N‐Heterocyclic Carbene‐Catalyzed [3+3] Annulation of Alkynyl Acyl Azolium with <i>β</i>‐Keto Ester for the Synthesis of Tri‐Substituted <i>α</i>‐Pyranones
Chengming Jiang, Ziyang Dong, Jiaming Wang, Changgui Zhao
Abstract
Abstract The reactivity of N‐Heterocyclic carbene (NHC)‐bound alkynyl acyl azoliums is underexplored in chemistry. We herein reported an NHC‐catalyzed [3+3] annulation of alkynyl acyl azoliums with β ‐keto esters. The strategy features mild reaction conditions and exhibits broad substrates scope, delivering a wide range of tri‐substituted α ‐pyrones in moderate to excellent yields (up to 95%). This approach extends the reactivity of alkynyl acyl azoliums to β ‐keto esters binucleophiles.
Topics & Concepts
ChemistryAnnulationCarbeneReactivity (psychology)CatalysisCombinatorial chemistryMedicinal chemistryStereochemistryOrganic chemistryAlternative medicineMedicinePathologyN-Heterocyclic Carbenes in Organic and Inorganic ChemistryCatalytic Cross-Coupling ReactionsCatalytic C–H Functionalization Methods