Synthesis of Spiro[chroman/tetrahydrothiophene‐3,3′‐oxindole] Scaffolds <i>via</i> Heteroatom‐Michael–Michael Reactions: Easily Controlled Enantioselectivity <i>via</i> Bifunctional Catalysts

Abstract

Abstract An efficient method for the construction of chiral spirooxindole‐chroman and spirooxindole‐tetrahydrothiophene scaffolds with three consecutive chiral centers including an all‐carbon quaternary spirocenter has been developed. This method features an asymmetric thia/oxa‐Michael–Michael cascade sequence in a single operation in the presence of chiral tertiary amine‐thioureas as the catalysts, providing the desired products in good chemical yields and optical purities. magnified image