Enantioselective addition of diethylzinc to aldehydes catalyzed by optically active C2‐symmetrical bis‐β‐amino alcohols

Abstract
The syntheses of new optically active C2‐symmetrical bis‐β‐amino alcohols 1‐6 from (S)‐2‐(1‐hydroxy‐1,1‐diphenylmethyl)‐pyrrolidine are described. Especially attention is focused on bridges, which link the two β‐amino alcohol units. These new chiral ligands have been successfully applied in the catalytic enantioselective addition of diethylzinc to aldehydes to give sec‐alcohols in good yields with up to 95% enantiomeric excess. Chirality 14:716–723, 2002.