CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Neste trabalho foram realizadas reaÃÃes de C-alquilaÃÃo via CatÃlise de TransferÃncia de Fase (CTF) com a finalidade de obter os precursores de aminoÃcidos para uma posterior resoluÃÃo cinÃtica enzimÃtica. As reaÃÃes de C-alquilaÃÃo ocorreram a 70 ÂC, vÃrios agentes transferidores de fase foram
testados, e o mais promissor foi o cloreto de benziltributilamÃnio (CBTBA). As reaÃÃes se processaram com o uso de 3 mmol do cianoacetoamido acetato de etila, 3 mmol de carbonato de potÃssio, 6 mmol do agente alquilante, cloreto de benzila.
ApÃs purificaÃÃo do produto, realizou-se uma reaÃÃo de hidrÃlise total com posterior proteÃÃo dos grupos amino e carboxila resultando em trÃs diferentes compostos rac-33, rac-34 e rac-35.
A resoluÃÃo cinÃtica enzimÃtica do rac-33 por reaÃÃo de interesterificaÃÃo usando o butirato de butila (PrCO2Bu) foi inicialmente testada com diversas lipases (Candida antarctica Lipase B e sua isoenzima Candida antarctica Lipase A, ACYLASE I obtida de Aspergillus melleus, PSL-C I, Lipase a partir da Candida rugosa e a LIPOZYME RM IM) variando tempo, temperatura e solvente. A LIPOZYME RM IM foi a Ãnica enzima capaz de promover a reaÃÃo de interesterificaÃÃo e com altos valores de enantiosseletividade (E). As melhores reaÃÃes ocorreram à temperatura de 55 ÂC.
A resoluÃÃo do rac-33 a 55 ÂC ocorreu em oito horas e quinze minutos, em sistema sem solvente, com uma conversÃo de 50%, ees >99%, eeP>99% com um alto valor de enantiosseletividade, E>200 (10633), Esquema 3. A resoluÃÃo cinÃtica do 2-acetilamino-3-fenil-propanoato de alila (rac-35) ocorreu em quatro horas e trinta minutos, sem solvente à temperatura de 55 ÂC, resultando em 49% de conversÃo, eeS98%, eeP>99% e E>200 (9278). / In this work reactions of C-alkylation were carried out via Phase Transfer Catalysis (PTC) in order to obtain precursors of amino acids and them to perform enzymatic kinetic resolution. The reactions of C-alkylation occurred at 70 ÂC, several phase transfer agents were tested, and the most promising was the benzyltributylammonium chloride (CBTBA). The reaction were performed using 3 mmol of ethyl cianoacetoamidoacetate, 3 mmol of potassium carbonate,
6 mmol of alkylating agent, benzylchloride.
After purification of the product, a reaction of total hydrolysis was carried out with subsequent protection of amino and carboxyl groups resulting in three different compounds rac-33 rac-34 and rac-35.
The enzymatic kinetic resolution of rac-33 via interesterification with butyl butyrate (PrCO2Bu) was initially tested with different lipases (Candida antarctica Lipase B and itâs isoenzyme, Lipase Candida antarctica Lipase A, ACYLASE I obtained from Aspergillus melleus, PSL-C I, Lipase from Candida rugosa and Lipozyme RM IM) varying time, temperature and solvent. The Lipozyme RM IM was the only enzyme capable of promoting the reaction of interesterification and with high values of enantioselectivity (E). The best reactions occurred at 55 ÂC.
The resolution of rac-33 at 55 Â C occurred in eight hours and fifteen minutes in system solvent free, with conversion of 50%, eeS>99%, eeP>99% with a high value of enantioselectivity, E > 200 (10633), Scheme 3. The kinetic resolution of allyl 2-acetylamino-3-phenyl-propanoate (rac-35) occurred in four hours and thirty minutes, without any solvent at 55 Â C, resulting in 49% of conversion, eeS>98%, eeP>99% and E > 200 (9278).
| Identifer | oai:union.ndltd.org:IBICT/oai:www.teses.ufc.br:4891 |
| Date | 14 August 2009 |
| Creators | Marcos Reinaldo da Silva |
| Contributors | Marcos Carlos de Mattos, Nilce Viana Gramosa Pompeu de Sousa Brasil, Vicente Gotor-FernÃndez |
| Publisher | Universidade Federal do CearÃ, Programa de PÃs-GraduaÃÃo em QuÃmica, UFC, BR |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFC, instname:Universidade Federal do Ceará, instacron:UFC |
| Rights | info:eu-repo/semantics/openAccess |
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