Regiodivergent Reactions of 2‐Alkynyl Aziridines with Grignard Reagents

Abstract Herein, we report regiodivergent nucleophilic attack of Grignard reagents to 2‐alkynyl aziridines. Under the catalysis of a Cu(I)‐diphosphine complex, benzylic Grignard reagents add to the carbon‐carbon triple bond of the aziridines to deliver α‐allenylamines in moderate to excellent yields; the direct addition of the Grignard reagents to the aziridines in the absence of catalyst provided homopropargylic amine derivatives. Both reactions could proceed in highly enantiospecific ways. Further synthetic manipulations of these products enable rapid access to diverse useful heterocyclic molecular scaffolds.