Bis‐Tetrasubstituted Centers Forming Formal [3+3] Cycloaddition Reaction via Bifunctional Organocatalysis: Synthesis of Spiro‐Oxindoles

An efficient method has been developed for Michael/Electrophilic substitution cascade reaction between 3‐pyrrolyl‐oxindoles and unsaturated ketoesters, utilizing bifunctional organocatalysis. This approach enables the synthesis of a diverse array of spiro‐oxindole derivatives bearing three stereogenic centers, two of them quaternary, achieving high yields and exceptional diastereoselectivities. Furthermore, the resulting products can be readily converted into tetrahydropyridine skeletons through an elimination process in one‐pot. This strategy, in conjunction with traditional metal‐catalysis, facilitates the switchable, chemodivergent synthesis of spiro‐oxindoles, offering significant synthetic flexibility and potential for broader applications.