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

摘要

Novel (4R)-HO-(2S)-Pro-(S)-Val derivative tagged to 1-methyl-imidazolium 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.