Day: December 9, 2022

Panteleev, Jane published the artcileDomino Rhodium-Catalyzed Alkyne Arylation/Palladium-Catalyzed N Arylation: A Mechanistic Investigation, Recommanded Product: (6-Ethoxypyridin-3-yl)boronic acid, the publication is Angewandte Chemie, International Edition (2011), 50(39), 9089-9092, S9089/1-S9089/32, database is CAplus and MEDLINE.

We report an example in which two different metals with two different phosphine ligands promote two out of three possible reactions and do so in a time-resolved way, thus leading to an efficient preparation of dihydroquinolines. Importantly, we show that one of the two phosphine ligands is selective in binding to only one of the metals, and the other ligand is nondiscriminating in its binding properties; yet one of the two metal-phosphine complexes is far more reactive and selectivity is observed This study raised the more general question of matching ligands and metals in order to efficiently promote only the desired reaction rather than competing processes. Thus, complex sequences of reactions that contain multiple catalytically active species can ultimately be created in a single reaction vessel.

Angewandte Chemie, International Edition published new progress about 612845-44-0. 612845-44-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Boronic acid and ester,Ether,Boronic Acids,Boronic acid and ester, name is (6-Ethoxypyridin-3-yl)boronic acid, and the molecular formula is C7H10BNO3, Recommanded Product: (6-Ethoxypyridin-3-yl)boronic acid.

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

Liao, Lihao published the artcileSelenium-π-Acid Catalyzed Oxidative Functionalization of Alkynes: Facile Access to Ynones and Multisubstituted Oxazoles, Application In Synthesis of 107263-95-6, the publication is ACS Catalysis (2018), 8(7), 6745-6750, database is CAplus.

In the presence of di-Ph diselenide, N-fluoropyridinium triflates, and water, propargyl phosphonates such as PhCCCH₂P(:O)(OEt)₂ and β,γ-alkynoates underwent regioselective oxidation to yield γ-ketoalkynyl phosphonates such as PhCOCCP(:O)(OEt)₂ and γ-keto-α,β-alkynoates. Ynamides such as PhCCN(CH₂Ph)R (R = MeSO₂, PhSO₂, 4-MeC₆H₄SO₂, 4-O₂NC₆H₄) underwent regioselective oxidative cycloadditions with acetonitrile or butanenitrile mediated by Selectfluor in the presence of di-Ph selenide to yield aminooxazoles such as I (R = MeSO₂, PhSO₂, 4-MeC₆H₄SO₂, 4-O₂NC₆H₄). N-Propargylamides underwent oxidative cyclization in the presence of di-Ph diselenide and mediated by Selectfluor to give 2-substituted-5-oxazolecarboxaldehydes. In all cases, the reactions are likely to involve the reactions of cationic phenylselenium species with alkynes to generate vinylselenium cations. The mechanism of the reactions were studied; vinyl selenides were prepared by reactions of phenylselenium triflate with propargyl phosphonates and ynamides and shown to yield the observed ketone and oxazole products upon elimination, while isotopic labeling experiments were undertaken to determine the fate of added water.

ACS Catalysis 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, Application In Synthesis of 107263-95-6.

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

Cao, Jingyi published the artcilePreparation and property of environmental friendly copper-free self-polishing antifouling coatings, COA of Formula: C23H20BN, the publication is Tuliao Gongye (2015), 45(3), 33-36, database is CAplus.

Title coatings were prepared from zinc-acrylate polymer as matrix, pyrithione zinc (ZnPT) and pyridine tri-Ph borane (PK) as biocides and other pigments. The basic properties of the antifouling coatings with different organic biocides are studied. Meanwhile, the antifouling property of the prepared coatings has been compared with that of the similar imported product via offshore immersion test. The title coatings comprising ZnPT and PK at mass ratio of 6:4 can exhibit excellent antifouling property.

Tuliao Gongye 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, COA of Formula: C23H20BN.

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

Alshreimi, Abdullah S. published the artcileSynthesis of Spirocyclic 1-Pyrrolines from Nitrones and Arynes through a Dearomative [3,3′]-Sigmatropic Rearrangement, Category: pyridine-derivatives, the publication is Angewandte Chemie, International Edition (2020), 59(35), 15244-15248, database is CAplus and MEDLINE.

A dearomative [3,3′]-sigmatropic rearrangement that converts N-alkenylbenzisoxazolines into spirocyclic pyrroline cyclohexadienones, e.g., I, has been developed by using the dipolar cycloaddition of an N-alkenylnitrone and an aryne to access these unusual transient rearrangement precursors. This cascade reaction affords spirocyclic pyrrolines that are inaccessible through dipolar cycloadditions of exocyclic cyclohexenones and provides a fundamentally new approach to novel spirocyclic pyrroline and pyrrolidine motifs that are common scaffolds in biol.-active mols. Diastereoselective functionalization processes have also been explored to demonstrate the divergent synthetic utility of the unsaturated spirocyclic products.

Angewandte Chemie, International Edition published new progress about 844501-00-4. 844501-00-4 belongs to pyridine-derivatives, auxiliary class Pyridine,Boronic acid and ester,Amide,Boronic Acids,Boronic acid and ester, name is (1-(tert-Butoxycarbonyl)-1,2,3,6-tetrahydropyridin-4-yl)boronic acid, and the molecular formula is C10H18BNO4, Category: pyridine-derivatives.

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

Liu, Xuemei published the artcileEffect of halogenated substituents on the metabolism and estrogenic effects of the equine estrogen, equilenin, Application In Synthesis of 107263-95-6, the publication is Chemical Research in Toxicology (2003), 16(6), 741-749, database is CAplus and MEDLINE.

Estrogen replacement therapy has been correlated with an increased risk for developing breast and endometrial cancers. One potential mechanism of estrogen carcinogenesis involves metabolism of estrogens to 2- and 4-hydroxylated catechols, which are further oxidized to electrophilic/redox active o-quinones that have the potential to both initiate and promote the carcinogenic process. Previously, the authors showed that the equine estrogens, equilin and equilenin, which are major components of the estrogen replacement formulation Premarin (Wyeth-Ayerst), are primarily metabolized to the catechol, 4-hydroxyequilenin. This catechol was found to autoxidize to an o-quinone causing oxidation and alkylation of DNA in vitro and in vivo. To block catechol formation from equilenin, 4-halogenated equilenin derivatives were synthesized. These derivatives were tested for their ability to bind to the estrogen receptor, induce estrogen sensitive genes, and their potential to form catechol metabolites. The authors found that the 4-fluoro derivatives were more estrogenic than the 4-chloro and 4-bromo derivatives as demonstrated by a higher binding affinity for estrogen receptors α and β, an enhanced induction of alk. phosphatase activity in Ishikawa cells, pS2 expression in S30 cells, and PR expression in Ishikawa cells. Incubation of these compounds with tyrosinase in the presence of GSH showed that the halogenated equilenin compounds formed less catechol GSH conjugates than the parent compounds, equilenin and 17β-hydroxyequilenin. In addition, these halogenated compounds showed less cytotoxicity in the presence of tyrosinase than the parent compounds in S30 cells. Also, as stated above, the 4-fluoro derivatives showed similar estrogenic effects as compared with parent compounds; however, they were less toxic in S30 cells as compared to equilenin and 17β-equilenin. Because 17β-hydroxy-4-halogenated equilenin derivatives showed higher estrogenic effects than the halogenated equilenin derivatives in vitro, the authors studied the relative ability of the 17β-hydroxy-4-halogenated equilenin derivatives to induce estrogenic effects in the ovariectomized rat model. The 4-fluoro derivative showed higher activity than 4-chloro and 4-bromo derivatives as demonstrated by inducing higher vaginal cellular differentiation, uterine growth, and mammary gland branching. However, 17β-hydroxy-4-fluoroequilenin showed a lower estrogenic activity than 17β-hydroxyequilenin and estradiol, which could be due to alternative pharmacokinetic properties for these compounds These data suggest that the 4-fluoroequilenin derivatives have promise as alternatives to traditional estrogen replacement therapy due to their similar estrogenic properties with less overall toxicity.

Chemical Research in Toxicology 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, Application In Synthesis of 107263-95-6.

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

Liu, Lantao published the artcileAsymmetric Synthesis of Planar Chiral Ferrocenes by Enantioselective Intramolecular C-H Arylation of N-(2-Haloaryl)ferrocenecarboxamides, Application of 2-Bromopyridin-3-amine, the publication is Organic Letters (2014), 16(20), 5336-5338, database is CAplus and MEDLINE.

The palladium-catalyzed intramol. C-H arylation reaction of N-(2-bromoaryl)ferrocenecarboxamides furnishes planar chiral ferrocene derivatives TADDOL-derived phosphoramide ligands induce enantioselectivities ranging from 91:9 to 98:2 er.

Organic Letters 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

Yu, Han published the artcileVisible-Light-Activated Asymmetric Addition of Hydrocarbons to Pyridine-Based Ketones, Product Details of C12H9NO, the publication is ACS Catalysis (2022), 12(9), 5136-5144, database is CAplus.

A combined system involving Er(III)-based chiral Lewis acid catalysis, Ir(III)-based photoredox catalysis, and bromide-radical-mediated hydrogen atom transfer was disclosed. The introduction of a bulky and nonredox chiral Lewis acid through the photoredox pathway enabled the radical addition process and inhibited the above competitive reactions. The visible-light-promoted catalytic asym. alkylation of heteroaryl-based ketones with diverse hydrocarbons (mainly benzyl) delivered a variety of congested enantioenriched tertiary alcs. (up to 97% yield, 96% enantiomeric excess (ee)).

ACS 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 C10H18O, Product Details of C12H9NO.

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

Dar’in, Dmitry published the artcileNon-chelating p-phenylidene-linked bis-imidazoline analogs of known influenza virus endonuclease inhibitors: Synthesis and anti-influenza activity, COA of Formula: C5H6BNO2, the publication is European Journal of Medicinal Chemistry (2019), 526-532, database is CAplus and MEDLINE.

A novel chemotype topol. similar to known influenza virus PA endonuclease inhibitors was designed. It was aimed to reproduce the extended topol. of the known metal-chelating ligands with a p-phenylidene-linked bis-imidazoline scaffold. It was envisioned that aromatic groups introduced to this scaffolds via metal-catalyzed N-arylation (Buchwald-Hartwig or Chan-Evans-Lam) would contribute to lipophilic binding to the target and one of the imidazoline nitrogen atoms would ensure non-chelating coordination to the prosthetic divalent metal ion. The compounds displayed appreciable anti-influenza activity in vitro and substantial concentration window from the general cytotoxicity range. Docking anal. of low-energy poses of the most active compound (as well as their comparison to the binding of an inactive compound) revealed that these compounds reproduced similar binding components to a known PA endonuclease inhibitor and displayed similar binding pose and desired monodentate metal coordination, as was initially envisioned. These findings warrant further study of the mechanism of action of the newly discovered series.

European Journal of Medicinal 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 C5H6BNO2, COA of Formula: C5H6BNO2.

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

Le Saux, Emilien published the artcilePhotochemical Organocatalytic Benzylation of Allylic C-H Bonds, Quality Control of 91-02-1, the publication is Journal of the American Chemical Society (2022), 144(3), 1113-1118, database is CAplus and MEDLINE.

Authors report a radical-based organocatalytic method for the direct benzylation of allylic C-H bonds. The process uses nonfunctionalized allylic substrates and readily available benzyl radical precursors and is driven by visible light. Crucial was the identification of a dithiophosphoric acid that performs two distinct catalytic roles, sequentially acting as a catalytic donor for the formation of photoactive electron donor-acceptor (EDA) complexes and then as a hydrogen atom abstractor. By mastering these orthogonal radical generation paths, the organic catalyst enables the formation of benzylic and allylic radicals, resp., to then govern their selective coupling. The protocol was also used to design a three-component radical process, which increased the synthetic potential of the chem.

Journal of the American Chemical Society 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 C12H9NO, Quality Control of 91-02-1.

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

Storozhenko, Olga A. published the artcileSynthesis of 2-aminochromene derivatives from 1-(2-imino-2H-chromen-3-yl)pyridin-1-ium perchlorates and nitromethane in basic medium, COA of Formula: C7H7ClN2, the publication is Chemistry of Heterocyclic Compounds (New York, NY, United States) (2020), 56(9), 1161-1166, database is CAplus.

Novel 2-amino-4-(nitromethylidene)chromenes were obtained as a result of the reaction of 1-(2-imino-2H-chromen-3-yl)pyridinium perchlorates and nitromethane by the action of DBU at reflux in trifluoroethanol. The starting 2-iminochromenes are readily accessible from the corresponding salicylic aldehydes and quaternary cyanomethyl pyridinium salts. The reaction is tolerant to substituents of different nature (alkyl, alkoxy, halogen); a limitation is the presence of strong electron-withdrawing substituents in the benzene ring of chromene. During the reaction, the products precipitate and can be isolated by filtration.

Chemistry of Heterocyclic Compounds (New York, NY, United States) published new progress about 17281-59-3. 17281-59-3 belongs to pyridine-derivatives, auxiliary class Pyridine,Nitrile,Salt, name is 1-(Cyanomethyl)pyridin-1-ium chloride, and the molecular formula is C9H5FO2, COA of Formula: C7H7ClN2.

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