Photoredox‐Catalyzed Metal‐Free Regio‐ & Stereoselective C(sp2)–H Amination of Enamides with N‐Aminopyridium Salts

Abstract

Comprehensive SummaryA visible‐light‐induced photoredox‐catalyzed regioselective and stereoselective C(sp2)–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 with 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 sulfonamidyl 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‐sulfonamidylated enamides. The operational simplicity, environmental friendliness and cost efficiency of this methodology allowed it to pave a new avenue to enrich the arsenal of synthetically crucial functionalized enamides and their related derivatives.