Multicomponent/Palladium-Catalyzed
Cascade Entry to
Benzopyrrolizidine Derivatives: Synthesis and Antioxidant Evaluation
Luis D. Miranda
Eduardo Hernández-Vázquez
10.1021/acs.joc.5b01742.s002
https://acs.figshare.com/articles/dataset/Multicomponent_Palladium_Catalyzed_Cascade_Entry_to_Benzopyrrolizidine_Derivatives_Synthesis_and_Antioxidant_Evaluation/2111794
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.
2015-11-06 00:00:00
cinnamic acid
Benzopyrrolizidine Derivatives
Z geometry
compound
antioxidant capacity
Antioxidant EvaluationA
heterocyclic scaffolds
sinapinic acids
thiobarbituric acid reactive substances assay
benzopyrrolizidine
chemistry scaffolds
antioxidants ferulic