• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Preparação e utilização de amino catalisadores - derivados do glicerol, D-manitol e L-aminoácidos - em reações de adição aldólica

Martins, Rafaela de Souza 03 August 2017 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-10-10T11:51:05Z No. of bitstreams: 1 rafaeladesouzamartins.pdf: 11994443 bytes, checksum: c42e2d285fd87e325b038e9bfe95bdf5 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-10-10T12:22:21Z (GMT) No. of bitstreams: 1 rafaeladesouzamartins.pdf: 11994443 bytes, checksum: c42e2d285fd87e325b038e9bfe95bdf5 (MD5) / Made available in DSpace on 2017-10-10T12:22:21Z (GMT). No. of bitstreams: 1 rafaeladesouzamartins.pdf: 11994443 bytes, checksum: c42e2d285fd87e325b038e9bfe95bdf5 (MD5) Previous issue date: 2017-08-03 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho descrevemos a preparação de oito amino catalisadores, obtidos na forma de sal do trifluoroacetato. Quatro destes catalisadores foram preparados na forma da mistura de dois estereoisômeros, a partir do glicerol e os aminoácidos L-leucina, L-valina, L-fenilalanina e a L-prolina. Os outros quatro amino catalisadores foram preparados, em sua forma estereoisomericamente pura, a partir do D-manitol e os aminoácidos L-leucina, L-valina, Lfenilalanina e a L-prolina. Os oito amino catalisadores foram capazes de catalisar a reação de adição aldólica entre a cicloexanona e o 4-nitrobenzaldeído. Os produtos de adição foram obtidos em rendimentos que variaram de 58-95 %, sendo a maior r.d. de 1 : 9,12 (sin:anti), determinada por RMN de 1H, e maior e.e. de 94 %, determinado por cromatografia líquida de alta eficiência. O melhor resultado, considerando o rendimento, a diastereo e a enantiosseletividade dos produtos formados, foi obtido quando o catalisador enantiomericamente puro derivado da L-prolina foi utilizado. / In this work we describe a preparation of eight amino-catalysts, obtained as a trifluoroacetate salt. Four of these catalysts were prepared, in the form of the mixture of two stereoisomers, from glycerol and the amino acids L-leucine, L-valine, L-phenylalanine and L-proline. The other four amino-catalysts were prepared in stereoisomerically pure form from D-mannitol and the amino acids L-leucine, L-valine, L-phenylalanine and L-proline. The eight aminocatalysts were able to catalyze the aldol addition reaction between cyclohexanone and 4nitrobenzaldehyde. The addition products were obtained in yields ranging from 58-95 %, the highest d.r. from 1:9.1 (sin: anti), determined by 1H NMR, and higher e.e. of 94 %, determined by high performance liquid chromatography. The best result, considering the yield, diastereomer and enantioselectivity of the formed products, was obtained when the enantiomerically pure L-proline derived catalyst was used.

Page generated in 0.0381 seconds