One-pot enantioselective aziridination of olefins catalyzed by a copper(I) complex of a novel diimine ligand by using PhI(OAc)2 and sulfonamide as nitrene precursors

A novel chiral C-2-symmetric 1,4-diamine with multistereogenic centers at the backbone of the ligand has been synthesized from cheap natural product D-mannitol through multistep transformations. Its diimine derivative (3a) was found to be highly effective for the enantioselective control of the copper-catalyzed asymmetric aziridination of olefin derivatives with PhI=NTs as the nitrene source, affording the corresponding N-sulfonylated azirindine derivatives in good to excellent yields with up to 99% ee (ee = enantiomeric excess). The catalyst system discovered in the present work was also extended to a one-pot enantioselective aziridination by using sulfonamide/iodobenzene diacetate as the nitrene source. In this case, most reactions proceeded smoothly to give the corresponding products in moderate yields with good to excellent enantiomeric excesses (75-96% ee).