Highly regio- and diastereoselective construction of spirocyclopenteneoxindoles through phosphine-catalyzed [3 + 2] annulation of Morita-Baylis-Hillman carbonates with isatylidene malononitriles.

Phosphine-catalyzed highly regio- and diastereoselective [3 + 2] annulation of Morita-Baylis-Hillman (MBH) carbonates with isatylidene malononitriles has been disclosed to give the corresponding spirocyclopenteneoxindoles in excellent yields under mild conditions. A plausible reaction mechanism has also been proposed on the basis of previous literature.