Stereoselective synthesis of dispiro heterocycles by [3 + 2] cycloaddition of azomethine ylides with a thiazolo[3,2- a]indole derivative

Org Biomol Chem. 2020 Oct 14;18(39):7822-7826. doi: 10.1039/d0ob01559h.

Abstract

A green one pot three component [3 + 2] cycloaddition of a thiazolo[3,2-a]indole derivative (generated by the reaction of thieno[2,3-b]indole-2,3-dione and dimethyl acetylenedicarboxylate) with isatin derived azomethine ylides is reported here. An eco-friendly acetyl choline iodide-ethylene glycol (ACI/EG)-mediated deep eutectic solvent system was adopted for the reaction. Spiropyrrolidine oxindoles incorporating multiple stereocenters were obtained in a highly diastereoselective manner in excellent yields.