Catalysis-chemistry

Goehner, Martin published the artcile2,3-Dihydro-4,5-diisopropyl-1,3-dimethylimidazol-2-ylidene and its chalcogenones, Application In Synthesis of 6972-05-0, the publication is Zeitschrift fuer Naturforschung, B: A Journal of Chemical Sciences (2015), 70(2), 91-94, database is CAplus.

2,3-Dihydro-4,5-diisopropyl-1,3-dimethylimidazol-2-ylidene (I) is prepared by reduction of the corresponding thione II with potassium. The selenium compound III is obtained from I and selenium. In the solid state, II and III exist as their isomers, as revealed by their crystal structures.

Zeitschrift fuer Naturforschung, B: A Journal of Chemical Sciences published new progress about 6972-05-0. 6972-05-0 belongs to catalysis-chemistry, auxiliary class Thiourea,Amine,Aliphatic hydrocarbon chain,Amide, name is 1,1-Dimethylthiourea, and the molecular formula is C3H8N2S, Application In Synthesis of 6972-05-0.

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

Von Ohe, Peter C. published the artcileStructural Alerts-A New Classification Model to Discriminate Excess Toxicity from Narcotic Effect Levels of Organic Compounds in the Acute Daphnid Assay, SDS of cas: 6972-05-0, the publication is Chemical Research in Toxicology (2005), 18(3), 536-555, database is CAplus and MEDLINE.

Quant. and qual. structure-activity relationships (QSARs) have a great potential to support the risk assessment of chems., provided there are tools available that allow evaluation of the suitability of QSARs for the compounds of interest. In this context, a pragmatic approach is to discriminate excess toxicity from narcotic effect levels, because the latter can be estimated from QSARs and thus have a low priority for exptl. testing. To develop a resp. scheme for the acute daphnid toxicity as one of the primary ecotoxicol. endpoints, 1067 acute toxicity data entries for 380 chems. involving the daphnid species Daphnia magna were taken from the online literature, and quality checks such as water solubility were employed to eliminate apparently odd data entries. For 36 known narcotics with LC₅₀ values referring to D. magna, a reference baseline QSAR is derived. Compounds with LC₅₀ values above a certain threshold defined relative to their predicted baseline toxicity are classified as exerting excess toxicity. Three simple discrimination schemes are presented that enable the identification of excess toxicity from structural alerts based on the presence or absence of certain heteroatoms and their chem. functionality. Moreover, a two-step classification approach is introduced that enables a prioritization of organic compounds with respect to their need for exptl. testing. The discussion includes reaction mechanisms that may explain the association of structural alerts with excess toxicity, a comparison with predictions derived from mode of action-based classification schemes, and a statistical anal. of the discrimination performance in terms of detailed contingency table statistics.

Chemical Research in Toxicology published new progress about 6972-05-0. 6972-05-0 belongs to catalysis-chemistry, auxiliary class Thiourea,Amine,Aliphatic hydrocarbon chain,Amide, name is 1,1-Dimethylthiourea, and the molecular formula is C4H10O2, SDS of cas: 6972-05-0.

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

Narkevich, V. B. published the artcileEffects of heptapeptide selank on the content of monoamines and their metabolites in the brain of BALB/C and C57BL/6 mice: a comparative study, Related Products of catalysis-chemistry, the publication is Eksperimental’naya i Klinicheskaya Farmakologiya (2008), 71(5), 8-12, database is CAplus and MEDLINE.

The effect of heptapeptide selank on the content of neurotransmitter monoamines and its metabolites in the brain structures of BALB/C and C57Bl/6 line mice under conditions of the open-field test were studied. Significant interstrain differences in the content of norepinephrine (NE), dopamine (DA), serotonin (5-HT) as well as in the levels of their metabolites in hippocampus, hypothalamus, striatum and frontal cortex of C57Bl/6 and BALB/C mice were demonstrated. In particular, the content of 5-HT and its metabolite 5-oxyindolacetic acid (5-HIAA) in hippocampus of BALB/C mice (with passive stress response) was higher than in the same structure of C57Bl/6 (stress-susceptible) animals. The injection of selank (0.3 mg/kg) led to an increase in the NE level in the hypothalamus of both mice strains. At the same time, selank produced opposite effects on the content of DA metabolites: the concentrations of dioxyphenylacetic (DO-PAC) and homovanillic (HVA) acids were found to increase in frontal cortex and hippocampus of C57Bl/6 mice, while the same parameters in BALB/C mice were demonstrated to decrease. Selank induced a decrease in 5-HT and 5-HIAA levels in the hippocampus of BALB/C mice, but did not affect these parameters in C57Bl/6 animals. The obtained results are indicative of selectivity of the anxiolytic effects of selank.

Eksperimental’naya i Klinicheskaya Farmakologiya 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 C10H10O6, Related Products of catalysis-chemistry.

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

Liu, Changqing published the artcileHighly Stereoselective Cationic Cyclization Assisted by a Sulfenyl Group. Scope, Limitation, and Mechanism, Quality Control of 22693-41-0, the publication is Journal of Organic Chemistry (1996), 61(2), 494-502, database is CAplus and MEDLINE.

When 8-acetoxy-2-methyl-9-(phenylthio)-2-nonene (1) was treated with an acid, followed by a base, alkylative cyclization proceeded to give a mixture of 1,2-disubstituted cyclohexanes. The stereochem. of the reaction was only slightly affected by the leaving group and the reaction conditions, such as the temperature, solvent, and acid. However, the bulkiness of the sulfenyl group had a great effect on the stereochem. course of the reaction. High trans selectivity was attained when a derivative of 1 with a bulkier sulfenyl group was used as a substrate. On the other hand, the length and rigidity of the carbon chain of the substrate also had a major effect on the stereochem. of the reaction; a high cis selectivity was observed when a one-carbon-fewer analog of 1 or a derivative with one more double bond in the carbon chain than in 1 was used as the substrate. The reaction proceeded via a 6,5- or 5,5-fused-ring intermediate. The sulfenyl-group-assisted reaction could be a useful method for the stereoselective cyclization of acetates of ¦Á-sulfenylated secondary alcs.

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, Quality Control of 22693-41-0.

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

Garcia, Joel published the artcilePhysical Properties of Eu²⁺-Containing Cryptates as Contrast Agents for Ultrahigh-Field Magnetic Resonance Imaging, Synthetic Route of 5411-14-3, the publication is European Journal of Inorganic Chemistry (2012), 2012(12), 2135-2140, database is CAplus and MEDLINE.

The kinetic stabilities and relaxivities of a series of Eu²⁺-containing cryptates have been investigated. Transmetallation studies, which monitored the change in the longitudinal relaxation rate of water protons in the presence of Ca²⁺, Mg²⁺, and Zn²⁺, demonstrated that the cryptate structure influenced the stability, and two of the cryptates studied were inert to transmetalation in the presence of these endogenous ions. The efficacy of these cryptates was determined at different magnetic field strengths, temperatures, and pH values. Cryptate relaxivity was found to be higher at ultrahigh field strengths (7 and 9.4 T) relative to clin. relevant field strengths (1.4 and 3 T), but the efficiency of these cryptates decreased as the temperature increased. In addition, a variation in pH did not yield significant changes in the efficacy of the cryptates. These studies establish a foundation of important properties that are necessary to develop effective pos. contrast agents for magnetic resonance imaging from Eu²⁺-containing cryptates.

European Journal of Inorganic Chemistry 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 C10H10O6, Synthetic Route of 5411-14-3.

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

Sang, Rui published the artcileSynthesis of Carboxylic Acids by Palladium-Catalyzed Hydroxycarbonylation, Application of 2-Methyl-4-phenylbutanoic acid, the publication is Angewandte Chemie, International Edition (2019), 58(40), 14365-14373, database is CAplus and MEDLINE.

The synthesis of carboxylic acids is of fundamental importance in the chem. industry and the corresponding products find numerous applications for polymers, cosmetics, pharmaceuticals, agrochems., and other manufactured chems. Although hydroxycarbonylations of olefins have been known for more than 60 years, currently known catalyst systems for this transformation do not fulfill industrial requirements, for example, stability. Presented herein for the first time is an aqueous-phase protocol that allows conversion of various olefins, including sterically hindered and demanding tetra-, tri-, and 1,1-disubstituted systems, as well as terminal alkenes, into the corresponding carboxylic acids in excellent yields. The outstanding stability of the catalyst system (26 recycling runs in 32 days without measurable loss of activity), is showcased in the preparation of an industrially relevant fatty acid. Key-to-success is the use of a built-in-base ligand under acidic aqueous conditions. This catalytic system is expected to provide a basis for new cost-competitive processes for the industrial production of carboxylic acids.

Angewandte Chemie, International Edition published new progress about 1949-41-3. 1949-41-3 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene, name is 2-Methyl-4-phenylbutanoic acid, and the molecular formula is C11H14O2, Application of 2-Methyl-4-phenylbutanoic acid.

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

Walter, Wolfgang published the artcileStructure of thioamides and their derivatives, XLII. N-(Trimethylsilyl)thioureas, HPLC of Formula: 6972-05-0, the publication is Liebigs Annalen der Chemie (1979), 263-77, database is CAplus.

N-silylation of mono- and disubstituted thioureas was carried out by treating them with Me₃SiCl/Et₃N. Monosilylated ureas could also be obtained from silylated amines and isothiocyanates. The trisubstituted thiourea Me₂NC(S)NHMe and monosilylated thioureas RNHC(S)NR¹SiMe₃ (R = Ph, R¹ = H, Ph; R = Me, R¹ = Ph) were silylated via metalation with BuLi and reaction with Me₃SiCl. Barriers to rotation about the C-N bond of the N-(trimethylsilyl)thioureas were determined

Liebigs Annalen der Chemie published new progress about 6972-05-0. 6972-05-0 belongs to catalysis-chemistry, auxiliary class Thiourea,Amine,Aliphatic hydrocarbon chain,Amide, name is 1,1-Dimethylthiourea, and the molecular formula is C17H37NO3, HPLC of Formula: 6972-05-0.

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

Manna, Kuntal published the artcileConcerted C-N/C-H Bond Formation in Highly Enantioselective Yttrium(III)-Catalyzed Hydroamination, Recommanded Product: 2,2-Diallylpent-4-en-1-amine, the publication is ACS Catalysis (2011), 1(11), 1637-1642, database is CAplus.

A highly active oxazolinylborato yttrium hydroamination catalyst provides 2-methyl-pyrrolidines with excellent optical purities. The proposed mechanism, in which a yttrium(amidoalkene)amine complex reacts by concerted C-N and C-H bond formation, is supported by the rate law for conversion, substrate saturation under initial rates conditions, kinetic isotope effects, and isotopic perturbation of enantioselectivity. These features are conserved between oxazolinylborato Mg-, Y-, and Zr-mediated aminoalkene cyclizations, suggesting related transition states for all three systems. However, inversion of the products’ absolute configuration between yttrium and zirconium catalysts coordinated by the same 4S-oxazolinylborate ligands highlight dissimilar mechanisms of stereoinduction.

ACS Catalysis published new progress about 928836-00-4. 928836-00-4 belongs to catalysis-chemistry, auxiliary class Alkenyl,Amine,Aliphatic hydrocarbon chain, name is 2,2-Diallylpent-4-en-1-amine, and the molecular formula is C11H19N, Recommanded Product: 2,2-Diallylpent-4-en-1-amine.

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

Padwa, Albert published the artcileRhodium(II)-catalyzed cyclization reactions of alkynyl-substituted ¦Á-diazo ketones, Safety of Allyldiphenylphosphine oxide, the publication is Journal of Organic Chemistry (1991), 56(7), 2523-30, database is CAplus.

Treatment of several o-alkynyl-substituted ¦Á-diazoacetophenone derivatives with rhodium(II) carboxylates results in the formation of substituted indenones. The simplest mechanism accounting for the results involves addition of a rhodium-stabilized carbenoid onto the acetylenic ¦Ð-bond to generate a vinyl carbenoid directly or possibly a highly strained cyclopropene derivative The vinyl carbenoid was found to undergo addition to a neighboring alkene tethered on the side chain to give an indenyl-substituted bicyclo[3.1.0]hexane derivative A number of related systems were examined so as to probe the scope and generality of the process. Treatment of 2-[CH₂:CHCH:CH(CH₂)₃Cú·C]C₆H₄COCHN₂ with rhodium(II) mandelate afforded a benzocyclopent[g]azulenone derivative I. The formation of this compound involves a divinylcyclopropane intermediate that readily undergoes a Cope rearrangement under the reaction conditions. The rhodium-catalyzed reaction of 2-[MeCO(CH₂)₃Cú·C]C₆H₄COCHN₂ in the presence of N-phenylmaleimide afforded a mixture of two cycloadducts II and III. Product II can be accounted for in terms of a cyclization of the vinyl carbenoid onto the oxygen atom of the neighboring carbonyl group to give a resonance-stabilized dipole. 1,3-Dipolar cycloaddition of the carbonyl ylide across the activated ¦Ð-bond of N-phenylmaleimide affords the observed product. The structure of II was confirmed by x-ray anal. The second cycloadduct III is formed by a 1,2-hydrogen shift of the initially produced vinyl carbenoid. The resulting diene undergoes a subsequent Diels-Alder reaction with N-phenylmaleimide.

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, Safety of Allyldiphenylphosphine oxide.

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

Tronov, B. V. published the artcileSynthesis of certain nitro and amino derivatives of diphenylamine and their complexes with acid reagents, Quality Control of 1821-27-8, the publication is Dokl. 2-oi [Vtoroi] Mezhvuz. Konf. po Khim. Org. Kompleksn. Soedin. (1963), 67-8, database is CAplus.

Formation of complexes of nitro and amino derivatives of Ph₂NH (I) was investigated. 4-Nitro- (Ia), 4,4′-dinitro- (Ib), 2,4-dinitro (Ic), 2,4-diamino (Id), and 4,4′-diaminodiphenylamine (Ie) were prepared Id and Ie were obtained by reduction of the corresponding nitro derivatives with SnCl₂ and HCl. The following complex compounds were prepared and extracted from alc. or C₆H₆ (composition of the complex, ratio of components, and m.p. given): Id + 2,4-dinitrophenol (II), 1:1, 83-4¡ã; Id + 2,6-dibromo-4-nitrophenol (III), 1:1, 156-8¡ã; Id + 2,6-dichloro-4-nitrophenol (IV), 1:1, 150-2¡ã; Id + picric acid (V), 1:1, 177-8¡ã; Ic + II, 1:1, 95-6¡ã; Ic + V, 1:1, 100-2¡ã; Ia + IV, 1:1, 94-6¡ã; Ia + III, 1:1, 98-9¡ã; Ie + V, 1:1, > 220¡ã; Ie + II, –, >220¡ã; Ie + IV, –, >220¡ã; Ie + III, –, >220¡ã.

Dokl. 2-oi [Vtoroi] Mezhvuz. Konf. po Khim. Org. Kompleksn. Soedin. 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 C12H19BrS, Quality Control of 1821-27-8.

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