Regio- and enantioselective copper-catalyzed addition of dialkylzinc reagents to cyclic 2-alkenyl aziridines

The reactions of some organocopper reagents with cyclic 2-alkenyl aziridines were examined. The stereoselectivity of the addition reaction of dialkylzinc can be strongly influenced by the use of phosphoramidites as ligands for copper. Chiral copper complexes of 2,2′-binaphthyl-based phosphoramidites were shown to be highly effective catalysts for the regio- (S_N2′) and anti-stereoselective addition of dialkylzinc reagents to these compounds according to a kinetic resolution protocol. The corresponding new cyclic allylic amine reaction products were obtained with a good enantioselectivity (83% ee).