Iodine catalysed synthesis of 4′H-dispiro[indoline-3,2′-pyrrole-3′,3″-indoline]-2,2″-dione through C–C bond formation

Spirooxindoles have become a privileged skeleton due to their wide and promising activities in pharmaceutical field. This work highlights metal-free synthetic approach for the construction of 4′H-dispiro[indoline-3,2′-pyrrole-3′,3″-indoline]-2,2″-dione by iodine catalyzed C–C bond formation reaction. This straight-forward benign synthetic pathway results in the formation of different spirooxindoles which can be used to synthesize various naturally occurring alkaloids and drugs. The reaction involves in-situ generation of imine by reaction of easily available isatin and (+)-(R)-α-phenyl/naphthyl ethanamine followed by C–C bond formation and further cyclization to construct a well-designed spirooxindole.