Facile Synthesis of Dispirooxindole-Fused Heterocycles via Domino 1,4-Dipolar Addition and Diels–Alder Reaction of in Situ Generated Huisgen 1,4-Dipoles

A facile synthetic protocol was developed for the efficient synthesis of complex dispirooxindole-fused heterocycles via a three-component reaction. The key strategies involve a domino 1,4-dipolar addition and Diels–Alder reaction of the in situ generated Huisgen 1,4-dipoles from the addition reaction of 4-dimethylaminopyridine with acetylenedicarboxylate to 3-phenacylideneoxindole