Copper ferrite nanoparticles: an efficient and reusable nanocatalyst for a green one-pot, three-component synthesis of spirooxindoles in water.

A green reaction of isatins, active cyanomethanes, and cyclic 1,3-dicarbonyl derivatives for the efficient and simple one-pot three-component synthesis of spirooxindole fused heterocycles in refluxing water by use of magnetically recoverable and reusable catalyst is reported. The features of this procedure are, the use of magnetically recoverable and reusable catalyst, mild reaction conditions, high to excellent product yields, operational simplicity, and easy workup procedures. Most importantly of all, easy magnetic separation of the catalyst eliminates the requirement of catalyst filtration after completion of the reaction. Furthermore, the catalyst remained highly active even after 5 repeated uses.