Three-Component Synthesis of Indanone-Fused Spirooxindole Derivatives

A simple, straightforward and versatile multicomponent protocol for the synthesis of indanone-fused spirooxindole derivatives has been developed. The strategy involves the one-pot three-component reaction of heterocyclic ketene aminals, 1H-indene-1,3(2H)-dione and the dicarbonyl compounds isatins or acenaphthenequinone in an ethanol/water medium catalysed by p-TSA at reflux. Mild reaction conditions, operational simplicity, wide substrate scope and overall excellent yields make this method highly efficient for the library synthesis of indanone-fused spirooxindole.