Category: esters-buliding-blocks

Schoneich, Sonia published the artcileDynamic pressure gradient modulation for comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry detection, Related Products of esters-buliding-blocks, the main research area is dynamics pressure modulation comprehensive gas chromatog flight mass spectrometry; Comprehensive two-dimensional gas chromatography; Dynamic pressure gradient modulation; Flow modulation; Mass spectrometry.

Dynamic pressure gradient modulation (DPGM) is studied for comprehensive 2-dimensional gas chromatog. (GC × GC) with time-of-flight mass spectrometry (TOFMS) detection. With DPGM, a com. pneumatic pulse valve is opened to introduce a suitably high auxiliary gas pressure at a T-junction connecting the 1st dimension (1D) and 2nd dimension (2D) columns during the modulation period (PM), temporarily stopping the 1D flow. The valve is then closed for the duration of a pulse width (pw) to re-inject temporally focused 1D eluate onto the 2D column for separation This flow modulation technique is compatible with TOFMS detection using a 2D flow rate of 4 mL/min for the separation of a 90-component test mixture A 25 min separation window using a PM = 1 s and pw = 200 ms for full modulation (and 100% duty cycle) provided an average 1Wb = 4.5 s and 2Wb = 130 ms for a 2-dimensional peak capacity of nc,2D = 2700 (100 peaks per min). The detector response enhancement factor (DREF) serves as a metric for the enhanced sensitivity of the modulated relative to the unmodulated 1D peaks, with DREFs ranging between 10 and 20 and about a 5-fold improvement in signal-to-noise ratio (S/N). The bilinear quality of the GC × GC data is studied using the chemometric method parallel factor anal. (PARAFAC). Since PARAFAC requires sufficiently trilinear data, the reproducibility of the 2D peak shape for a given analyte is confirmed using lack-of-fit (LOF) and percent variation (R2) metrics. The limit-of-detection (LOD) for the representative analyte hexadecane is determined using PARAFAC, providing an LOD of 0.7 ppb (±0.03 ppb) for 3 replicates. Seven heavily overlapped analytes are also fully resolved by PARAFAC down to the part-per-million (ppm) concentration level, producing reproducible spectra with a majority of spectral match values (MV) over 800 (relative standard deviation ≤ 7.1%). This study provides promising results for DPGM as a flow modulation technique compatible with GC × GC-TOFMS, providing high sensitivity data suitable for chemometric anal.

Journal of Chromatography A published new progress about Alkanes Role: ANT (Analyte), PEP (Physical, Engineering or Chemical Process), PRP (Properties), ANST (Analytical Study), PROC (Process). 110-42-9 belongs to class esters-buliding-blocks, name is Methyl decanoate, and the molecular formula is C11H22O2, Related Products of esters-buliding-blocks.

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

Yuan, Qian published the artcileTriptycene-based dicationic guanidinium ionic liquid: A novel stationary phase of high selectivity towards a wide range of positional and structural isomers, Product Details of C11H22O2, the main research area is triptycene derivative dicationic guanidinium ionic liquid stationary GC isomer; Aromatic and aliphatic isomers; Dicationic guanidinium ionic liquid, gas chromatography; Essential oil; Separation performance; Triptycene-based stationary phase.

This work presents a new triptycene-based dicationic guanidinium ionic liquid (TPG) as the stationary phase for gas chromatog. (GC). To knowledge, this is the 1st example of employing a dicationic guanidinium ionic liquid (GIL) for chromatog. analyses. As a result, the TPG column exhibited moderate polarity and column efficiency of 3840 plates/m and 3120 plates/m measured by naphthalene and 1-octanol at 120°, resp. Particularly, the TPG column exhibited distinctly advantageous performance for the challenging Grob test mixture and the isomer mixture of phenols and anilines over the monocationic GIL and its counterpart with dicationic immidazolium units (TP-2IL). Also, it showed higher selectivity towards the isomers of alkanes, alcs., diethylbenzenes, bromotoluenes, bromonitrobenzenes than the com. DB-35MS column. Also, the TPG column achieved improved thermal stability over the GIL column and excellent repeatability with the relative standard deviation values of 0.01-0.05% for run-to-run, 0.11-0.24% for day-to-day and 2.4-4.1% for column-to-column. Its application to GC-MS anal. of the essential oil of Mentha haplocalyx proved its good potential for anal. of complex samples.

Journal of Chromatography A published new progress about Alkanes Role: ANT (Analyte), PEP (Physical, Engineering or Chemical Process), PRP (Properties), ANST (Analytical Study), PROC (Process). 110-42-9 belongs to class esters-buliding-blocks, name is Methyl decanoate, and the molecular formula is C11H22O2, Product Details of C11H22O2.

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

Nykaza, Trevor V. published the artcilePIII/PV=O Catalyzed Cascade Synthesis of N-Functionalized Azaheterocycles, Application of Methyl 2-(4,5-dimethoxy-2-nitrophenyl)acetate, the main research area is azaheterocycle preparation organophosphorus catalyst cascade; cross-coupling; cyclization; nitrogen heterocycles; organocatalysis; phosphorus.

An organocatalytic method for the modular synthesis of diverse N-aryl and N-alkyl azaheterocycles (indoles, oxindoles, benzimidazoles, and quinoxalinediones) is reported. The method employs a small-ring organophosphorus-based catalyst (1,2,2,3,4,4-hexamethylphosphetane P-oxide) and a hydrosilane reductant to drive the conversion of ortho-functionalized nitroarenes into azaheterocycles through sequential intermol. reductive C-N cross coupling with boronic acids, followed by intramol. cyclization. This method enables the rapid construction of azaheterocycles from readily available building blocks, including a regiospecific approach to N-substituted benzimidazoles and quinoxalinediones.

Angewandte Chemie, International Edition published new progress about Benzimidazoles Role: SPN (Synthetic Preparation), PREP (Preparation). 2982-53-8 belongs to class esters-buliding-blocks, name is Methyl 2-(4,5-dimethoxy-2-nitrophenyl)acetate, and the molecular formula is C11H13NO6, Application of Methyl 2-(4,5-dimethoxy-2-nitrophenyl)acetate.

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

Wang, Xueqin published the artcileHeadspace Volatiles and Endogenous Extracts of Prunus mume Cultivars with Different Aroma Types, Name: Benzyl acetate, the main research area is Prunus mume endogenous extract aroma gas chromatog mass spectrometry; GC-MS; HS-SPME; OSE; Prunus mume; aroma types; endogenous extracts; headspace volatiles.

Prunus mume is a traditional ornamental plant, which owed a unique floral scent. However, the diversity of the floral scent in P. mume cultivars with different aroma types was not identified. In this study, the floral scent of eight P. mume cultivars was studied using headspace solid-phase microextraction (HS-SPME) and organic solvent extraction (OSE), combined with gas chromatog.-mass spectrometry (GC-MS). In total, 66 headspace volatiles and 74 endogenous extracts were putatively identified, of which phenylpropanoids/benzenoids were the main volatile organic compounds categories. As a result of GC-MS anal., benzyl acetate (1.55-61.26%), eugenol (0.87-6.03%), benzaldehyde (5.34-46.46%), benzyl alc. (5.13-57.13%), chavicol (0-5.46%), and cinnamyl alc. (0-6.49%) were considered to be the main components in most varieties. However, the volatilization rate of these main components was different. Based on the variable importance in projection (VIP) values in the orthogonal partial least-squares discriminate anal. (OPLS-DA), differential components of four aroma types were identified as biomarkers, and 10 volatile and 12 endogenous biomarkers were screened out, resp. The odor activity value (OAV) revealed that several biomarkers, including (Z)-2-hexen-1-ol, pentyl acetate, (E)-cinnamaldehyde, Me salicylate, cinnamyl alc., and benzoyl cyanide, contributed greatly to the strong-scented, fresh-scented, sweet-scented, and light-scented types of P. mume cultivars. This study provided a theor. basis for the floral scent evaluation and breeding of P. mume cultivars.

Molecules published new progress about Biomarkers. 140-11-4 belongs to class esters-buliding-blocks, name is Benzyl acetate, and the molecular formula is C9H10O2, Name: Benzyl acetate.

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

Joung, Seewon published the artcileNi-catalyzed 1,2-benzylboration of 1,2-disubstituted unactivated alkenes, Quality Control of 140-11-4, the main research area is nickel catalyzed benzylboration disubstituted unactivated alkene.

Nickel-catalyzed 1,2-carboboration of alkenes is emerging as a useful method for chem. synthesis. Prior studies have been limited to only the incorporation of aryl groups. In this manuscript, a method for the 1,2-benzylboration of unactivated alkenes is presented. The reaction combines readily available alkenes, diboron reagents and benzylchlorides to generate synthetically versatile products with control of stereochem. The utility of the products as well as the mechanistic details of the process are also presented.

Chemical Science published new progress about Borylation (benzylboration). 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

Mangas-Sanchez, Juan published the artcileAsymmetric synthesis of primary amines catalyzed by thermotolerant fungal reductive aminases, Computed Properties of 539-88-8, the main research area is ketone ammonia fungal aminase catalyst enantioselective reductive amination; amine preparation.

The structural and biochem. characterization as well as synthetic applications of two RedAms from Neosartorya spp. was described. (NfRedAm and NfisRedAm) that displayed a distinctive activity amongst fungal RedAms, namely a superior ability to use ammonia as the amine partner. Using these enzymes, The synthesis of a broad range of primary amines, with conversions up to >97% and excellent enantiomeric excess was demonstrated . Temperature dependent studies showed that these homologues also possess greater thermal stability compared to other enzymes within this family. Their synthetic applicability was further demonstrated by the production of several primary and secondary amines with turnover numbers (TN) up to 14 000 as well as continous flow reactions, obtaining chiral amines such as (R)-2-aminohexane in space time yields up to 8.1 g L-1 h-1. The remarkable features of NfRedAm and NfisRedAm highlight their potential for wider synthetic application as well as expanding the biocatalytic toolbox available for chiral amine synthesis.

Chemical Science published new progress about Aspergillus fischeri. 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

Xu, Longjie published the artcilePreparation of scented teas by sustained-release of aroma from essential oils-casein nanocomposites, HPLC of Formula: 140-11-4, the main research area is green tea aroma essential oil casein nanocomposite.

The traditional scenting process is complicated and limited by the short flower season. In this study, formulated jasmine essential oil-casein nanoparticles (JEO-CS-NPs) were prepared for scenting green tea, in this case, Huangshan Maofeng. The freeze-dried JEO-CS-NPs (FD-JEO-CS-NPs) with a JEO/CS ratio of 0.25 encapsulated more than 70% of the JEO, and the JEO could be sustainably released for 60 days. After being scented by placing FD-JEO-CS-NPs in the tea package for 50-60 days at room temperature, the tea leaves effectively adsorbed and retained the aromatic compounds and presented a favorable smell of jasmine fragrance with good aroma maintenance. This could be ascribed to the sustained-release of aromatic compounds from the FD-JEO-CS-NPs. The new technol. also avoided destroying the color of the soaked tea liquid and infused leaf since the scenting process is performed in the tea package using the antioxidative jasmine essential oil. The research showed that the new scenting technol. can be extensively applied for the production of tea leaves scented with various flower fragrances.

LWT–Food Science and Technology published new progress about Essential oils Role: BSU (Biological Study, Unclassified), FFD (Food or Feed Use), NAN (Nanomaterial), BIOL (Biological Study), USES (Uses). 140-11-4 belongs to class esters-buliding-blocks, name is Benzyl acetate, and the molecular formula is C9H10O2, HPLC of Formula: 140-11-4.

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

Schweitzer-Chaput, Bertrand published the artcilePhotochemical generation of radicals from alkyl electrophiles using a nucleophilic organic catalyst, COA of Formula: C9H10O2, the main research area is photochem generation carbon radical alkyl electrophile nucleophilic thiocarbamate organocatalyst.

Chemists extensively use free radical reactivity for applications in organic synthesis, materials science, and life science. Traditionally, generating radicals requires strategies that exploit the bond dissociation energy or the redox properties of the precursors. Here, we disclose a photochem. catalytic approach that harnesses different phys. properties of the substrate to form carbon radicals. We use a nucleophilic dithiocarbamate anion catalyst, adorned with a well-tailored chromophoric unit, to activate alkyl electrophiles via an SN2 pathway. The resulting photon-absorbing intermediate affords radicals upon homolytic cleavage induced by visible light. This catalytic SN2-based strategy, which exploits a fundamental mechanistic process of ionic chem., grants access to open-shell intermediates from a variety of substrates that would be incompatible with or inert to classical radical-generating strategies. We also describe how the method’s mild reaction conditions and high functional group tolerance could be advantageous for developing C-C bond-forming reactions, for streamlining the preparation of a marketed drug, for the late-stage elaboration of biorelevant compounds and for enantioselective radical catalysis.

Nature Chemistry published new progress about Alkenes, electron-deficient 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, COA of Formula: C9H10O2.

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

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