Three-component electrosynthesis of spirooxindole-pyran derivatives through a simple and efficient method

An eco-friendly and highly efficient process has been applied to synthesize spirooxindole-pyran derivatives in a one-pot container via a three-component reaction of isatins, malononitrile, and an enolizable C-H-activated compound of diethyl 3-oxopentanedioate under constant current in n-propanol under a temperature of 50 degrees C. The proposed method shows high yields through green reaction conditions along with other significant advantages. Among which stand out applying clean electrons as a reproducible source of energy instead of an organic catalyst, using an environmentally friendly solvent for instance propanol, a multicomponent reaction with mild condition happening in a one-pot container, and no chromatographic separation.