Efficient One-Pot Synthesis of Spirooxindole Derivatives Catalyzed by L-Proline in Aqueous Medium

An efficient one-pot synthesis of spirooxindole derivatives by three-component reaction of isatins, malononitrile (cyanoacetic ester) and 1,3-dicarbortyl Compounds in water in the presence of L-proline is reported. This new protocol has the advantages of environmental friendliness, higher yields, shorter reaction times, low cost, and convenient operation.