Metal‐Free Visible‐Light Catalytic Deoxygenation of Azaaryl N‐Oxides: Harnessing Photons for Efficient Greener Synthesis

Abstract

AbstractRegio‐ and chemo‐selective functionalization of electron deficient azaarenes often required their transformations to corresponding N‐oxides and subsequent removal of oxygen after functionalization to get back the desired substituted azaarenes. An efficient metal‐free visible‐light photo‐redox catalytic deoxygenation of N‐oxides of azaheterocyclic compounds has been developed using acridinium based organo‐photocatalyst in blue LED light. High efficiency and mildness of this methodology has been demonstrated through higher deoxygenation yield of wide variety of azaheterocyclic N‐oxides with reactive functional groups. Robustness of the photocatalytic reduction has been demonstrated through easy scaling‐up of the reaction to gram level without much change in the reaction yield.