Stitching Triazoles to Arenes via a Transition Metal-Free Aryne Diels-Alder/1,3-Prototropic Shift/Dehydrobromination Cascade.

The 1,2,3-triazole-fused polyaromatic frameworks are traditionally obtained through transition metal-catalyzed C-H/C-X arylation of the preinstalled triazoles at a very high temperature. Herein, a transition metal-free direct synthesis via an aryne Diels-Alder/1,3-prototropic shift/dehydrobromination cascade is reported. This method gives access to triazole-fused aromatics as well as the corresponding dihydrocarbocycles under mild reaction conditions.