Rapid synthesis of hexahydropyrrolo[3,4-b]pyrrole-fused quinolines via a consecutive [3 + 2] cycloaddition and reduction/intramolecular lactamization cascade†
Yan-Liang Lin,Yun-Ta Lee,Yi-Ting Huang
Organic Chemistry Frontiers Pub Date : 08/10/2020 00:00:00 , DOI:10.1039/D0QO00858C
Abstract

An unprecedented synthesis of novel hexahydropyrrolo[3,4-b]pyrrole-fused quinolines is achieved through the sequential [3 + 2] cycloaddition reaction of azomethine ylides with maleimides followed by intramolecular lactamization. Condensation of the α-amino acid methyl ester with 2-nitrobenzaldehyde leads to an ester stabilized azomethine ylide which further reacts with maleimide to form hexahydropyrrolo[3,4-c]pyrrole. After the reduction of a nitro group, an unusual transamidation reaction is observed, furnishing the novel hexahydropyrrolo[3,4-b]pyrrole-fused quinolines. Isolation of the hexahydropyrrolo[3,4-c]pyrrole amide intermediate revealed the pathway of the reaction mechanism.

Graphical abstract: Rapid synthesis of hexahydropyrrolo[3,4-b]pyrrole-fused quinolines via a consecutive [3 + 2] cycloaddition and reduction/intramolecular lactamization cascade