Facile one-pot synthesis of coumarins linked to 1,2,3-triazoles by combining Sonogashira and CuAAC reaction

A facile, one-pot, atom economic approach has been developed for the synthesis of 1-(hetero)aryl-1,2,3-triazoles linked to coumarins under mild conditions. The reaction initially proceeds by the palladium-catalyzed Sonogashira cross-coupling reaction of coumarin fluorosulfates with trimethylsilylacetylene (TMS acetylene), followed by the deprotection of TMS group and subsequent copper-catalyzed azide-alkyne cycloaddition (CuAAC) reactions. The salient features of this developed methodology are: step-economic one-pot synthetic approach, utilization of coumarin fluorosulfate as an atom-economical electrophilic coupling partner for Sonogashira coupling, and easy access to pharmacologically relevant 1,2,3-triazole derivatives.