Iron-Catalyzed Asymmetric Amino-Pyrazolation of Vinylarenes

Abstract Stereoselective pyrazole N-alkylation has emerged as a highly sought-after transformation in both synthetic and medicinal chemistry. Despite substantial advances, existing methods have relied on two-component coupling strategies that require tailored alkylating reagents and/or noble transition metal catalysts. Herein, we report an iron-catalyzed asymmetric olefin difunctionalization platform that enables the simultaneous incorporation of both primary amino and pyrazole groups. The resulting β-primary amino pyrazoles serve as versatile synthetic linchpins that are amenable to diverse postfunctionalization reactions, thereby substantially expanding the accessible chemical space of enantioenriched N-alkyl pyrazoles. The synthetic utility of this method is further demonstrated by the streamlined synthesis of a bioactive molecule and its structural analogues. Preliminary mechanistic investigations suggest that the reaction proceeds through an enantioselective aziridination and ring-opening pyrazolation sequence.