Photoredox-catalyzed chemoselective aerobic Cα–H oxidation of propargylamines: synthesis of substituted 2-ynamide and oxazolo[2,3-a]isoquinolinone derivatives

Abstract

An efficient approach for visible-light-induced chemoselective aerobic Cα–H oxidation of propargylamines via molecular oxygen as an oxidant using rose bengal as a photoredox catalyst is reported. The photochemical protocol was employed for the direct oxygenation of Cα–H 2-propynyl-tertiary amines to 2-ynamides and further cyclization of oxazolo[2,3-a]isoquinolinone derivatives from phenylpropynyltetrahydroisoquinoline was established.