Regioselective synthesis of diverse thio-, seleno-substituted 1,2,3-triazoles

Thio-, seleno-substituted triazoles are useful scaffolds employed in the fields of organic synthesis, medicinal chemistry, and material science. A number of synthetic approaches to efficient formation of thio-and seleno-triazoles have been disclosed, including the interception of copper(I) triazolides generated in-situ, cycloaddition of internal alkynes (thio-, halo-, and metalated alkynes) to azides, and the coupling of azides and non-alkyne substrates. This mini-review intends to summarize the synthetic methods toward thio-, seleno-1,2,3-triazoles and the relative reaction mechanisms.