Cyano-Substituted Phenoxazine Moiety as an Organophotoredox Catalyst for C-C, C-B and C-P Coupling Reactions with Aryl Halides

Abstract

Phenoxazine-based organophotoredox catalyst PC-A was prepared using a two-step process starting from 2-(3,5-di-tert-butyl-2hydroxyphenylamino)benzonitrile, with a catalytic amount of MnCl2•4H2O, and finally by substituting the NH proton of the phenoxazine moiety with EtBr. Catalyst PC-A exhibited a reversible oxidation at E1/2 = 0.85 V vs. SCE, with absorption and emission maxima at 380 nm and 475 nm, respectively. It photocatalyzed various C-C, C-B, and C-P bond-forming reactions with redox-inert substrates when excited at 395 nm.12