Regio‐ and Stereoselective Multicomponent Synthesis of Novel Chromeno‐Annulated Pyrrolizine and Thiazolizine Scaffolds via 1,3‐Dipolar Cycloaddition Reactions

Abstract

An efficient protocol for the construction of chromeno annulated pyrrolizine and thiazolizines derivatives through an in-situ formation of an azomethine ylides and zwitterionic intermediate followed by 1,3-dipolar cycloaddition reaction is described. This novel one-pot reaction paves the way for the successful assembly of salicaldehydes, dialkyl acetylenedicarboxylates and L-proline or thiazolidine-4-carboxylic acid in the presence of a basic catalyst. This domino process affords polycyclic chromeno annulated pyrrolizines and chromenothiazolizines in good yields.

Use of Dialkyl Acetylenedicarboxylates in the Multicomponent Synthesis of Heterocyclic Structures

“…Based on the optimal condition, the corresponding products 190 were obtained in good to high yields (Scheme 78). [103] …”

“…Based on the optimal condition, the corresponding products 190 were obtained in good to high yields (Scheme 78). [103] Mukhopadhyay et al in 2019 established an efficient method for the synthesis of N-aryl polyhydroquinoline derivatives 192 through the one-pot and four-component reaction of dialkyl acetylenedicarboxylate 1, substituted aromatic aldehyde 6, cyclohexane 1,3-dione 191, and substituted aromatic amine…”