Bisoxazolidine-catalyzed enantioselective Reformatsky reaction.

A readily available chiral bisoxazolidine catalyzes the asymmetric Reformatsky reaction between ethyl iodoacetate and aldehydes. In the presence of 10 mol % of the ligand, dimethylzinc, and air, this method produces ethyl 3-hydroxy-3-(4-aryl)propanoates in high yields and in 75 to 80% ee at room temperature within 1 h. In contrast to aromatic substrates, relatively low ee's are obtained with aliphatic aldehydes.