Isatin <i>N</i>,<i>N</i>′-Cyclic Azomethine Imine 1,3-Dipole and Abnormal [3 + 2]-Cycloaddition with Maleimide in the Presence of 1,4-Diazabicyclo[2.2.2]octane

Abstract

A new isatin N,N'-cyclic azomethine imine synthon was devised, and an unexpected abnormal [3 + 2]-cycloaddition with maleimide catalyzed by 1,4-diazabicyclo[2.2.2]octane (DABCO) has been disclosed. A variety of tricyclic spiropyrrolidine oxindoles bearing a dinitrogen heterocycle and succinimide scaffold were obtained in excellent yields (up to 96%) and diastereoselectivities (up to 97:3) under mild conditions.