Cu/Pd-Catalyzed, Three-Component Click Reaction of Azide, Alkyne, and Aryl Halide: One-Pot Strategy toward Trisubstituted Triazoles

A Cu/Pd-catalyzed,
three-component click reaction of azide, alkyne,
and aryl halide has been developed. By using this Cu/Pd transmetalation
relay catalysis, a variety of 1,4,5-trisubstituted 1,2,3-triazoles
were quickly assembled in one step in high yields with complete regioselectivity,
just like assembling Lego bricks. Notably, different from the well-established
CuAAC click reactions only working on terminal alkynes, this reaction
offers an alternative solution for the problem of the click reaction
of internal alkynes.