Chiral Allylic Amine Synthesis Enabled by the Enantioselective Cp^XRh(III)-Catalyzed Carboaminations of 1,3-Dienes

Abstract

Considering the importance of the chiral allylic amine structural motif and the rarity of synthetic methods toward their construction, herein, we report a CpXRh(III)-catalyzed enantioselective intermolecular carboamination of 1,3-dienes via N-phenoxy amides-derived intermolecular aryl C–H activation and intramolecular amide transfer. The methodology enables the direct synthesis of a variety of chiral allylic amines with the embedment of phenol functionalities and proceeds under mild conditions with sequential formation of a completely regioselective C–C bond and a highly enantioselective C–N bond. Integrated experimental and computational mechanistic studies reveal an unusual Rh(III)–Rh(I)–Rh(III) catalytic pathway, in which an alkene insertion/π-allylation/intramolecular nucleophilic substitution cascade was involved for this transformation. Besides, synthetic application in the derivation of natural products and the late-stage assembly of bioactive complexes has also been demonstrated, which further strengthens the synthetic utility of this approach.