Synthesis of triazole-fused tetracyclic spirooxindole derivatives via metal-free Huisgen cycloaddition.

We report an efficient, metal free method for synthesizing tetracyclic spirooxindole derivatives from N -protected isatins and propargyl bromide via Huisgen cycloaddition. This simple and practicle method provides access to spirooxindoles containing five-, six-, or seven-membered rings fused to a triazole ring.