l-Proline in an ionic liquid as an efficient and reusable catalyst for direct asymmetric α-aminoxylation of aldehydes and ketones

Abstract

Proline-catalyzed direct asymmetric α-aminoxylation of aldehydes and ketones in the room temperture ionic liuqid 1-n-butyl-3-methylimidazolium tetrafluoroborate achieved high yields and high enantioselectivities, even when just 1–5% of proline was used as the catalyst; immobilisation of the catalyst in an ionic liquid phase offers simple product isolation and the reuse of the catalytical system at least four times in subsequent reactions.