Catalytic Enantioselective Synthesis of 3-Substituted Benzosultams via Corey-Bakshi-Shibata Reduction of Cyclic N-Sulfonylimines

The catalytic asymmetric synthesis of 3-substituted benzo-fused sultams employing the Corey-Bakshi-Shibata reduction with catecholborane of the corresponding cyclic N-sulfonylimines is reported. Good to excellent yields (74-95%) and enantiomeric excesses (69-94%) are obtained.