Nickel-Catalyzed Reductive 1,4-Alkylarylation of 1,3-Enynes with Aziridines and Aryl Electrophiles: A Route to γ-Sulfonamide Allenes.

A nickel-catalyzed system for the three-component reductive cross-electrophile reactions with 1,3-enynes, aryl iodides, and aziridines is reported. This practical transformation is characterized by its high chemoselectivity and regioselectivity for ring opening of aziridines, facilitating the efficient synthesis of a wide range of valuable β-functionalized ethylamine-containing tetrasubstituted allenes in up to 95% yields. Mechanistic studies suggest that such a reductive 1,4-alkylarylation method proceeds via a radical pathway, which involves a secondary radical generated from a nonregioselective halide (bromide or iodide) ring opening of aziridines.