Tag: M.W=100-150

Ye, Lei published the artcileHZ-ZrP Catalysts with Adjustable Ratio of Bronsted and Lewis Acids for the One-Pot Value-Added Conversion of Biomass-Derived Furfural, Computed Properties of 539-88-8, the main research area is catalyst adjustable ratio Bronsted Lewis acid pot biomass furfural.

Bifunctional heterogeneous catalysts (HZ-ZrP) were prepared by using HZSM-5 as the carrier to support zirconium phosphate (ZrP) active component for the one-pot value-added conversion of biomass-derived furfural (FAL). By changing the loading amount of ZrP, the ratio of Lewis to Bronsted acid (2.7-15.4) and the acid strength of the catalysts can be adjusted. HZ-ZrP-5 and HZ-ZrP-16 were selected for the production of different value-added chems., and a total yield of up to 93.8% (i-PL and GVL) and 64.2% (GVL) were obtained using isopropanol as the hydrogen donor under optimized conditions, resp. Furthermore, stability and recyclability of the catalyst were also tested and showed no significant drop in total yield after re-calcination. The catalysts have high activity (Ea = 27.05 ± 3.08 kJ mol-1), but the ring-opening reaction restricted the cascade reaction. In addition, possible reaction pathway and mechanism for the FAL conversion was proposed.

ACS Sustainable Chemistry & Engineering published new progress about Activation energy. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Computed Properties of 539-88-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

da Silva, Evellyn Patricia Santos published the artcileInvestigation of solvent-free esterification of levulinic acid in the presence of tin(IV) complexes, Synthetic Route of 539-88-8, the main research area is tin complex catalyst levulinic acid solvent free esterification.

In this study, for the first time, the use of dibutyltin dichloride (Bu2SnCl2), dimethyltin dichloride (Me2SnCl2), butyltin trichloride (BuSnCl3) and Bu stannoic acid (BuSnO(OH)) as catalysts in the esterification of levulinic acid (LA) was investigated through a comparison with reactions performed without the use of a catalyst. The most active system (BuSnCl3) led to 93% conversion of LA in 360 min at 110°C with an LA:EtOH:CAT molar ratio of 1:5:0.01. The apparent rate constants (kap) for LA conversion confirm these results, and values of 6.2 × 10-3, 12.5 × 10-3 and 19.4 × 10-3 min-1 were obtained at 70, 90 and 110°C, resp. The activation energy for LA conversion was determined employing BuSnCl3 and the value was 31.2 kJ mol-1.

Molecular Catalysis published new progress about Activation energy. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Synthetic Route of 539-88-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Yu, Xin published the artcileEthylene glycol co-solvent enhances alkyl levulinate production from concentrated feeds of sugars in monohydric alcohols, SDS of cas: 539-88-8, the main research area is alkyl levulinate production ethylene glycol monohydric alc concentrated feed.

Conversion of carbohydrates at concentrated feeds represents highly desirable for the industrial deployment of biobased fuels and chems. but challenging. One key bottleneck is that the excessive formation of polymeric humins greatly diminishes the utilization rate of feedstocks and the destination product yield. We report that the use of ethylene glycol as co-solvent for acid-catalyzed conversion of concentrated sugars enhances desirable alkyl levulinate (AL) production compared to reactions carried out in single monohydric alcs. (e.g., methanol, ethanol). Ethylene glycol served not only as a solubilizer of sugars in the reaction medium to lessen their tendency to polymerize by protecting reactive hydroxyl groups in sugars with alcs., but also as a supporter to restrain the condensation of furan intermediates. With 10 vol% ethylene glycol as the co-solvent of ethanol, an improved yield of Et levulinate (EL) from 45% to 56% was accomplished from concentrated feeds of glucose (200 g/L). In particular, high space time yield and EL concentration resp. up to 30 kg/m3·h and 90 g/L were obtained in a batch reactor. The solvents and catalyst could be isolated from the products, and showed good reusability. This contribution opens a reliable avenue for converting highly concentrated feeds of biomass-related sugars to oxygenated liquid fuels and versatile chems.

Fuel published new progress about Activation energy. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, SDS of cas: 539-88-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Ahmad, Ejaz published the artcileUnderstanding reaction kinetics, deprotonation and solvation of bronsted acidic protons in heteropolyacid catalyzed synthesis of biorenewable alkyl levulinates, Safety of Ethyl 4-oxopentanoate, the main research area is levulinic acid heteropolyacid catalyst esterification kinetics IR spectra.

In search of a ‘descriptor’ for Bronsted acid-catalyzed biorenewable transformations in a complex reaction environment, two concepts related to the reactivity of Bronsted acid catalysts are explored. A simple reaction involving the esterification of levulinic acid in three different alc. mediums (ethanol, 1-propanol, and 1-butanol) is experimented with two different Keggin heteropolyacid (HPA) catalysts to synthesize alkyl levulinates. On the same HPA catalyst, and different solvent medium, apparent activation energies of the esterification reaction are observed to increase by an average of âˆ? kJ/mol on increasing the alkyl chain length of the alc. medium by one carbon. Obtained apparent activation energies are corresponding with the solvation energies of the Bronsted proton in the resp. alc. medium. In contrast, on changing the HPA catalyst and keeping the same alc. medium, the apparent activation energies are observed to differ by an average of âˆ?9 kJ/mol. This directly correlates with the difference (âˆ?0 kJ/mol) in the vapor phase deprotonation energies (DPE) of the two HPA catalysts. Thus, in the solvent environment, DPE values and the degree of solvation of the Bronsted acidic protons are describing the reactivity of the HPA catalysts.

Chemical Engineering Journal (Amsterdam, Netherlands) published new progress about Activation energy. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Safety of Ethyl 4-oxopentanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Gao, Guoming published the artcileCrystal facet-dependent activity of h-WO3 for selective conversion of furfuryl alcohol to ethyl levulinate, HPLC of Formula: 539-88-8, the main research area is crystal facet WO3 furfuryl alc ethyl levulinate.

The use of WO3 as an acid catalyst has received extensive attention in recent years. However, the correlation between the catalytic activity and the predominantly exposed surface with varied acidic sites needs further understanding. Herein, the effects of the Bronsted and Lewis acid sites of different crystal facets of WO3 on the catalytic conversion of furfuryl alc. (FA) to Et levulinate (EL) in ethanol were investigated in detail. A yield of EL up to 93.3% over WO3 with the (110) facet exposed was achieved at 170°C, while FA was mainly converted to polymers over (001) faceted nanosheets and nanobelts with exposed (002) and (100) facets. This was attributed to the different distribution of the acidic sites on different exposed crystal facets. The (110) faceted WO3 possessed abundant and strong Bronsted acid sites, which favored the conversion of FA to EL, while the (100) faceted WO3 with stronger Lewis acid sites and weaker Bronsted acid sites mainly led to the formation of polymers. In addition, the (110) faceted WO3 showed excellent sustainability in comparison with the (100) faceted counterpart.

Physical Chemistry Chemical Physics published new progress about Crystal morphology. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, HPLC of Formula: 539-88-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Wang, Dong-Hao published the artcileAsymmetric Reductive Amination of Structurally Diverse Ketones with Ammonia Using a Spectrum-Extended Amine Dehydrogenase, Application of Ethyl 4-oxopentanoate, the main research area is asym reductive amination reductive engineered amine dehydrogenase.

Amine dehydrogenase-catalyzed reductive amination of prochiral ketones with ammonia is a promising method for the synthesis of optically pure amines in the pharmaceutical and fine chem. industries. However, previously reported amine dehydrogenases show restricted catalytic capacity toward bulky ketones, which limits their widespread applications toward the production of chiral amines. Herein, we expanded the substrate scope of an engineered amine dehydrogenase GkAmDH from Geobacillus kaustophilus via laboratory evolution for the reductive amination of an extensive set of ketones. Several beneficial mutants were identified with a up to 2.2 U mg-1 activity toward bulky benzylacetone, 110-fold higher than that of M0. Using the engineered M3 and M8, structurally diverse bulky chiral amines could be synthesized with up to >99% conversion, >99% ee, and up to 18,900 TON. Among them, two key chiral intermediates used in the synthesis of the drugs medroxalol and dilevalol were produced on a gram scale in up to 85% yield and >99% ee. Addnl., the engineered enzymes M3 and M8 displayed considerable thermostability with a half-life of more than three days at 50 °C. These results demonstrate that these engineered amine dehydrogenases are promising biocatalysts for the synthesis of chiral amines. Mol. dynamics simulations provide insights into how mutations improve the amination activity toward bulky ketones and the thermostability.

ACS Catalysis published new progress about Directed evolution. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Application of Ethyl 4-oxopentanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Li, Zhan-Ku published the artcileEthanol and formic acid as synergistic solvents for converting lignite to platform chemicals, Formula: C7H12O3, the main research area is ethanol formic acid phenol ester lignite ethanolysis.

Formic acid (FA)-catalyzed ethanolysis of Xilinguole lignite (XL) was carried out with FA to ethanol ratio of 0-1:6 mL/mL at 220-320 °C. The optimal conditions were determined to be 300 °C and FA to ethanol ratio of 1:10 mL/mL based on ethanol-soluble portion (ESP) yield and the maximum ESP yield is 48.0 wt%. Both carbon balance and Fourier transform IR spectrometric analyses confirm that FA and ethanol involved in ethanolysis of XL. Three major platform chems., i.e., arenes, phenols, and esters, were identified in ESPs by gas chromatog./mass spectrometry. The yields of arenes and phenols significantly increased from 15.67 to 58.33 mg/g and 36.02 to 168.44 mg/g with adding FA to ethanolysis of XL, resp. The alkyl groups of arenes and phenols are more abundant in ESPs from FA-catalyzed ethanolysis of XL. The results suggest that FA enhanced hydrogenolysis of aryl ethers and alkylation of ethanol during XL ethanolysis. Hydrogen generated from FA hindered dehydrogenation of ethanol, resulting in the decrease of ethanol-derived esters. Ethanol acts as in-situ hydrogen donor for hydrogenolysis and reactant for alkylation, aldol condensation, and esterification, while FA serves as acid catalyst and in-situ hydrogen donor for hydrogenolysis. Addnl., possible pathways for FA-catalyzed ethanolysis of XL were proposed.

Fuel published new progress about Aldol condensation. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Formula: C7H12O3.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Wu, Hongguo published the artcileHot water-promoted catalyst-free reductive cycloamination of (bio-)keto acids with HCOONH4 toward cyclic amides, Recommanded Product: Ethyl 4-oxopentanoate, the main research area is keto acid ammonium formate tandem reductive cycloamination; cyclic amide preparation.

HCOONH4 was demonstrated to be capable of acting as both hydrogen and nitrogen source in the absence of any catalyst and additive for the reductive cycloamination of bio-based levulinic acid (LA) to 5-methyl-2-pyrrolidone (MPL) with more than 90% in just 60 min at 180°. Pressurized hot water remarkably enabled the reaction efficiency and rate by promoting the hydrolysis of HCOONH4 to liberated ammonia and formic acid for the cascade reactions and this catalyst-free protocol was also applicable to the efficient synthesis of various cyclic amides from relevant keto acids. Moreover, the reaction pathways were investigated by conducting deuterium-labeling experiments and kinetic studies of selected reactions.

Journal of Supercritical Fluids published new progress about Amidation kinetics. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Recommanded Product: Ethyl 4-oxopentanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Tiong, Yong Wei published the artcileOptimisation studies on the conversion of oil palm biomass to levulinic acid and ethyl levulinate via indium trichloride-ionic liquids: A response surface methodology approach, SDS of cas: 539-88-8, the main research area is oil palm biomass LA EL indium trichloride ionic liquid.

This work is a continuation and extension of previously published study on the conversions of oil palm empty fruit bunch and mesocarp fiber biomass to levulinic acid and Et levulinate via an eco-friendly indium trichloride-1-methylimidazolium hydrogen sulfate (Tiong et al., 2017). Herein, a response surface methodol. based on a central composite design method was used to optimize the operating conditions of the conversions. The conversions consisted of a two-sequential steps, i.e., depolymerization to levulinic acid, followed by esterification to Et levulinate. The optimum depolymerization occurred at 177°C in 4.8 h with 0.15 mmol indium trichloride in ionic liquids-to-biomass ratio of 6.6:1 (weight/weight) and 22.7% (weight/weight) of water, while esterification was at 105°C in 12.2 h with ethanol to substrate ratio of 7.2:1 (volume/volume). The maximum levulinic acid yields of 17.7% and 18.4%, and the subsequent Et levulinate yields of 18.7% and 20.1% were achieved from the conversions of oil palm empty fruit bunch and mesocarp fiber biomass, resp. LA and EL efficiencies were >63% for both biomass conversions. The ionic liquids could be recycled up to three consecutive runs with a minimal loss of <25% of Et levulinate yield. This study highlighted the potential of proposed ionic liquids for biorefinery processing of renewable feedstock in a greener and sustainable approach. Industrial Crops and Products published new progress about Biomass (Oil palm). 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, SDS of cas: 539-88-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Jiang, Wei published the artcileGene mining, codon optimization and analysis of binding mechanism of an aldo-keto reductase with high activity, better substrate specificity and excellent solvent tolerance, SDS of cas: 539-88-8, the main research area is Candida aldo keto reductase gene mining codon substrate specificity.

The biosynthesis of chiral alcs. has important value and high attention. Aldo-keto reductases (AKRs) mediated reduction of prochiral carbonyl compounds is an interesting way of synthesizing single enantiomers of chiral alcs. due to the high enantio-, chemo- and regioselectivity of the enzymes. However, relatively little research has been done on characterization and apply of AKRs to asym. synthesis of chiral alcs. In this study, the AKR from Candida tropicalis MYA-3404 (C. tropicalis MYA-3404), was mined and characterized. The AKR shown wider optimum temperature and pH. The AKR exhibited varying degrees of catalytic activity for different substrates, suggesting that the AKR can catalyze a variety of substrates. It is worth mentioning that the AKR could catalytic reduction of keto compounds with benzene rings, such as cetophenone and phenoxyacetone. The AKR exhibited activity on N,N-dimethyl-3-keto-3-(2-thienyl)-1-propanamine (DKTP), a key intermediate for biosynthesis of the antidepressant drug duloxetine. Besides, the AKR still has high activity whether in a reaction system containing 10%-30% V/V organic solvent. What’s more, the AKR showed the strongest stability in six common organic solvents, DMSO, acetonitrile, Et acetate, isopropanol, ethanol, and methanol. And, it retains more that 70% enzyme activity after 6 h, suggesting that the AKR has strong solvent tolerance. Furthermore, the protein sequences of the AKR and its homol. were compared, and a 3D model of the AKR docking with coenzyme NADPH were constructed. And the important catalytic and binding sites were identified to explore the binding mechanism of the enzyme and its coenzyme. These properties, predominant organic solvents resistance and extensive substrate spectrum, of the AKR making it has potential applications in the pharmaceutical field.

PLoS One published new progress about Candida tropicalis. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, SDS of cas: 539-88-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics