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

Abstract

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 proceeded smoothly to afford 5-halo-1,2,3-triazole-fused tricyclic benzocondensed compounds. Leveraging the remaining halogen groups, carbon-chain extension via Mizoroki–Heck or Suzuki–Miyaura coupling reactions, followed by an intramolecular Friedel–Crafts reaction, furnished polycyclic systems incorporating fused triazole rings. Furthermore, transformation of the halogen groups into 2-nitrobenzene derivatives via Suzuki–Miyaura cross-coupling, followed by a Cadogan reaction using triphenylphosphine, provided a series of fluorescent pentacyclic compounds.