Month: December 2022

Wang, Yiming published the artcileTemporal profiles, source analysis, and health risk assessments of parent polycyclic aromatic hydrocarbons (PPAHs) and their derivatives (NPAHs, OPAHs, ClPAHs, and BrPAHs) in PM_2.5 and PM_1.0 from the eastern coastal region of China: Urban coastal area versus coastal background area, Formula: C24H12, the publication is Chemosphere (2022), 133341, database is CAplus and MEDLINE.

The eastern coastal region of China is the area with the highest emission of PAHs in China. Therefore, understanding the sources and health risk of parent polycyclic aromatic hydrocarbons (PPAHs) and their derivatives in eastern coastal cities of China is the main basis for air pollution control. In this study, we measured the concentrations of 18 parent PAHs, 17 nitrated PAHs, 7 oxygenated PAHs, 8 chlorinated PAHs, and 13 brominated PAHs in PM1.0 and PM2.5 samples collected at an urban coastal city site and a coastal background site in 2019. We analyzed the temporal distribution, mol. composition, and sources and performed health risk assessments for both winter and summer samples. The average concentration of the PPAHs and their derivatives (all 63 compounds combined) in the PM_1.0 samples accounted for 75.57% of the PAHs concentration in PM_2.5 samples. The average concentration of PM_2.5– and PM_1.0– bound PPAHs in winter was 114.70 times higher than in summer, and their derivatives was 27.51 times. Both the combined concentrations of the 18 PPAHs and the combined concentrations of the 45 derivatives were higher in the coastal city compared to the background site during the winter (1.90 and 1.48 times, resp.), but they were comparable during the summer. The pos. matrix factorization anal. indicated that the compounds mainly originated from coal/biomass combustion, industrial sources, vehicle emissions, and secondary formation. In addition, the concentration-weighted trajectories model revealed that the PAHs were mainly emitted locally in Shandong Province and surrounding areas, such as Hebei Province, Henan Province, and Bohai Sea. The compounds 1-NPYR, 2+9-BrPHE, 9,10-Cl2PHE, and 1-ClPYR dominantly contributed to the derivatives of TEQ during the winter due to their high concentrations or the high TEFs of these compounds

Chemosphere published new progress about 191-07-1. 191-07-1 belongs to catalysis-chemistry, auxiliary class Electronic Materials, name is Coronene, and the molecular formula is C22H28ClN7O3S, Formula: C24H12.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

de Silva, Nilamuni H. published the artcileMicrowave-assisted rapid synthesis of spirooxindole-pyrrolizidine analogues and their activity as anti-amyloidogenic agents, Synthetic Route of 4230-93-7, the publication is Bioorganic Chemistry (2021), 105128, database is CAplus and MEDLINE.

A library of Sox-pyrrolizidines was rapidly prepared by microwave-assisted, one-pot, three-component, 1,3-dipolar cycloaddition of azomethine ylides from L-proline and isatin, with various ¦Â-nitrostyrenes. Nitro-Sox compounds, I, 4d and 4e inhibit HEWL amyloid fibril formation by ThT studies with percentages of fluorescence intensity of 55.4, 42.9 and 40.3%, resp. Further studies with MTT assay, Raman spectroscopy, TEM and mol. docking supported these promising candidates for activity against amyloid misfolding, a phenomenon leading to Alzheimer’s disease pathol.

Bioorganic Chemistry published new progress about 4230-93-7. 4230-93-7 belongs to catalysis-chemistry, auxiliary class Alkenyl,Nitro Compound,Benzene,Ether, name is 1,2-Dimethoxy-4-(2-nitrovinyl)benzene, and the molecular formula is C10H11NO4, Synthetic Route of 4230-93-7.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Hernawan published the artcileAmino-functionalized porous chitosan as a solid base catalyst for solvent-free synthesis of chalcones, Category: catalysis-chemistry, the publication is Journal of the Taiwan Institute of Chemical Engineers (2022), 104354, database is CAplus.

Amino-functionalized porous chitosan with high sp. surface area has promising properties and used as a solid base catalyst for solvent-free synthesis of chalcones I [R = H, Cl, Me; R¹ = H, Me, OMe, Cl, OH] synthesis via Claisen-Schmidt condensation of benzaldehydes and acetophenones was reported. Amino-functionalized porous chitosan as a solid base catalyst was fabricated from porous chitosan grafted with aminopropyltriethoxysilane (APTMS). The prepared hybrid materials were characterized with pore and sp. surface area (N₂-sorption), FTIR, SEM, and accessible amine. The results revealed that the amount of APTMS had a significant effect on the physicochem. properties of amino-functionalized porous chitosan catalysts. The catalyst offered good yield synthesis, lower temperature, less reaction time, highly selective, stable, recoverable, and can be reused four times without significant loss in performance.

Journal of the Taiwan Institute of Chemical Engineers published new progress about 13822-56-5. 13822-56-5 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is 3-(Trimethoxysilyl)propan-1-amine, and the molecular formula is C6H17NO3Si, Category: catalysis-chemistry.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Shah, V. H. published the artcileSome new aryloxyacetic acid, Computed Properties of 5411-14-3, the publication is Journal of the Institution of Chemists (India) (2003), 75(2), 62-63, database is CAplus.

A number of aryloxyacetic acids were prepared The constitution of the products was supported by elemental analyses, IR and PMR spectral data. The products were screened for antimicrobial activity. All the compounds showed moderate activity.

Journal of the Institution of Chemists (India) published new progress about 5411-14-3. 5411-14-3 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ether, name is 2,2-(1,2-Phenylenebis(oxy))diacetic acid, and the molecular formula is C14H10N2O, Computed Properties of 5411-14-3.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Shumaila, Abdullah M. A. published the artcileSynthesis of tetrahydro-5-azaindoles and 5-azaindoles using Pictet-Spengler reaction-appreciable difference in products using different acid catalysts, Recommanded Product: 1,2-Dimethoxy-4-(2-nitrovinyl)benzene, the publication is Tetrahedron (2011), 67(5), 936-942, database is CAplus.

Pictet-Spengler condensation of 2-(aryl)-2-(1H-pyrrol-2-yl)ethanamines using conventional acid catalysts like TMSCl or TFA resulted in the formation of substituted 5-azaindoles involving a tandem one pot four step reaction sequence. By contrast, use of glacial acetic acid furnished the targeted tetrahydro-5-azaindoles in diastereoselective manner. These were readily dehydrogenated to 5-azaindoles.

Tetrahedron published new progress about 4230-93-7. 4230-93-7 belongs to catalysis-chemistry, auxiliary class Alkenyl,Nitro Compound,Benzene,Ether, name is 1,2-Dimethoxy-4-(2-nitrovinyl)benzene, and the molecular formula is C5H11NO2S, Recommanded Product: 1,2-Dimethoxy-4-(2-nitrovinyl)benzene.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Shumaila, Abdullah M. A. published the artcileDiastereoselective synthesis of tetrasubstituted-octahydro-3,6-diazacarbazoles and tetrasubstituted-3,6-diazacarbazoles via double Pictet-Spengler reaction, Category: catalysis-chemistry, the publication is Tetrahedron Letters (2011), 52(21), 2661-2663, database is CAplus.

Pictet-Spengler condensation of 2,5-bis(2-phenyl-1-aminoethyl)pyrrole using glacial acetic acid afforded only one diastereomer of unreported tetrasubstituted-octahydro-3,6-diazacarbazoles, e.g. I. These were readily dehydrogenated to tetrasubstituted-3,6-diazacarbazoles, e.g. II. The stereoselectivity in the Pictet-Spengler reaction has been demonstrated using single crystal X-ray anal.

Tetrahedron Letters published new progress about 4230-93-7. 4230-93-7 belongs to catalysis-chemistry, auxiliary class Alkenyl,Nitro Compound,Benzene,Ether, name is 1,2-Dimethoxy-4-(2-nitrovinyl)benzene, and the molecular formula is C6H8O6, Category: catalysis-chemistry.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Chevalley, Alice published the artcileModel Studies for a Ring-Closing Metathesis Approach to the Bafilomycin Macrolactone Core from a 2,2-Dimethoxy Tetraenic Ester Precursor, Name: Allyldiphenylphosphine oxide, the publication is European Journal of Organic Chemistry (2013), 2013(36), 8265-8278, database is CAplus.

A ring-closing metathesis strategy is reported for the construction of the 16-membered macrolactone core of bafilomycin. One decisive key feature is the presence of a 2,2-dimethoxy-ketal functionality at C-2 that provides the required flexibility to the tetraene acid ester precursor, allowing the ring-closing metathesis reaction to take place. Three different model esters of increasing complexity were successfully subjected to the 1,3-diene-ene ring-closing metathesis reaction. The best promoter for the simplest esters was the Grubbs first-generation pre-catalyst. A Hoveyda-Grubbs-type trifluoroacetamide-containing pre-catalyst developed by Mauduit’s group gave satisfactory results for the most complex ester. In all experiments, the (12Z)-configured isomer was obtained as the major product. Subsequent microwave-promoted methanol elimination was achieved on the simplest model compound using camphorsulfonic acid (CSA) as a catalyst. Under these conditions, a (E/Z)-isomerization of the double bond at C-4, as well as ca. 50% isomerization of the (12Z)-double bond into the corresponding (12E)-isomer, were observed The synthesis of the target compounds was achieved using (4R,5R)-2,2-dimethyl-1,3-dioxolane-4,5-dicarboxylic acid 4,5-di-Me ester as a chiral source. The title compounds thus formed included a maacrolactone (macrolide) (I) and related substances.

European Journal of Organic Chemistry published new progress about 4141-48-4. 4141-48-4 belongs to catalysis-chemistry, auxiliary class Aryl phosphine ligand,Mono-phosphine Ligands, name is Allyldiphenylphosphine oxide, and the molecular formula is C15H15OP, Name: Allyldiphenylphosphine oxide.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Legnani, Luca published the artcileEfficient access to unprotected primary amines by iron-catalyzed aminochlorination of alkenes, Application of O-Pivaloylhydroxylamine trifluoromethanesulfonate, the publication is Science (Washington, DC, United States) (2018), 362(6413), 434-439, database is CAplus and MEDLINE.

Primary amines are essential constituents of biol. active mols. and versatile intermediates in the synthesis of drugs and agrochems. However, their preparation from easily accessible alkenes remains challenging. Here, the authors report a general strategy to access primary amines from alkenes through an operationally simple iron-catalyzed aminochlorination reaction. A stable hydroxylamine derivative and benign sodium chloride act as the resp. nitrogen and chlorine sources. The reaction proceeds at room temperature under air; tolerates a large scope of aliphatic and conjugated alkenes, including densely functionalized substrates; and provides excellent anti-Markovnikov regioselectivity with respect to the amino group. The reactivity of the 2-chloroalkylamine products, an understudied class of amphoteric mols., enables facile access to linear or branched aliphatic amines, aziridines, aminonitriles, azido amines, and homoallylic amines.

Science (Washington, DC, United States) published new progress about 1293990-73-4. 1293990-73-4 belongs to catalysis-chemistry, auxiliary class Aliphatic Chain, name is O-Pivaloylhydroxylamine trifluoromethanesulfonate, and the molecular formula is C6H12F3NO5S, Application of O-Pivaloylhydroxylamine trifluoromethanesulfonate.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Legnani, Luca published the artcileDirect and Practical Synthesis of Primary Anilines through Iron-Catalyzed C-H Bond Amination, Product Details of C6H12F3NO5S, the publication is ACS Catalysis (2016), 6(12), 8162-8165, database is CAplus.

The direct C-H amination of arenes is an important strategy to streamline the discovery and preparation of functional mols. Herein, we report an operationally simple arene C-H amination reaction that, in contrast to most literature precedence, affords directly the synthetically versatile primary aniline products without relying on protecting group manipulations. Inexpensive Fe(II) sulfate serves as a convenient catalyst for the transformation. The reaction tolerates a wide scope of arenes, including structurally complex drugs. Importantly, the arene substrates are used as limiting reagents in the transformation. This operationally simple transformation should considerably accelerate the discovery of medicines and functional mols.

ACS Catalysis published new progress about 1293990-73-4. 1293990-73-4 belongs to catalysis-chemistry, auxiliary class Aliphatic Chain, name is O-Pivaloylhydroxylamine trifluoromethanesulfonate, and the molecular formula is C6H12F3NO5S, Product Details of C6H12F3NO5S.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Cho, Inha published the artcileEnantioselective aminohydroxylation of styrenyl olefins catalyzed by an engineered hemoprotein, HPLC of Formula: 1293990-73-4, the publication is Angewandte Chemie, International Edition (2019), 58(10), 3138-3142, database is CAplus and MEDLINE.

Chiral 1,2-amino alcs. are widely represented in biol. active compounds from neurotransmitters to antivirals. While many synthetic methods have been developed for accessing amino alcs., the direct aminohydroxylation of alkenes to unprotected, enantio-enriched amino alcs. remains a challenge. Using directed evolution, we have engineered a hemoprotein biocatalyst based on a thermostable cytochrome c that directly transforms alkenes to amino alcs. with high enantioselectivity (up to 2500 TTN and 90 % ee) under anaerobic conditions with O-pivaloylhydroxylamine as an aminating reagent. The reaction is proposed to proceed via a reactive iron-nitrogen species generated in the enzyme active site, enabling tuning of the catalyst’s activity and selectivity by protein engineering.

Angewandte Chemie, International Edition published new progress about 1293990-73-4. 1293990-73-4 belongs to catalysis-chemistry, auxiliary class Aliphatic Chain, name is O-Pivaloylhydroxylamine trifluoromethanesulfonate, and the molecular formula is C6H12F3NO5S, HPLC of Formula: 1293990-73-4.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia