Development of New Chiral P,N Ligands and Their Application in the Cu-Catalyzed Enantioselective Conjugate Addition of Diethylzinc to Enones.

High enantioselectivity (up to 98 % ee) has been achieved for the conjugate addition of diethylzinc to acyclic enones utilizing Cu(I) complexes of the novel chiral P,N ligands 1. The high enantioselectivities are best achieved using [Cu(OTf)](2) small middle dotC(6)H(6) as the copper catalyst precursor in nonpolar solvents such as toluene or Cl(CH(2))(2)Cl. R=H, CH(3); Tf=F(3)CSO(2).