Enantioselective N<i>‐</i>Heterocyclic Carbene Catalyzed Annulation Reactions with Imidazolidinones

Abstract

Add acetic acid: A highly stereoselective N-heterocyclic carbene (NHC)-catalyzed formal [4+2] annulation between α,β-unsaturated aldehydes and imidazolidinones for the synthesis of imidazoles has been developed. Acetic acid serves as a key additive to achieve high chemoselectivity for the formal [4+2] annulation product.