Facile Synthesis of 5‐Halo‐1,2,3‐Triazole‐Fused Benzotricyclic Frameworks from 1‐(ω‐Azidoalkyl)‐2‐(2,2‐Dihalovinyl)Arenes and their Application in Fluorescent Triazole Derivatives

By heating 1‐(ω‐azidoalkyl)‐2‐(2,2‐dihalovinyl)arenes in DMF, intramolecular Huisgen cycloaddition between the azido group and the 1,1‐dihalovinyl moiety proceeds smoothly to afford 5‐halo‐1,2,3‐triazole‐fused tricyclic benzocondensed compounds. Leveraging the remaining halogen groups, the carbon chain extension via the Mizoroki–Heck or Suzuki–Miyaura coupling reactions, followed by an intramolecular Friedel–Crafts reaction, furnish polycyclic systems that incorporate fused triazole rings. Furthermore, the transformation of the halogen groups into the 2‐nitrobenzene derivatives via Suzuki–Miyaura cross‐coupling, followed by a Cadogan reaction using triphenylphosphine, provides a series of fluorescent pentacyclic compounds.