Synthesis of polycyclic aromatics and heteroaromatics via electrophilic cyclization

A variety of substituted polycyclic aromatics are readily prepared in good to excellent yields under very mild reaction conditions by the reaction of 2-(1-alkynyl)biphenyls with ICl, I-2, NBS, and p-O2NC6H4SCl. This methodology readily accommodates various functional groups and has been successfully extended to systems containing a variety of polycyclic and heterocyclic rings.