Asymmetric Synthesis of Spirooxindoles with Seven Stereocenters via Organocatalyzed One‐pot Three‐component Sequential Cascade Reactions

A bifunctional squaramide‐catalyzed one‐pot three‐component Michael/Mannich‐Michael/cyclization sequential cascade reaction for the construction of bispirooxindole‐spirooxindoles was developed in good yields with excellent stereoselectivities (up to >20:1 dr, 99% ee). A series of original cinnamoyl‐3‐ylideneoxindoles have been applied to this sequential cascade strategy for the first time. This new strategy provides a process for the enantioselective construction of bispirooxindole‐spirooxindoles with seven stereocenters, of which three are quaternary spiro‐stereocenters.