Catalysis by Amino Acid-Derived Tetracoordinate Complexes:  Enantioselective Addition of Dialkylzincs to Aliphatic and Aromatic Aldehydes

Me(2)Zn and Et(2)Zn added to aromatic and aliphatic aldehydes in the presence of 3 mol % of 2. (S)-1-Phenylethanol (91% ee) and (S)-1-phenylpropanol (86% ee) were synthesized from benzaldehyde and (S)-1-furan-2-yl-1-propanol (86% ee) from 2-furaldehyde. Nonanal and 3-phenylpropanal provided (S)-3-undecanol (96% ee) and (S)-1-phenyl-3-pentanol (94% ee). A solid-phase variant was effective with reduced ee's (e.g., 86% ee --> 79% ee) for (S)-1-phenylpropanol.