Asymmetric Addition of Diethylzinc to Diphenylphosphinoyl-Imines Catalyzed by Copper(II) Trifluoromethanesulfonate-Chiral (2′-Ethylamino-[1,1′]binaphthalenyl-2-yl)-thiophosphoramidic Acid O,O′-Diaryl Ester Ligands

The chiral binaphthylthiophosphoramide L1 prepared from the reaction of O,O-diphenyl chlorothiophosphate with (R)-(+)-N-ethyl-1,1'-bi-naphthyl-2,2'-diamine was used as a catalytic chiral ligand in the copper(II) trifluoromethanesulfonate-promoted asymmetric addition of diethylzinc to di-phenylphosphinoyl-imines to give the corresponding adducts in 90-98% ee and good yields under mild conditions.