One‐pot synthesis of spiropyrrolidine‐pyrrolo[2,3‐b]quinoline derivatives via metal‐free post‐Ugi bis‐annulation reactions

Abstract

AbstractSynthesis of a diastereomeric mixture of new spiropyrrolidine‐pyrrolo[2,3‐b]quinoline derivatives by utilizing post‐Ugi reaction is described. The Ugi‐adducts obtained via a four‐component reaction (4CR) of 2‐chloroquinoline‐3‐carbaldehydes, amines, coumarin‐3‐carboxylic acids and isocyanides underwent KOtBu‐promoted intramolecular bis‐annulations followed by coumarin ring opening. This array allowed to assemble spiro‐γ‐lactam‐pyrrolo[2,3‐b]quinoline scaffolds in moderate to good yields.