Unsymmetrical bisazides containing chelating and nonchelating azido groups undergo
chemoselective three-component copper (I)-catalyzed azide–alkyne conjugation reactions
with two different alkyne molecules. In conjunction with the reactivity gap between aromatic
and aliphatic alkynes, a bistriazole molecule can be generated with excellent regioselectivity
by mixing two alkynes and a bisazide in a single reaction container. This method is
applicable in aqueous solutions at neutral pH, which may lend utilities in bioconjugation …

A procedure for one-pot, three-component conjugation via two triazolyl linkages will be
discussed. The bisazide linkers contain chelating and non-chelating azido groups, which
offer different reactivities in copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC)
reactions. The chelating azido group undergoes the CuAAC reaction with an alkyne in the
presence of Cu (OAc) 2, while the non-chelating azide requires the company of a reducing
reagent, such as sodium ascorbate, to be reactive. Also capitalizing the reactivity gap …