Alkylation
Mostrando 1-12 de 451 artigos, teses e dissertações.
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1. Heteroannulation Reaction of α-Aminoketones for the Efficient Synthesis of 4-Imidazolin-2-ones and 2-Thiones
The hydrogenation of α-oximinoketones in methanol/HCl afforded α-aminoketones, which were applied without purification to the synthesis of 4-imidazolin-2-ones and 2-thiones, including chiral derivatives. The latter two series were obtained in high yields by a heteroannulation reaction of α-aminoketones with isocyanates and isothiocyanates, respectively. A
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. New α-Hydroxy-1,2,3-triazoles and 9H-Fluorenes-1,2,3-triazoles: Synthesis and Evaluation as Glycine Transporter 1 Inhibitors
Two series of new compounds containing 1,2,3-triazole moiety were designed as putative GlyT1 inhibitors aiming the discovery of new hits with activity in cognitive disorders. 1,4-Disubstituted α-hydroxy-1,2,3-triazoles were obtained as racemates in moderate to good yields by the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction (click chemistry)
J. Braz. Chem. Soc.. Publicado em: 2020-06
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3. Are Imidazoles Versatile or Promiscuous in Reactions with Organophosphates? Insights from the Case of Parathion
Is the broad mechanistic versatility of imidazole towards organophosphates (OPs), that has inspired many catalysts and sensors, beneficial? Herein, a thorough analysis is given seeking to unravel this puzzle. For OPs from the P=O family, imidazole attacks the phosphorus atom exclusively (N-phosphorylates). With the P=S family which are less reactive, an unus
J. Braz. Chem. Soc.. Publicado em: 21/10/2019
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4. SÍNTESE E AVALIAÇÃO DAS ATIVIDADES FOTOPROTETORA, CITOTÓXICA E ANTIVIRAL CONTRA O ZIKA VÍRUS DE DERIVADOS TRIAZÓLICOS DA BENZOFENONA
The benzophenones are synthetic and natural compounds presenting a variety of activities, including photoprotective, cytotoxic and antiviral. It is herein described the preparation of a series of twenty-seven benzophenone derivatives bearing 1,2,3-triazole functionalities and the evaluation of their photoprotective, cytotoxic and antiviral on Zika Virus (ZIK
Quím. Nova. Publicado em: 18/07/2019
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5. PREPARATION AND CHARACTERIZATION OF A QUERCETIN-TETRAETHYL ETHER-BASED PHOTOPROTECTIVE NANOEMULSION
Although Quercetin absorbs in the UVA/UVB electromagnetic region, it is limited for applications as a UV filter due to its low lipophilicity and capacity to penetrate the epidermis. In order to overcome this limitation, we synthetized and evaluated the photo protective properties of a derivative obtained from Quercetin. The derivative was prepared by alkylat
Quím. Nova. Publicado em: 27/05/2019
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6. Streamlined Synthesis of 6-((1H-1,2,3-Triazol-4-yl)methyl)-1H-pyrrolo [3,4-d]pyridazin-1-one System via Sequential N-Alkylation, CuAAC, and [4 + 2] Cyclization Reactions
An efficient sequential three-step reaction methodology for the synthesis of three new series-1-(prop-2-yn-1-yl)-1H-pyrroles, methyl 4-acetyl-1-((1H-1,2,3-triazol-4-yl)methyl)-1H-pyrrole-3-carboxylates and 6-((1H-1,2,3-triazol-4-yl)methyl)-2,6-dihydro-1H-pyrrolo[3,4-d]pyridazin-1-ones-is reported. The methodology comprises: (i) N-alkylation reactions of poly
J. Braz. Chem. Soc.. Publicado em: 23/05/2019
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7. Proteome of fraction from Tityus serrulatus venom reveals new enzymes and toxins
Abstract Background: Tityus serrulatus venom (Ts venom) is a complex mixture of several compounds with biotechnological and therapeutical potentials, which highlights the importance of the identification and characterization of these components. Although a considerable number of studies have been dedicated to the characterization of this complex cocktail, t
J. Venom. Anim. Toxins incl. Trop. Dis. Publicado em: 18/04/2019
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8. Rhodium(III)-Catalyzed Addition of Indoles with Boc-Imines via C-H Bond Activation
A rhodium-catalyzed alkylation reaction of indoles with N-Boc-imines has been developed via C-H activation to afford a series of substituted 2-indolyl-methanamine derivatives with good functional group tolerance and regioselectivity. A wide range of indole-based alkylation products could be obtained in up to 95% yield.
J. Braz. Chem. Soc.. Publicado em: 2018-06
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9. Total Synthesis of Altissimacoumarin D, a Small Molecule Sirtuin1 Activator
The total synthesis of the plant natural product altissimacoumarin D was achieved by the Mitsunobu alkylation of isofraxidin by geraniol. Isofraxidin was prepared from 2,4-dihydroxybenzaldehyde in five steps. The key reaction was the Knoevenagel condensation of an ortho-hydroxybenzaldehyde with Meldrum's acid under neutral conditions in water and one-pot aci
J. Braz. Chem. Soc.. Publicado em: 2018-05
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10. SÍNTESE E AVALIAÇÃO DA ATIVIDADE CITOTÓXICA DE DERIVADOS DO EUGENOL CONTENDO NÚCLEOS 1,2,3-TRIAZÓLICOS
Eugenol is an aromatic compound found in several plant species. It presents important biological activities including cytotoxicity. In this paper, it is described the synthesis and the evaluation of the cytotoxic activity of eugenol derivatives bearing 1,2,3-triazole functionalities. Eugenol, extracted via hydrodistillation from dried flower buds of Eugenia
Quím. Nova. Publicado em: 2018-05
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11. Deacylative alkylation (DaA) of N-methyl-3-acetyl-2-oxindole for the synthesis of symmetrically 3,3-disubstituted 2-oxindoles. An access gate to anticancer agents and natural products.
ABSTRACT The synthesis of 3,3-disubstituted N-methyloxindoles, starting from 3-acetyl-2-hydroxy-1-methyloxindole employing a sequential one-pot synthesis, is studied. The process involves a first alkylation in the presence of 1 equiv. of both organic halide and Triton B and the second one employs another 1.5 equiv. of each in moderate to high yields. This pr
An. Acad. Bras. Ciênc.. Publicado em: 2018
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12. 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