Decatungstate-Photocatalyzed Hydroamidomethylation of Azobenzenes with N,N-Dimethylamides

A photocatalytic hydroamidomethylation of azobenzenes with N,N-dimethylamides has been developed. Using tetrabutylammonium decatungstate (TBADT) as a photocatalyst, an array of azobenzenes and N,N-dimethylamides reacted smoothly under visible light irradiation, affording previously unreported N-amidomethyl-N,N′-diarylhydrazines in generally high yields. Mechanistic studies indicate that the reaction is enabled by TBADT-mediated hydrogen atom transfer (HAT) photocatalysis. This work is fundamentally different from the previously reported reaction of N,N-dimethylformamide with azobenzenes.