Organocatalytic Highly Regio- and Enantioselective Umpolung Michael Addition Reaction of α-Imino Esters

Abstract The catalytic asymmetric umpolung reaction of ketimines is of great importance, because it can easily provide chiral amines bearing a tetrasubstituted carbon atom on its asymmetric center. Because amino acids with a tetrasubstituted carbon center are useful due to their wide applicability as pharmaceuticals and chiral building blocks, their enantioselective synthesis has great significance in organic synthesis. Herein, we demonstrate a metal‐free novel phase‐transfer‐catalyzed highly regio‐ and enantioselective umpolung Michael reaction of α‐imino esters, which provides amino acid derivatives in high yields with up to 98 % ee . The products are successfully converted into chiral amino acid derivative and δ‐lactone with high enantiopurity.