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.