A simple and effective approach to the synthesis of new diverse tricyclic-benzazoles containing a sulfonyl scaffold

A copper-catalyzed one-pot three-component reaction between a terminal alkyne, trichloro acetonitrile, and benzo (thiazole-oxazole-imidazole) to construct an array of functionalized fused-ring heterocyclic compounds has been developed. This methodology provides an effective route to directly form the tricyclic-benzazole derivatives from easily-affordable and simple starting materials, under mild reaction conditions with moderate to good yields. Then, considering the potential of the synthesized derivatives due to the presence of the CCl3 group as a leaving group in the system, these compounds were investigated for reaction with sulfinate salt under simple conditions and room temperature in THF solvent. Finally, 15 new heterocyclic compounds from the tricyclic-benazole family have been synthesized in this project in two steps using a simple, rapid, and efficient method.