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

Abstract

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.

Aryne Annulations for the Synthesis of Carbocycles and Heterocycles: An Updated Review

“…Very recently, Tiwari and co-workers introduced a 1,2,3triazole-fused polyaromatic framework 104 via a transition metal-free aryne Diels−Alder/1,3-prototropic shift/dehydrobromination reaction with 4-vinyl-1,2,3-triazoles 103 (Scheme 41). 36 This protocol laid its compatibility towards broad substrate scope bearing electro-variant functionalities for both aryne precursors 1 as well as 4-vinyl-1,2,3-triazoles 103. N-Aryl fragment with electron deficient functionalities like fluoro, chloro, or bromo did not affect the reaction, as such resulted in smooth formation of dihydronaphthotriazoles in good yields (104b-104e).…”

Eco-friendly one-step synthesis of highly functionalized-spirooxindole-pyranopyrazoles and their in-vitro anticancer studies

“…According to structure-activity relationship (SAR), most therapeutic druglike properties are shown by SOXs, which contain nitrogen, sulphur, oxygen atoms, and primary alkyl groups in their skeleton [23][24][25][26][27][28][29]. Therefore, in this study, we synthesized five-membered spirooxindole-pyranopyrazole derivatives as anticancer agents via Knoevenagel condensation and Michael addition reactions [30].…”