STERIC EFFECTS OF CHIRAL LIGANDS IN A NEW TYPE OF ALDOL CONDENSATIONS CATALYZED BY ZINC(II) COMPLEXES OF α-AMINO ACID ESTERS

Abstract

Abstract The aldol condensations of p-nitrobenzaldehyde with acetone have been found to be catalyzed by Zn2+ complexes of α-amino acid esters under mild and neutral conditions to afford enantiomeric excess aldol type product along with some of the dehydrated product. The complexes with ligands containing benzene ring such as esters of Phe, Tyr, and Trp are much more effective both on catalytic activity and asymmetric induction.