Fig. 1: NHC-catalyzed normal and higher-order cycloaddition.
From: N-Heterocyclic carbene-catalyzed enantioselective hetero-[10 + 2] annulation
a NHC-catalyzed normal order cycloaddition. b NHC-catalyzed high order cycloaddition. c NHC-catalyzed higher-order cycloaddition (this work).
