A long-range chiral relay via tertiary amide group in asymmetric catalysis: new amino acid-derived N,P-ligands for copper-catalysed conjugate addition.

New N,P-ligands 4-6, derived from valinol and prolinol, respectively, have been developed for the asymmetric, copper(I)-catalysed conjugate addition of diethylzinc to unsaturated ketones; the tertiary amide group has been shown to effectively relay the chiral information from the ligand backbone to the active centre.