123-66-0Relevant articles and documents
Catalytic performance of divanadium-substituted molybdophosphate acid, H5PMo10V2O40, in liquid-phase esterification of hexanoic acid
Bamoharram, Fatemeh F.,Heravi, Majid M.,Roshani, Mina,Mir, Hamzeh
, p. 3119 - 3125 (2009)
Divanadium-substituted molybdophosphate acid, H5PMo 10V2O40, efficiently catalyzes the synthesis of ethylhexanoate from hexanoic acid and ethanol at reflux temperature and under solventless conditions. Comparison of H5PMo10V 2O40 with the other heteropolyacids showed that this catalyst gives the highest total yield of ethylhexanoate. The effects of the molar ratio of acid:alcohol, reaction times, and temperatures were studied.
Kinetic model for the esterification of ethyl caproate for reaction optimization
De Barros, Dragana P.C.,Pinto, Fatima,Fonseca, Luis P.,Cabral, Joaquim M.S.,Lemos
, p. 16 - 22 (2014)
The present work aims to achieve additional insight on a mechanism describing the fundamental steps involved in the esterification reactions catalyzed by cutinase. The synthesis of ethyl caproate has been used as a model system to obtain a suitable kinetic model to estimate the activation energies involved in the various steps of the reaction pathway. Kinetic measurements have been made for the enzymatic esterification of caproic acid with ethyl alcohol catalyzed by recombinant Fusarium solani pisi cutinase expressed in Saccharomyces cerevisiae SU50. Different temperature conditions, from 25 to 50 C, were tested for two different alcohol/acid molar ratios (R = 1 and R = 2). The third ordered Ping Pong Bi Bi mechanism with alcohol inhibition was shown to be able to describe the experimental results. The model shows that the productivity decreases as the reaction temperature increases.
Kinetic cutinase-catalyzed esterification of caproic acid in organic solvent system
De Barros, Dragana P. C.,Lemos, Francisco,Fonseca, Luis P.,Cabral, Joaquim M. S.
, p. 285 - 293 (2010)
Practical application of any chemical reaction requires the knowledge of its kinetics; in particular if one wishes to be able to describe a chemical reactor over an extended range of reaction conditions or if one intends to optimize the reaction conditions, a suitable kinetic model must be obtained. In order to ensure that the model is applicable over a wide range of experimental conditions it should be based on a mechanistic scheme describing the fundamental steps involved in the reaction; the development of these kind of models can also be used to provide insight into the processes that are taking place. A kinetic study, using experiments carried out in a batch stirred reactor, has been made for the enzymatic esterification of caproic acid with ethyl alcohol catalyzed by Fusarium solani pisi cutinase. Different acid and alcohol concentrations (whilst also varying the acid/alcohol molar ratio) were tested and the results were used to identify the best reaction scheme to describe the results obtained over an extended range of conditions. Several different approaches were used to identify the most adequate mechanistic model, namely by resorting to the quasi stationary state and the rate-limiting hypothesis. The main kinetic characteristics observed in esterification reaction were found to follow an ordered Ping-Pong Bi-Bi mechanism but different modifications were used o ensure that the kinetic model was applicable over the entire range of experimental conditions that were covered.
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.
MOFs based on 1D structural sub-domains with Br?nsted acid and redox active sites as effective bi-functional catalysts
Díaz, Urbano,Moreno, José María,Velty, Alexandra
, p. 3572 - 3585 (2020/06/25)
A novel family of lamellar MOF-type materials, which contain Br?nsted acid sites together with redox active centers, based on assembled 1D organic-inorganic nanoribbons were obtained through direct solvothermal synthesis routes, using specific monotopic benzylcarboxylate spacers with thiol substituents in thepara-position like structural modulator compounds and effective post-synthesis oxidized treatments to generate accessible sulfonic groups. Low-dimensional aluminum metal-organic materials, containing free sulfonic pendant groups (Al-ITQ-SO3H), were successfully tested in several acid reactions, such as acetalization, esterification and ring opening of epoxides with a significant impact on fine chemistry processes. The direct introduction of stabilized Pd nanoparticles, cohabitating with pendant sulfonic groups, allowed the preparation of active bi-functional MOF-type hybrid materials (Al-ITQ-SO3H/Pd) capable of carrying out one-pot two-step oxidation-acetalization reactions, exhibiting high yield and high activity during consecutive catalytic cycles.
Synthesis of α,β- and β-Unsaturated Acids and Hydroxy Acids by Tandem Oxidation, Epoxidation, and Hydrolysis/Hydrogenation of Bioethanol Derivatives
Faria, Jimmy,Komarneni, Mallik R.,Li, Gengnan,Pham, Tu,Resasco, Daniel E.,Ruiz, Maria P.,Santhanaraj, Daniel
supporting information, p. 7456 - 7460 (2020/03/23)
We report a reaction platform for the synthesis of three different high-value specialty chemical building blocks starting from bio-ethanol, which might have an important impact in the implementation of biorefineries. First, oxidative dehydrogenation of ethanol to acetaldehyde generates an aldehyde-containing stream active for the production of C4 aldehydes via base-catalyzed aldol-condensation. Then, the resulting C4 adduct is selectively converted into crotonic acid via catalytic aerobic oxidation (62 % yield). Using a sequential epoxidation and hydrogenation of crotonic acid leads to 29 % yield of β-hydroxy acid (3-hydroxybutanoic acid). By controlling the pH of the reaction media, it is possible to hydrolyze the oxirane moiety leading to 21 % yield of α,β-dihydroxy acid (2,3-dihydroxybutanoic acid). Crotonic acid, 3-hydroxybutanoic acid, and 2,3-dihydroxybutanoic acid are archetypal specialty chemicals used in the synthesis of polyvinyl-co-unsaturated acids resins, pharmaceutics, and bio-degradable/ -compatible polymers, respectively.
Enantioselective Synthesis of β-Amino Acid Derivatives Enabled by Ligand-Controlled Reversal of Hydrocupration Regiochemistry
Buchwald, Stephen L.,Guo, Sheng,Zhu, Jiaqi
supporting information, p. 20841 - 20845 (2020/09/16)
A Cu-catalyzed enantioselective hydroamination of α,β-unsaturated carbonyl compounds for the synthesis of β-amino acid derivatives was achieved through ligand-controlled reversal of the hydrocupration regioselectivity. While the hydrocupration of α,β-unsaturated carbonyl compounds to form α-cuprated species has been extensively investigated, we report herein that, in the presence of an appropriate ancillary chiral ligand, the opposite regiochemistry can be observed for cinnamic acid derivatives, leading to the delivery of the copper to the β-position. This copper can react with an electrophilic aminating reagent, 1,2-benzisoxazole, to provide enantioenriched β-amino acid derivatives, which are important building blocks for the synthesis of natural products and bioactive small molecules.
Oxidative esterification of aliphatic aldehydes and alcohols with ethanol over gold nanoparticle catalysts in batch and continuous flow reactors
Taketoshi,Ishida,Murayama, Toru,Honma, Tetsuo,Haruta, Masatake
, (2019/08/26)
Selective esterification of aliphatic aldehydes and alcohols with ethanol in the absence of a base is a more difficult reaction than that with methanol. Gold nanoparticles on ZnO were found to catalyze the oxidative esterification of octanal to ethyl octanoate with high selectivity. In addition, it was found that Au/ZnO was the most effective catalyst for yielding the desired ethyl ester without a base by direct esterification of 1-octanol with ethanol. As far as we know, this is the first report on oxidative esterification to give aliphatic ethyl esters from less reactive aliphatic alcohols and aldehydes without a base. The optimal size of gold NPs ranged from 2 to 6 nm and the presence of Au(0) was indispensable for this reaction. Au/ZnO exhibited the highest catalytic activity in both batch and flow reactors. The conversion was maintained for more than 20 h with 95% selectivity to the desired ethyl ester in the flow system.
'Clean' hydrolase reactions using commercial washing powder
Zhang, Jie,Tonin, Fabio,Zhang, Wuyuan,Hagedoorn, Peter-Leon,Mallée, Lloyd,Hollmann, Frank
, p. 24039 - 24042 (2019/08/15)
We report the use of commercial laundry powder as a biocatalyst for a range of lipase-catalysed reactions including (trans)esterification, ester hydrolysis and chemoenzymatic epoxidation reactions. The enzymatic laundry powder exhibited excellent stability and recyclability, making it a readily available and cheap biocatalyst for chemical transformations.
Selective hydrogenation of α,β-unsaturated carbonyl compounds on silica-supported copper nanoparticles
Mendes-Burak, Jorge,Ghaffari, Behnaz,Copéret, Christophe
supporting information, p. 179 - 181 (2019/01/04)
Silica-supported copper nanoparticles prepared via surface organometallic chemistry are highly efficient for the selective hydrogenation of various α,β-unsaturated carbonyl compounds yielding the corresponding saturated esters, ketones, and aldehydes in the absence of additives. High conversions and selectivities (>99%) are obtained for most substrates upon hydrogenation at 100-150 °C and under 25 bar of H2.
