Photochemical Synthesis of Anilines via Ni-Catalyzed Coupling of Aryl Halides with Ammonium Salts

Easy, efficient, and economic synthesis of anilines remains an important challenge in synthetic chemistry. In this study, a Ni(OAc)2-bipyridine complex is shown to readily catalyze the amination of aryl halides with ammonium salts under direct excitation of light, allowing a broad array of aryl chlorides and bromides to be converted into the corresponding primary (hetero)arylamines in the absence of an external photosensitizer. Late-stage modification of drug molecules and 15N-labeling of primary aryl amines are also demonstrated with a number of examples. Photoinduced generation of Ni(I)-bipyridine species is believed to be the key step in the reaction, enabling a Ni(I)/Ni(III) cycle for catalytic turnover.

Automated summary

This study demonstrates an easy, efficient, and economic method for synthesizing anilines. By directly exciting light, the amination of aryl halides with ammonium salts can be catalyzed using a Ni(OAc)2-bipyridine complex, allowing a broad range of aryl chlorides and bromides to be converted into primary (hetero)arylamines without the need for an external photosensitizer. The photoinduced generation of Ni(I)-bipyridine species is believed to play a key role in this catalytic cycle.