N-Heterocyclic Carbene-Catalyzed Enantioselective Annulation of Bromoenal and 1,3-Dicarbonyl Compounds

Abstract Highly enantioselective [3+3] annulation reactions of bromoenals and 1,3‐dicarbonyl compounds are reported. In addition, both enantiomers of the resultant dihydropyranone could be easily obtained by choosing N‐heterocyclic carbenes (NHCs) with the same stereocenter but different substituents under the optimized reaction conditions.