Construction of a new type of chiral bidentate NHC ligands: copper-catalyzed asymmetric conjugate alkylation

We synthesized in three steps simple chiral bidentate NHC compounds that carry an achiral coordinating group as N-substituent and revealed that they serve as efficient chiral auxiliaries for the copper-catalyzed asymmetric conjugate addition of dialkylzinc to acyclic enones (up to 97% ee).