Organozinc
Mostrando 1-4 de 4 artigos, teses e dissertações.
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1. Estudo das condiÃÃes experimentais para o Homo e Hetero-acoplamento 2-bromopiridinas utilizando um sistema eletroquÃmico
The homocoupling reaction of 2-bromomethylpyridines and 2- bromopyridine was investigated. NiBr2 catalyst was employed using an electrochemical process, DMF as solvent, Zn or Fe as sacrificial anode, NaI or tetraalkyl ammonium salts as supporting electrolyte, an undivided cell and ambient temperature (~26ÂC). The synergetic effect caused by supporting elect
Publicado em: 2004
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2. Theoretical studies of models with chiral amplification in asymmetrical catalysis and autocatalysis reactions in organozinc additions to aldehydes / Estudos teÃricos de modelos de catÃlise assimÃtrica e autocatÃlise em reaÃÃo de adiÃÃo de organozinco a aldeÃdos
Foram realizados cÃlculos de quÃmica quÃntica de otimizaÃÃo de geometria, incluindo estados de transiÃÃo, de molÃculas e de complexos contendo Ãtomos de zinco envolvidos em reaÃÃes de adiÃÃo de organozinco a aldeÃdos por meio de catÃlise e autocatÃlise assimÃtrica que apresentam elevados excessos enantiomÃricos. Os resultados obtidos demons
Publicado em: 2004
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3. Estudo da reação de Simmons-Smith : obtenção vinilciclopropanos substituidos de interesse industrial
Of the procedures described in the literature, that of Rawson e Harrison gives under standard conditions the best results for the cyclopropanation of cyclohexene. We found that the noble metal salt used to activate the metallic zinc has a more important role than to clean its surface, as the yield of the reaction is strongly influenced by the anion. In the p
Publicado em: 1990
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4. Asymmetric autocatalysis: Novel structures, novel mechanism?
The amplifying asymmetric autocatalysis discovered by Soai and coworkers in 1995 does not fit easily into the extensively investigated framework of organozinc alkylation of aldehydes. In that case the catalyst is a monomeric Zn chelate that functions as both Lewis acid and Lewis base, permitting the simultaneous coordination of both dialkylzinc reagent and a
National Academy of Sciences.