Asymmetric 1,4-addition of diethylzinc to α,β-unsaturated enones catalyzed by chiral imino-thiophosphoramide ligands and copper(I)

In the presence of a catalytic amount of chiral imino-thiophosphoramide ligand L7 (6 mol %) and Cu(I) salt (3 mol %), the asymmetric addition of diethylzinc to α,β-unsaturated carbonyl compounds could be achieved in good yields with moderate ees (up to 75% ee) at −20 °C in toluene. A novel chiral imino-thiophosphoramide ligand system for this asymmetric 1,4-addition reaction has been explored. [Copyright &y& Elsevier]