Month: December 2022

Feng, Chengqi published the artcileAcidolysis mechanism of lignin from bagasse during p-toluenesulfonic acid treatment, SDS of cas: 134-96-3, the publication is Industrial Crops and Products (2022), 114374, database is CAplus.

Lignin was efficiently separated from lignocellulosic biomass using p-toluenesulfonic acid (p-TsOH) treatment. However, lignin depolymerization and acidolysis have not been studied to date. In this study, the mechanism of lignin acidolysis was investigated. The structure of lignin in bagasse before and after the p-TsOH treatment was analyzed. The efficiency and selectivity of lignin depolymerization were evaluated. The lignin removal rate reached 88.81%. Hemicellulose was completely removed from lignin, and cellulose destruction was inhibited. The structure of lignin in bagasse was analyzed using NMR. The results revealed that α-methoxylated β-O-4 intermediates were formed during lignin depolymerization This indicated that the benzyl ether bonds were effectively catalyzed and broke, thereby promoting lignin dissolution The lignin-carbohydrate complex structure was destroyed. The insoluble and soluble lignin in the hydrolyzate were analyzed using NMR and gas chromatog.-mass spectrometry. The results indicated that the catalyst promoted breaking of the C_β-O bonds in the β-O-4 structures. Phenols and Hibbert ketones were formed. In addition, lignin sulfonation was confirmed by the presence of di-o-tolusulfone and di-p-tolusulfone. The low contents of β-β and β-5 bonds in the reaction products indicated that lignin condensation was inhibited. The results demonstrated that lignin acidolysis was synergistically catalyzed by H⁺ and p-TsOH. It provides important theor. support for efficient and clean separation of lignin using the p-TsOH treatment.

Industrial Crops and Products published new progress about 134-96-3. 134-96-3 belongs to ethers-buliding-blocks, auxiliary class Immunology/Inflammation,COX,Natural product, name is 4-Hydroxy-3,5-dimethoxybenzaldehyde, and the molecular formula is C9H10O4, SDS of cas: 134-96-3.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Yan, Boyu published the artcileCatalyst-free reductive hydrogenation or deuteration of aryl-heteroatom bonds induced by light, SDS of cas: 93-04-9, the publication is Organic Chemistry Frontiers (2021), 8(19), 5244-5249, database is CAplus.

A simple and catalyst-free photochem. strategy for the direct reduction of aryl trimethylammonium salts ArNMe₃OTf (Ar = biphenyl-4-yl, 2-naphthyl, quinolin-3-yl, etc.), aryl triflates Ar¹OTf (Ar¹ = biphenyl-3-yl, 1,6-dimethylpyridin-4-yl, benzothiazol-5-yl, etc.), and haloarenes Ar²X (Ar² = biphenyl-4-yl, 2-naphthyl, quinolin-4-yl, etc.; X = Cl, Br, I) to arenes ArH/Ar¹H or deuterium-labeled arenes ArD/Ar¹D/Ar²D was described. A broad range of substrate scope was demonstrated with high yields and deuterium incorporations. Radical clock experiments indicate the formation of aryl radical intermediates that can also be trapped by phenols.

Organic Chemistry Frontiers published new progress about 93-04-9. 93-04-9 belongs to ethers-buliding-blocks, auxiliary class Naphthalene,Ether, name is 2-Methoxynaphthalene, and the molecular formula is C19H14O2, SDS of cas: 93-04-9.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Sabat, Nazarii published the artcileUnbiased C3-Electrophilic Indoles: Triflic Acid Mediated C3-Regioselective Hydroarylation of N-H Indoles, Product Details of C8H10O2, the publication is Angewandte Chemie, International Edition (2022), 61(30), e202204400, database is CAplus and MEDLINE.

The direct dearomative addition of arenes to the C3 position of unprotected indoles is reported under operationally simple conditions, using triflic acid at room temperature The present regioselective hydroarylation is a straightforward manner to generate an electrophilic indole at the C3 position from unbiased indoles in sharp contrast to previous strategies. This atom-economical method delivers biol. relevant 3-arylindolines and 3,3-spiroindolines in high yields and regioselectivities from both intra- and intermol. processes. DFT computations suggest the stabilization of cationic or dicationic intermediates with H-bonded (TfOH)n clusters.

Angewandte Chemie, International Edition published new progress about 91-16-7. 91-16-7 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether,Inhibitor,Inhibitor,Inhibitor, name is 1,2-Dimethoxybenzene, and the molecular formula is C8H10O2, Product Details of C8H10O2.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Wang, Yuexin published the artcileCooperative Photocatalysis with 4-Amino-TEMPO for Selective Aerobic Oxidation of Amines over TiO₂ Nanotubes, Formula: C8H11NO, the publication is Chemistry – An Asian Journal (2021), 16(18), 2659-2668, database is CAplus and MEDLINE.

Attaching π-conjugated mols. onto TiO₂ can form surface complexes that could capture visible light. However, to make these TiO₂ surface complexes durable, integrating 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) or its analogs as a redox mediator with photocatalysis is the key to constructing selective chem. transformations. Herein, sodium 6,7-dihydroxynaphthalene-2-sulfonate (DHNS) was obtained by extending the π-conjugated system of catechol by adding a benzene ring and a substituent sodium sulfonate (-SO₃^–Na⁺). The DHNS-TiO₂ showed the best photocatalytic activity towards the blue light-induced selective aerobic oxidation of benzylamine. Compared to TEMPO, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl (4-amino-TEMPO) could rise above 70% in conversion of benzylamine over the DHNS-TiO₂ photocatalyst. Eventually, a wide range of amines could be selectively oxidized into imines with atm. O₂ by cooperative photocatalysis of DHNS-TiO₂ with 4-amino-TEMPO. Notably, superoxide (O₂^•-) is crucial in coupling the photocatalytic cycle of DHNS-TiO₂ and the redox cycle of 4-amino-TEMPO. This work underscores the design of surface ligands for semiconductors and the selection of a redox mediator in visible light photocatalysis for selective chem. transformations.

Chemistry – An Asian Journal published new progress about 6850-57-3. 6850-57-3 belongs to ethers-buliding-blocks, auxiliary class Amine,Benzene,Ether, name is (2-Methoxyphenyl)methanamine, and the molecular formula is C15H12O8, Formula: C8H11NO.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Liu, Panpan published the artcileDynamic changes in the aroma profile of Qingzhuan tea during its manufacture, Formula: C8H10O2, the publication is Food Chemistry (2022), 131847, database is CAplus and MEDLINE.

Changes in key odorants and aroma profiles of Qingzhuan tea (QZT) during its manufacture were determined using headspace solid-phase microextraction gas chromatog.-mass spectrometry/olfactometry. An aroma profile was constructed to illustrate sensory changes during manufacture The characteristic aroma of QZT was aged fragrance, which was mostly developed during pile fermentation and was enhanced during the aging and drying stages. Using volatile compounds found in the raw materials, sun-dried green tea and QZT finished product were compared by orthogonal partial least square-discriminant anal. Among 108 detected volatiles, 19 were significantly upregulated and 15 were downregulated. (E)-β-Ionone, (E,Z)-2,6-nonadienal, 1-octen-3-one, (E,E)-2,4-heptadienal, (E,E)-2,4-nonadienal, safranal, (E)-2-nonenal, α-ionone, and 1,2,3-trimethoxybenzene were found to be significant contributors to the aged QZT fragrance, reflecting their high odor-activity values and aroma intensities. Finally, the metabolic transformation of key aroma-active compounds was systematically analyzed. This study provided a theor. basis for improving the processing and quality of QZT.

Food Chemistry published new progress about 91-16-7. 91-16-7 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether,Inhibitor,Inhibitor,Inhibitor, name is 1,2-Dimethoxybenzene, and the molecular formula is C8H10O2, Formula: C8H10O2.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Yuan, Tao published the artcileCeramic boron carbonitrides for unlocking organic halides with visible light, Safety of 2-Methoxynaphthalene, the publication is Chemical Science (2021), 12(18), 6323-6332, database is CAplus and MEDLINE.

Here, boron carbonitride (BCN) ceramics were such a system and can reduce organic halides, including (het)aryl and alkyl halides, with visible light irradn was reported. Cross-coupling of halides to afford new C-H, C-C, and C-S bonds was proceeded at ambient reaction conditions. Hydrogen, (het)aryl, and sulfonyl groups were introduced into the arenes and heteroarenes at the designed positions by means of mesolytic C-X (carbon-halogen) bond cleavage in the absence of any metal-based catalysts or ligands. BCN was used not only for half reactions, like reduction reactions with a sacrificial agent, but also redox reactions through oxidative and reductive interfacial electron transfer. The BCN photocatalyst showed tolerance to different substituents and conserved activity after five recycles. The apparent metal-free system opened new opportunities for a wide range of organic catalysts using light energy and sustainable materials, which were metal-free, inexpensive and stable.

Chemical Science published new progress about 93-04-9. 93-04-9 belongs to ethers-buliding-blocks, auxiliary class Naphthalene,Ether, name is 2-Methoxynaphthalene, and the molecular formula is C9H9ClN2, Safety of 2-Methoxynaphthalene.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Sun, Chen published the artcileMechanochemical cleavage of lignin models and lignin via oxidation and a subsequent base-catalyzed strategy, HPLC of Formula: 183303-74-4, the publication is Green Chemistry (2020), 22(11), 3489-3494, database is CAplus.

Mechanochem. cleavage of lignin dimer model compounds to phenolic monomers has been developed via a two-step strategy under milling conditions. In the first step of this process, the secondary benzylic alc. of lignin β-O-4 linkages was selectively oxidized to the corresponding ketones over a 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)/NaNO₂ catalytic system under milling conditions. In the subsequent step, mechanochem. selective cleavage of the C_β-O bonds and C_α-C_β bonds of lignin β-O-4 ketones to acids and phenols was promoted by NaOH-catalyzed depolymerization In addition, this two-step strategy was performed to depolymerize organosolv birch lignin, giving aromatic monomers with good selectivity for syringate. This approach provides an efficient method to convert the β-O-4 linkages of lignin to valuable aromatic monomers under mild reaction conditions.

Green Chemistry published new progress about 183303-74-4. 183303-74-4 belongs to ethers-buliding-blocks, auxiliary class Benzene,Alcohol,Ether, name is 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol, and the molecular formula is C12H10F2Si, HPLC of Formula: 183303-74-4.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Ou, Jiamin published the artcileSpeciated OVOC and VOC emission inventories and their implications for reactivity-based ozone control strategy in the Pearl River Delta region, China, SDS of cas: 1589-47-5, the publication is Science of the Total Environment (2015), 393-402, database is CAplus and MEDLINE.

Increasing ground-level O₃ concentrations, accompanied by decreasing SO₂, NO₂, PM₁₀, and PM_2.5 concentrations due to recently implemented air pollution control measures, initiated a serious challenge to control volatile organic compound (VOC) emissions in the Pearl River Delta (PRD) region, China. A speciated VOC emission inventory is fundamental to estimate O₃ formation potential (OFP) and identify key reactive VOC species and sources to formulate efficient O₃ control strategies. Using the latest bulk VOC emission inventory and local source profiles, this work developed PRD regional speciated oxygenated VOC (OVOC) and VOC emission inventories to identify key emission-based and OFP-based VOC sources and species. Results showed: Me alc., acetone, and Et acetate were major constituents in OVOC emissions from industrial and household solvents, architectural paints, and biogenic sources; from an emission-based perspective, aromatics, alkanes, OVOC, and alkenes comprised 39.2, 28.2, 15.9, and 10.9% of anthropogenic VOC; from an OFP-based perspective, aromatics and alkenes were predominant with contributions of 59.4 and 25.8% resp.; ethene, m/p-xylene, toluene, 1,2,4-tri-Me benzene, and other high OFP-contributing compounds were key reactive species contributing up to 52% of anthropogenic emissions and up to 80% of OFP; and industrial solvents and processes, gasoline-fueled vehicles and motorcycles were major emission sources of these key reactive species. Policy implications for O₃ control strategy are discussed. An OFP cap was proposed to regulate VOC control policies in the PRD due to its flexibility in reducing overall VOC emission source VOC in practice.

Science of the Total Environment published new progress about 1589-47-5. 1589-47-5 belongs to ethers-buliding-blocks, auxiliary class Aliphatic hydrocarbon chain,Alcohol,Ether, name is 2-Methoxypropan-1-ol, and the molecular formula is C4H10O2, SDS of cas: 1589-47-5.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Al-Dalali, Sam published the artcileTracking volatile flavor changes during two years of aging of Chinese vinegar by HS-SPME-GC-MS and GC-O, Safety of 1,2-Dimethoxybenzene, the publication is Journal of Food Composition and Analysis (2022), 104295, database is CAplus.

Aging is an essential step for enriching the aroma profiles of Chinese vinegar. This study aimed to track the volatile flavor changes in the same batch of Chinese vinegar for the first time during two years of aging with the aid of HS-SPME-GC-MS. The aroma-active compounds were characterized at 0, 6, and 12 mo of aging using GC-O coupled with a modified frequency method. A total of 67 volatile compounds and 30 aroma-active compounds were identified during the different stages of aging. Most alcs., esters, ketones, acids, and phenols decreased during the aging from 628.4, 105.4, 132.1, 22.1, and 21.4μg/L at 0 mo to 228.7, 7.2, 9.69, 17.24, and 11.6μg/L at 24 mo sep., except aldehydes and pyrazines, which showed slight increases. Many aroma-active compounds were generated during the aging, such as methional, trimethylpyrazine, acetophenone, and 2-acetyl-3-ethylpyrazine, while pyrazines were formed during 24 mo of aging. Three aroma-active compounds with high odor activity values (OAVs) showed significant contributions to the aroma profile of vinegar, which included isovaleric acid (2743, 340, and 3139), 4-ethylguaiacol (580, 429, and 516), and γ-nonalactone (324, 640, and 442) at 0, 6, and 12 mo of aging, resp.

Journal of Food Composition and Analysis published new progress about 91-16-7. 91-16-7 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether,Inhibitor,Inhibitor,Inhibitor, name is 1,2-Dimethoxybenzene, and the molecular formula is C8H10O2, Safety of 1,2-Dimethoxybenzene.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Yu, Haiyan published the artcileComprehensive two-dimensional gas chromatography mass spectrometry-based untargeted metabolomics to clarify the dynamic variations in the volatile composition of Huangjiu of different ages, Application of 4-Hydroxy-3,5-dimethoxybenzaldehyde, the publication is Journal of Food Science (2022), 87(4), 1563-1574, database is CAplus and MEDLINE.

Aging plays an important role in the formation of aroma characteristics of Huangjiu, a traditional Chinese alc. beverage. Comprehensive two-dimensional gas chromatog. mass spectrometry (GCxGC-qMS)-based untargeted metabolomics combined with a multivariate anal. was used to investigate the dynamic variations in the aroma profile of Huangjiu during aging process and to establish the relationship between the changing volatile metabolite profiles and the age-dependent sensory attributes. A total of 144 volatile metabolites were identified by GCxGC-qMS and 63 were selected as critical metabolites based on variable importance in projection values and p-values. Based on the results of principal component anal., orthogonal partial least-squares discriminant anal., and hierarchical clustering anal., the samples of six different ages were divided into three groups: 1Y and 3Y samples, 5Y and 8Y samples, and 10Y and 15Y samples. The partial least-squares anal. results further revealed the relationship between the aromas attributes and variations of these volatile compounds The high esters, aldehydes, and lactones contents contributed to the high intensities of the sweet and ester aroma attributes of the aged Huangjiu, while the high alcs. and Et esters contents contributed to the alc. and fruity aroma attributes of the newly brewed Huangjiu. These results improve our understanding of the chem. nature of the aroma characteristics of aged Huangjiu. Huangjiu is often labeled with its age as a measure of quality, which influences consumers’ choice. Dynamic variations in volatile compounds of Huangjiu during aging and its contribution to the aroma characteristics of Huangjiu were figured out, which will assist the industry to produce better quality aged Huangjiu for consumers.

Journal of Food Science published new progress about 134-96-3. 134-96-3 belongs to ethers-buliding-blocks, auxiliary class Immunology/Inflammation,COX,Natural product, name is 4-Hydroxy-3,5-dimethoxybenzaldehyde, and the molecular formula is C15H14O3, Application of 4-Hydroxy-3,5-dimethoxybenzaldehyde.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem