Asymmetric Synthesis of Spirocyclic Oxindole‐Fused Tetrahydrothiophenes via N,N′‐Dioxide–Nickel(II) Catalyzed Domino Reaction of 1,4‐Dithiane‐2,5‐diol with 3‐Alkenyloxindoles

Abstract

AbstractA highly efficient chiral N,N′‐dioxide–nickel(II) complex system has been developed to catalyze the domino thia‐Michael/aldol reaction of 1,4‐dithiane‐2,5‐diol with 3‐alkenyloxindoles. A series of the desired spirocyclic oxindole‐fused tetrahydrothiophenes was obtained in good yields with excellent ee and dr (up to 97% yield, 98% ee, >19:1 dr). Besides, based on the X‐ray crystal structure of the catalyst as well as the absolute configuration of the product, a catalytic model was proposed to explain the stereocontrol process.magnified image