Synthesis of Triarylbenzenes via Tandem Aryne Reaction of Aryl Grignards with Polyhalobenzenes

Article abstract of DOI:10.1021/jo00250a026

Aryl Grignards react with 1,2,3,4-tetrahalobenzenes to give primarily (2,3,4-triaryphenyl)magnesium halides.The mechanism involves Grignard exchange at one of the "outer" halogens followed by three cycles of magnesium halide loss and regioselective capture of the resulting aryne by the aryl Grignard agent (Scheme II).