(S)-2-hidroxipropanoato de 2-N, N-dimetilaminoetila: síntese e investigação da atividade organocatalítica na reação de Morita-Baylis-Hilman.

• Ano de defesa: 2012
• Autor(a) principal: Silva, Wagner André Vieira da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraí­ba; BR; Química; Programa de Pós-Graduação em Química; UFPB
• Palavras-chave em Português: Reação de Morita-Baylis-Hilman (RMBH); Catalisador multifuncional; Organocatálise; Enantiômero; (S)-2-hidroxipropanoato de 2-N; Ndimetilaminoetila; Transferência de hidrogênio; Reaction of Morita-Baylis-Hillman (BHMA); Multifunctional catalyst; Organocatalysis; Enantiomer; (S)-2 hydroxypropanoate 2-N; N-dimetilaminoetila; Hydrogen transfer; CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/tede/7079

This study was performed in order to synthesize and evaluate a new chiral tertiary amine, (S)-2-hydroxypropanoate 2-N, N-dimetilaminoetila according to the concept of multifunctional catalyst, which allows one same molecule presents various characteristics such as Bronsted acid and Lewis base. Allied to the interests of organocatalysis of simplicity and low operating costs, resulting in products that do not have contaminants like metals, designed in order to be able to catalyze / promote the reaction of Morita-Baylis-Hillman (MBH). The synthesis was performed starting from cheap raw materials and good commercial availability, S-lactic acid and 2-N, Ndimetilaminoetan-1-ol in one step reaction (98%). Based on current mechanistic proposal of the MBH reaction, the mechanism of Cantillo and Kappe, we investigated the reaction conditions, where there is a hydrogen transfer in aprotic media and also in the presence of phenols as additives, checking the influence speeds, reaction yields and asymmetric induction. We investigated the reaction between pnitrobenzaldehyde and acrylonitrile as reaction MBH pattern, varying experimental conditions such as solvent, quantity of (S)-2-hydroxypropanoate 2-N, Ndimetilaminoetila time, temperature and addition of phenolic additives. In addition, a new method was developed for the separation of enantiomers for the racemic compound antiparasitic 2 - [Hydroxy (4-nitrophenyl) methyl] acrylonitrile by gas chromatography with high resolution capillary columns packed with chiral phases. Chemical yields were obtained 2 - [hydroxy (4-nitrophenyl) methyl] <1 to 98% and enantiomeric excesses up to 20.5%. Mechanistic aspects are discussed in this paper, based on the results and computations, using the theory DFT and QTAIM.