Carbon Carbon Bond Formation
Mostrando 1-12 de 52 artigos, teses e dissertações.
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1. BIODEGRADACION FUNGICA DE POLIURETANO RÍGIDO
Polyurethane (PU) is one of the most widely used polymer materials. This generates a serious environmental problem because of its poor biodegradability since most of the native microorganisms cannot use it as a source of nutrients. Several techniques involving mechanical and chemical processes have been used for its recovery and reuse; however, the problem o
Quím. Nova. Publicado em: 2017-09
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2. Catalisadores à base de platina frente a correntes de H2 contendo acetaldeído geradas via reforma do etanol / Platinum-based catalystic in the face of current H2 containing acthaldehyde generated via reforming of ethanol
Due to the greenhouse effect, hydrogen production from bioethanol reforming is a very important subject in heterogeneous catalysis research. Pt based catalysts are employed in H2 purification processes and also as electrocatalysts of PEM (Proton Exchange Membrane) fuel cells. Hydrogen obtained from ethanol reforming may contain acetaldehyde and small amounts
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 23/05/2011
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3. Estudo da Aplicação de Brometo de Índio(I) em Reações para Formação de Ligações Carbono-Carbono / Studies on the Application of Indium(I) Bromide in Carbon-Carbon
This PhD thesis describes our results on the application of indium(I) bromide in carbon-carbon bond forming reactions. Indium enolates, generated in situ from the reaction between indium(I) bromide and α,α-dichloroketones, react with carbonyl compounds and electron-deficient alkenes. Reactions of indium enolate with α,α-dichloroketones, i
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/03/2011
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4. Síntese, Reatividade e Caracterização Estrutural de Haletos de Telúrio e Ariltelurenila com Estados de Oxidação Incomuns ou Mistos. / Synthesis, Reactivity and Structural Characterization of Tellurium and Aryltellurenyl Halides with Unusual or Mixed Oxidation States.
This work presents a study related to the halogenation of diarylditellurides (RTe)2 in order to obtain tellurium and aryltellurenyl halides with unusual or mixed oxidation states. Although regarded as essentially unstable, the aryltellurenyl monohalides (RTeX) were generated in situ and captured from the reaction milieu in many ways, forming stable adducts o
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2011
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5. Heck arylation reaction with arenediazonium salts : applications in the total synthesis of polyhydroxylated prolines and pyrrolidines, rolipram and baclofen analogues, and in the formal synthesis of prepolycitrin A and polycitrin A / Reação de arilação de Heck com sais de arenodiazonio : aplicações nas sinteses totais de prolinas e pirrolidinas poliidroxiladas, rolipram e analogos do baclofeno, e na sintese formal de prepolicitrina A e policitrina A
The Heck-Matsuda arylation reaction is a valuable and extremely versatile synthetic procedure for carbon-carbon bond formation, based on the coupling of an olefin with an arenediazonium salt in the presence of a zerovalent palladium organometallic specie. Recently, the use of this reaction has been gaining space in total syntheses, demonstrating its viabilit
Publicado em: 2008
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6. tri-n-butyltin hydride-mediated radical reaction of a 2-iodobenzamide: formation of an unexpected carbon-tin bond
A reação radicalar mediada por hidreto de tri-n-butilestanho de 2,3-di-O-benzil-4-O-trans-cinamil-6-desoxi-6-(2-iodobenzoilamino)- alfa-D-galactopyranosídeo de metila levou à formação de um produto inesperado, o 2,3-di-O-benzil-4-O-trans-cinamil-6-desoxi-6-(2-tri- n-butilestanhobenzoilamino)-alfa-D-galactopyranosídeo de metila. A estrutura do produto
Journal of the Brazilian Chemical Society. Publicado em: 2007-04
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7. Estudo das propriedades termomecanicas e estruturais de filmes finos amorfos de carbono e nitretos de carbono / Study of the thermomechanical and structural properties in amorphous carbon and carbon nitride
In this work, we studied thenno mechanical and structural properties of hydrogenated amorphous carbon (a-C: H), hydrogenated carbon nitride (a-C:H:Nx) and carbon nitride (a-C:Nx) thin films. Two techniques were used to prepare the samples: glow discharge for depositing hydrogenated amorphous carbon (a-C:H) and carbon nitride (a-C:H:Nx) and ion beam assisting
Publicado em: 2004
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8. Raman analyses of residual stress in diamond thin films grown on Ti6Al4V alloy
The stress evolution in diamond films grown on Ti6Al4V was investigated in order to develop a comprehensive view of the residual stress formation. Residual stress is composed of intrinsic stress induced during diamond film growth and extrinsic stress caused by the different thermal expansion coefficients between the film and substrate. In the coalescence sta
Materials Research. Publicado em: 2003-01
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9. Poli(oxido de etileno-co-epicloridrina) : degradação foto-oxidativa e termica, e blenda com polipropileno
Polymers derived from ethylene oxide and epichlorohydrin, like poly(epichlorohydrin-co-ethylene oxide) elastomer, are studied as polymer electrolyte for application in photo-electrochemical devices. These materiaIs present the ability to form complexes with alkali salts, presenting high ionic conductivity. In these devices the conversion of the solar energy
Publicado em: 2003
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10. Projeto de catalisadores para reações com gas de sintese
A partir do gás de síntese (que constitui uma mistura gasosa de óxidos de carbono e hidrogênio), pode-se obter hidrocarbonetos, álcoois e aldeídos. Estes podem ser obtidos também através da via petroquímica. Portanto, a produção desses compostos a partir do gás de síntese constituem vias alternativas que podem ser exploradas em função de aspec
Publicado em: 2001
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11. Íons carbônio
Carbonium ions are carbocations with a pentacoordinated carbon atom, where the electronic octet is maintained. They possess a three center two electron bond in order to keep the tetravalence of the carbon atom. This paper reviews the concept of carbonium ions, their formation, stability and reactions.
Química Nova. Publicado em: 2000-06
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12. Preparação, caracterização e avaliação de catalisadores heterogeneos a base de Pt na hidrogenação enantiosseletiva do piruvato de metila em presença de cinconidina
Platinum based catalysts were prepared by impregnation on different supports, namely C, Al303, TiO2 and La203. The commercial activated carbon was oxidized by different methods in order to modify its surface. The main surface groups identified were carboxylic acid, when HN03 is the oxidizing agent, and carbonyl, phenol and quinone, when the oxidation is made
Publicado em: 2000