Highly efficient and diastereoselective construction of bispirooxindoles through a cascade Michael-cyclization reaction

A series of bispirooxindole derivatives have been synthesized via a cascade Michael-Cyclization reaction between isothiocyanato oxindoles and methyleneindolinones with high yields (up to 98%) and excellent diastereoselectivities (up to >95:5 dr) under mild conditions. The structure and effect on the reaction of less studied 4-substituted methyleneindolinones have also been investigated.