Synthesis of polycyclic aromatic iodides via ICI-induced intramolecular cyclization

The reaction of 2-(arylethynyl)biphenyls with ICI at -78 degreesC affords substituted polycyclic aromatic iodides in good to excellent yields. The aryl substituents can be either electron-donating or electron-withdrawing groups such as OMe, Me, CHO, CO2Et or NO2 groups. This chemistry has been successfully extended to systems containing a variety of polycyclic and heterocyclic rings.