Carboxylic acid-promoted copper(I)-catalyzed azide-alkyne cycloaddition.

ABSTRACT

In this article, we proved that all three key steps in the catalytic cycle of CuAAC can proceed in the presence of carboxylic acids and the latter two steps can be promoted significantly by carboxylic acids. Benzoic acid showed the best promotion activity, and the acids with strong chelating ability to Cu(I) ion could not serve for this purpose. Thus, the first carboxylic acid-promoted highly efficient CuAAC was established.