Cp*CoIII-Catalyzed C(7)-H Bond Annulation of Indolines with Alkynes.

An efficient protocol for the synthesis of biologically essential pyrroloquinolinones has been developed under Cp*CoIII catalysis, which involves a cascade reaction of C(7)-H alkenylation with alkynes followed by nucleophilic addition. A wide variety of internal alkynes including enyne, diyne, and ynamide and more challenging terminal alkynes were successfully employed for the annulation in good to excellent yield with high regioselectivity.