Month: December 2022

McCourt, Ruairi O. published the artcileA Sequential Acyl Thiol-Ene and Thiolactonization Approach for the Synthesis of δ-Thiolactones, Quality Control of 539-88-8, the main research area is thiolactone synthesis unsaturated ester acyl thiol ene Steglich thiolactonization.

A novel strategy for the synthesis of δ-thiolactones from inexpensive and readily available γ-unsaturated esters has been developed. This strategy incorporates a radical acyl thiol-ene reaction as the key C-S bond forming step. Cyclization is achieved via a Steglich-type thiolactonization of 5-mercaptopentanoic acids. We report the facile and scalable synthesis of δ-thiolactones in moderate to good yield under mild reaction conditions with tolerance for a range of functional groups.

Organic Letters published new progress about Johnson-Claisen rearrangement (for synthesis of γ-unsaturated esters). 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

Wang, Tao published the artcileSynthesis, catalysis, and DFT study of a ruthenium carbene complex bearing a 1,2-dicarbadodecaborane (12)-1,2-dithiolate ligand, Formula: C10H10O2, the main research area is ruthenium carbene dicarbadodecaborane dithiolate complex preparation DFT calculation study; carbene ruthenium dicarbadodecaborane dithiolate ring opening metathesis polymerization catalyst; ring opening cross metathesis catalyst carbene ruthenium dicarbadodecaborane dithiolate; crystal structure mol ruthenium carbene dicarbadodecaborane dithiolate complex optimized.

A ruthenium carbene catalyst containing a 1,2-dicarbadodecaborane(12)-1,2-dithiolate ligand was synthesized, and the structure was determined by single crystal x-ray diffraction. This new ruthenium carbene catalyst can catalyze the ring opening metathesis polymerization (ROMP) reaction of norbornene to give the corresponding Z-polymer (Z/E ratio, 98:2) in high yield (93%); ring opening cross metathesis (ROCM) reactions of norbornene/5-norbornene-2-exo, 3-exo-dimethanol with styrene or 4-fluorostyrene to give the corresponding Z-olefin products (Z/E ratios, 97:3-98:2), resp., in high yields (73%-88%); cross metathesis (CM) reactions of terminal alkenes with (Z)-but-2-ene-1,4-diol to give high Z-olefin products in low yields; homometathesis reactions of terminal alkenes to give olefin products in low yields. Like other ruthenium carbene catalysts, the new complex tolerates many different functional groups. DFT calculations were also performed in order to understand the process of forming Z-olefin products and the decomposition process of catalysts.

Dalton Transactions published new progress about Crystal structure. 583-04-0 belongs to class esters-buliding-blocks, name is Allyl benzoate, and the molecular formula is C10H10O2, Formula: C10H10O2.

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

Khidr, T. T. published the artcilePreparation and evaluation of n-alkyl methylacrylatemethylacrylate-vinyl acetate-methacrylic acid terpolymers as pour point depressant for fuel, Name: Dodecyl 2-methylacrylate, the main research area is alkyl methylacrylate vinyl acetate terpolymer pour point depressant fuel.

A variety of techniques have been employed in order to reduce problems caused by the crystallization of paraffin during the production Four different alkyl chain length of n-alkyl methacrylate-vinyl acetate-methacrylic acid terpolymers were prepared and characterized by the IR spectrometer, and the mol. weight of the prepared additives was determined by using gel permeation chromatog. anal. The performance of the prepared terpolymers as pour point depressants additives for fuel oil. The efficiency of the prepared compounds on pour point depressants for fuel oil increases by increasing the concentration of these additives and the alkyl chain length of n-alkyl methacrylate. The X- ray diffractometer patterns of wax in the absence and presence of investigated additives were studied. Comparison of morphologies and structures of waxy crystals in fuel oil beneficiated with and without a pour point depressant was made by micro photog. studies which show the modification in wax morphol. due to the additive.

Petroleum & Coal published new progress about Crystallization. 142-90-5 belongs to class esters-buliding-blocks, name is Dodecyl 2-methylacrylate, and the molecular formula is C16H30O2, Name: Dodecyl 2-methylacrylate.

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

Hamulic, Damir published the artcileThe influence of length of alkyl chain on the chemical structure and corrosion resistance of silica-polyacrylic hybrid coatings on structural steel, Product Details of C16H30O2, the main research area is methacrylic polysiloxane anticorrosive coating transparency morphol wettability impedance.

Hybrid coatings were prepared, via a sol-gel route from 3-(trimethoxysilyl)propyl methacrylate (MAPTMS), tetra-Et orthosilicate (TEOS), and derivatives of methacrylate (methyl-, ethyl-, butyl-, hexyl-, octyl- and dodecyl methacrylate). The main goal of this study was to evaluate how the length of the alkyl chain of the ester part of a methacrylate influences the anti-corrosion property of the coatings. Fourier transform IR spectroscopy, NMR spectroscopy, contact angle measurements, and SEM with chem. anal. were used to determine the chem. composition, structure, wettability and morphol. of the coatings. The contact angle of the coatings increased from methyl- to butyl-containing coating (from 60° up to 80°); at the same time the surface free energy decreased. For longer chains, a plateau was reached (≈75°), which was in contrast to the prediction that a longer chain would result in reduced wettability due to its nonpolar alkyl part. The anti-corrosion behavior in 3.5 weight % NaCl of the coatings deposited on structural steel was studied by electrochem. impedance spectroscopy. The coatings with Et and Bu groups exhibited the best anti-corrosion performance and remained intact over six months of immersion. The related values of impedance magnitude at low frequency was 1010 Ω cm2 after six months. This high corrosion resistance was due to the appropriate combination of condensation degree and wettability. Coatings with longer alkyl chains (hexyl, octyl, and dodecyl) showed poor corrosion resistance due to lower heterocondensation and a larger nonpolar effect that resulted in non-homogenous mixing, which could not produce dense and protective coatings.

Progress in Organic Coatings published new progress about Anticorrosive coating materials. 142-90-5 belongs to class esters-buliding-blocks, name is Dodecyl 2-methylacrylate, and the molecular formula is C16H30O2, Product Details of C16H30O2.

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

Issa, Marwa Y. published the artcileVolatiles distribution in jasmine flowers taxa grown in Egypt and its commercial products as analyzed via solid-phase microextraction (SPME) coupled to chemometrics, Quality Control of 140-11-4, the main research area is Jasminum solid phase microextraction chemometric.

Jasmine is one of the most valuable com. oil bearing plants from family Oleaceae used for the production of jasmine scent mostly in the form of concrete and absolute Being an export commodity, development of reliable anal. methods for its jasmine species and derived products authentication and or adulterants detection should now follow. A comparative volatiles profiling of Jasminum grandiflorum L., J. multiflorum (Burm. f.) Andrews and J. sambac (L.) Aiton flowers in addition to J. grandiflorum products viz., concrete and absolute at different time periods was performed using solid phase microextraction (SPME) coupled to GC/MS. A total of 77 volatiles were identified belonging to esters, alcs., sesquiterpenes, ketones, aldehydes, phenols, hydrocarbons and nitrogenous compounds The phenylpropanoid/benzenoid and terpenoid classes were the major volatile classes in jasmine. Benzyl acetate was the chief scent volatile whereas major terpenoids included linalool, nerolidol, α-farnesene and cis-jasmone. Results revealed aroma variation among different flowers and products obtained from J. grandiflorum at different months. This study provides the first comprehensive and comparative aroma profile for Egyptian Jasminum species along with its products that could be used for its future quality control in industry.

Industrial Crops and Products published new progress about Aldehydes Role: ANT (Analyte), COS (Cosmetic Use), PUR (Purification or Recovery), ANST (Analytical Study), BIOL (Biological Study), USES (Uses), PREP (Preparation). 140-11-4 belongs to class esters-buliding-blocks, name is Benzyl acetate, and the molecular formula is C9H10O2, Quality Control of 140-11-4.

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

Imyen, Thidarat published the artcileInvestigation of ZSM-12 nanocrystals evolution derived from aluminosilicate nanobeads for sustainable production of ethyl levulinate from levulinic acid esterification with ethanol, Quality Control of 539-88-8, the main research area is aluminosilicate nanobead zeolite nanocrystal ethanol levulinic acid esterification.

The evolution of hierarchical ZSM-12 nanosized crystals as a function of crystallization time has been demonstrated using amorphous aluminosilicate (AS) nanobeads as simultaneous silica and alumina sources and cyclic diquaternary ammonium as a structure-directing agent (SDA) in a one-pot hydrothermal synthesis. The physicochem. properties of the derived ZSM-12 products were characterized by means of x-ray diffraction (x-ray diffraction), x-ray fluorescence spectroscopy (XRF), Fourier transform IR (FTIR) spectroscopy, SEM, TEM, energy dispersive x-ray spectroscopy (EDS) elemental anal., N2 physisorption, temperature-programmed desorption of ammonia (NH3-TPD), and pyridine adsorption. It is clearly demonstrated that crystallinity, textural properties, and acidity of the zeolite products are enhanced as a function of crystallization time. The structure of nanocrystalline ZSM-12 is well-developed after 120 h of crystallization and the corresponding zeolite product exhibits the promising catalytic performance for sustainable production of Et levulinate (EL) from levulinic acid (LA) esterification with ethanol. This contribution illustrates an alternative way to synthesize hierarchical zeolite nanocrystals with MTW framework via the use of homogeneously dispersed aluminosilicate nanobeads as the starting materials and opens up the perspectives for the sustainable application of zeolites nanosized crystals in a bulky-mol. reaction of bio-based chem. synthesis.

Microporous and Mesoporous Materials published new progress about Bronsted acidity. 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

Gu, Wen-Ting published the artcileNon-targeted metabolomic analysis of variation of volatile fractions of ginseng from different habitats by HS-SPME-GC-MS coupled with chemometrics, Formula: C10H20O2, the main research area is Panax metabolomic volatile compound chemometrics solid phase microextraction.

Cultivated ginseng (CG), transplanted ginseng (TG) and mountain cultivated ginseng (MCG) classified by the habitat type all belong to Panax ginseng and were reported to have similar types of secondary metabolites. Nonetheless, owing to the distinctly diverse habitats in which these ginseng types grow, their pharmacol. effects differ. In the present study, an emerging anal. approach involving headspace solid-phase microextraction-gas chromatog.-mass spectrometry (HS-SPME-GC-MS) was established to effectively distinguish among CG, TG and MCG. First, the volatile components were analyzed and identified by using the NIST library combined with measured retention indexes (Kovats′, RI), and a total of 78 volatile components were finally characterized, which included terpenes, alcs., esters, aldehydes and alkynols. Furthermore, multivariate statistical approaches, principal component anal. (PCA) and orthogonal partial least-squares discrimination anal. (OPLS-DA) were subsequently utilized to screen for compounds of significance. Under optimized HS-SPME-GC-MS conditions, 12, 16, and 16 differential markers were screened in the CG-TG, CG-MCG and TG-MCG groups, resp. Our study suggested that HS-SPME-GC-MS anal. combined with metabolomic anal. methods and chemometric techniques can be applied as potent tools to identify chem. marker candidates to distinguish CG, TG and MCG.

Analytical Methods published new progress about Aldehydes Role: BSU (Biological Study, Unclassified), PUR (Purification or Recovery), THU (Therapeutic Use), BIOL (Biological Study), PREP (Preparation), USES (Uses). 106-32-1 belongs to class esters-buliding-blocks, name is Ethyl octanoate, and the molecular formula is C10H20O2, Formula: C10H20O2.

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

Gu, Wen-Ting published the artcileNon-targeted metabolomic analysis of variation of volatile fractions of ginseng from different habitats by HS-SPME-GC-MS coupled with chemometrics, SDS of cas: 41114-00-5, the main research area is Panax metabolomic volatile compound chemometrics solid phase microextraction.

Cultivated ginseng (CG), transplanted ginseng (TG) and mountain cultivated ginseng (MCG) classified by the habitat type all belong to Panax ginseng and were reported to have similar types of secondary metabolites. Nonetheless, owing to the distinctly diverse habitats in which these ginseng types grow, their pharmacol. effects differ. In the present study, an emerging anal. approach involving headspace solid-phase microextraction-gas chromatog.-mass spectrometry (HS-SPME-GC-MS) was established to effectively distinguish among CG, TG and MCG. First, the volatile components were analyzed and identified by using the NIST library combined with measured retention indexes (Kovats′, RI), and a total of 78 volatile components were finally characterized, which included terpenes, alcs., esters, aldehydes and alkynols. Furthermore, multivariate statistical approaches, principal component anal. (PCA) and orthogonal partial least-squares discrimination anal. (OPLS-DA) were subsequently utilized to screen for compounds of significance. Under optimized HS-SPME-GC-MS conditions, 12, 16, and 16 differential markers were screened in the CG-TG, CG-MCG and TG-MCG groups, resp. Our study suggested that HS-SPME-GC-MS anal. combined with metabolomic anal. methods and chemometric techniques can be applied as potent tools to identify chem. marker candidates to distinguish CG, TG and MCG.

Analytical Methods published new progress about Aldehydes Role: BSU (Biological Study, Unclassified), PUR (Purification or Recovery), THU (Therapeutic Use), BIOL (Biological Study), PREP (Preparation), USES (Uses). 41114-00-5 belongs to class esters-buliding-blocks, name is Ethyl pentadecanoate, and the molecular formula is C17H34O2, SDS of cas: 41114-00-5.

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

Feng, Ming-Xin published the artcileEvolution of volatile profile and aroma potential of ‘Gold Finger’ table grapes during berry ripening, Computed Properties of 106-32-1, the main research area is grape berry ripening volatile aromatic compound; aroma potential; aroma profile; ripening; ‘Gold Finger’ grape.

‘Gold Finger’ is a grape cultivar with a finger-like shape and a milk flavor. The process by which its aroma profile evolves during ripening is unclear. Thus, changes in the free and bound volatile compounds present in ‘Gold Finger’ grapes during ripening were investigated using headspace sampling-solid-phase microextraction-gas chromatog.-mass spectroscopy (HS-SPME-GC-MS). A total of 83 volatile aroma components were identified in the grapes, with aldehydes, esters, acids, and alcs. being the main components. The total aroma compound content exhibited significant differences between the bound and free forms. The total content of bound volatile compounds did not change significantly during fruit development, although the free aroma compound content was significantly higher than the bound content. The total content of free aldehydes, free alcs., bound norisoprenoids, and ketones gradually increased for up to 70 days after flowering (DAF), while the total free ester, terpene, and acid content decreased. The characteristic aroma compounds of ‘Gold Finger’ grapes were identified as hexanal, (E)-2-hexenal, and Et hexanoate. These results give a foundation for the further development of ‘Gold Finger’ grapes and provide a theor. basis for the selection and breeding of novel aromatic grape varieties. 2021 Society of Chem. Industry.

Journal of the Science of Food and Agriculture published new progress about Alcohols Role: ANT (Analyte), FFD (Food or Feed Use), PUR (Purification or Recovery), ANST (Analytical Study), BIOL (Biological Study), USES (Uses), PREP (Preparation). 106-32-1 belongs to class esters-buliding-blocks, name is Ethyl octanoate, and the molecular formula is C10H20O2, Computed Properties of 106-32-1.

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

Ponomareva, Ekaterina published the artcileNovel reactivation allows effective reuse of Nafion super-acid nano-catalyst, SDS of cas: 111-11-5, the main research area is octanoic acid methanol Nafion zeolite esterification catalyst.

The reactivation strategy makes use of advanced oxidation processes (Fenton and non-Fenton) to remove the organic deposits generated from sequential catalytic cycles. Hot water treatment was considered as a control case to evaluate the extraction capacity of water itself at the oxidative conditions. Advanced oxidation processes were effective in reactivating the Nafion SAC-13 resin, which also rendered a cleaner and more sustainable reactivation process. Beta zeolite was studied as model fouled system prior to the Nafion SAC-13. Even though zeolites are considered to be thermally stable, this approach can be used when a full preservation of the acid sites is required. As far as resin Nafion SAC-13 is concerned, organic species deposition was found to be responsible of a selective poisoning of the sulfonic groups in Nafion, with a consequent drop in catalytic activity of the octanoic acid esterification with methanol. The Nafion resin was reactivated either with H2O2 or with Fenton chem.; the resin remained stable under these oxidative conditions, which is the benefit of the presented nonthermal methodologies as compared to calcination. The optimal method showed full recovery of the initial activity and 90% of the final conversion. This methodol. seems attractive for a whole-range of organic catalytic reactions, including those related to biomass valorization, that require the use of highly acidic catalysts, such as acidic resins, in liquid phase reactions.

Applied Catalysis, A: General published new progress about Beta zeolites, NH4 Role: CAT (Catalyst Use), PEP (Physical, Engineering or Chemical Process), PRP (Properties), USES (Uses), PROC (Process) (CP 814E). 111-11-5 belongs to class esters-buliding-blocks, name is Methyl octanoate, and the molecular formula is C9H18O2, SDS of cas: 111-11-5.

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