Amination of Phenols and Halophenols via Pyridinium–Iridium Dual Photocatalysis

Abstract

In this study, we present a photochemical method for the amination of phenols (C–H) and halophenols (S_NAr), facilitated by dual catalytic pathways involving both Ir(III) photocatalysis and phenol–pyridinium electron donor–acceptor complexation. By incorporating a pyridinium additive, we achieved efficient C–N coupling between phenols and diverse aromatic nitrogen nucleophiles, delivering high yields (up to 99%) across a wide range of substrates, including pharmaceuticals and natural products. We investigate reaction selectivity and substrate compatibility/limitations through a combination of experimental and computational techniques. Moreover, we highlight the synthetic versatility of the amination products through various late-stage functionalizations including the grafting of two different heteroarenes onto one phenol scaffold.