Catalytic Atroposelective Aerobic Oxidation Approaches to Axially Chiral Molecules

A copper and chiral nitroxide co-catalyzed aerobic enantioselectiveoxidation process has been developed that allows access to axiallychiral molecules. Two complementary atroposelective approaches, oxidativekinetic resolution (OKR) and desymmetrization, were studied usingambient air as the stoichiometric terminal oxidant. OKR of rac-N-arylpyrrole alcohols and rac-biaryl alcohols affords the optically pure compoundswith er up to 3.5:96.5 and 5.5:94.5, respectively.Desymmetrization of prochiral diols provides axially chiral biarylcompounds with er up to 99:1.