Category: ethers-buliding-blocks

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

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

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

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

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

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

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

Hickey, Jennifer L. published the artcilePassive Membrane Permeability of Macrocycles Can Be Controlled by Exocyclic Amide Bonds, Product Details of C25H23NO4, the publication is Journal of Medicinal Chemistry (2016), 59(11), 5368-5376, database is CAplus and MEDLINE.

We have developed a strategy for synthesizing passively permeable peptidomimetic macrocycles. The cyclization chem. centers on using aziridine aldehydes in a multicomponent reaction with peptides and isocyanides. The linker region in the resulting product contains an exocyclic amide positioned α to the peptide backbone, an arrangement that is not found among natural amino acids. This amide provides structural rigidity within the cyclic peptidomimetic and promotes the creation of a stabilizing intramol. hydrogen bonding network. This exocyclic control element also contributes to the increased membrane permeability exhibited by multicomponent-derived macrocycles with respect to their homodetic counterparts. The exocyclic control element is employed along with a strategic placement of N-Me and D-amino acids to produce passively permeable peptides, which contain multiple polar residues. This strategy should be applicable in the pursuit of synthesizing therapeutically relevant macrocycles.

Journal of Medicinal Chemistry published new progress about 77128-73-5. 77128-73-5 belongs to ethers-buliding-blocks, auxiliary class Inhibitor, name is (S)-2-((((9H-Fluoren-9-yl)methoxy)carbonyl)(methyl)amino)-3-phenylpropanoic acid, and the molecular formula is C25H23NO4, Product Details of C25H23NO4.

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

Chen, Shengxin published the artcileEpoxide ring-opening reaction promoted by ionic liquid reactivity: interplay of experimental and theoretical studies, Recommanded Product: 2-Methoxypropan-1-ol, the publication is Catalysis Science & Technology (2019), 9(20), 5567-5571, database is CAplus.

Ionic liquids (ILs) have been widely introduced recently into the epoxide ring-opening reaction as catalysts or solvent without considering the chem. stability of ILs in propylene oxide (PO). Through a combination of electrospray-ionization quadrupole time-of-flight mass spectrometry (ESI-QTOF-MS) investigations and quantum-chem. calculations, we demonstrate that AC- (acetate) and MC-(Me carbonate) based ILs exhibit modified activity for ring opening of PO compared with the reaction between ILs and epoxide compounds The chem. unstable ILs and the solvent effect can also dominate the catalytic performance of the coupling reaction of PO with methanol. Based on these findings, we further design the reaction process for highly efficient synthesis of propylene glycol Me ether, in which the yield of the main product increased more than 40% under the same ILs catalysts. The results explained how the chem. instability and substrate affected the PO coupling reaction and further controlled it.

Catalysis Science & Technology 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, Recommanded Product: 2-Methoxypropan-1-ol.

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

Adriani, John published the artcileThe comparative potency and effectiveness of topical anesthetics in man, Safety of 4-(3-(4-Butoxyphenoxy)propyl)morpholine hydrochloride, the publication is Clinical Pharmacology & Therapeutics (New York, NY, United States) (1964), 49-62, database is CAplus and MEDLINE.

A technique with the use of elec. stimulation was developed. The tip of the tongue is the most sensitive area in the body to this type of stimulation. Over 40 drugs with topical activity were studied with the tip of the tongue as the test site. The most potent and effective compounds are tetracaine, cocaine, dibucaine, lidocaine, and dyclonine (I). With exception of I, these are toxic systemically if used in excess. The addition of vasoconstrictors, detergents, demulcents, cations, hyaluronidase, and other often-suggested potentiating agents does extend the period of activity.

Clinical Pharmacology & Therapeutics (New York, NY, United States) published new progress about 637-58-1. 637-58-1 belongs to ethers-buliding-blocks, auxiliary class Inhibitor, name is 4-(3-(4-Butoxyphenoxy)propyl)morpholine hydrochloride, and the molecular formula is C17H28ClNO3, Safety of 4-(3-(4-Butoxyphenoxy)propyl)morpholine hydrochloride.

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