Ferrocene-Based Planar Chiral Imidazopyridinium Salts for Catalysis

Planar chirality remains an underutilized control element in asymmetric catalysis. Factors that have limited its broader application in catalysis include poor catalyst performance and difficulties associated with the economical production of enantiopure planar chiral compounds. The construction of planar chiral azolium salts that incorporate a sterically demanding iron sandwich complex is now reported. Applications of this new N‐heterocyclic carbene as both an organocatalyst and a ligand for transition‐metal catalysis demonstrate its unprecedented versatility and potential broad utility in asymmetric catalysis. Planar chiral azolium salts that incorporate a sterically demanding iron sandwich complex are synthesized. These new N‐heterocyclic carbenes can be employed both as organocatalysts and as ligands for transition‐metal catalysis, which demonstrates their unprecedented versatility and potential broad utility in asymmetric catalysis.