Application of polyamines and amino acid derivatives based on 2-azabicycloalkane backbone in enantioselective aldol reaction

Abstract

Carbon–carbon bond forming reactions, such as aldol reaction and condensation, belong to extremely desired transformations as manifested by >25,000 entries in SciFinder. Their stereoselective variant requires the use of an appropriate catalyst with a strictly defined structure. Hence, chiral 2-azabicycloalkane-based catalysts were designed, synthesized and tested in a stereoselective aldol reaction between cyclic/acyclic ketone and p-nitrobenzaldehyde both in organic and aqueous media. Among catalysts containing a chiral bicyclic backbone, amide based on 2-azabicyclo[3.2.1]octane and pyrrolidine units showed the best catalytic activity and afforded aldol product in excellent chemical yields (up to 95%) and good diastereo-and enantioselectivity (dr 22:78, ee up to 63%).