Fusing Triazoles: Toward Extending Aromaticity

A novel method to extend aromaticity by one benzene and two triazole rings was developed and optimized. This two-step route employs the copper-catalyzed azide-haloalkyne cycloaddition reaction of an ortho-bis(iodoacetylene) system and the subsequent intramolecular homocoupling fusion of the neighboring iodotriazoles, a process in which an additional benzene ring is formed. This versatile methodology allows one to extend the core size of chromophores and, consequently, to tune the material's properties.