Molecular Hybridization-Guided One-Pot Multicomponent Synthesis of Turmerone Motif-Fused 3,3′-Pyrrolidinyl-dispirooxindoles via a 1,3-Dipolar Cycloaddition Reaction

Described herein is the development of a facile and efficient methodology for the synthesis of novel turmerone motif-fused 3,3′-pyrrolidinyl-dispirooxindoles 3–5 via a multicomponent 1,3-dipolar cycloaddition of dienones 2 with azomethine ylides (thermally generated in situfrom isatins and proline or thioproline or sarcosine). Products bearing four or three consecutive stereocenters consist of two oxindole moieties and a pyrrolidinyl core, including vicinal spiroquaternary stereocenters fused in one ring structure were smoothly obtained in high yields (up to 93% yield) with good diastereoselectivity (up to >20:1). Another valuable application of this method was for the design of new hybrid architectures for biological screening through the adequate fusion of these sub-units of turmerone and 3,3′-pyrrolidinyl-dispirooxindole, generating drug-like molecules.