Mechanosynthesis of Pyrrole-2-carboxylic Acids via Copper-Catalyzed Spiroannulation/Ring-Opening Aromatization of 4-Arylidene Isoxazol-5-ones with Enamino Esters
Mingjun Li, Hui-Juan Xiao, Peng Xu, Luan-Ting Wu, Siqi Chen, Ze Zhang, Hui Xu
Abstract
An efficient and practical tandem reaction of 4-arylidene isoxazol-5-ones with enamino esters catalyzed by an inexpensive copper salt has been established in a ball mill. This innovative approach yields a diverse array of structurally novel pyrrole-2-carboxylic acids, showing excellent tolerance toward different functional groups. By integrating spiroannulation and ring-opening aromatization processes, this protocol introduces a facile and cost-effective strategy for synthesizing highly functionalized pyrrole derivatives.
Topics & Concepts
AromatizationChemistryCatalysisPyrroleRing (chemistry)TandemOrganic chemistryCopperCombinatorial chemistryMaterials scienceComposite materialSynthesis and Characterization of PyrrolesSynthesis and Reactivity of HeterocyclesCatalytic C–H Functionalization Methods