Artículo
Room Temperature Ionic Liquids in Asymmetric Hetero-Ene Type Reactions: Improving Organocatalyst Performance at Lower Temperatures
Autor/es | Bisogno, Fabricio R.
Fernández Fernández, Rosario Fátima Lassaletta Simón, José María Gonzalo Calvo, Gonzalo de |
Departamento | Universidad de Sevilla. Departamento de Química Orgánica |
Fecha de publicación | 2021-01 |
Fecha de depósito | 2021-02-12 |
Publicado en |
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Resumen | Abstract: Room temperature ionic liquids (RTILs) have been widely used as (co)solvents in several
catalytic processes modifying, in most of the cases, the catalyst activity and/or the selectivity for
the studied reactions. ... Abstract: Room temperature ionic liquids (RTILs) have been widely used as (co)solvents in several catalytic processes modifying, in most of the cases, the catalyst activity and/or the selectivity for the studied reactions. However, there are just a few examples of their use in hydrogen bonding organocatalysis. In this paper, we show the positive effect of a set of imidazole-based ionic liquids ([bmim]BF4 and [hmim]PF6 ) in the enantioselective addition of formaldehyde tert-butylhydrazone to prochiral α-keto esters catalyzed by a sugar-based chiral thiourea. Reactions performed in the presence of low percentages of RTILs led to an increase of the catalyst activity, thereby making possible to work at lower temperatures. Thus, the chiral tert-butyl azomethyl tertiary alcohols could be obtained with moderate to good conversions and higher enantioselectivities for most of the studied substrates when using up to 30 vol% of [hmim]PF6 as a cosolvent in processes performed in toluene. |
Agencias financiadoras | Ministerio de Economia, Industria y Competitividad (MINECO). España European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER) Junta de Andalucía |
Identificador del proyecto | CTQ2016- 76908-C2-1-P
CTQ2016- 76908-C2-2-P P18-FR-3531 |
Cita | Bisogno, F.R., Fernández Fernández, R., Lassaletta Simón, J.M. y Gonzalo Calvo, G.d. (2021). Room Temperature Ionic Liquids in Asymmetric Hetero-Ene Type Reactions: Improving Organocatalyst Performance at Lower Temperatures. Molecules, 26 (2), 355. |
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