Asymmetric Construction of Bispiro[oxindole-pyrrolidine-rhodanine]s via Squaramide-Catalyzed Domino Michael/Mannich [3 + 2] Cycloaddition of Rhodanine Derivatives with <i>N</i>-(2,2,2-Trifluoroethyl)isatin Ketimines

Abstract

Squaramide-catalyzed asymmetric domino Michael/Mannich [3 + 2] cycloaddition reaction between rhodanine derivatives and N-(2,2,2-trifluoroethyl)isatin ketimines has been developed to synthesize various bispiro[oxindole-pyrrolidine-rhodanine]s with good to excellent yields (up to 99%) and excellent stereoselectivities (up to >99% ee and >99:1 dr). The biologically active rhodanine, oxindole, and pyrrolidine moieties were embedded in these novel bispirocyclic products, which will provide some support for the enrichment of chiral heterocyclic compound databases with potential medical value.