Diastereoselective Synthesis of Chromeno[3,2-<i>d</i>]isoxazoles via Brønsted Acid Catalyzed Tandem 1,6-Addition/Double Annulations of <i>o</i>-Hydroxyl Propargylic Alcohols
Li Zhu, Pei-Xu Zhang, Zhao-Zhao Li, Xing-Lu Zhang, Hong-Yuan Cao, Yu‐Ning Gao, Ming Bian, Hui‐Yu Chen, Zhenjiang Liu
Abstract
A Brønsted acid catalyzed tandem process to access densely functionalized chromeno[3,2-d]isoxazoles with good to excellent yields and diastereoselectivities was disclosed. The procedure is proposed to involve a 1,6-conjugate addition/electrophilic addition/double annulations process of alkynyl o-quinone methides (o-AQMs) in situ generated from o-hydroxyl propargylic alcohols with nitrones. Mild conditions, good functional group compatibility, easy scale-up of the reaction, and further product transformation demonstrated its potential application.
Topics & Concepts
ChemistryTandemCatalysisElectrophileBrønsted–Lowry acid–base theoryCombinatorial chemistryConjugateOrganic chemistryMedicinal chemistryMaterials scienceMathematical analysisComposite materialMathematicsSynthesis of Indole DerivativesSynthesis of Organic CompoundsChemical Synthesis and Reactions