Iron-Catalyzed Regioselective Synthesis of 3-Arylindoles

An interesting iron-catalyzed synthesis of 3-arylindoles from their corresponding nitrosoarenes and alkynes has been developed. By using iron(II) phthalocyanine as the catalyst precursor and CO as the reductant, broad range of nitrosoarenes and alkynes were transformed into the corresponding indoles in good yields with excellent functional groups tolerance. Remarkably, CO gas can be replaced by other reductants such as isopropanol as well.