An Organocatalytic Cascade Spirocycloaddition Reaction for the Construction of Spiro[indoline-3,3′-piperidin]-6′-ones

Abstract A cascade intramolecular spirocycloaddition reaction of TBS-O-protected indole-alkynamides in the presence of a chiral bifunctional thiourea, which involves in situ deprotection, dearomatization, and intramolecular spirocycloaddition under mild conditions, is developed. This approach enables the efficient construction of a wide range of polycyclic spiro[indoline-3,3′-piperidin]-6′-one scaffolds in excellent yields (up to 98%) and with good enantioselectivities (up to 94:6 er).