In this paper, commercially available ZnO was found to be a highly effective catalyst for three-component
coupling reactions of alkynes, aldehydes/or ketone and amines (A3-coupling) via C-H activation. The reactions could be
applied to both aromatic and aliphatic aldehydes. Nearly quantitative yields of the desired products were obtained in most
cases. No co-catalyst or activator is required, and water is the only by-product in the reactions. Heterogeneous nature of
the catalyst made it reusable for further chemical reactions.