Day: December 5, 2022

Tsunemasa, Noritaka published the artcileContamination of an alternative antifoulant in coastal waters of Hiroshima Bay, Product Details of C23H20BN, the publication is Kankyo Kagaku (2006), 16(2), 201-211, database is CAplus.

It is well known that organotin (OT) compounds, which are used as effective antifouling biocides, have deleterious effects on nontarget marine organisms when released into water from the coatings applied to boat hulls, and environmental studies have indicated OT contamination of the marine environment on a worldwide scale. In Oct. 2001, the International Maritime Organization (IMO) adopted the International Convention on the Control of Harmful Antifouling Systems (AFS Convention), which prohibited the use of OTs as active ingredients in antifouling systems for ships. Following the international restrictions on the use of OT-based antifoulants, paint manufactures have developed many alternative products. In Japan, more than 20 chem. substances have been used or proposed as alternative compounds In the present study, Sea-nine211, KH101, Diuron, Irgarol 1051 and the latters degradation product M1 were investigated in water from Hiroshima Bay. Concentrations of Sea-nine211, Diuron, Irgarol 1051 and M1 in water samples were in the range of <0.023âˆ?.10, <0.040âˆ?.43, <0.092, and <0.031âˆ?.3 μg/L, resp. KH101 was not detected in the water samples.

Kankyo Kagaku published new progress about 971-66-4. 971-66-4 belongs to pyridine-derivatives, auxiliary class Pyridine,Benzene, name is Triphenyl(pyridin-1-ium-1-yl)borate, and the molecular formula is C8H10O2, Product Details of C23H20BN.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Weber, Jeremy E. published the artcileElectronic and Spin-State Effects on Dinitrogen Splitting to Nitrides in a Rhenium Pincer System, Computed Properties of 971-66-4, the publication is Inorganic Chemistry (2021), 60(9), 6115-6124, database is CAplus and MEDLINE.

Bimetallic nitrogen (N₂) splitting to form metal nitrides is an attractive method for N₂ fixation. Although a growing number of pincer-supported systems can bind and split N₂, the precise relation between the ligand properties and N₂ binding/splitting remains elusive. Here the authors report the first example of an N₂-bridged rhenium(III) complex, [(trans-P₂^tBuPyrr)ReCl₂]₂(μ-η¹:η¹-N₂) (P₂^tBuPyrr = [2,5-(CH₂P^tBu₂)₂C₄H₂N]^–). In this case, N₂ binding occurs at a higher oxidation level than that in other reported pincer analogs. Anal. of the electronic structure through computational studies shows that the weakly π-donor pincer ligand stabilizes an open-shell electronic configuration that leads to enhanced binding of N₂ in the bridged complex. Using SQUID magnetometry, the authors demonstrate a singlet ground state for this Re-N-N-Re complex, and the authors offer tentative explanations for antiferromagnetic coupling of the two local S = 1 sites. Reduction and subsequent heating of the rhenium(III)-dinitrogen complex leads to chloride loss and cleavage of the N-N bond with isolation of the terminal rhenium(V) nitride complex (P₂^tBuPyrr)ReNCl.

Inorganic Chemistry published new progress about 971-66-4. 971-66-4 belongs to pyridine-derivatives, auxiliary class Pyridine,Benzene, name is Triphenyl(pyridin-1-ium-1-yl)borate, and the molecular formula is C5H5F3O2, Computed Properties of 971-66-4.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Kawatsura, Motoi published the artcileTransition Metal-Catalyzed Addition of Amines to Acrylic Acid Derivatives. A High-Throughput Method for Evaluating Hydroamination of Primary and Secondary Alkylamines, Application of 2,6-Bis((di-tert-butylphosphino)methyl)pyridine, the publication is Organometallics (2001), 20(10), 1960-1964, database is CAplus.

Several new classes of transition metal-catalyzed reactions of amines with the C:C bond of acrylic acid derivatives were discovered using a high-throughput colorimetric assay. This assay is general for the reactions of primary and secondary alkylamines with acrylic acid derivatives, and the screening of potential catalysts using this assay revealed a number of different metal/ligand combinations that promote these hydroaminations. The colorimetric assay revealed catalysts for the addition of piperidine to methacrylonitrile, crotononitrile, Et crotonate, and Et methacrylate, as well as catalysts for reactions of butylamine and aniline with methacrylonitrile, with product yields of 89-99%. A catalyst for the addition of aniline to crotononitrile at 100° was also discovered. Thus, treating crotononitrile with aniline in presence of 10% Pd(OAc)₂ and 10% 1,3-bis[(di-tert-butylphosphino)methyl]benzene gave 90% 2-anilinopropyl cyanide. The products of these reactions are basic building blocks for the synthesis of β-amino acids, amino alcs., and diamines. These reactions may ultimately produce an enantioselective route to optically active difunctional materials from commodity reagents.

Organometallics published new progress about 338800-13-8. 338800-13-8 belongs to pyridine-derivatives, auxiliary class Bis-phosphine Ligands, name is 2,6-Bis((di-tert-butylphosphino)methyl)pyridine, and the molecular formula is C23H43NP2, Application of 2,6-Bis((di-tert-butylphosphino)methyl)pyridine.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Rozatian, Neshat published the artcileKinetics of Electrophilic Fluorination of Steroids and Epimerisation of Fluorosteroids, Category: pyridine-derivatives, the publication is Chemistry – A European Journal (2020), 26(52), 12027-12035, database is CAplus and MEDLINE.

Fluorinated steroids, which are synthesized by electrophilic fluorination, form a significant proportion of marketed pharmaceuticals. To gain quant. information on fluorination at the 6-position of steroids, kinetics studies were conducted on enol ester derivatives of progesterone, testosterone, cholestenone and hydrocortisone with a series of electrophilic N-F reagents. The stereoselectivities of fluorination reactions of progesterone enol acetate and the kinetic effects of additives, including methanol and water, were investigated. The kinetics of epimerization of 6β-fluoroprogesterone to the more pharmacol. active 6α-fluoroprogesterone isomer in HCl/acetic acid solutions are detailed.

Chemistry – A European Journal published new progress about 107263-95-6. 107263-95-6 belongs to pyridine-derivatives, auxiliary class Fluorination reagent, name is 1-Fluoropyridiniumtriflate, and the molecular formula is C6H5F4NO3S, Category: pyridine-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Zhao, Zhijian published the artcileSynthesis and optimization of N-heterocyclic pyridinones as catechol-O-methyltransferase (COMT) inhibitors, COA of Formula: C5H6BNO2, the publication is Bioorganic & Medicinal Chemistry Letters (2016), 26(12), 2952-2956, database is CAplus and MEDLINE.

A series of N-heterocyclic pyridinone catechol-O-methyltransferase (COMT) inhibitors were synthesized. Physicochem. properties, including ligand lipophilic efficiency (LLE) and clog P, were used to guide compound design and attempt to improve inhibitor pharmacokinetics. Incorporation of heterocyclic central rings provided improvements in physicochem. parameters but did not significantly reduce in vitro or in vivo clearance. Nevertheless, compound I was identified as a potent inhibitor with sufficient in vivo exposure to significantly affect the dopamine metabolites homovanillic acid (HVA) and dihydroxyphenylacetic acid (DOPAC), and indicate central COMT inhibition.

Bioorganic & Medicinal Chemistry Letters published new progress about 197958-29-5. 197958-29-5 belongs to pyridine-derivatives, auxiliary class Pyridine,Boronic acid and ester, name is 2-Pyridinylboronic acid, and the molecular formula is C18H24N6O6S4, COA of Formula: C5H6BNO2.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Yang, Yang published the artcileSynthetic versatility of 2-substituted-6-methyl 2,3-dihydropyridinones in the synthesis of polyfunctional piperidine-based compounds and related β amino acid derivatives, Recommanded Product: 2-Pyridinylboronic acid, the publication is Organic & Biomolecular Chemistry (2017), 15(40), 8576-8593, database is CAplus and MEDLINE.

Chiral 2-substituted-6-Me 2,3-dihydropyidinones (I) (R¹ = cyclohexyl, n-pentyl, CH₂TBSO, n-butyl), which can be facilely obtained from an asym. vinylogous Mannich reaction (VMR) with 1,3-bis-trimethylsilyl enol ether, were used as versatile intermediates in constructing chiral polyfunctional piperidine-based compounds The 6-Me group of such compounds can be conveniently functionalized via alkylation and acylation reactions to provide efficient entries to the synthesis of a variety of chiral multi-substituted piperidine-based compounds Further elaboration of the corresponding intermediates also provided access to polyfunctional indolizidine-based compounds These methods were showcased in an asym. synthesis of 2,6-di-substituted piperidine compound (II), reported as the key intermediate in the synthesis of (+)-calvine and a natural alkaloid (-)-indolizidine 209D. Furthermore, selective C5 iodination of compound I enabled the installation of addnl. functional groups at this position. Finally, we demonstrated that the oxidative cleavage of 2-substituted-6-methyl-2,3-dihydropyidinones is a practical and efficient method for the enantioselective synthesis of β-amino acids, which can undergo further intra-mol. cyclization to give the corresponding chiral four-membered β-lactam derivatives

Organic & Biomolecular Chemistry published new progress about 197958-29-5. 197958-29-5 belongs to pyridine-derivatives, auxiliary class Pyridine,Boronic acid and ester, name is 2-Pyridinylboronic acid, and the molecular formula is C13H18BNO3, Recommanded Product: 2-Pyridinylboronic acid.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Umemoto, Teruo published the artcileN-F 19-fluorine nuclear magnetic resonance of N-fluoropyridinium salts, HPLC of Formula: 107263-95-6, the publication is Journal of Fluorine Chemistry (1991), 53(3), 369-77, database is CAplus.

The completely ionic structure of N-fluoropyridinium salts is supported by their N-F ¹⁹F chem. shifts which are independent of the nature of the counteranions. The ¹⁹F chem. shifts of β- and γ-substituted N-fluoropyridinium salts are both correlated to pKa values of the corresponding pyridines, but in different ways. However, the shifts of α-substituted N-fluoro salts except for those with alkyl substituents were abnormally shifted upfield due to nonbonded electronic interactions, regardless of their pKa’s. The relationship between variable fluorinating power and ¹⁹F chem. shifts of N-fluoropyridinium salt is also discussed.

Journal of Fluorine Chemistry published new progress about 107263-95-6. 107263-95-6 belongs to pyridine-derivatives, auxiliary class Fluorination reagent, name is 1-Fluoropyridiniumtriflate, and the molecular formula is C27H39ClN2, HPLC of Formula: 107263-95-6.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Umemoto, Teruo published the artcileSyntheses and properties of N-fluoropyridinium salts, Safety of 1-Fluoropyridiniumtriflate, the publication is Bulletin of the Chemical Society of Japan (1991), 64(4), 1081-92, database is CAplus.

Various stable N-fluoropyridinium salts with a non- or weakly nucleophilic counter anion such as triflate, FSO₃^–, BF₄^–, SbF₆^–, ClO₄^–, CH₃SO₃^– etc., or with an electron-donating or -withdrawing substituent(s) on the pyridine ring were synthesized and their properties investigated. N-Fluoropyridinium-2-sulfonates, N-fluoroquinolinium triflate, and highly hindered N-fluoro-2,6-di-tert-butylpyridinium salts were also synthesized. They were synthesized by counter anion displacement reactions of unstable pyridine-F₂ compounds, fluorination of salts of pyridines with protonic acids or silyl esters with F, and/or fluorination of Lewis acid complexes of pyridines. The scope of each method was examined in detail. The stability of the N-fluoropyridinium salts depended on the nucleophilicity or basicity of the counter anions and electronic nature or position of the ring substituents. These results and NMR analyses clearly showed the unstable pyridine-F₂ compounds to have N-fluoropyridinium fluoride salt structure. Some N-fluoropyridinium triflates were hydrolyzed and the products were examined, suggesting a unique hydrolysis mechanism. The authors warn of the toxicity of fluorine.

Bulletin of the Chemical Society of Japan published new progress about 107263-95-6. 107263-95-6 belongs to pyridine-derivatives, auxiliary class Fluorination reagent, name is 1-Fluoropyridiniumtriflate, and the molecular formula is C9H12O, Safety of 1-Fluoropyridiniumtriflate.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Tsuruta, Keisuke published the artcileElectrochemical Condensation of Methylviologen on Specifically-adsorbed Anion Layers, Product Details of C22H18Cl2N2, the publication is Electroanalysis (2019), 31(6), 1150-1154, database is CAplus.

The adsorption of methylviologen dications (MV²⁺) on single-crystalline Au electrodes in both H₂SO₄ and HClO₄ was examined MV²⁺ strongly interacted with sulfate and bisulfate anions adsorbed on the Au(111) electrode surface in 0.05 M H₂SO₄ under a controlled potential of 1.25 V vs. the reversible hydrogen electrode (RHE). A characteristic non-Faradaic current was observed at 1.10 V vs. RHE. When adsorption of MV²⁺ was carried out in 0.1 M HClO₄, the electrochem. response of MV²⁺ was less than that obtained in H₂SO₄. The results show that the formation of a highly ordered sulfate/bisulfate adlayer plays an important role in the formation of condensed MV²⁺ layers. Examination of polycrystalline Au and Au(100) electrodes revealed a poor electrochem. response due to the surface roughness of the Au substrate, but the electrochem. detection was applicable to polycrystalline Au electrodes. A systematic investigation of the structural dependency of viologen derivatives showed that mol. size is important for electrostatic interactions with a highly ordered sulfate/bisulfate adlayer. The findings of the present study demonstrate successful detection of MV²⁺ at a concentration of â‰? pM with a non-Faradaic current.

Electroanalysis published new progress about 47369-00-6. 47369-00-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Salt,Benzene,Organic ligands for MOF materials,Nitrogen containing MOF ligands,Nitrogen containing MOF ligands, name is 1,1′-Diphenyl-[4,4′-bipyridine]-1,1′-diium chloride, and the molecular formula is C6H9BN2O2, Product Details of C22H18Cl2N2.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Burns, D. Thorburn published the artcileSpectrophotometric or spectrofluorimetric determination of cobalt in steels by extraction as bis[1-(2-pyridylmethylene)-2-(2-pyridyl)hydrazine]cobalt(III) dimethoxyanthracenesulfonate, Synthetic Route of 2215-33-0, the publication is Analytica Chimica Acta (1983), 151(1), 245-9, database is CAplus.

The steel sample was dissolved and Co was reacted with 1-(2-pyridylmethylene)-2-(2-pyridyl)hydrazine (PAPY) and dimethoxyanthracenesulfonate (DMAS) at pH 3 to form an ion-pair complex. The latter was extracted into 1:9 Me₂CO-1,2-dichloroethane. The absorbance and fluorescence of the organic phase was measured at 496 nm and 450 nm (λ_exc = 396 nm), resp. Beer’s law was obeyed for 0-5 μg Co/10 mL. The relative standard deviation was 1.3 and 1.5% for the spectrophotometric and fluorometric, resp., determination of 4 μg Co. The molar absorptivity of the Co(PAPY)₂DMAS ion-pair complex was 3.23 × 10⁴. The detection limit was 0.003 and 0.004 μg Co/mL for the spectrophotometric and fluorometric determination, resp. The effect of diverse ions was studied.

Analytica Chimica Acta published new progress about 2215-33-0. 2215-33-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, and the molecular formula is C11H10N4, Synthetic Route of 2215-33-0.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem