Enantioselective hydrogenation of ethyl pyruvate in flow reactor overpt-cd/si0(2) catalysts
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DORIS RUIZ [1] ; PATRICIO REYES [1]
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[1] Universidad de Concepción
Universidad de Concepción
Comuna de Concepción, Chile
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- Localización: Journal of the Chilean Chemical Society (Boletín de la Sociedad Chilena de Química), ISSN-e 0717-6309, ISSN 0366-1644, Vol. 53, Nº. 4, 2008, págs. 1740-1742
- Idioma: inglés
- Enlaces
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Resumen
The continuous enantioselective hydrogenation of ethyl pyruvate (EP) in a continuous flow reactor at 25°C on l%Pt-CD/Si0(2) catalysts has been studied. The catalytic study included the analysis of variables such as: particle size, feed flow, H2 pressure and the addition of chiral modifier to the reactor feed. The catalysts were prepared using impregnation of Pt colloids which are stabilized with different quantities of cinchonidine (CD) on Si0(2). This process gives chiral properties to the catalyst and allows changing the particle size for the reaction of interest. The catalysts were characterized by adsorption/desorption isotherms of N2 a 77 K, TEM, XPS and the analysis of producis by GC-MS. The monitoring of the reaction indicates a significant increases in the conversion when deereasing the contact time and a maximum in the enantiomeric excess (ee) of 63 % to the (R)-ethyl lactate which is obtained after using 200mg of l%Pt/Si0(2) catalyst (1.6nm) at 10 bar of H2 and a flow of 0.3 mL/min of a mixture EP (0.01M) and CD (0.034M) in cyclohexane.
