The synthesis of 1, 2, 3-triazoles recently became popular with the copper-catalyzed version of the azide–alkyne Huisgen cycloaddition, developed independently by the groups of Sharpless [1a] and Meldal.[1b] While this powerful and highly regioselective reaction can be performed in various media by using several sources of copper or ruthenium catalysts,[2] it is usually restricted to terminal alkynes.[3] Another access to 1, 2, 3-triazoles is the highly ...
