Synthesis of polycyclic aromatics and heteroaromatics via electrophilic cyclization.

[reaction: see text] 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-O(2)NC(6)H(4)SCl. This methodology readily accommodates various functional groups and has been successfully extended to systems containing a variety of polycyclic and heterocyclic rings.