Category: esters-buliding-blocks

Hojo, Makoto published the artcileReductive Generation of Enolates Using a Chromium(III) Ate-Type Reagent as a Reductant and Reactions of the Enolates with Electrophiles, Category: esters-buliding-blocks, the main research area is chromium ate reagent ketone ester enolate formation reaction electrophile; stereoselective reaction ketone ester enolate aldehyde chromium ate reagent; aldehyde reaction ketone ester enolate chromium ate reagent; alkyl halide reaction ketone ester enolate chromium ate reagent; chemoselective reaction enolate keto ester chromium ate reagent; imine reaction enolate bromoacetate chromium ate reagent; cross aldol adduct synthesis chromium ate reagent.

The Cr ate-type reagent Bu6CrLi3 reacted cleanly with ketones and esters bearing a leaving group at the α-position to produce enolates under mild conditions, where the Cr ate reagent acts as a formal two-electron reductant. In a stepwise manner, the generated enolates reacted with a variety of electrophiles with high selectivity. In general, a well-dried 50 mL two-necked round bottom flask containing a magnetic stirring bar and ground Cr(III) chloride (0.52 mmol) was fitted with a rubber septum and a three-way stopcock connected to a balloon filled with Ar. The apparatus was purged with Ar by pumping-filling via a three-way stopcock. THF (4 mL) was introduced to the flask via a syringe, and the suspension was stirred at room temperature for 5 min. The flask was cooled to -78°, and a solution of BuLi in hexane (3.12 mmol; 1.57 M) was slowly added to the suspension, and the mixture was stirred for further 30 min at -78°. Enolate precursor (0.5 mmol) was added slowly to the mixture at -20 to -78°. After stirring for the specified period of time, an electrophile (3.64 mmol) was added to the mixture The reaction mixture was once cooled to -78°, and the reaction was quenched with a saturated solution of aqueous ammonium chloride at -78°. After extraction with ether, washing the ethereal solution with aqueous NaHCO3, and drying on Na2SO4, solvents were evaporated A crude mixture was subjected to chromatog. on silica gel to afford a pure product. For example, Et 2-bromopropionate and HexCHO gave 88% 3-hydroxy-2-methylnonanoic acid Et ester (80/20 syn/anti); Et 2-bromoisobutyrate and OctI gave 96% 2,2-dimethyldecanoic acid Et ester; Et 2-bromoisobutyrate and PhCH:NTs gave 88% 2,2-dimethyl-3-phenyl-3-(toluene-4-sulfonylamino)propionic acid Et ester; α,α-dibromobutyrophenone and EtCHO gave 29% (2,3-diethyloxiranyl)phenylmethanone, 23% 2-ethyl-1-phenylpent-2-en-1-one and 36% syn-2-ethyl-3-hydroxy-1-phenylpentan-1-one.

Organometallics published new progress about Aldehydes Role: RCT (Reactant), RACT (Reactant or Reagent). 86549-27-1 belongs to class esters-buliding-blocks, name is Ethyl 2,2-dimethylpent-4-enoate, and the molecular formula is C9H16O2, Category: esters-buliding-blocks.

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

Arata, Shogo published the artcileAn isolable iron(II) bis(supersilyl) complex as an effective catalyst for reduction reactions, Application In Synthesis of 140-11-4, the main research area is iron supersilyl complex catalyst preparation crystal structure; hydrosilylation reductive silylation catalyst iron supersilyl complex.

An isolable 14-electron iron bis(supersilyl) complex, Fe[Si(SiMe3)3]2(THF)2, was successfully synthesized from the reaction of FeBr2 with K[Si(SiMe3)3] and its structure was unambiguously determined by single-crystal x-ray diffraction anal. The complex is coordinatively unsaturated and exhibits high catalytic activity toward the hydrosilylation of carbonyl compounds and the reductive silylation of dinitrogen.

Dalton Transactions published new progress about Aldehydes Role: RCT (Reactant), RACT (Reactant or Reagent). 140-11-4 belongs to class esters-buliding-blocks, name is Benzyl acetate, and the molecular formula is C9H10O2, Application In Synthesis of 140-11-4.

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

Singh, Randolph R. published the artcileExpanded coverage of non-targeted LC-HRMS using atmospheric pressure chemical ionization: a case study with ENTACT mixtures, HPLC of Formula: 110-42-9, the main research area is liquid chromatog HRMS atm pressure chem ionization ENTACT; Atmospheric pressure chemical ionization (APCI); EPA’s Non-Targeted Analysis Collaborative Trial (ENTACT); Electrospray ionization (ESI); High-resolution mass spectrometry (HRMS); Non-targeted analysis (NTA).

Non-targeted anal. (NTA) is a rapidly evolving anal. technique with numerous opportunities to improve and expand instrumental and data anal. methods. NTA was performed on eight synthetic mixtures containing 1264 unique chem. substances from the U. S. Environmental Protection Agency’s Non-Targeted Anal. Collaborative Trial (ENTACT). These mixtures were analyzed by atm. pressure chem. ionization (APCI) and electrospray ionization (ESI) using both pos. and neg. polarities for a total of four modes. Out of the 1264 ENTACT chem. substances, 1116 were detected in at least one ionization mode, 185 chems. were detected using all four ionization modes, whereas 148 were not detected. Forty-four chems. were detected only by APCI, and 181 were detected only by ESI. Mol. descriptors and physicochem. properties were used to assess which ionization type was preferred for a given compound One ToxPrint substructure (naphthalene group) is enriched in compounds only detected using APCI, and eight ToxPrints (e.g., several alc. moieties) were enriched in compounds only detected using ESI. Examination of physicochem. parameters for ENTACT chems. suggests that those with higher aqueous solubility preferentially ionized by ESI-. While ESI typically detects a larger number of compounds, APCI offers chromatograms with less background, fewer coelutions, and addnl. chem. space coverage, suggesting both should be considered for broader coverage in future NTA research.

Analytical and Bioanalytical Chemistry published new progress about Atmospheric pressure chemical ionization mass spectrometry. 110-42-9 belongs to class esters-buliding-blocks, name is Methyl decanoate, and the molecular formula is C11H22O2, HPLC of Formula: 110-42-9.

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

Hadhoum, Loubna published the artcileBio-oil recovery from olive mill wastewater in sub-/supercritical alcohol-water system, HPLC of Formula: 929-77-1, the main research area is biooil Olive mill wastewater subsupercrit alc water hydrothermal liquefaction.

Olive mill wastewater was converted into bio-oil via thermochem. liquefaction with alc./water mixtures in an autoclave (998 mL). The influence of operating conditions on the yield of liquefaction products was investigated. Liquefaction experiments were performed at various reaction temperatures in the range of 240-320 °C. Exptl. results indicated that alc. (methanol or ethanol)/water mixtures had synergistic effects on olive mill wastewater direct liquefaction. The ratio 50% (weight/weight) co-solvent of either ethanol-water or methanol-water and a reaction temperature of 280 °C were found to be the most effective. Under these conditions and for a reaction time of 30 min, the bio-oil yield was 92.31 wt% for ethanol-water and 77.97 wt% for methanol-water. The bio-oil produced with methanol-water mixture has higher energy content (43.20 MJ/kg) compared to the one obtained with ethanol-water mixture (39.21 MJ/kg). In addition, Fourier transform IR spectroscopy and gas chromatog.-mass spectrometry analyses showed high esters concentrations and low free fatty acid content in the obtained bio-oils.

Fuel published new progress about Alcohols Role: NUU (Other Use, Unclassified), USES (Uses). 929-77-1 belongs to class esters-buliding-blocks, name is Methyl docosanoate, and the molecular formula is C23H46O2, HPLC of Formula: 929-77-1.

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

Tetrisyanda, Rizky published the artcileLiquid-liquid equilibria of ternary aqueous mixtures containing alcohols and alkyl levulinates, Computed Properties of 539-88-8, the main research area is alc alkyl levulinate LLE ternary aqueous mixture.

The liquid-liquid equilibrium (LLE) data were measured for the ternary systems of water + methanol + Et levulinate, water + ethanol + Et levulinate, and water + n-butanol + Bu levulinate in a temperature range of 298.15 K to 328.15 K and at 101.3 kPa. Among the investigated mixtures, the Et levulinate-containing systems are categorized as a type-I LLE and their areas of two-liquid-phase region decreases with increasing temperature The ternary system of water + n-butanol + Bu levulinate behaves as a type-II LLE and interestingly its area of two-liquid-phase region increases with an increase of temperature over the exptl. condition. These new LLE tie-lines data were correlated accurately with the NRTL model.

Journal of Chemical Thermodynamics published new progress about Alcohols Role: NUU (Other Use, Unclassified), USES (Uses). 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

He, Aiyong published the artcileHigh-Efficiency Catalytic Transfer Hydrogenation of Biomass-Based 5-Hydroxymethylfurfural to 2,5-Bis(hydroxymethyl)furan over a Zirconium-Carbon Coordination Catalyst, Computed Properties of 539-88-8, the main research area is catalytic transfer hydrogenation hydroxymethylfurfural hydroxymethylfuran zirconium carbon.

Constructing a cheap and high-performance catalyst is very important for the selective synthesis of biomass-based 2,5-bis(hydroxymethyl)furan (BHMF) from 5-hydroxymethylfurfural via the strategy of catalytic transfer hydrogenation (CTH). Herein, we synthesized a neoteric zirconium-carbon coordination catalyst (Zr-HTC) via a simple self-assembly method, in which glucose-derived hydrothermal carbon (HTC) containing abundant carboxyl and phenolic hydroxyl groups was directly used as a low-cost organic ligand. Satisfyingly, Zr-HTC showed an outstanding catalytic activity for the selective synthesis of BHMF in isopropanol (iPrOH). After 4 h at a mild temperature of 120°C, 99.2% BHMF yield with 5.61 h-1 turnover frequency (TOF) could be obtained. Detailed exptl. results demonstrated that this outstanding catalytic activity of Zr-HTC was mainly contributed by the synergetic effects of Lewis acid-base sites (Zr4+-O2-) with high contents, proper ratios, and strengths under the aid of good hydrophilicity. In addition, Zr-HTC displayed superior catalytic stability, and when it was repeatedly used for five reaction cycles, no noticeable decrease in BHMF yield was found. More significantly, Zr-HTC could also effectively convert a wide range of carbonyl compounds, such as 1-butanal, 1-hexanal, furfural, cyclohexanal, benzaldehyde, phenylacetaldehyde, cyclopentanone, cyclohexanone, levulinic acid, and Et levulinate, to the relevant products in iPrOH. Overall, this work offers a new viewpoint to develop more practical zirconium-containing coordination catalysts for the selective synthesis of valuable chems. via CTH.

ACS Sustainable Chemistry & Engineering published new progress about Alcohols Role: NUU (Other Use, Unclassified), USES (Uses). 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

Pinheiro, Patricia Fontes published the artcileOne-pot synthesis of alkyl levulinates from biomass derivative carbohydrates in tin(II) exchanged silicotungstates-catalyzed reactions, Quality Control of 539-88-8, the main research area is tin exchanged Keggin heteropolyacid catalysis carbohydrate alcoholysis alkyl levulinate.

Biomass is an attractive source of carbohydrates that can be converted to fuels and fine chems. Acid-catalyzed alcoholysis of biomass derivatives provides alkyl levulinates, which are fuel bioadditives, intermediates in the synthesis of drugs and agrochems. In this work, we developed a one-pot route to obtain alkyl levulinates using Sn(II) exchanged Keggin heteropolyacids (i.e., H3PW12O40, H3PMo12O40, and H4SiW12O40) as catalysts, in alcoholysis reactions of various carbohydrates. All the catalysts were characterized by FT-IR, XRD, EDS/SEM, TG/DSC, and BET anal. The tin(II) silicotungstate was the most active and selective catalyst. After 2 h of reaction carried out at 423 K, an almost complete conversion was achieved on the ethanolysis of the fructose, sucrose and inulin, which gave high yields of Et levulinate (ca. 78, 71 and 61 mol%, resp.). In all reactions, 5-ethoxymethylfurfural was always the secondary product. Maltose, galactose, and glucose were almost unreactive. The effects of main parameters of reaction, such as temperature, catalyst load, and type of alcs. were assessed. The Sn2SiW12O40 catalyst was easily recovered and successfully reused for 7 cycles, without loss activity.

Cellulose (Dordrecht, Netherlands) published new progress about Alcohols Role: RCT (Reactant), RACT (Reactant or Reagent). 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Quality Control of 539-88-8.

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

Annatelli, Mattia published the artcileAlkyl Levulinates from Furfuryl Alcohol Using CT151 Purolite as Heterogenous Catalyst: Optimization, Purification, and Recycling, Application of Ethyl 4-oxopentanoate, the main research area is alkyl levulinate preparation; furylmethanol alkyl alc purolite catalyst alcoholysis.

Com. available Purolite CT151 demonstrated to be an efficient acid catalyst for the synthesis of alkyl levulinates via alcoholysis of furfuryl alc. (FA) at mild temperatures (80-120°C) and short reaction time (5 h). Reaction conditions were first optimized for the synthesis of Et levulinate and then tested for the preparation of methyl-, propyl-, isopropyl-, Bu, sec-butyl- and allyl levulinate. Preliminary scale-up tests were carried out for most of the alkyl levulinates (starting from 5.0 g of FA) and the resulting products were isolated as pure by distillation in good yields (up to 63%). Furthermore, recycling experiments, conducted for the preparation of Et levulinate, showed that both the Purolite CT151 and the exceeding ethanol was recovered and reused for four consecutive runs without any noticeable loss in the catalyst activity.

Sustainable Chemistry published new progress about Alcohols Role: RCT (Reactant), RACT (Reactant or Reagent). 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

Pelosi, Azzurra published the artcileReductive Etherification of Aldehydes and Ketones with Alcohols and Triethylsilane Catalysed by Yb(OTf)3: an Efficient One-Pot Benzylation of Alcohols, HPLC of Formula: 5405-41-4, the main research area is ether preparation; aldehyde ketone alc reductive etherification triethylsilane ytterbium triflate catalyst.

The one-pot synthesis of sym. and unsym. ethers from aldehydes and ketones can be conveniently performed using Yb(OTf)3 as catalyst and triethylsilane as reducing agent in presence of alcs. This methodol. leads to the synthesis of ether derivatives with good yields. Notably, this process resulted a useful tool to protect alcs. as benzyl ether derivatives using differently substituted benzaldehydes as protecting agents under mild conditions. A plausible mechanism was also proposed.

Advanced Synthesis & Catalysis published new progress about Alcohols Role: RCT (Reactant), RACT (Reactant or Reagent). 5405-41-4 belongs to class esters-buliding-blocks, name is Ethyl 3-hydroxybutanoate, and the molecular formula is C6H12O3, HPLC of Formula: 5405-41-4.

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

Bernardo, Joana R. published the artcileHReO4 as highly efficient and selective catalyst for the conversion of carbohydrates into value added chemicals, Computed Properties of 539-88-8, the main research area is HReO4 catalyst carbohydrate conversion.

This work describes the first catalyst (HReO4) that promotes the efficient and selective conversion of several carbohydrates into four compounds, Et levulinate (EL), 5-ethoxymethylfurfural (EMF), 5-hydroxymethylfurfural (HMF) and levulinic acid (LA), through a one-pot reaction strategy adjusting the reaction conditions. The reaction of fructose in ethanol at 160 °C gave EL in 80% yield after 16 h and in a mixture of ethanol/THF at 140 °C produced EMF in 73% yield after 1 h. HMF and LA can also be obtained selectively with 100% yield from fructose at 140 °C after 1 h, in DMSO or 1,4-dioxane, resp. EL, HMF, LA and EMF were also produced in moderate to good yields from other carbohydrates such as inulin and sucrose. The catalyst HReO4 can be used in gram scale for the production of EL, EMF, HMF and LA with good yields and in at least 8 catalytic cycles on the conversion of fructose into EL with no significant reduction in its activity.

Molecular Catalysis published new progress about Carbohydrates Role: RCT (Reactant), RACT (Reactant or Reagent). 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