Design of a Binaphthyl-Based Axially Chiral Amino Acid as an Organocatalyst for Direct Asymmetric Aldol Reactions

摘要

A novel and robust bi-naphthyl-based amino acid was de-signed and successfully applied to the direct asymmetric aldol reaction.In some cases,this catalyst leads to higher yields and selectivities than the well-known proline catalyst.For instance,the direct asymmetric aldol reaction of acetone with 4-nitrobenzaldehyde in the presence of the binaphthyl-based amino acid catalyst proceeded smooth-ly to give the aldol adduct in 82% yield with 95% ee.This catalyst was also found to catalyze effectively the reactions of cyclic or unsymmetrical ketones to give the corresponding aldol adducts with excellent diastereo-and enantioselectivities.