Phosphine-Catalyzed (4 + 2) Cycloaddition of Conjugated Dienes with Enones and Its Asymmetric Variant
Ke Li, Zhenjie Gan, Er‐Qing Li, Zheng Duan
Abstract
Herein we reported a novel phosphine-catalyzed (4 + 2) cyclization reaction of electron-deficient conjugated dienes with enones to generate functionalized dihydropyran skeletons. A mechanistic investigation reveals that the reaction produces a new phosphonium zwitterion, which undergoes consecutive reactions. In addition, an asymmetric variant was developed by efficient and economical chiral phosphine catalysis.
Topics & Concepts
ChemistryPhosphineDihydropyranCycloadditionPhosphoniumZwitterionConjugated systemCatalysisCombinatorial chemistryOrganic chemistryMoleculePolymerAsymmetric Synthesis and CatalysisSynthetic Organic Chemistry MethodsAdvanced Synthetic Organic Chemistry