Multicomponent approach to silica-grafted peptide catalysts : A 3 D continuous-flow organocatalytic system with on-line monitoring of conversion and stereo-selectivity

• Ano de defesa: 2014
• Autor(a) principal: Scatena, Gabriel dos Santos
• Orientador(a): Paixão, Márcio Weber
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Carlos; Câmpus São Carlos
• Programa de Pós-Graduação: Programa de Pós-Graduação em Química - PPGQ
• Palavras-chave em Inglês: Asymmetric organocatalysis; Flow chemistry; Multicomponent reactions; Microreactor
• Área do conhecimento CNPq: CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ORGANICA
• Link de acesso: https://repositorio.ufscar.br/handle/20.500.14289/8017

The derivatization of organocatalysts with functional appendages suitable to anchor onto solid supports is usually achieved by stepwise syntheses. As an alternative to such a strategy, this work describes a one-pot approach to silylated prolyl-peptide catalysts by a multicomponent reaction that enables the simultaneous incorporation of the catalytic and the heterogenizable (triethoxysilane) moieties. A microreactor with high catalytic efficacy and reproducibly in the conjugate addition of aldehydes to nitroolefins was obtained by grafting onto HPLC-grade silica (10 μm) and packing into a column with a selected catalyst. A 3 D continuous-flow system that includes the on-line monitoring of the reaction outcome was set up. For that, the microreactor was coupled to a chromatographic column for the separation of the remaining substrates from the Michael adduct in the second dimension, followed by a chiral polysaccharide column for the analysis of conversion and stereoselectivity. This approach represents a new instrumental setup that combines the advantages of multidimensional chromatography and flow catalysis.