Chiral N-heterocyclic carbene catalyzed annulation of α,β-unsaturated aldehydes with 1,3-dicarbonyls

Abstract

Chiral N-heterocyclic carbene catalyzed annulations of ynals and enals with 1,3-dicarbonyls have been described. The two reactions provided direct and efficient methods for enantioselective synthesis of functionalized dihydropyranones. Comparatively, the reactions starting from ynals were atom-economical; furthermore the reactions of enals demonstrated broader substrate compatibility.