Prolines proline-derived CILs

The synthesis of a new CIL [S-(—)-2-hydroxymethyl-l,l-dimethylpyrrolidinium tetrafluoroborate] derived from L-proline alcohol have been reported by Maier et al. [78]. This CIL was found to be an effective additive to acidic background electrolytes affording the separation of a mixture of five tricyclic antidepressants using capillary zone electrophoresis (CZE). The addition of the CIL to acidic background electrolytes leads to suppression of the magnitude of electroosmotic flow (EOF) and gradually reversed the direction of the EOF. Baseline separation of the five model analytes was achieved. It was observed that the proline-derived CIL offers relatively smaller anodic EOF compared to cationic surfactants that are mostly used for... 

Scheme 22.19 Proline-derived CILs and their use in asymmetric aldol reactions.

In recent years, a-amino acid (especially proline) derivatives incorporating ionic groups have been synthesized and gained widespread applications as recoverable organocatalysts in asymmetric aldol reactions. The catalysts commonly melt below 100-150°C and can be considered as task-specific CILs [71]. 

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