Design and synthesis of chiral NHCs and their related TM-complexes for enantioselective catalysis
Keywords: NHC, CAA(r)C, Copper, Enantioselectivity
Due to their unique topology and a highly modular steric environment around the metal, chiral N-heterocyclic carbenes (NHCs) rapidly emerged as powerful stereo-directing ligands for a wide range of Transition Metal (TM)-catalyzed transformations. In this context, we designed the first chiral hydroxyalkyl-NHCs, which gave excellent enantioselectivities (up to 99% ee) in copper-catalyzed enantioselective alkylation involving Zn-, Mg-, and B-based reagents. Thus, numerous enantioenriched building-blocks were produced in high yields and used in the synthesis of natural molecules. Currently, we are involved in the development of original C1 and C2-symmetric TM-complexes from prochiral NHCs as well as from chiral Cyclic(Alkyl)(Amino)Carbenes (CAACs).