Month: December 2022

Ren, Hailong published the artcileCobalt-Catalyzed Regioselective Borylation of Arenes: N-Heterocyclic Silylene as an Electron Donor in the Metal-Mediated Activation of C-H Bonds, Name: 2,3-Dimethyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine, the publication is Chemistry – A European Journal (2017), 23(24), 5663-5667, database is CAplus and MEDLINE.

C-H Borylation of arenes has been a subject of great interest recently because of its atom-economy and the wide applicability of borylated products in value-added synthesis. A new bis(silylene)cobalt(II) complex bearing a bis(N-heterocyclic silylene)-pyridine pincer ligand (SiNSi) has been synthesized and structurally characterized. It enabled the regioselective catalytic C-H borylation of pyridines, furans, and fluorinated arenes. Notably, it exhibited complementary regioselectivity for the borylation of fluorinated arenes compared to previously known catalytic systems, demonstrating that N-heterocyclic silylene donors have enormous potential in metal-catalyzed catalytic applications.

Chemistry – A European Journal published new progress about 741709-65-9. 741709-65-9 belongs to pyridine-derivatives, auxiliary class Pyridine,Boronic acid and ester,Pyridine,Boronate Esters,Boronic Acids,Boronic acid and ester, name is 2,3-Dimethyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine, and the molecular formula is C13H20BNO2, Name: 2,3-Dimethyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine.

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

Yang, Wenqing published the artcileDesign, Synthesis, Antifungal and Antibacterial Activities of N-phenyl and N-pyridinyl-5-(trifluoromethyl)-pyrazole-4-carboxamide Derivatives, Recommanded Product: 4-Amino-2-picoline, the publication is Journal of Heterocyclic Chemistry (2018), 55(10), 2261-2269, database is CAplus.

A series of N-Ph and N-pyridinyl-5-(trifluoromethyl)-pyrazole carboxamides, compounds I [R = Ph, 2-pyridinyl, 2-fluoro-4-pyridinyl, etc.] were designed and synthesized. Bioassay results indicated that antifungal and antibacterial activities of title compounds could be obviously improved by placing trifluoromethyl on the 5-position of the pyrazole ring and substituted 4-pyridinyl at the amine side of the amide bond. The EC₅₀ values of compound I [R = 4-pyridinyl] against Gibberella zeae, Cytospora mandshurica, and Fusarium oxysporum were 14.7, 21.1, and 32.7 μg/mL, resp., better than hymexazol (30.2, 47.3, and 42.5 μg/mL) and carboxin (34.2, >200, and >200 μg/mL). And the EC₅₀ values of compounds I [R = 2-fluoro-4-pyridinyl, 2,6-dichloro-4-pyridinyl, 3,5-dichloro-4-pyridinyl, 6-methyl-2-pyridinyl, 2-methylphenyl, 2-fluorophenyl, 4-chlorophenyl and 4-methoxyphenyl] against rice bacterial leaf blight were 17.0, 21.8, 21.9, 18.6, 16.8, 25.9, 9.4, and 24.4 μg/mL, resp., much better than bismerthiazol (70.5 μg/mL).

Journal of Heterocyclic Chemistry published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C9H21NO3, Recommanded Product: 4-Amino-2-picoline.

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

Wang, Anwei published the artcileMn(III) active site in hydrotalcite efficiently catalyzes the oxidation of alkylarenes with molecular oxygen, Computed Properties of 91-02-1, the publication is Molecular Catalysis (2021), 111276, database is CAplus.

Developing efficient heterogeneous catalytic systems based on easily available materials and mol. oxygen for the selective oxidation of alkylarenes is highly desirable. In the present research, NiMn hydrotalcite (Ni₂Mn-LDH) was found as an efficient catalyst in the oxidation of alkylarenes using mol. oxygen as the sole oxidant without any additive. Impressive catalytic performance, excellent stability and recyclability, broad applicable scope and practical potential for the catalytic system were observed Mn³⁺ species is proposed to be the efficient active site, and Ni²⁺ played an important role in stabilizing the Mn³⁺ species in the hydrotalcite structure. The kinetic study showed that the aerobic oxidation of diphenylmethane is a first-order reaction over Ni₂Mn-LDH with the activation energy (E_a) and pre-exponential factor (A₀) being 85.7 kJ mol^-1 and 1.8 x 10⁹ min^-1, resp. The Gibbs free energy (ΔG^≠) is -10.4 kJ mol^-1 K^-1 for the oxidation based on Eyring-Polanyi equation, indicating the reaction is exergonic. The mechanism study indicated that the reaction proceeded through both radical and carbocation intermediates. The two species were then trapped by mol. oxygen and H₂O or hydroxyl species, resp., to yield the corresponding products. The present research might provide information for constructing highly efficient and stable active site for the catalytic aerobic oxidation based on available and economic material.

Molecular Catalysis published new progress about 91-02-1. 91-02-1 belongs to pyridine-derivatives, auxiliary class Pyridine,Benzene,Ketone, name is Phenyl(pyridin-2-yl)methanone, and the molecular formula is C12H17NO2, Computed Properties of 91-02-1.

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

He, Dian published the artcileDesign, Synthesis and Activity Evaluation of N-(pyridin-4-yl) Salicylamides as Antimycobacterial Agents, Computed Properties of 18437-58-6, the publication is Asian Journal of Chemistry (2014), 26(21), 7269-7275, 7 pp., database is CAplus.

A series of N-(pyridin-4-yl) salicylamides derivatives I (R¹ = H, Cl, CH₃; R² = R⁴ = H, Cl; R³ = H, Cl, CF₃; R⁵ = H, OCH₃; R⁶ = H, Cl, Br, CF₃) were prepared through acylation of the corresponding acetylsalicyloyl chlorides with substituted 4-aminopyridines. The compounds I were evaluated in vitro for antimycobacterial activities against Mycobacterium tuberculosis (TB) and Mycobacterium avium (A) by the min. inhibitory concentrations (MIC) values. Eight of the compounds I exhibited lower MIC against Mycobacterium avium than the one of isoniazide, meanwhile, four of the compounds I exhibited good anti-TB activity compared to isoniazide. Antimycobacterial activities of compounds I were influenced by the balance between hydrophobicity and electron withdrawing substituent effects on the Ph and pyridine ring.

Asian Journal of Chemistry published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C6H8N2, Computed Properties of 18437-58-6.

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

Yang, Wan-jing published the artcileEffect of vestibular rehabilitation training combined with betahistine mesylate on elderly patients with benign paroxysmal positional vertigo, Category: pyridine-derivatives, the publication is Huanan Guofang Yixue Zazhi (2016), 30(1), 71-72, database is CAplus.

Objective To investigate the effect of vestibular rehabilitation training combined with betahistine mesylate on elderly patients with benign positional paroxysmal vertigo (BPPV). Methods 120 elderly patients with BPPV were randomized into three groups: group A was treated with vestibular rehabilitation training, group B was treated by oral administration of betahistine mesylate, and group C was treated by vestibular rehabilitation training combined with oral administration of betahistine mesylate. Results The total effective rate of group C was significantly higher than that of group A and group B (χ²=11.61, P<0.05), and the total effective rate of group B was significantly higher than that of group A (χ²=8.90, P<0.05). The incidence of adverse reactions of group C was significantly lower than that of group A and group B (χ²=4.50, P<0.05), and the incidence of adverse reactions of group B was significantly lower than that of group A (χ²=3.53, P<0.05). The recurrence rate of group C was significantly lower than that of group A and group B (χ²=6.13, P<0.05), and the recurrence rate of group B was significantly lower than that of group A (χ²=5.00, P<0.05). Conclusion Vestibular rehabilitation training combined with betahistine mesylate had obvious effect for treating elderly patients with BPPV, which could effectively shorten treatment period and decrease recurrence rate.

Huanan Guofang Yixue Zazhi published new progress about 54856-23-4. 54856-23-4 belongs to pyridine-derivatives, auxiliary class Pyridine,Salt,Amine,Inhibitor,Inhibitor, name is N-Methyl-2-(pyridin-2-yl)ethan-1-amine dimethanesulfonate, and the molecular formula is C18H23N3O4S, Category: pyridine-derivatives.

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

Appelhans, Dietmar published the artcileOligosaccharide-modified poly(propyleneimine) dendrimers: synthesis, structure determination, and Cu^II complexation, SDS of cas: 971-66-4, the publication is Macromolecular Bioscience (2007), 7(3), 373-383, database is CAplus and MEDLINE.

The multiple application of reductive amination on primary amino groups of first and second generation poly(propyleneimine) dendrimers is used as a one-pot approach to introduce twice the amount of the oligosaccharide units as surface groups, compared to initially present amino groups in the first and second generation dendrimers. This was proven by ¹H NMR, MALDI-TOF-MS, and LILBID-MS anal. The size of these dendrimers was determined by the hydrodynamic radius using pulsed field gradient NMR and dynamic light scattering. Mol. modeling confirmed the presence of dense-shell dendrimers. These dendrimers exhibit a generation dependent Cu^II/dendrimer ratio in an aqueous environment, highlighting these materials as possible metal-carrier systems with a well-defined oligosaccharide protection shell for application in a biol. environment.

Macromolecular Bioscience 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 C23H20BN, SDS of cas: 971-66-4.

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

Zheng, Wei-Xiang published the artcileSynthesis of Aryl Ketones from Carboxylic Acids and Arylboronic Acids Using 2-Chloroimidazolium Chloride as a Coupling Reagent, Synthetic Route of 91-02-1, the publication is Synthesis, database is CAplus.

Carboxylic acids are an abundant and structurally diverse class of com. available materials, which are commonly used as stable reagents in organic synthesis. The Suzuki-Miyaura coupling reaction directly using carboxylic acid as a substrate has been rarely reported. Here, authors report an efficient coupling reaction of carboxylic acids with arylboronic acids in toluene in the presence of IPrCl-Cl, Pd(OAc)₂, PPh₃, and K₃PO₄·7H₂O at 90 °C to give the corresponding aryl ketones.

Synthesis published new progress about 91-02-1. 91-02-1 belongs to pyridine-derivatives, auxiliary class Pyridine,Benzene,Ketone, name is Phenyl(pyridin-2-yl)methanone, and the molecular formula is C12H10F2Si, Synthetic Route of 91-02-1.

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

Liang, Ren-Xiao published the artcileEnantioselective Arylation of Tetrasubstituted Enamines: Access to Enantioenriched Indolenine and 1H-Indole Derivatives, Application of 2-Bromopyridin-3-amine, the publication is ACS Catalysis (2021), 11(3), 1827-1832, database is CAplus.

Palladium-catalyzed intramol. enantioselective β-arylation of tetrasubstituted endocyclic and exocyclic enamines was developed. A range of optically active medium-ring fused indolenines or 3,3′-spiroindolenines were achieved in enantiomeric ratios up to 98:2 with Cs₂CO₃ or K₃PO₄ as the base in the presence of chiral PHOX ligands. The use of Ag₃PO₄ as a base led to enantioenriched 1H-indoles in good enantiomeric ratios (up to 89:11) with (S)-DIFLUORPHOS as a chiral ligand, which proceeded via a possible domino enamine-isomerization/β-arylation sequence.

ACS Catalysis published new progress about 39856-58-1. 39856-58-1 belongs to pyridine-derivatives, auxiliary class Pyridine,Bromide,Amine, name is 2-Bromopyridin-3-amine, and the molecular formula is C5H5BrN2, Application of 2-Bromopyridin-3-amine.

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

Obdyakov, V. F. published the artcileStabilization of palladium in homogeneous chlorideless catalysts of oxidation of olefins C₂-C₄ by oxygen into carbonyl compounds, HPLC of Formula: 636-73-7, the publication is Kataliz v Promyshlennosti (2007), 19-25, database is CAplus.

The first step of homogeneous oxidation of olefins C₂-C₄ by oxygen in the presence of catalyst Pd + GPK-x, were GPK-x is phosphovanadomolybdic heteropoly acid H_3+xPV^V_x Mo_12-xO₄₀, consist in reduction of GPK-x with olefin in the presence Pd-complexes at 30-60° into H_mGPK-x where m=[V^IV]_∑/[GKP-x] – is excellent reduction catalyst. In this case the redox-system Pd¹₂/Pd⁰₂ works and with increasing of temperature in converts into system Pd²⁺/Pd_MET with higher redox-potential. During this transformation interval of values m is diminished where the catalyst remained as homogeneous and from reduced solution metallic Pd begins to precipitate To prevent the Pd precipitation it needs to introduce in catalyst the stabilizers stable from oxidation As stabilizers can be used 3-pyridinesulfonic acid of more cheaper 2,6-pyridinecarboxylic (dipicolinic) acid (I). In the presence of the stabilizers the activity of catalyst is diminished but the area of its homogeneity will extend. Complexes of Pd with I are stable at temperatures of regeneration of catalyst (150-160°). Therefore I is considered as rather perspective stabilizer of Pd in catalysts Pd + GPK-x and can be used in industrial homogeneous processes of oxidation of olefins C₂-C₄ with oxygen.

Kataliz v Promyshlennosti published new progress about 636-73-7. 636-73-7 belongs to pyridine-derivatives, auxiliary class Pyridine,Sulfonic acid, name is Pyridine-3-sulfonic acid, and the molecular formula is C5H5NO3S, HPLC of Formula: 636-73-7.

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

Wu, De-Zhi published the artcileAn efficient method for the construction of 2-Aminothiazolo[5,4-c]pyridines via K₃[Fe(CN)₆] oxidized SP² C-H Functionalization, Computed Properties of 18437-58-6, the publication is Tetrahedron (2016), 72(52), 8610-8616, database is CAplus.

A practical approach to synthesize 2-aminothiazolo[5,4-c]pyridines from simple asym. pyridylthioureas was achieved by utilizing K₃[Fe(CN)₆] as the oxidant [e.g., I → II (97%)]. These reactions went through an intramol. oxidation and finally led to the formation of C-S bond. Furthermore, the possible oxidative cyclization mechanism was also explored by the addition of radical scavengers, which showed that the oxidative cyclization was promoted via a free radical mechanism.

Tetrahedron published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C7H16Cl2Si, Computed Properties of 18437-58-6.

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