Reductive coupling of acrylamides and carbonyls via solvated electrons from excited-state acridyl radicals

Abstract

The reductive coupling of carbonyls and alkenes is primarily promoted by super stoichiometric quantities of samarium diiodide (SmI₂). This reductant requires fresh preparation under moisture-free anaerobic conditions for successful reactivity. Herein, we describe a method for reductively coupling acrylamides with unactivated ketones and aldehydes by employing acridine radicals as excited-state reductants. Ultrafast transient absorption spectroscopy experiments provide a clearer picture of the excited-state acridine radical and its mechanism of action, which most likely proceeds via the formation of solvated electrons in acetonitrile.