Month: December 2022

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

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

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

Schoneich, Sonia published the artcileDynamic pressure gradient modulation for comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry detection, Product Details of C9H18O2, 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). 111-11-5 belongs to class esters-buliding-blocks, name is Methyl octanoate, and the molecular formula is C9H18O2, Product Details of C9H18O2.

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

Seo, Jin Young published the artcilePorphyrin-cored amphiphilic star block copolymer photocatalysts: Hydrophobic-layer effects on photooxidation, HPLC of Formula: 142-90-5, the main research area is porphyrin amphiphilic star block copolymer photocatalyst photooxidation.

Pd-contained porphyrin-cored (P(Pd)) amphiphilic star block copolymers with a hydrophobic interior, including either poly(Me methacrylate) (PMMA) or poly(dodecyl methacrylate) (PDMA), and poly(ethylene glycol) Me ether methacrylate (PEGMA) hydrophilic outer layer were synthesized by Ru-catalyzed atom transfer radical polymerization (ATRP). The acquired star polymer photocatalysts were examined for photooxidation of furfural. The star polymers with the PDMA hydrophobic interior led to higher efficiency in the photooxidation of furfural than the star polymers without hydrophobic interior and with the PMMA interior. In addition, the grater hydrophobic PDMA fraction exhibited a higher photooxidation efficiency. Those exptl. demonstrated the importance of the hydrophobic interior toward efficient photooxidation We believe that this study provides a fundamental idea in developing amphiphilic star block copolymer photocatalysts.

Materials Letters published new progress about Amphiphiles. 142-90-5 belongs to class esters-buliding-blocks, name is Dodecyl 2-methylacrylate, and the molecular formula is C16H30O2, HPLC of Formula: 142-90-5.

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

Helberg, Julian published the artcilePyridinyl Amide Ion Pairs as Lewis Base Organocatalysts, Product Details of C9H10O2, the main research area is Lewis base organocatalyst pyridinyl amide ion pair; aza Morita Baylis Hillman reaction hindered electrophile isocyanate alc.

Pyridinyl amide ion pairs carrying various electron-withdrawing substituents were synthesized with selected ammonium or phosphonium counterions. Compared to neutral pyridine-based organocatalysts, these new ion pair Lewis bases display superior catalytic reactivity in the reaction of isocyanates with alcs. and the aza-Morita-Baylis-Hillman reaction of hindered electrophiles. The high catalytic activity of ion pair catalysts appears to be due to their high Lewis basicities toward neutral electrophiles as quantified through quantum chem. calculated affinity data.

Journal of Organic Chemistry published new progress about Basicity, Lewis. 140-11-4 belongs to class esters-buliding-blocks, name is Benzyl acetate, and the molecular formula is C9H10O2, Product Details of C9H10O2.

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

Zhang, Xinyuan published the artcileOptimization and validation of a head space solid-phase microextraction-arrow gas chromatography-mass spectrometry method using central composite design for determination of aroma compounds in Chinese liquor (Baijiu), Category: esters-buliding-blocks, the main research area is Baijiu aroma SPME GC MS; Aroma compounds; Central composite design; Chinese liquor (Baijiu); Gas chromatography–mass spectrometry; Headspace solid-phase microextraction Arrow.

A headspace solid-phase microextraction Arrow (HS-SPME Arrow) method coupled with gas chromatog.-mass spectrometry (GC-MS) was developed for the quantitation of a large number of aroma compounds in Chinese liquor (Baijiu). Optimization of extraction conditions by a central composite exptl. design revealed that the dilution of the alc. content of 5 mL of Baijiu to 10%, followed by the addition of 1.5 g of NaCl and subsequent SPME Arrow extraction with DVB/CAR/PDMS fiber coating over 45 min at 45°C was the most suitable. The quant. method allowed the extraction and identification of 82 aroma compounds (esters, alcs., fatty acids, aldehydes & ketones, furans, pyrazines, sulfur compounds, phenols, terpenes, and lactones) in the Baijiu sample. The method was validated with good repeatability, inter and intra-day precision (almost below 15%), and accuracy (almost in the range of 81.5-119.96%). Furthermore, the method was validated successfully for the most significant compounds and was applied to study the composition of volatile compounds in different types of Baijiu. This research proved that SPME Arrow is an effective method for the extraction of aroma compounds in Baijiu and other distilled spirits. This developed method will allow improved anal. of other distilled spirits.

Journal of Chromatography A published new progress about Alcohols Role: ANT (Analyte), ANST (Analytical Study). 106-32-1 belongs to class esters-buliding-blocks, name is Ethyl octanoate, and the molecular formula is C10H20O2, Category: esters-buliding-blocks.

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

Khacef, Leila published the artcileEffect of Solvent on the Mechanical and Structural Properties of N-Alkyldiamide Organogels, COA of Formula: C9H10O2, the main research area is effect solvent mech structural property alkyldiamide organogel.

Here, we study organogels prepared thanks to a new organogelator, the N-oleyldiamide mol., which shows a remarkable propensity to gelify a large scope of solvents, from aprotic to high protic solvents. The solvent plays a key role in the formation and stability of supramol. self-assemblies. However, the understanding and the control of its effects can be complex as many parameters are a priori involved. This study aims to understand the effect of solvent on the structures of organogels and on their final mech. properties. Five solvent classes have been selected ranking from low protic to high protic, according to the Hansen H-bond parameter δh. The solvent proticity appears to be one of the main parameters that affect the organogel internal structure and therefore the final rheol. properties. For a given organogelator fraction, the terminal elastic modulus measured by oscillatory rheol. is observed to increase significantly with the Hansen H-bond solvent parameter δh. Materials of different mech. properties are then shown to display various structures, which are investigated thanks to cryo-SEM. Besides, wide-angle X-ray scattering (WAXS) has been used to probe the gelator organization at the mol. scale with regard to the solvent nature, to understand the supramol. self-assembly of this promising mol.

Langmuir published new progress about Alkanes Role: NUU (Other Use, Unclassified), PEP (Physical, Engineering or Chemical Process), PRP (Properties), USES (Uses), PROC (Process). 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

Liu, Dong-Huang published the artcileCatalytic One-Pot Conversion of Renewable Platform Chemicals to Hydrocarbon and Ether Biofuels through Tandem Hf(OTf)4+Pd/C Catalysis, Name: Ethyl 4-oxopentanoate, the main research area is alkane cyclic ether biofuel biomass catalyst hydrogenation hydrodeoxygenation; biomass; cyclic ethers; hydrocarbons; platform chemicals; tandem catalyst.

Efficient conversion of renewable biomass platform chems. into high-quality fuels remains challenging. A one-pot catalytic approach has been developed to synthesize various structurally defined biofuels by using Hf(OTf)4 and Pd/C for selective tandem catalysis and 2-methylfuran (2-MF) as a renewable feedstock. 2-MF first undergoes Lewis acid-catalyzed hydroxyalkylation/alkylation (HAA) condensation with carbonyl compounds to afford intermediates containing the targeted carbon skeletons of hydrocarbon or ether products, and these intermediates then undergo hydrogenation or hydrodeoxygenation to afford the target products, catalyzed by metal triflate+Pd/C in the same pot. The present process can produce structurally defined alkanes and cyclic ethers under mild conditions.

ChemSusChem published new progress about Biofuels. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Name: Ethyl 4-oxopentanoate.

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

Matsumoto, Mayuko published the artcileOrthogonal Folding of Amphiphilic/Fluorous Random Block Copolymers for Double and Multicompartment Micelles in Water, Related Products of esters-buliding-blocks, the main research area is folding amphiphilic fluorous random copolymer micelle.

Here, we report orthogonal folding and self-assembly systems of amphiphilic/fluorous random block copolymers for double core and multicompartment micelles in water. For this, we developed the precision folding techniques of polymer chains via the selective self-assembly of the pendant groups. Typically, A/C-B/C random block copolymers were designed: Hydrophobic dodecyl groups (A) and fluorous fluorinated octyl groups (B) were introduced into the resp. blocks, while hydrophilic poly(ethylene glycol) chains (C) were randomly incorporated into all the segments. By controlling the chain length and composition of the resp. blocks, the copolymers induce orthogonal single-chain folding in water to form double-compartment micelles comprising hydrophobic and fluorous cores. The copolymers were site-selectively folded in a fluoroalc. to result in tadpole unimer micelles comprising a hydrophobic A/C unimer micelle and an unfolded fluorous B/C chain. Addnl., asym. A/C-B/C random block copolymers with short and highly hydrophobic or fluorous segments were effective for multicompartment micelles in water.

ACS Macro Letters published new progress about Acrylic polymers, polyoxyalkylene-, fluorine-containing, block, triblock, graft Role: PRP (Properties), SPN (Synthetic Preparation), PREP (Preparation). 142-90-5 belongs to class esters-buliding-blocks, name is Dodecyl 2-methylacrylate, and the molecular formula is C16H30O2, Related Products of esters-buliding-blocks.

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