A Photo- and Cobalt-Catalyzed Enantioselective Hydroamination of Unactivated Alkenes with Amines

The transition-metal-catalyzed direct enantioselective addition of N─H bonds to unactivated alkenes is of great significance as it creates high-value-added chiral alkylamines from two abundant chemical feedstocks, yet it has long been a considerable challenge. Current state-of-the-art advancements rely on the use of olefins with a tethered heteroatom or heteroaromatic amine, which can readily coordinate with metal catalysts to achieve high stereoselectivity. Herein, we report a photoredox/cobalt-catalyzed enantioselective hydroamination of nonactivated alkenes with simple amines through Co(III)H-mediated hydrogen atom transfer followed by a nucleophilic amination of alkylcobalt(IV), enabling the synthesis of α-chiral tertiary amines in high yields and enantioselectivities. The strategy demonstrates a unique capability to control enantioselectivity of the in situ generated alkyl radicals, efficiently differentiating two alkyl substituents (methyl versus methylene), which is significantly less explored in enantioselective radical transformation. This research will spark new ideas for the asymmetric radical hydrofunctionalization of unactivated alkenes with various nucleophiles.