New Organocatalytic Asymmetric Synthesis of Highly Substituted Chiral 2-Oxospiro-[indole-3,4′- (1′,4′-dihydropyridine)] Derivatives

Herein, we report our preliminary results concerning the first promising asymmetric synthesis of highly functionalized 2-oxospiro-[indole-3,4′-(1′,4′-dihydropyridine)] via the reaction of an enamine with isatylidene malononitrile derivatives in the presence of a chiral base organocatalyst. The moderate, but promising, enantioselectivity observed (30%–58% ee (enantiomeric excess)) opens the door to a new area of research for the asymmetric construction of these appealing spirooxindole skeletons, whose enantioselective syntheses are still very limited.