From C2- to D2-symmetry: atropos phosphoramidites with a D2-symmetric backbone as highly efficient ligands in Cu-catalyzed conjugate additions

Atropos phosphoramidites with the D2-symmetric biphenyl backbone were diastereoselectively prepared with ease from achiral tetrahydroxy biphenyls. This type of ligands is proved to be highly efficient in the Cu-catalyzed conjugate additions of diethylzinc to α,β-unsaturated ketones and nitroalkenes. The unique D2-symmetric backbone endows the ligands with an excellent chiral environment.