Solution Phase Synthesis of a Spiro[pyrrolidine-2,3′-oxindole] Library via a Three- Component 1,3-Dipolar Cycloaddition Reaction.

Abstract A combinatorial library of 26,500 spiro[pyrrolidine-2,3′-oxindoles] was prepared in a single-compound format by a facile intermolecular 1,3-dipolar cycloaddition. An azomethine ylide, generated by the decarboxylative condensation of an isatin 1 with an α-amino acid 2, was trapped by a trans-chalcone3 to afford heterocycles of the general structure 4. The regio- and stereochemistry of a representative product was determined by single crystal X-ray structure.