Ionic liquid supported 4-HO-Pro-Val derived organocatalysts for asymmetric aldol reactions in the presence of water

Abstract

Novel (4R)-HO-(2S)-Pro-(S)-Val derivative tagged to 1-methylimidazolium cation and PF6¯ anion efficiently catalyzes asymmetric aldol reactions of cyclic ketones with aromatic aldehydes in aqueous environment to afford the corresponding aldols in high yield with moderate to high anti-diastereo- (dr up to 99: 1) and enantioselectivity (up to 98% ee). The catalyst was recycled 9 times in the same reaction without any decrease in selectivity values.