A Novel and Efficient Isocyanide-Catalyzed Addition Reaction of Enaminones to Isatin Derivatives for Oxindoles Synthesis

Abstract

A mild, efficient and novel pseudo three-component condensation reaction approach has been designed for straightforward synthesis of 3,3’-bis-substitued-2-oxindole derivatives. The products were prepared through one-pot and pseudo three-component condensation reactions of anilinolactones, isatin derivatives, and cyclohexyl isocyanide in acetonitrile solvent. The key features of this approach include using cyclohexyl isocyanide, which unpredictably has not participated in the condensation reaction and instead of that, plays a fascinating catalytic role. The 3,3’-bis-substitued-2-oxindoles have been afforded in excellent isolated yields, with high purity, straightforward work-up procedure and short reaction times.