalysts that are phase-anchored in solvents like PAO. The effectivenes of these catalysts was demonstrated by their use in esterifications, acetalizations, and multicomponent condensations. These catalysts and the PAO solvent phase show excellent recyclability in schemes where products are efficiently separated. For example, this non-volatile polymeric solvent and the PIB-bound catalyst can be recycled quantitatively when volatile products are separated and purified by distillation. In other cases, product purification can be effected by product self-separation or by extraction.