Abstract
An innovative two stage liquid–liquid biphasic homogeneous protocol for the asymmetric organocatalytic aldol reaction isproposed, based on the use of the cis-ion-tagged proline 8 dissolved in the liquid film of a multilayered ionic liquid covalently bonded to silica gel 4. The resulting catalytically active material9 is first soaked with cyclohexanone in the presence of water, resulting in a semi-transparent gel, then the aldehyde isadded and the mixture stirred at RT. In the first stage, 4 acts as a catalyst reservoir that delivers 8 to the cyclohexanone phaseallowing the reaction to take place homogeneously. In the second stage, cyclohexanone is removed under vacuum andthe resulting slurry is extracted with anhydrous diethylether.Now 4 acts as a catalyst sponge, redissolving 8. Product extractionis extremely selective; no trace of catalyst is detected in the product-containing phase, and 9 can be easily reused several times with high cumulative productivity values (up to 523).
Lingua originale | English |
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pagine (da-a) | 1000-1006 |
Numero di pagine | 7 |
Rivista | ChemCatChem |
Volume | 4 |
Stato di pubblicazione | Published - 2012 |
All Science Journal Classification (ASJC) codes
- ???subjectarea.asjc.1500.1503???
- ???subjectarea.asjc.1600.1606???
- ???subjectarea.asjc.1600.1605???
- ???subjectarea.asjc.1600.1604???