Rhodium(III)-Catalyzed Annulation of Pyridinones with Alkynes via Double C-H Activation: A Route to Functionalized Quinolizinones.

A Rh(III)-catalyzed oxidative annulation of pyridin-2(1H)-ones with alkynes via double C-H activation to produce highly functionalized 4H-quinolizin-4-ones is disclosed. This reaction features easily available starting materials, simple manipulation, a relatively wide substrate scope, and good functional group tolerance. The application of this protocol is demonstrated by the synthesis of a known fluorescent quinolizino[3,4,5,6-ija]quinolinium salt.