Synthesis of Indolo-Fused Nitrogen Heterocycles

Significance

The synthesis of fused seven- to nine-membered heterocyclic ring indole derivatives by Pd-catalyzed intramolecular Heck-type cyclization is reported. The precursors are derived by standard amide bond forming reactions from readily available materials. The reactions proceed in modest to excellent yields. For the less reactive aryl bromides, microwave irradiation improved the yields of the cyclization reaction.