Photoredox-Catalyzed Metal-free Regio- & Stereoselective C(sp2)-H Amination of Enamides with N-aminopyridium salts

A visible-light-induced photoredox-catalyzed regioselective and stereoselective C(sp)-H amination of enamides with bench-stable and easily accessible N-aminopyridium salts is developed, affording synthetically and biologically prominent vicinal 1,2-diamine scaffolds in broad substrate scope and excellent functional group compatibility. The transformation proceeded through a radical pathway involving the Giese addition of the relatively electrophilic N-centered amidyl radical species to nucleophilic β-olefinic position of enamides followed by the ensuing single electron oxidation and β-H elimination, delivering geometrically-defined Z-configured β-amino enamides. The operational simplicity, environmentally friendliness and cost efficiency of this methodology has paved a new avenue to enrich the arsenal of synthetically crucial functionalized enamides and their derivatives.