Catalytic Asymmetric Addition of Diethylzinc to Benzaldehyde Using α-Pinene-Derived Ligands

The amines obtained from -pinene and containing a phenol or pyridine fragment can be used as ligands in the asymmetric addition of diethylzinc to aromatic aldehydes; the enantiomeric excess (ee) was up to 80%. The enantioselectivity of the reaction is not very sensitive to the nature of substituents in the aromatic ring of aldehydes.