Pyridines
Mostrando 1-12 de 23 artigos, teses e dissertações.
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1. A Comparative Study on the Groebke-Blackburn-Bienaymé Three-Component Reaction Catalyzed by Rare Earth Triflates under Microwave Heating
Over the last twenty years, the Groebke-Blackburn-Bienaymé (GBB) reaction has been emerged as a powerful tool to access different nitrogen-based heterocycles as privileged scaffolds in medicinal chemistry. This multicomponent reaction is usually catalyzed by ordinary Brønsted or Lewis acid catalysts. Herein, we present a comparative study on the catalytic
J. Braz. Chem. Soc.. Publicado em: 2020-07
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2. Imidazo[1,2-a]pyridine A3-Coupling Catalyzed by a Cu/SiO2 Material
In this work, we report the preparation of a copper-silica material (Cu/SiO2) by a sol-gel methodology and its characterization concerning composition and textural properties. The Cu/SiO2 material was successfully applied as a Lewis acid heterogeneous catalyst for the A3-coupling from 2-aminopyridine, aldehydes and alkynes to imidazo[1,2-a]pyridines (45-82%)
J. Braz. Chem. Soc.. Publicado em: 16/09/2019
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3. Synthesis of New Conjugates 1H-Pyrazolo[3,4-b]pyridine-phosphoramidate and Evaluation against Leishmania amazonensis
In this research three series of substituted 1H-pyrazolo[3,4-b]pyridine phosphoramidates were synthesized and characterized by infrared, 1H, 13C, and 31P nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry. The products were obtained in good yields (67-83%) under mild conditions by nucleophilic aromatic substitution reaction o
J. Braz. Chem. Soc.. Publicado em: 2018-01
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4. Cascade Synthesis of Thieno[2,3-b]pyridines by Using Intramolecular Cyclization Reactions of 3-Cyano-2-(organylmethylthio)pyridines
2-Amino-4-aryl-6-mercaptopyridine-3,5-dicarbonitriles as starting materials have been prepared by reducing of 2-amino-4-aryl-6-(phenylthio)pyridine-3,5-dicarbonitrile derivatives which were synthesized on stepwise one-pot three component reaction of malononitrile, aldehydes and thiophenol in the presence of base catalysts such as triethylamine, high surface
J. Braz. Chem. Soc.. Publicado em: 2016-04
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5. Synthesis of 3-(1H-1,2,3-Triazol-1-yl)-2-(arylselanyl)pyridines by Copper-Catalyzed 1,3-Dipolar Cycloaddition of 2-(Arylselanyl)-3-azido-pyridines with Terminal Alkynes
We present here our results in the synthesis of eleven new 3-(1H-1,2,3-triazol-1-yl)-2-(arylselanyl)pyridines by copper-catalyzed azide-alkyne cycloaddition reactions. The reactions were performed in the presence of catalytic amount of copper(II) acetate and sodium ascorbate using a mixture of tetrahydrofuran/water (1:1) as solvent at room temperature in air
J. Braz. Chem. Soc.. Publicado em: 2015-11
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6. Synthesis, Structure Elucidation, Antioxidant and Antimicrobial Activity of Novel 2-(5-Trifluoromethyl-1H-pyrazol-1-yl)-5-(5-trihalomethyl-1H-pyrazol-1-yl-1- carbonyl)pyridines
This paper describes an efficient approach for the synthesis of a novel series of sixteen 2-(5-trifluoromethyl-1H-pyrazol-1-yl)-5-(5-trihalomethyl-1H-pyrazol-1-yl-1-carbonyl) pyridines, for the first time with non-identical substituents in both pyrazole rings, through the cyclocondensation reaction of 4-methoxy-4-alkyl(aryl/heteroaryl-1,1,1-trihaloalk-3-en-2
J. Braz. Chem. Soc.. Publicado em: 2015-11
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7. Coordenação a centros de rutênio e polimerização via metátese de um novo monômero-ligante do tipo norborneno-piridina / Coordination to ruthenium centers and polymerization via metathesis of a new monomer-ligand of type norbornene-pyridine
O monômero-ligante (3amdpy)2NBE foi sintetizado e caracterizado por análise elementar (CHN), infravermelho e RMN (1H e 13C), tratando-se de um novo ligante quelante que apresenta duas piridinas conectadas ao monômero norborneno via grupos amidas. Esse monômero-ligante foi ligado a um centro de Ru(II)-polipiridínico e o complexo resultante foi caracteriz
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/03/2012
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8. Complexos fosfínicos de rutênio contendo os ligantes nitro, nitrosilo ou piridinas, com atividades antitumorais e antituberculose / Phosphine ruthenium complexes containing the ligands nitrite, nitrosyl or pyridines with antitumoral and antituberculosis activities
Neste trabalho, uma série de complexos cis-[RuCl(L)(dppb)(5-mebipy)]PF6 (L=piridina, 4-metilpiridina, 4-fenilpiridina, 4-vinilpiridina, 4-terc-butilpiridina e 4- aminopiridina); o cis-[RuCl(NO2)(dppb)(5-mebipy)], o cis-[Ru(NO2)2(dppb)(5- mebipy)], o ct-[RuCl(NO)(dppb)(5-mebipy)](PF6)2, e o cc-[RuCl(CH3CN)(dppb)(5- mebipy)]PF6 [dppb = 1,4-bis(difenilfosfina)
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/11/2010
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9. Aplicação de α-oxoceteno ditiocetais em síntese orgânica
The synthesis and reactivity of α-oxoketenes dithioacetals (S,S-acetals), general structure [(R¹C=OC(R²)=C(SR³)(SR4)], are reported. We also showed the application of S,S acetals as synthons for efficient synthesis of isoxazoles, pyrazoles, indazoles, thiophenes, dithiol thiones, pyridines, pyrimidines and other heterocycles. This work aims to review the
Química Nova. Publicado em: 2010
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10. Síntese de derivados do fulereno-C60
Presently, C60 fullerene and its derivatives are of great importance in chemistry, mainly due to their physical properties and biological activities. One of the main problems related to C60 is its low solubility in the commonly used solvents, which limits its application. Aiming to study their physicochemical properties, 17 new C60 derivatives with appropria
Publicado em: 2010
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11. Synthesis of new disulfonamides from different substituted diamino pyridines
A series of novel disulfonamide derivatives were synthesized and characterized by FT-IR, ¹H NMR and MS techniques. In order to prepare new disulfonamides, at first we synthesized new diamines containing a pyridine ring. Then, they have been reacted with sulfonyl chlorides to give corresponding disulfonamides.
Eclética Química. Publicado em: 2009
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12. Catalyst: and solvent-free synthesis of imidazo[1,2-a]pyridines
Um método altamente eficiente e simples foi descrito para a síntese de imidazo[1,2-a]piridinas pela condensação de α-halocetonas (ArCOCHXR², Ar = C6H5, 4-MeOC6H4, 4-ClC6H4, 2,4-Cl2C6H3; X = Br, Cl; R² = H, CH3) com 2-aminopiridinas, apresentando rendimentos entre bons a excelentes sem a necessidade de adição de catalisador e solvente.
Journal of the Brazilian Chemical Society. Publicado em: 2009