Catalyst-Controlled Chemoselective Transformation of Cyanopyridines over Cyanoarenes Enabled by a DATB–Phenothiazine Hybrid Photocatalyst

Abstract

A catalyst-dependent chemoselective photoredox reaction of cyanopyridines and cyanoarenes with N-aryl tertiary amines is described. In competitive reactions under visible-light irradiation, a conventional iridium photocatalyst preferentially promoted coupling of the cyanoarene component, whereas phenothiazine-based catalyst systems, including a DATB–phenothiazine hybrid, favored formation of cyanopyridine-derived products. The cyanopyridine-selective product distribution was observed across several combinations of amines, cyanopyridines, and competing cyanoarenes. These results show that the identity of the photocatalyst can govern the relative substrate preference of closely related cyano(hetero)arene acceptors in photoredox catalysis.