Proline bulky substituents consecutively act as steric hindrances and directing groups in a Michael/Conia-ene cascade reaction under synergistic catalysis.

In this study, we report a highly stereoselective and versatile synthesis of spiro pyrazolones, promising motifs that are being employed as pharmacophores. The new synthetic strategy merges organocatalysis and metal catalysis to create a synergistic catalysis using proline derivatives and Pd catalysts. This protocol is suitable for late-stage functionalization, which is very important in drug discovery.