Phase Transfer Catalysis
Mostrando 1-11 de 11 artigos, teses e dissertações.
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1. ORGANOCATÁLISE ENANTIOSSELETIVA: EVOLUÇÃO E ASPECTOS RECENTES
In the last two decades, enantioselective organocatalysis has established itself as one of the three pillars of asymmetric catalysis. The rapid growth in the area is due to the rationalization of organocatalysis based on the generic modes of catalyst activation, being applied to several types of reactions, in a rather generic and predictable way and providin
Quím. Nova. Publicado em: 27/05/2019
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2. Synthesis of unnatural α-amino acids, precursors of the inhibitors of thrombin - via Phase Transfer Catalysis (PTC) / Síntese de α-aminoácidos não naturais -precursores de agentes inibidores da trombina - via Catálise de Transferência de Fase (CTF)
Seven novel a-aminoacids precursors were prepared by the alkylation reaction of ethyl acetamidocyanoacetate 112 using bromohexane, benzyl chloride, allyl bromide, 9-(chloro-methyl)antracene, 3-nitrobenzyl bromide, 4-nitrobenzyl bromide, 4-metoxibenzyl bromide and 2-methyl-naphtyl bromide as alkylating agents via Phase Transfer Catalysis (PTC). These reaction
Publicado em: 2009
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3. Investigation of a New Synthetic Route to (R)-Baclofen / Estudo de uma nova rota sintética para o fármaco (R)-baclofen
In this work, the feasibility of a new synthetic route to Baclofen was investigated. The starting material, a cis-aziridine, was prepared by ring closure of (2S,3R)-(4-clorophenyl)- serine, under phase transfer conditions (PTC). As for the preparation of the required ß- hydroxy-α-aminoacid, two alternative synthetic strategies were investigated. (i) th
Publicado em: 2007
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4. Catálise de transferência de fase
Since its discovery, phase transfer catalysis (PTC) has grown considerably and nowadays is one of the most versatile preparative methods. The search for new catalysts, their use in PTC asymmetric synthesis and the attempts to understand their mechanistic role are modern and exciting topics of investigation. A review on main achievements in the last two decad
Química Nova. Publicado em: 2000-10
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5. Nonconventional amide bond formation catalysis: programming enzyme specificity with substrate mimetics
This article reports on the design and characteristics of substrate mimetics in protease-catalyzed reactions. Firstly, the basis of protease-catalyzed peptide synthesis and the general advantages of substrate mimetics over common acyl donor components are described. The binding behavior of these artificial substrates and the mechanism of catalysis are furthe
Brazilian Journal of Medical and Biological Research. Publicado em: 2000-05
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6. Síntese de 1,3,5-triazinas substituídas e avaliação da toxicidade frente a Artemia Salina leach
The synthesis of ten symmetrically and unsymmetrically substituted 1,3,5-triazines by Phase Transfer Catalysis (PTC) method is described. Their toxicities were determined against Artemia salina Leach. The LD50 values have also been obtained for these compounds.
Química Nova. Publicado em: 2000-02
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7. Aplicação da catálise de trasnferência de fase na avaliação de rotas alternativas para obtenção industrial da dicicloverina caramifeno e amiodarona / The use of phase transfer catalysis, in the development of alternative routes for industrial production of dicycloverine, caramiphen and amiodarone
O emprego da catálise de transferência de fase substituindo uma ou mais etapas da síntese de um fármaco, pode ser um recurso vantajoso sob o ponto de vista tecnológico. Empregado na síntese de importantes fármacos que são a dicicloverina, caramifeno eamiodarona, a catálise de transferência de fase revelou-se muito vantajosa na síntese dos dois pri
Publicado em: 1994
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8. Estrutura e reatividade de sulfóxidos de rutênio com bases heterocíclicas nitrogenadas / Structure and reactivity of ruthenium sulfoxides containing nitrogen heterocyclic bases
Ruthenium(II) sulfoxides are compounds of great interest in oxidative catalysis and in chemotherapy. In order to contribute for the understanding of the chemistry and electronic structure of this class of compounds, it has been studied a series of [RuCl2(S-dmso)2Lx] complexes, where x = 1 (polymeric compounds) or 2 (monomers) and L = N-heterocyclic ligands (
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/11/1990
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9. Apparent dependence of interactions between cytochrome b5 and cytochrome b5 reductase upon translational diffusion in dimyristoyl lecithin liposomes.
Dimyristoyl lecithin liposomes, containing cytochrome b5 reductase (NADH:ferricytochrome b5 oxidoreductase, EC 1.6.2.2) and varying amounts of cytochrome b5, were used to measure flavoprotein catalysis alone and catalysis requiring electron transfer between the reductase and cytochrome as a function of temperature. Whereas flavoprotein catalysis showed a sim
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10. Catalysis of S-nitrosothiols formation by serum albumin: The mechanism and implication in vascular control
Nitric oxide (NO⋅) is a short-lived physiological messenger. Its various biological activities can be preserved in a more stable form of S-nitrosothiols (RS-NO). Here we demonstrate that at physiological NO⋅ concentrations, plasma albumin becomes saturated with NO⋅ and accelerates formation of low-molecular-weight (LMW) RS-NO in vitro and in vivo. The
The National Academy of Sciences.
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11. Electron transfer between hemes in mammalian cytochrome c oxidase
Fast intraprotein electron transfer reactions associated with enzymatic catalysis are often difficult to synchronize and therefore to monitor directly in non-light-driven systems. However, in the mitochondrial respiratory enzyme cytochrome oxidase aa3, the kinetics of the final electron transfer step into the active site can be determined: reverse electron f
National Academy of Sciences.