Enantioselective diethylzinc addition to aromatic and aliphatic aldehydes using (3 R,5 R)-dihydroxypiperidine derivatives catalyst

Abstract

A series of chiral (3 R,5 R)-dihydroxypiperidine derivatives 3a– f were conveniently prepared from trans-4-hydroxy- l-proline and applied to the catalytic enantioselective addition of diethylzinc to benzaldehyde and heptanal. Among them, 3d was found to show the best asymmetric induction in promoting the addition of Et 2Zn to various aldehydes, providing ( R)-secondary alcohols in up to 98% ee.