Divergent heterocycle synthesis enabled by switchable reaction of azobenzenes with alkynes
José A. García-García, José Luis Aceña, Patricia García-García, David Sucunza*
Azobenzenes are iconic photochromic molecules whose reversible light-induced E–Z isomerization underpins decades of applications in dyes, polymers, molecular switches, and therapeutic agents. Beyond this hallmark, their potential as synthetic building blocks has only recently emerged. In particular, the reactivity of azobenzenes with alkynes is unveiling a new frontier in heterocycle synthesis. Under metal-catalyzed, photocatalytic, or thermal conditions, these transformations provide streamlined access to indazoles, cinnolines, carbazoles, and related nitrogen heterocycles relevant to pharmaceuticals and materials science. This review discusses how distinct activation modes, transition-metal catalysis, photoredox processes, and thermal pathways enable divergent outcomes from common precursors, repositioning azobenzenes from passive chromophores to active scaffolds for functional molecular architectures.
Trends Chem. 2025
DOI: https://doi.org/ 10.1016/j.trechm.2025.12.003
