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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Síntese e resolução cinética de dióis alílicos trans promovida por lipases

SILVA, Emmanuel Dias da 12 February 2016 (has links)
Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-07-28T18:13:32Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação de Mestrado Emmanuel Dias - ver Biblioteca 3.pdf: 5438340 bytes, checksum: 493d14db263ba9635f4d797c2d7f26cf (MD5) / Made available in DSpace on 2016-07-28T18:13:32Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação de Mestrado Emmanuel Dias - ver Biblioteca 3.pdf: 5438340 bytes, checksum: 493d14db263ba9635f4d797c2d7f26cf (MD5) Previous issue date: 2016-02-12 / CNPQ / Compostos orgânicos contendo dióis alílicos com configuração trans são substancias orgânicas muito úteis na área de síntese orgânica. Além disso, esses compostos podem ser encontrados na natureza, apresentando importantes atividades biológicas. Estes compostos também podem ser empregados como building blocks na preparação de moléculas bioativos de interesse. Dentre as várias metodologias existentes para preparar estes compostos, muitas empregam reagentes nocivos ao meio ambiente e/ou catalisadores metálicos, em rotas de síntese contendo numerosas etapas reacionais. Com isso, tivemos o interesse de desenvolver um método alternativo, visando à síntese destes compostos, em um processo mais limpo, de enantiosseletividade. A metodologia proposta consistiu no uso de lipases para obtenção dos compostos de forma seletiva. Com isso, após submeter os compostos em sua forma racêmica à resolução na presença de lipases, mono e diacetatos poderiam ser obtidos com alto grau de pureza óptica. A rota quimioenzimática proposta levou a preparação de uma biblioteca de (E)-dióis alílicos, com elevado excesso enantiomérico. / Organic compounds containing trans allylic diols are useful substances in organic synthesis. Furthermore, these compounds can be find in nature showing a wide range of biological activity. In addition, these compounds can be employed as building blocks in the preparation of bioactive compounds as target substances. Among several methodologies to prepare these compounds, the majority employs toxic reagents and/or metallic catalysts, in multistep pathway. Thereby, our interest was develop an alternative method aiming at the synthesis of these compounds, in a greener and enantioselective process. This proposal has consisted in employ lipases as a manner to achieve the related compounds selectively. Thus, after subjecting the racemic compounds to an enzymatic resolution, mono and bis acetates could be generated in high optical purity. The proposal chemo-enzymatic approach lead to the preparation of an enantioenriched library of (E)-allylic diols.

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