Rhodium(III)-Catalyzed Enantioselective C–H Activation/Annulation of Ferrocenecarboxamides with Internal Alkynes

Efficient synthesis of planar chiral ferrocene-fused heterocyclic molecules is challenging in asymmetric synthesis. Herein, we report an enantioselective C–H activation/annulation of ferrocenecarboxamides with internal alkynes promoted by CpRh(III) catalysis. Trisubstituted chiral Cp-derived Rh complexes are found to be enabling catalysts, which lead to a broad substrate scope with good functional group compatibility. Planar chiral ferrocene-fused pyridone products are obtained in high yields (up to 90%) with excellent enantioselectivity (up to 99% ee). Combined experimental and computational studies support the proposed reaction mechanism.