498-23-7Relevant academic research and scientific papers
Synthesis of an Acylphosphate Driven by a Proton Gradient. A Model for H(+)-ATPase
Colton, Ian J.,Kazlauskas, Romas J.
, p. 7005 - 7006 (1992)
We describe the first model for a proton pump, H(+)-ATPase.This model uses the energy from an indirect transfer of two protons from a solution at pH 0.3 to a solution at pH 10 to drive the synthesis of a high-energy phosphate, citraconyl phosphate.
Synthesis and pH-dependent hydrolysis profiles of mono- and dialkyl substituted maleamic acids
Su, Shan,Du, Fu-Sheng,Li, Zi-Chen
, p. 8384 - 8392 (2017)
Maleamic acid derivatives as weakly acid-sensitive linkers or caging groups have been used widely in smart delivery systems. Here we report on the controlled synthetic methods to mono- and dialkyl substituted maleamic acids and their pH-dependent hydrolysis behaviors. Firstly, we studied the reaction between n-butylamine and citraconic anhydride, and found that the ratio of the two n-butyl citraconamic acid isomers (α and β) could be finely tuned by controlling the reaction temperature and time. Secondly, we investigated the effects of solvent, basic catalyst, and temperature on the reaction of n-butylamine with 2,3-dimethylmaleic anhydride, and optimized the reaction conditions to efficiently synthesize the dimethylmaleamic acids. Finally, we compared the pH-dependent hydrolysis profiles of four OEG-NH2 derived water-soluble maleamic acid derivatives. The results reveal that the number, structure, and position of the substituents on the cis-double bond exhibit a significant effect on the pH-related hydrolysis kinetics and selectivity of the maleamic acid derivatives. Interestingly, for the mono-substituted citraconamic acids (α-/β-isomer), we found that their hydrolyses are accompanied by the isomerization between the two isomers.
Synthesis of bio-based methacrylic acid from biomass-derived itaconic acid over barium hexa-aluminate catalyst by selective decarboxylation reaction
Bohre, Ashish,Novak, Uro?,Grilc, Miha,Likozar, Bla?
, (2019/07/31)
An environmentally-benign, efficient and inexpensive high-surface-area barium hexa-aluminate (BaAl12O19, BHA) was developed as a catalyst for the decarboxylation of the biomass-derived itaconic acid (IA) to bio-based methacrylic acid (MAA). A maximal 50% final yield of MAA with a high product selectivity was obtained under relatively mild synthesis reaction conditions (250 °C; 20 bar N2). The reported selective MAA production was elevated, operating process characteristics were significantly less harsh, and no depleting critical raw materials were utilized when paralleled to the procedures with alkaline mineral bases, noble metal-containing heterogeneous catalysis systems and unrenewable feed resources (e.g. isobutene), applied previously. It was found that the doping of palladium on BHA support (Pd@BHA) did not improve MAA productivity. The effect of the time (25–300 min), temperature (175–275 °C), pressure (10–40 bar), reacting substrate concentration (0.10–0.19 mol L–1), metallic oxide mass (0.5–3.0 g) and type on IA conversion, MAA content MAA content and rates was determined, examining also recyclability. BHA catalyst was characterized with various structural techniques, such as energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD), CO2 temperature-programmed desorption (TPD), scanning electron microscopy (SEM) and N2 physisorption.
Methacrylic acid production method
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Page/Page column 9; 14-15, (2018/12/11)
A method of producing methacrylic acid using a hydrotalcite catalyst and subcritical water is described.
BIO-BASED METHACRYLIC ACID AND OTHER ALKENOIC-DERIVED MONOMERS VIA CATALYTIC DECARBOXYLATION
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Paragraph 0054-0055; 0056-0057, (2018/04/26)
A novel method for the catalytic selective decarboxylation of a starting material to produce an organic acid is disclosed. According to at least one embodiment, the method may include placing a reaction mixture into a reaction vessel, the reaction mixture including a solvent, a starting material, and a catalyst, subjecting the reaction mixture to a predetermined pressure and temperature, and allowing the reaction to continue for 1-3 hours. The starting material may be at least one of a dicarboxylic acid, a tricarboxylic acid, and an anhydride of a dicarboxylic or tricarboxylic acid. As an exemplary embodiment, itaconic acid may be a starting material and the organic acid may be methacrylic acid. The predetermined temperature may be 250° C. or less, and the reaction pressure may be less than 425 psi. Further, a polymerization inhibitor may be used.
Synthesis of Bio-Based Methacrylic Acid by Decarboxylation of Itaconic Acid and Citric Acid Catalyzed by Solid Transition-Metal Catalysts
Le N?tre, Jér?me,Witte-van Dijk, Susan C. M.,van Haveren, Jacco,Scott, Elinor L.,Sanders, Johan P. M.
, p. 2712 - 2720 (2016/12/23)
Methacrylic acid, an important monomer for the plastics industry, was obtained in high selectivity (up to 84 %) by the decarboxylation of itaconic acid using heterogeneous catalysts based on Pd, Pt and Ru. The reaction takes place in water at 200–250 °C without any external added pressure, conditions significantly milder than those described previously for the same conversion with better yield and selectivity. A comprehensive study of the reaction parameters has been performed, and the isolation of methacrylic acid was achieved in 50 % yield. The decarboxylation procedure is also applicable to citric acid, a more widely available bio-based feedstock, and leads to the production of methacrylic acid in one pot in 41 % selectivity. Aconitic acid, the intermediate compound in the pathway from citric acid to itaconic acid was also used successfully as a substrate.
A biocompatible alkene hydrogenation merges organic synthesis with microbial metabolism
Sirasani, Gopal,Tong, Liuchuan,Balskus, Emily P.
supporting information, p. 7785 - 7788 (2014/08/05)
Organic chemists and metabolic engineers use orthogonal technologies to construct essential small molecules such as pharmaceuticals and commodity chemicals. While chemists have leveraged the unique capabilities of biological catalysts for small-molecule production, metabolic engineers have not likewise integrated reactions from organic synthesis with the metabolism of living organisms. Reported herein is a method for alkene hydrogenation which utilizes a palladium catalyst and hydrogen gas generated directly by a living microorganism. This biocompatible transformation, which requires both catalyst and microbe, and can be used on a preparative scale, represents a new strategy for chemical synthesis that combines organic chemistry and metabolic engineering. Reduction to practice: A hydrogenation reaction has been developed that employs hydrogen generated in situ by a microorganism and a biocompatible palladium catalyst to reduce alkenes on a synthetically useful scale. This type of transformation, which directly combines tools from organic chemistry with the metabolism of a living organism for small-molecule production, represents a new strategy for chemical synthesis.
A PROCESS FOR THE PRODUCTION OF METHACRYLIC ACID AND ITS DERIVATIVES AND POLYMERS PRODUCED THEREFROM
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Page/Page column 26, (2013/11/18)
A process for the production of methacrylic acid by the base catalysed decarboxylation of at least one dicarboxylic acid selected from itaconic, citraconic or mesaconic acid or mixtures thereof is described. The decarboxylation is carried out at a temperature in the range from 100 to 199°C. A method of preparing polymers or copolymers of methacrylic acid or methacrylic acid esters is also described.
PROCESS FOR THE PRODUCTION OF METHACRYLIC ACID AND ITS DERIVATIVES AND POLYMERS PRODUCED THEREFROM
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Paragraph 0118-0128, (2013/11/19)
A process for the production of methacrylic acid is described. The process comprises the base catalysed decarboxylation of at least one or a mixture of dicarboxylic acids selected from itaconic, citraconic or mesaconic acid. The decarboxylation is carried out in the range greater than 240 and up to 275° C. to provide high selectivity. The methacrylic acid product may be esterified to produce an ester. A method of preparing polymers or copolymers of methacrylic acid or methacrylic acid esters using the process is also described. Optionally, the process may be preceded with a decarboxylation and, if necessary, a dehydration step on a source of pre-acid such as citric acid or isocitric acid.
A three-enzyme system involving an ene-reductase for generating valuable chiral building blocks
Mangan, David,Miskelly, Iain,Moody, Thomas S.
, p. 2185 - 2190,6 (2020/09/02)
The use of ene-reductase (ERED) enzymes for the asymmetric reduction of olefins offers a green, renewable alternative to metal-catalysed asymmetric reduction. We report herein the first example of an ERED-catalysed enantiospecific reduction carried out at large scale using a carbonyl reductase (CRED) enzyme in the cofactor recycle. This reaction has been paired with a hydrolase-mediated regioselective ester hydrolysis to generate a valuable chiral building block using a straightforward one-pot process. Copyright
