Catalysis-chemistry

Eisner, Ludmila published the artcileDoped silica sol layer coatings on evanescent field fiber Bragg gratings for optical detection of nitroaromate based explosives, Product Details of C6H17NO3Si, the publication is Sensors and Actuators, A: Physical (2022), 113687, database is CAplus.

Evanescent field etched fiber Bragg gratings (eFBG) were prepared with doped and non-doped nanoporous silica sol coatings for optical detection of the nitroarom. explosives 2,4-dinitrotoluene (DNT), 1,3-dinitrobenzene (DNB) and trinitrotoluene (TNT). We used 3-aminopropyltrimethoxysilane (APTMS) and tetrabutylammonium hydroxide based receptors (TBAH, C16H37NO) as dopants in order to increase the specific identification of the nitroaromates. In nitroarom. trace gas atm. the induced wavelength shift of the Bragg reflection signal was highest for the sensor with TBAH-doped silica sol receptor coating. Within the first two minutes during exposure the change of the signal intensity, reflecting the adsorption dynamics of the nitroarom. explosives, was most significant and characteristically depending on the type of receptor dopant used. The cross sensitivities of the sensor with TBAH-doped silica sol receptor coating with four common solvents like acetone, ethanol, 2-propanol and THF (THF) in comparison to the sensitivity of the tested explosives was more than six orders of magnitude (106) lower than that of solvents, indicating a very high selectivity of the sensor. By applying a simplified diffusion model correlated to a series of measurements with different distances to the target we estimated the limit of detection for a sensor coated with TBAH doped silica sol with 35.8 ¡À 0.9 ppb for DNB and 140.2 ¡À 1.8 ppb for DNT in air at room temperature Using a more etched FBG (but mech. less robust) sensor we were able to detect TNT as well at concentrations about 5 ppb at room temperature in air. A major result of our investigations was to demonstrate, that the nanoporous silica sol host matrix is suited for fast adapting with low technol. effort the affinity of the receptor coating for silica-based evanescent field sensors. For future applications a set of sensors of silica-sol coatings with different dopants in combination with pattern recognition of the sensor signals could be used for clear identification of explosives.

Sensors and Actuators, A: Physical 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, Product Details of C6H17NO3Si.

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

Alauddin, Mian M. published the artcileSynthesis of [¹⁸F]-labeled adenosine analogs as potential PET imaging agents, Formula: C17H37NO3, the publication is Journal of Labelled Compounds & Radiopharmaceuticals (2003), 46(9), 805-814, database is CAplus.

The syntheses of adenosine analogs, 2′-deoxy-2′-[¹⁸F]fluoro-9-¦Â-D-arabinofuranosyladenine ([¹⁸F]-FAA) and 3′-deoxy-3′-[¹⁸F]fluoro-9-¦Â-D-xylofuranosyladenine ([¹⁸F]-FXA) from adenosine via reaction with tetrabutylammonium[¹⁸F]fluoride, are reported. Crude preparations were purified by HPLC to obtain the desired pure products. The radiochem. yields were 10-18% decay corrected (d.c.) for [¹⁸F]-FAA and 30-40% (d.c.) for [¹⁸F]-FXA in 4 and 3 runs, resp. Radiochem. purity was >99% and specific activity was > 74 GBq/¦Ìmol at the end of synthesis (EOS). The synthesis time was 90-95 min from the end of bombardment (EOB).

Journal of Labelled Compounds & Radiopharmaceuticals published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C17H37NO3, Formula: C17H37NO3.

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

Wu, Shengde published the artcileFramework for Identifying Chemicals with Structural Features Associated with the Potential to Act as Developmental or Reproductive Toxicants, Category: catalysis-chemistry, the publication is Chemical Research in Toxicology (2013), 26(12), 1840-1861, database is CAplus and MEDLINE.

Developmental and reproductive toxicity (DART) end points are important hazard end points that need to be addressed in the risk assessment of chems. to determine whether or not they are the critical effects in the overall risk assessment. These hazard end points are difficult to predict using current in silico tools because of the diversity of mechanisms of action that elicit DART effects and the potential for narrow windows of vulnerability. DART end points have been projected to consume the majority of animals used for compliance with REACH; thus, addnl. nonanimal predictive tools are urgently needed. This article presents an empirically based decision tree for determining whether or not a chem. has receptor-binding properties and structural features that are consistent with chem. structures known to have toxicity for DART end points. The decision tree is based on a detailed review of 716 chems. (664 pos., 16 neg., and 36 with insufficient data) that have DART end-point data and are grouped into defined receptor binding and chem. domains. When tested against a group of chems. not included in the training set, the decision tree is shown to identify a high percentage of chems. with known DART effects. It is proposed that this decision tree could be used both as a component of a screening system to identify chems. of potential concern and as a component of weight-of-evidence decisions based on structure-activity relationships (SAR) to fill data gaps without generating addnl. test data. In addition, the chem. groupings generated could be used as a starting point for the development of hypotheses for in vitro testing to elucidate mode of action and ultimately in the development of refined SAR principles for DART that incorporate mode of action (adverse outcome pathways).

Chemical Research in Toxicology 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 C9H12O3S, Category: catalysis-chemistry.

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

Gandomkar, Somayyeh published the artcileEnantioselective Oxidative Aerobic Dealkylation of N-Ethyl Benzylisoquinolines by Employing the Berberine Bridge Enzyme, Category: catalysis-chemistry, the publication is Angewandte Chemie, International Edition (2015), 54(50), 15051-15054, database is CAplus and MEDLINE.

N-Dealkylation methods are well described for organic chem. and the reaction is known in nature and drug metabolism; however, to our knowledge, enantioselective N-dealkylation has not been yet reported. In this study, exclusively the (S)-enantiomers of racemic N-Et tertiary amines (1-benzyl-N-ethyl-1,2,3,4-tetrahydroisoquinolines) were dealkylated to give the corresponding secondary (S)-amines in an enantioselective fashion at the expense of mol. oxygen. The reaction is catalyzed by the berberine bridge enzyme, which is known for C-C bond formation. The dealkylation was demonstrated on a 100 mg scale and gave optically pure dealkylated products (ee>99 %).

Angewandte Chemie, International Edition published new progress about 1860-58-8. 1860-58-8 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ether, name is 2-(3-(Benzyloxy)phenyl)acetic acid, and the molecular formula is C15H14O3, Category: catalysis-chemistry.

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

Schaub, Thomas published the artcileC-F Activation of Fluorinated Arenes using NHC-Stabilized Nickel(0) Complexes: Selectivity and Mechanistic Investigations, Computed Properties of 1206-46-8, the publication is Journal of the American Chemical Society (2008), 130(29), 9304-9317, database is CAplus and MEDLINE.

The reaction of [Ni₂(ⁱPr₂Im)₄(COD)] 1a or [Ni(ⁱPr₂Im)₂(¦Ç²-C₂H₄)] 1b with different fluorinated arenes is reported. These reactions occur with a high chemo- and regioselectivity. In the case of polyfluorinated aromatics of the type C₆F₅X such as hexafluorobenzene (X = F) octafluorotoluene (X = CF₃), trimethyl(pentafluorophenyl)silane (X = SiMe₃), or decafluorobiphenyl (X = C₆F₅) the C-F activation regioselectively takes place at the C-F bond in the para position to the X group to afford the complexes trans-[Ni(ⁱPr₂Im)₂(F)(C₆F₅)] 2, trans-[Ni(ⁱPr₂Im)₂(F)(4-(CF₃)C₆F₄)] 3, trans-[Ni(ⁱPr₂Im)₂(F)(4-(C₆F₅)C₆F₄)] 4, and trans-[Ni(ⁱPr₂Im)₂(F)(4-(SiMe₃)C₆F₄)] 5. Complex 5 was structurally characterized by x-ray diffraction. The reaction of 1a with partially fluorinated aromatic substrates C₆H_xF_y leads to the products of a C-F activation trans-[Ni(ⁱPr₂Im)₂(F)(2-C₆FH₄)] 7, trans-[Ni(ⁱPr₂Im)₂(F)(3,5-C₆F₂H₃)] 8, trans-[Ni(ⁱPr₂Im)₂(F)(2,3-C₆F₂H₃)] 9a and trans-[Ni(ⁱPr₂Im)₂(F)(2,6-C₆F₂H₃)] 9b, trans-[Ni(ⁱPr₂Im)₂(F)(2,5-C₆F₂H₃)] 10, and trans-[Ni(ⁱPr₂Im)₂(F)(2,3,5,6- C₆F₄H)] 11. The reaction of 1a with octafluoronaphthalene yields exclusively trans-[Ni(ⁱPr₂Im)₂(F)(1,3,4,5,6,7,8-C₁₀F₇)] 6a, the product of an insertion into the C-F bond in the 2-position, whereas for the reaction of 1b with octafluoronaphthalene the two isomers trans-[Ni(ⁱPr₂Im)₂(F)(1,3,4,5,6,7,8-C₁₀F₇)] 6a and trans-[Ni(ⁱPr₂Im)₂(F)(2,3,4,5,6,7,8-C₁₀F₇)] 6b are formed in a ratio of 11:1. The reaction of 1a or of 1b with pentafluoropyridine at low temperatures affords trans-[Ni(ⁱPr₂Im)₂(F)(4-C₅NF₄)] 12a as the sole product, whereas the reaction of 1b performed at room temperature leads to the generation of trans-[Ni(ⁱPr₂Im)₂(F)(4-C₅NF₄)] 12a and trans-[Ni(ⁱPr₂Im)₂(F)(2-C₅NF₄)] 12b in a ratio of approx. 1:2. The detection of intermediates as well as kinetic studies gives some insight into the mechanistic details for the activation of an aromatic carbon-fluorine bond at the {Ni(ⁱPr₂Im)₂} complex fragment. The intermediates of the reaction of 1b with hexafluorobenzene and octafluoronaphthalene, [Ni(ⁱPr₂Im)₂(¦Ç²-C₆F₆)] 13 and [Ni(ⁱPr₂Im)₂(¦Ç²-C₁₀F₈)] 14, have been detected in solution They convert into the C-F activation products. Complex 14 was structurally characterized by x-ray diffraction. The rates for the loss of 14 at different temperatures for the C-F activation of the coordinated naphthalene are first order and the estimated activation enthalpy ¦¤H^? for this process was determined to be ¦¤H^? = 116 ¡À 8 kJ mol^-1 (¦¤S^? = 37 ¡À 25 J K^-1 mol^-1). Furthermore, d. functional theory calculations on the reaction of 1a with hexafluorobenzene, octafluoronaphthalene, octafluorotoluene, 1,2,4-trifluorobenzene, and 1,2,3-trifluorobenzene are presented.

Journal of the American Chemical Society published new progress about 1206-46-8. 1206-46-8 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is Trimethyl(perfluorophenyl)silane, and the molecular formula is C9H9F5Si, Computed Properties of 1206-46-8.

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

Neugebauer, Franz A. published the artcileAminyls. 4. Thermal decomposition of p-substituted tetraarylhydrazines, Quality Control of 1821-27-8, the publication is Chemische Berichte (1971), 104(3), 886-9, database is CAplus.

Thermal decomposition of (p-RC6H4)2NN(C6H4R-p)2 (I, where R = Br, Cl, NO2, Me, or OMe) yielded the corresponding (p-RC6H4)2NH (II) and 2,7-di-(R-substituted)-5,10-bis[p-(R-substituted)phenyl]-5,10-dihydrophenazines (III). In the thermal decomposition of I (where R = Me or MeO) the corresponding 4,2-R[(p-RC6H4)2N]C6H3NHC6H4-R-p and [4,2-R[(p-RC6H4)2N]C6H3]2NH were also formed. The thermal decomposition of I (R = NO2) gave only the corresponding II.

Chemische Berichte 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

Cheloha, Ross W. published the artcileImproved GPCR ligands from nanobody tethering, Name: Dbco-maleimide, the publication is Nature Communications (2020), 11(1), 2087, database is CAplus and MEDLINE.

Abstract: Antibodies conjugated to bioactive compounds allow targeted delivery of therapeutics to cell types of choice based on that antibody’s specificity. Here we develop a new type of conjugate that consists of a nanobody and a peptidic ligand for a G protein-coupled receptor (GPCR), fused via their C-termini. We address activation of parathyroid hormone receptor-1 (PTHR1) and improve the signaling activity and specificity of otherwise poorly active N-terminal peptide fragments of PTH by conjugating them to nanobodies (VHHs) that recognize PTHR1. These C-to-C conjugates show biol. activity superior to that of the parent fragment peptide in vitro. In an exploratory experiment in mice, a VHH-PTH peptide conjugate showed biol. activity, whereas the corresponding free peptide did not. The lead conjugate also possesses selectivity for PTHR1 superior to that of PTH(1-34). This design approach, dubbed “conjugation of ligands and antibodies for membrane proteins” (CLAMP), can yield ligands with high potency and specificity.

Nature Communications 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 C25H21N3O4, Name: Dbco-maleimide.

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

Igoumnov, S. M. published the artcileTrimethyl(pentafluorophenyl)silane C₆F₅Si(CH₃)₃, Quality Control of 1206-46-8, the publication is Fluorine Notes [online computer file] (2001), No pp. given, database is CAplus.

A review on the different methods of producing trimethyl(pentafluorophenyl)silane (referred to as silane). Silane was used as a reagent for introducing a pentafluorophenyl group under conditions of nucleophilic catalysis. The reactions of silane with various compounds, including carbonyl compounds, noncarbonyl electrophilic compounds, electrophilic compounds containing multiple bonds and Xe difluoride, are also described.

Fluorine Notes [online computer file] published new progress about 1206-46-8. 1206-46-8 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is Trimethyl(perfluorophenyl)silane, and the molecular formula is C9H9F5Si, Quality Control of 1206-46-8.

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

Martin, M. L. published the artcileApplication of nitrogen-15 spectroscopy and dynamic NMR to the study of ureas, thioureas, and their Lewis acid adducts, Synthetic Route of 6972-05-0, the publication is Organic Magnetic Resonance (1980), 13(6), 396-402, database is CAplus.

Rotational barriers and ¹⁵N chem. shifts in 34 ureas and thioureas were measured, and several previously unobsd. rotational barriers were detected using lanthanide reagents or a high-field spectrometer. Nearly constant effects on the rotational activation energy and the ¹⁵N shift were produced on going from ureas to the corresponding thioureas, and correlations were observed between the ¦¤G? and ¦Ä(¹⁵N) values. The results are discussed in terms of lone-pair delocalization, and anomalies with respect to the general behavior may be due to the effect of steric torsion in crowded structures on ¹⁵N shifts and rotation barriers.

Organic Magnetic Resonance 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, Synthetic Route of 6972-05-0.

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

Juszkiewicz, A. published the artcileUltrasonic velocity hydration numbers of polyamines, Quality Control of 10517-44-9, the publication is Ultrasonics (1990), 28(6), 391-3, database is CAplus and MEDLINE.

Ultrasonic velocity hydration numbers of diamines, triamines, and tetraamines and hydrochlorides of these amines were determined by measuring the maximum velocity of ultrasound in aqueous-ethanolic solutions The results are interpreted on the basis of the hydrogen-bonded framework model of the water structure.

Ultrasonics 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