Palladium-catalyzed domino Heck/cyanation: synthesis of 3-cyanomethyloxindoles and their conversion to spirooxoindoles

3′-Alkyl-3-cyanomethyloxindoles, prepared by a palladium-catalyzed domino Heck/cyanation, were efficiently converted to spiropyrrolidinyl-, spiropiperidinyl- and spirocyclopropyl-oxindoles. The so-obtained spirooxindoles bearing three diversity points were further functionalized via selective N-acylation, N-alkylation, N-sulfonylation, SNAr reaction and Buchwald–Hartwig N-arylation reaction to reach diverse set of heterocycles.