Dearomative Higher‐Order Cycloaddition for the Construction of Dihydropyrimidin‐4(1 <i>H</i> )‐One Scaffold Employing <i>N</i> ‐Heterocyclic Carbene Catalysis

In this article, we demonstrate that dearomative higher‐order cycloaddition constitutes a useful method for the construction of biologically relevant dihydropyrimidin‐4(1 H )‐one scaffold. The reaction utilizes indole‐7‐carbaldehydes acting as higherene precursors that under N ‐heterocyclic carbene (NHC) catalysis, lead to the generation of NHC‐bound aza‐ o ‐quinodimethanes. Their cycloaddition with cyclic trifluoromethyl ketimines, acting as hetero‐higherenophiles, proceeds in an asymmetric fashion opening access to high molecular complexity in a single step.