Nickel/SKP-Catalyzed Markovnikov Regio- and Enantioselective Hydroamination of Vinylarenes with Hydroxylamines.

A Ni-catalyzed enantioselective hydroamination of vinylarenes has been developed, affording a wide variety of α-branched chiral alkylamines in good yields with exclusive Markovnikov regioselectivity and excellent enantioselectivity. The SKP ligand was found to be crucial to both the reactivity enhancement and enantiocontrol of the reaction. The synthetic utility of the protocol was exemplified in a gram-scale reaction and late-stage modification of medicinally relevant molecules. The deuterium-labeling experiment revealed that the irreversible hydronickelation of vinylarenes is most likely the enantioselectivity-determining step.