Diastereoselective Addition of Anisoles to N-tert-butanesulfinyl Imines Via Four-Membered Lithium Cycles.

A highly regio- and diastereo-selective ortho-lithiation/addition of anisoles to N-tert-butanesulfinyl imines resulting in the selective formation of chiral -branched amines is described. This method is also efficient for highly regioselective benzylic lithiation of o-methylanisoles, followed by diastereoselective addition to N-tert-butanesulfinyl imines.