Catalysis-chemistry

Sekar, K. G. published the artcileKinetics of oxidation of phenoxyacetic acids by nicotinium dichromate, Synthetic Route of 1798-04-5, the publication is Oxidation Communications (2011), 34(2), 314-319, database is CAplus.

The kinetics of oxidation of phenoxyacetic acid and several para- and meta-substituted phenoxyacetic acids by nicotinium dichromate (NDC) in the presence of perchloric acid was studied in 60% (volume/volume) aqueous acetic acid. The reaction shows unit order dependence each with respect to oxidant and substrate. The order with respect to hydrogen ion concentration is two. The rate of oxidation increases with increase in the percentage of acetic acid and increase in ionic strength has negligible effect on the rate. The reaction does not induce the polymerization of acrylonitrile. The addition of Mn²⁺ ion had a noticeable catalytic effect on the reaction rate. In general, electron-releasing substituents accelerate the rate while electron attracting substituents retard the rate and the rate data obey the Hammett relation.

Oxidation Communications published new progress about 1798-04-5. 1798-04-5 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ether, name is 2-(4-(tert-Butyl)phenoxy)acetic acid, and the molecular formula is C15H21BO2, Synthetic Route of 1798-04-5.

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

Liu, Hui published the artcileNanosheet-Enhanced Rhodium(III)-Catalysis in C-H Activation, Related Products of catalysis-chemistry, the publication is ACS Catalysis (2014), 4(10), 3543-3550, database is CAplus.

Rhodium(III)-catalyzed C-H activation has been promoted impressively with layered double hydroxide (LDH)-bound ligand nanosheets. A yield of >99% and a regioisomeric ratio of >20:1 have been produced in the coupling of alkenes with N-(pivaloyloxy)benzamide [e.g., N-(pivaloyloxy)benzamide + Me acrylate â†?I]. The nanosheets have been revealed to enhance the catalytic activity by affording the desired basicity and improve the regioselectivity by serving as the rigid substitution of α-amino acid ligands.

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, Related Products of catalysis-chemistry.

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

Heo, Ji Won published the artcilePreparation of amine-functionalized lignins for the selective adsorption of Methylene blue and Congo red, SDS of cas: 13822-56-5, the publication is Chemosphere (2022), 133815, database is CAplus and MEDLINE.

Research on low-cost bio-adsorbents for the removal of harmful substances from effluents has recently attracted significant attention. In this study, three types of amino-silane-modified lignins (ASLs) with primary, secondary, and tertiary amine groups were prepared, and their adsorption behavior toward cationic and anionic dyes was investigated. Chem. structural analyses indicated that the three amino-silane reagents resulted in different mol. self-assembly structures on the lignin surface. The ASLs exhibited enhanced thermal stabilities and increased surface areas with different surface charges in different pH ranges. Owing to the high d. of primary, secondary, and tertiary amine groups, the ASLs exhibited excellent adsorption capacities for cationic and anionic dyes. Addnl., they selectively adsorb anionic and cationic dyes according to the pH conditions. The ASL with primary amine had the highest adsorption capacity for Methylene blue and Congo red, reaching 187.27 and 293.26 mg·g^-1, resp., followed by ASLs with the secondary amine and tertiary amine. All adsorption processes followed the Langmuir and Temkin isotherms and had pseudo-second-order kinetics. The hypothesized adsorption mechanism mainly involves electrostatic interaction, NH-π interaction, hydrogen bonding interaction and π-π interaction.

Chemosphere 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, SDS of cas: 13822-56-5.

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

Li, Tianguo published the artcileMineralogical and iron recovery from CCS flotation tails by physico-interfacial separation: separation of magnetite and iron silicates, Synthetic Route of 2016-56-0, the publication is Oxidation Communications (2016), 39(1), 25-40, database is CAplus.

Copper converter slag (CCS) discharge causes significant environmental problems. In this work, on the basis of a study of mineralogical characteristics, the recovery of iron from CCS flotation tails using a combined process of magnetic separation and reverse flotation was investigated. The study revealed that CCS flotation tails are primarily composed of magnetite (21.49%) and iron silicates (72.52%). The iron content of CCS flotation tails is as high as 49.60%, while only 30.31% of the iron distributed in the magnetite and ferroalloy shows significant magnetic properties. Zeta-potential studies of magnetite, quartz and fayalite samples have shown that amines are well adsorbed, both on the surfaces of the magnetite and also on the surfaces of the iron silicates, within a pH range of 5-10. The iron content of CCS flotation tails can be effectively upgraded to 59.61% using magnetic separation Amines with different mol. structures performed different selectivity for iron silicates when reverse flotation was used to remove iron silicates from the magnetic concentrate The use of mixtures of cationic and anionic collectors provided a formation of a stable hydrophobic adsorption layer on the surface of the iron silicates and magnetite-silicate aggregates; this improved the flotation of these mineral particles, even in the presence of a starch, which acted as a depressant of Fe oxides. The scheme of combining magnetic separation and reverse flotation is a promising method to use to (a) recover iron and (b) produce iron concentrates with Si02 content of 6.59% and Fe content of up to 63.35% from CCS flotation tails with Si02 content as high as 36.40%.

Oxidation Communications published new progress about 2016-56-0. 2016-56-0 belongs to catalysis-chemistry, auxiliary class Active Esterification, name is Dodecylamineacetate, and the molecular formula is C14H31NO2, Synthetic Route of 2016-56-0.

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

Wang, Hui published the artcileTranscriptome analysis revealed growth phase-associated changes of a centenarian-originated probiotic Bifidobacterium animalis subsp. lactis A6, Formula: C5H11NO2S, the publication is BMC Microbiology (2022), 22(1), 61, database is CAplus and MEDLINE.

The physiol. and application characteristics of probiotics are closely associated with the growth phase. Bifidobacterium animalis subsp. lactis A6 is a promising probiotic strain isolated from the feces of a healthy centenarian in China. In this study, RNA-seq was carried out to investigate the metabolic mechanism between the exponential and the stationary phase in B. lactis A6. Differential expression anal. showed that a total of 815 genes were significantly changed in the stationary phase compared to the exponential phase, which consisted of 399 up-regulated and 416 down-regulated genes. The results showed that the transport and metabolism of cellobiose, xylooligosaccharides and raffinose were enhanced at the stationary phase, which expanded carbon source utilizing profile to confront with glucose consumption. Meanwhile, genes involved in cysteine-cystathionine-cycle (CCC) pathway, glutamate dehydrogenase, branched-chain amino acids (BCAAs) biosynthesis, and Clp protease were all up-regulated in the stationary phase, which may enhance the acid tolerance of B. lactis A6 during stationary phase. Acid tolerance assay indicated that the survival rate of stationary phase cells was 51.07% after treatment by pH 3.0 for 2h, which was 730-fold higher than that of 0.07% with log phase cells. In addition, peptidoglycan biosynthesis was significantly repressed, which is comparable with the decreased growth rate during the stationary phase. Remarkably, a putative gene cluster encoding Tad pili was up-regulated by 6.5 to 12.1-fold, which is consistent with the significantly increased adhesion rate to mucin from 2.38% to 4.90% during the transition from the exponential phase to the stationary phase. This study reported growth phase-associated changes of B. lactis A6 during fermentation, including expanded carbon source utilizing profile, enhanced acid tolerance, and up-regulated Tad pili gene cluster responsible for bacterial adhesion in the stationary phase. These findings provide a novel insight into the growth phase associated characteristics in B. lactis A6 and provide valuable information for further application in the food industry.

BMC Microbiology published new progress about 63-68-3. 63-68-3 belongs to catalysis-chemistry, auxiliary class Natural product, name is (S)-2-Amino-4-(methylthio)butanoic acid, and the molecular formula is C12H17NO2, Formula: C5H11NO2S.

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

Wang, Ziqi published the artcileAddressable peptide self-assembly on the cancer cell membrane for sensitizing chemotherapy of renal cell carcinoma, HPLC of Formula: 1395786-30-7, the publication is Advanced Materials (Weinheim, Germany) (2019), 31(11), n/a, database is CAplus and MEDLINE.

Chemotherapy has been validated unavailable for treatment of renal cell carcinoma (RCC) in clinic due to its intrinsic drug resistance. Sensitization of chemo-drug response plays a crucial role in RCC treatment and increase of patient survival. Herein, a recognition-reaction-aggregation (RRA) cascaded strategy is utilized to in situ construct peptide-based superstructures on the renal cancer cell membrane, enabling specifically perturbing the permeability of cell membranes and enhancing chemo-drug sensitivity in vitro and in vivo. First, P1-DBCO can specifically recognize renal cancer cells by targeting carbonic anhydrase IX. Subsequently, P2-N₃ is introduced and efficiently reacts with P1-DBCO to form a peptide P3, which exhibits enhanced hydrophobicity and simultaneously aggregates into a superstructure. Interestingly, the superstructure retains on the cell membrane and perturbs its integrity/permeability, allowing more doxorubicin (DOX) uptaken by renal cancer cells. Owing to this increased influx, the IC₅₀ is significantly reduced by nearly 3.5-fold compared with that treated with free DOX. Finally, RRA strategy significantly inhibits the tumor growth of xenografted mice with a 3.2-fold enhanced inhibition rate compared with that treated with free DOX. In summary, this newly developed RRA strategy will open a new avenue for chem. engineering cell membranes with diverse biomedical applications.

Advanced Materials (Weinheim, Germany) published new progress about 1395786-30-7. 1395786-30-7 belongs to catalysis-chemistry, auxiliary class Inhibitor, name is Dbco-maleimide, and the molecular formula is C13H26N2, HPLC of Formula: 1395786-30-7.

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

De Proft, F. published the artcileQuantum-Chemical Study of the Acidity of Substituted Acetic Acids with Density Functional Theory Based Descriptors, Product Details of C3H4F2O2, the publication is Journal of Physical Chemistry (1994), 98(20), 5227-33, database is CAplus.

Acidity differences of substituted acetic acids XCH₂COOH are interpreted in terms of the nature of the group X. Traditional quantum-chem. and d. functional theory based descriptors of chem. reactivity are calculated for 15 acids and are correlated with exptl. acidities in aqueous solution and in the gas phase. The results are interpreted within the framework of Pearson’s hard and soft acids and bases principle, stating that hard acids prefer to bond to hard bases and soft acids prefer to bond to soft bases. Calculated parameters, which are a measure of local hardness, show a pos. correlation with the exptl. acidities. The acidities in aqueous solution show almost no dependence on the softness (polarizability) of the group X, while this group softness seems to play an important role in the gas phase, although it is a minor one in comparison to the hard parameters.

Journal of Physical Chemistry published new progress about 155142-69-1. 155142-69-1 belongs to catalysis-chemistry, auxiliary class Difluoromethyl,Fluoride,Carboxylic acid,Aliphatic hydrocarbon chain, name is 3,3-Difluoropropanoic acid, and the molecular formula is C3H4F2O2, Product Details of C3H4F2O2.

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

Freidlina, R. Kh. published the artcileRearrangement of radicals in the process of telomerization of ethylene with acetic acid, COA of Formula: C10H20O2, the publication is Doklady Akademii Nauk SSSR (1964), 156(5), 1133-6, database is CAplus.

Heating C₂H₄ at 1540 atm. with AcOH in the presence of a catalytic amount (Me₃CO)₂ in an autoclave at 140° gave the normally expected telomer acids Et(CH₂CH₂)_nCH₂CO₂H. However, also isolated were isooctanoic and isodecanoic acids and α-ethylcaproic acid, b₁₃ 120°, n²⁰_D 1.4290, d₂₀ 0.9014 (S-benzylthiuronium salt m. 127-8°), as well as α-butylcaproic acid, b₁₂ 137-8°, 1.4459, 0.9216. The higher boiling products were found to consist of C_16-18 acids. Formation of the branched acids indicated some isomerization of radicals such as •CH₂(CH₂)₃CH₂CO₂H.

Doklady Akademii Nauk SSSR published new progress about 3115-28-4. 3115-28-4 belongs to catalysis-chemistry, auxiliary class Aliphatic Chain, name is 2-Butylhexanoic acid, and the molecular formula is C10H20O2, COA of Formula: C10H20O2.

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

Allott, Louis published the artcileRadiolabelling an ¹⁸F biologic via facile IEDDA “click” chemistry on the GE FASTLab platform, Recommanded Product: (4-(6-Methyl-1,2,4,5-tetrazin-3-yl)phenyl)methanamine trifluoroacetic acid, the publication is Reaction Chemistry & Engineering (2021), 6(6), 1070-1078, database is CAplus and MEDLINE.

The use of biologics in positron emission tomog. (PET) imaging is an important area of radiopharmaceutical development and new automated methods are required to facilitate their production We report an automated radiosynthesis method to produce a radiolabeled biol. via facile inverse electron demand Diels-Alder (IEDDA) “click” chem. on a single GE FASTLab cassette. We exemplified the method by producing a fluorine-18 radiolabeled interleukin-2 (IL2) radioconjugate from a trans-cyclooctene (TCO) modified IL2 precursor. The radioconjugate was produced using a fully automated radiosynthesis on a single FASTLab cassette in a decay-corrected radiochem. yield (RCY, d.c.) of 19.8 ± 2.6% in 110 min (from start of synthesis); the molar activity was 132.3 ± 14.6 GBq μmol^-1. The in vitro uptake of [¹⁸F]TTCO-IL2 correlated with the differential receptor expression (CD25, CD122, CD132) in PC3, NK-92 and activated human PBMCs. The automated method may be adapted for the radiosynthesis of any TCO-modified protein via IEDDA chem.

Reaction Chemistry & Engineering published new progress about 1466420-02-9. 1466420-02-9 belongs to catalysis-chemistry, auxiliary class Copper-Free Click Chemistry,Tetrazine, name is (4-(6-Methyl-1,2,4,5-tetrazin-3-yl)phenyl)methanamine trifluoroacetic acid, and the molecular formula is C12H12F3N5O2, Recommanded Product: (4-(6-Methyl-1,2,4,5-tetrazin-3-yl)phenyl)methanamine trifluoroacetic acid.

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

Levens, Alison published the artcileEnantioselective (4+2) Annulation of Donor-Acceptor Cyclobutanes by N-Heterocyclic Carbene Catalysis, Recommanded Product: (E)-3-(2,4-Dimethoxyphenyl)acrylic acid, the publication is Angewandte Chemie, International Edition (2016), 55(52), 16136-16140, database is CAplus and MEDLINE.

Herein we report the enantioselective (4+2) annulation of donor-acceptor cyclobutanes and unsaturated acyl fluorides using N-heterocyclic carbene catalysis. The reaction allows a 3-step synthesis of cyclohexyl β-lactones (25 examples) in excellent chem. yield (most â‰?0 %) and stereochem. integrity (all >20:1 d.r., most â‰?7:3 e.r.). Mechanistic studies support ester enolate Claisen rearrangement, while derivatizations provide functionalized cyclohexenes and dihydroquinolinones.

Angewandte Chemie, International Edition published new progress about 16909-09-4. 16909-09-4 belongs to catalysis-chemistry, auxiliary class Alkenyl,Carboxylic acid,Benzene,Ether, name is (E)-3-(2,4-Dimethoxyphenyl)acrylic acid, and the molecular formula is C11H12O4, Recommanded Product: (E)-3-(2,4-Dimethoxyphenyl)acrylic acid.

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