ChemInform Abstract: Organocatalytic [4 + 1]‐Annulation Approach for the Synthesis of Densely Functionalized Pyrazolidine Carboxylates.

Abstract A cascade reaction of α‐amination/Wittig olefination and either Corey—Chaykovsky reaction or intramolecular Michael addition reaction in presence of L‐proline provides access to functionalized pyrazolidines in a highly enantio‐ and diastereoselective fashion.