Multicomponent/Palladium-Catalyzed Cascade Entry to Benzopyrrolizidine Derivatives: Synthesis and Antioxidant Evaluation


A versatile and efficient protocol for the synthesis of highly substituted benzopyrrolizidines (tetrahydro-3<i>H</i>-pyrrolo­[2,1-<i>a</i>]­isoindol-3-ones) is reported. The strategy consisted of an Ugi four-component reaction/elimination methodology to afford dehydroalanines containing <i>trans-</i>cinnamic acid derivatives and different substituted 2-bromobenzylamines, followed by a palladium-catalyzed 5-exo-trig/5-exo-trig cascade carbocyclization process. Gratifyingly, benzopyrrolizidines were obtained in moderate to good yields (42–77%) with a <i>Z</i> geometry due to the structural requirements for <i>syn</i>-β-hydride elimination. The prepared heterocyclic scaffolds are decorated with several substituents and incorporate a benzopyrrolizidine-fused system, along with an embedded cinnamic acid derivative, two privileged medicinal chemistry scaffolds. Additionally, since some of the compounds are derived from the well-known antioxidants ferulic and sinapinic acids, they were tested for their in vitro antioxidant capacity. The data suggested that compounds having a <i>p-</i>hydroxyl group showed moderate 2,2-diphenyl-1-picrylhydrazyl-radical-scavenging activity and were effective antioxidants in preventing lipoperoxidation in a thiobarbituric acid reactive substances assay

Similar works

Full text

oai:figshare.com:article/2111788Last time updated on 2/12/2018

This paper was published in FigShare.

Having an issue?

Is data on this page outdated, violates copyrights or anything else? Report the problem now and we will take corresponding actions after reviewing your request.