Two tandem sequential reactions catalyzed by [Au], N-heterocyclic carbenes (NHC) and organic bases

Herein we describe two coupling reactions of aldehydes and activated alkynes to give chalcones or alkenyl esters depending on the base used. Chalcones were obtained by activation of alkynes by AuI and of aldehydes by NHC in presence of triethylamine. Alkenyl esters were obtained via generation of gold nanoparticles, aerial oxidation of aldehydes to carboxylates and their subsequent nucleophilic addition to the alkyne functionality.