Catalysis-chemistry

Shanmugaraj, Krishnamoorthy published the artcileNoble metal nanoparticles supported on titanate nanotubes as catalysts for selective hydrogenation of nitroarenes, Name: 3-(Trimethoxysilyl)propan-1-amine, the publication is Catalysis Today (2022), 93-104, database is CAplus.

Platinum (Pt) and palladium (Pd) nanoparticles (NPs) supported on titanate nanotubes (TiNTs) Pt@TiNT and Pd@TiNT were prepared for the liquid-phase hydrogenation of nitroarenes at 25¡ãC Initially, TiNT was modified with 3-aminopropyl-trimethoxysilane to provide a strong anchoring site to trap the Pt and Pd NPs, which prevent the metal NPs from leaching. As-prepared 1 wt% of metal loading catalysts were characterized by transmission electron microscopy (TEM), nitrogen adsorption-desorption isotherms, X-ray diffraction, and XPS measurements. The TEM images confirmed that the Pt (1.70 ¡À 0.19 nm) and Pd (2.80 ¡À 0.43 nm) NPs were mainly confined into the channel of TiNTs. Both catalysts exhibited excellent catalytic performances for the reduction of nitrobenzene as a model compound under mild reaction conditions. The superior catalytic activity for the hydrogenation of nitroarenes is attributed to the small size of the Pt and Pd NPs. However, the operational stability showed that Pt@TiNT retained its catalytic performance after 10 cycles, while Pd@TiNT suffered deactivation by metal sintering after the sixth cycle. The Pt@TiNT system exhibited high efficiency in the hydrogenation of different substituted nitroarenes of pharmaceuticals interest, and it showed an excellent activity and selectivity toward the production of desired substituted anilines.

Catalysis Today 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 C19H21N3O3S, Name: 3-(Trimethoxysilyl)propan-1-amine.

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

Shanmugaraj, Krishnamoorthy published the artcileGold nanoparticles supported on mesostructured oxides for the enhanced catalytic reduction of 4-nitrophenol in water, COA of Formula: C6H17NO3Si, the publication is Catalysis Today (2022), 383-393, database is CAplus.

In this work, Au nanoparticles supported on aluminum oxide (Au/ANT) and titanate (Au/TNT) nanotubes were synthesized for their use as catalysts in the reduction of 4-nitrophenol to produce 4-aminophenol with NaBH₄ as the reducing agent. The catalysts were prepared with a 0.5% metal loading employing the nanotube supports modified with 3-aminopropyl-trimethoxysilane (APTMS) to provide plentiful anchoring sites to trap the Au nanoparticles and prevent their agglomeration. All materials were characterized using a range of anal. techniques, and it was found that Au zero-valent nanoparticles were homogenously supported on the inner/outer surfaces of the nanotubular-structured carriers. Both catalytic systems were highly active and selective in the reduction of 4-nitrophenol, giving TOF values of 20,561 and 19,560 h^-1 for Au/TNT and Au/ANT, resp. The excellent catalytic activity was attributed to the highly dispersed Au clusters on the support surfaces through enhanced functionalization with APTMS, and the confinement effect of the nanotubular carriers. Furthermore, Au/TNT exhibited a high operational stability for the reduction of 4-nitrophenol reaching 10 catalytic cycles with only a moderate decrease in the conversion level after the seventh cycle, which was attributed to a degree of metal leaching. Finally, the catalytic reduction performance of the Au/TNT catalyst was tested in different nitroarene-substituted pharmaceuticals, and revealed a high activity (>99% after 60 min of reaction) and selectivity toward production of the desired substituted anilines, thereby highlighting the potential of this catalyst for application in these processes.

Catalysis Today 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 C18H34N4O5S, COA of Formula: C6H17NO3Si.

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

Ocak, Mirac published the artcileThermodynamic data for the formation of 1:1 and 2:1 complexes of ¦Á,¦Ø-diamino dihydrochlorides with 18-crown-6 in aqueous solution, Quality Control of 10517-44-9, the publication is Journal of Solution Chemistry (2008), 37(5), 595-601, database is CAplus.

Calorimetric titrations are used to study the interactions between the crown ether 18-crown-6 and several ¦Á,¦Ø-diamino dihydrochlorides in aqueous solution These complexes are formed by ion-dipole interactions between the pos. charged nitrogen atoms and the oxygen donor atoms of the crown ether. Depending on the exptl. conditions, the formation of 1:1 or 2:1 complexes (ligand:diamines) can be studied. The solvation of the ligand and the amines are responsible for the observed thermodn. values. The number of water mols. released during the reaction were calculated from the determined reaction entropies. Formation of 1:1 complexes distorts the solvation shell around the mols. As a result, the number of solvent mols. released during the formation of the 2:1 complexes is slightly smaller than the number released from formation of the 1:1 complex. No exptl. evidence is observed for the formation of 1:1 complexes between one crown ether and two protonated amino groups.

Journal of Solution Chemistry published new progress about 10517-44-9. 10517-44-9 belongs to catalysis-chemistry, auxiliary class Salt,Amine,Aliphatic hydrocarbon chain, name is Propane-1,3-diamine dihydrochloride, and the molecular formula is C3H12Cl2N2, Quality Control of 10517-44-9.

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

Meschke, C. published the artcileComplexes of cucurbituril with mono- and diammonium ions in aqueous formic acid studied by calorimetric titrns, Related Products of catalysis-chemistry, the publication is Thermochimica Acta (1997), 297(1-2), 43-48, database is CAplus.

The thermodn. data of the complexation reaction between the ligand cucurbituril and different alkylmonoamine and alkyldiamine hydrochlorides have been studied in aqueous formic acid. The stability constants, the reaction enthalpies and the reaction entropies are obtained from calorimetric titrations At both rims of the cavity of cucurbituril the carbonyl groups interact with ions by ion-dipole interactions. If ammonium ions with longer alkyl chains enter the hydrophobic cavity of cucurbituril hydrophobic interactions participate in the complex formation. The hydrophobic contribution to the reaction enthalpy is calculated for the alkyl monoammonium ions. In 50% (volume/volume) formic acid the enthalpies of the hydrophobic interactions contribute more to the exptl. reaction enthalpy that the ion-dipole interactions.

Thermochimica Acta published new progress about 10517-44-9. 10517-44-9 belongs to catalysis-chemistry, auxiliary class Salt,Amine,Aliphatic hydrocarbon chain, name is Propane-1,3-diamine dihydrochloride, and the molecular formula is C3H12Cl2N2, Related Products of catalysis-chemistry.

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

Molander, Gary A. published the artcileSynthesis and Application of Chiral Cyclopropane-Based Ligands in Palladium-Catalyzed Allylic Alkylation, Safety of 2,4,6-Triisopropylbenzenethiol, the publication is Journal of Organic Chemistry (2004), 69(23), 8062-8069, database is CAplus and MEDLINE.

A series of chiral, cyclopropane-based phosphorus/sulfur ligands have been synthesized and evaluated in the palladium-catalyzed allylic alkylation of 1,3-diphenylpropenyl acetate with di-Me malonate. Variation of the ligand substituents at phosphorus, sulfur, and the carbon backbone revealed [2-[(1R)-1-(methylthio)ethyl]cyclopropyl]diphenylphosphine (I) to have the optimal configuration for this reaction, giving the product in high yield and with good enantioselectivity (93%). A model for the observed enantioselectivity is discussed within the context of existing models, using X-ray crystallog. data, solution-phase NMR studies, and the absolute stereochem. of the products. Selected ligands were also evaluated in the palladium-catalyzed intermol. Heck reaction and the rhodium-catalyzed hydrogenation of a dehydroamino acid.

Journal of Organic Chemistry published new progress about 22693-41-0. 22693-41-0 belongs to catalysis-chemistry, auxiliary class Other Functionalization Reagent, name is 2,4,6-Triisopropylbenzenethiol, and the molecular formula is C15H24S, Safety of 2,4,6-Triisopropylbenzenethiol.

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

Carreiro, Elisabete Palma published the artcileArylid-OX and Arylid-BOX derived catalysts: applications in catalytic asymmetric cyclopropanation, Recommanded Product: (E)-3-(2,4-Dimethoxyphenyl)acrylic acid, the publication is Tetrahedron: Asymmetry (2009), 20(11), 1272-1278, database is CAplus.

A novel family of chiral non-racemic monodentate oxazoline ligands known as Arylid-OXs I (R = Ph, t-Bu) was prepared in good overall yields. These ligands were screened in bench-mark Cu(I)-catalyzed cyclopropanations and gave ees as high as 58%. Both ¹H NMR and computational studies using I (R= Ph) indicated that the active catalyst was most likely to be the di-coordinated complex, Cu(I)-I (R= Ph)₂ (MeCN)₂. Two novel ortho-substituted Arylid-BOX ligands II (X = Cl, OMe) were also synthesized in very good yields. These ligands were tested in the same reaction as for I (R = Ph, t-Bu) and, although excellent yields could be obtained with II (R = OMe), which is assumed to be due to an electron-donating effect from the ortho-methoxy group, a best ee of only 56% was obtained with II (R = Cl). In fact, both the enantioselectivities and diastereoselectivities obtained with these ortho-substituted ligands were in line with those previously obtained with the para-substituted series.

Tetrahedron: Asymmetry 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

Puodziukynaite, E. published the artcileAniline-based bis(enamines) as new amorphous molecular charge transport materials, Quality Control of 1821-27-8, the publication is Synthetic Metals (2007), 157(18-20), 696-701, database is CAplus.

New aniline-based bis(enamines) were synthesized. The full characterization of their structure is presented. The thermal, optical and photoelec. properties of the newly synthesized enamines are discussed. The reported compounds constitute materials with high thermal stability with 5% weight loss temperatures exceeding 390¡ã as characterized by TGA. They form glasses with the glass transition temperatures ranging from 135 to 154¡ã as established by DSC. Photoelec. properties of the materials were examined by electron photoemission and time of flight technique. The electron photoemission spectra of the layers revealed the ionization potentials of 5.12-5.70 eV. Room temperature hole drift mobility of one newly synthesized derivative molecularly doped in bisphenol Z polycarbonate reached 10^-5 cm² V^-1 s^-1 at high elec. fields.

Synthetic Metals published new progress about 1821-27-8. 1821-27-8 belongs to catalysis-chemistry, auxiliary class Nitro Compound,Amine,Benzene, name is Bis(4-nitrophenyl)amine, and the molecular formula is C12H9N3O4, Quality Control of 1821-27-8.

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

Saenz de Urturi, Diego published the artcileMethionine adenosyltransferase 1a antisense oligonucleotides activate the liver-brown adipose tissue axis preventing obesity and associated hepatosteatosis, Application of (S)-2-Amino-4-(methylthio)butanoic acid, the publication is Nature Communications (2022), 13(1), 1096, database is CAplus and MEDLINE.

Altered methionine metabolism is associated with weight gain in obesity. The methionine adenosyltransferase (MAT), catalyzing the first reaction of the methionine cycle, plays an important role regulating lipid metabolism However, its role in obesity, when a plethora of metabolic diseases occurs, is still unknown. By using antisense oligonucleotides (ASO) and genetic depletion of Mat1a, here, we demonstrate that Mat1a deficiency in diet-induce obese or genetically obese mice prevented and reversed obesity and obesity-associated insulin resistance and hepatosteatosis by increasing energy expenditure in a hepatocyte FGF21 dependent fashion. The increased NRF2-mediated FGF21 secretion induced by targeting Mat1a, mobilized plasma lipids towards the BAT to be catabolized, induced thermogenesis and reduced body weight, inhibiting hepatic de novo lipogenesis. The beneficial effects of Mat1a ASO were abolished following FGF21 depletion in hepatocytes. Thus, targeting Mat1a activates the liver-BAT axis by increasing NRF2-mediated FGF21 secretion, which prevents obesity, insulin resistance and hepatosteatosis.

Nature Communications 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 C5H11NO2S, Application of (S)-2-Amino-4-(methylthio)butanoic acid.

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

Watile, Rahul A. published the artcileIntramolecular substitutions of secondary and tertiary alcohols with chirality transfer by an iron(III) catalyst, Formula: C10H10O3, the publication is Nature Communications (2019), 10(1), 1-9, database is CAplus and MEDLINE.

A simple, inexpensive, and environmentally benign iron(III) catalyst promotes the direct intramol. substitution of enantiomerically enriched secondary and tertiary alcs. with O-, N-, and S-centered nucleophiles, e.g., (1S)-3-[2-[(4-methoxyphenyl)amino]phenyl]-1-phenylpropan-1-ol to generate valuable 5-membered, 6-membered and aryl-fused 6-membered heterocyclic compounds, e.g., I with chirality transfer and water as the only byproduct has been demonstrated. The power of the methodol. is demonstrated in the total synthesis of (+)-lentiginosine from D-glucose where iron-catalysis is used in a key step. Adoption of this methodol. will contribute towards the transition to sustainable and bio-based processes in the pharmaceutical and agrochem. industries.

Nature Communications published new progress about 2051-95-8. 2051-95-8 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ketone, name is 3-Benzoylpropionicacid, and the molecular formula is C8H5F3N4, Formula: C10H10O3.

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

Meikle, Peter J. published the artcilePreparation of polysaccharide-enzyme conjugates for competitive binding assays, Application In Synthesis of 10517-44-9, the publication is Glycoconjugate Journal (1990), 7(3), 207-18, database is CAplus.

A variety of bacterial O-polysaccharides were covalently linked to enzymes and it was demonstrated with three discrete monoclonal antibodies that enzyme-glycoconjugates function as convenient labeled antigens in direct enzyme immunoassays, particularly competitive assays that quantify bacterial O-antigens. Two strategies, each involving reductive amination, were used to couple O-polysaccharides to enzymes, while retaining high enzymic activity. Reduction of the Schiff base formed between 1,3-diaminopropane and the terminal reducing ketodeoxyoctanoic acid (KDO) residue present in the majority of the lipopolysaccharide (LPS) core domains, following mild acid removal of Lipid A, offered the most direct route to mono-aminated polysaccharide. Alternatively, mild periodate oxidation of KDO and heptose residues generated multiple aldehyde targets for Schiff base formation, without affecting the O-antigenic determinant. Hetero- and homobifunctional coupling reagents, sulfosuccinimidyl-4-(N-maleimidomethyl)-cyclohexane-1-carboxylate and disuccinimidyl suberate, activated polysaccharide for coupling to enzymes at amino and sulphydryl sites and produced conjugates that retained at least 95% of the original enzymic activity. The most suitable enzyme conjugates, especially for competitive inhibition EIA were those bearing one polysaccharide chain, and these were easily prepared from horse-radish peroxidase. Although the extent of conjugation of activated polysaccharide to ¦Â-galactosidase and alk. phosphatase could be controlled by reaction stoichiometry, the use of these enzymes were a less effective utilization of valuable antigen and enzyme.

Glycoconjugate Journal published new progress about 10517-44-9. 10517-44-9 belongs to catalysis-chemistry, auxiliary class Salt,Amine,Aliphatic hydrocarbon chain, name is Propane-1,3-diamine dihydrochloride, and the molecular formula is C3H12Cl2N2, Application In Synthesis of 10517-44-9.

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