Catalytic Asymmetric Synthesis of α-Tetrasubstituted α-Trifluoromethyl Homoallylic Amines by Ir-Catalyzed Umpolung Allylation of Imines

A general and mild method to prepare enantioenriched alpha-trifluoromethyl, alpha-stereogenic homoallylic amines is established. This reaction, which involves an Ir-catalyzed umpolung allylation of imines and a 2-aza-Cope rearrangement cascade, could yield both tetrasubstituted and trisubstituted stereocenters. This transformation employs readily available starting materials and displays broad substrate scope. The isolation and structural determination of reaction intermediates revealed factors critical for the efficiency and stereoselectivity of this transformation.