Photo-induced metal-free dehydrogenative N-N homo-coupling

We report a photo-induced dehydrogenative N-N coupling of diarylimines, diarylamines, carbazoles, and anilines. These homo-coupling reactions require only the combination of readily available di-tert-butyl peroxide (DTBP) and light irradition. The operationally simple protocol works under catalyst- and metal-free conditions and exhibits a good substrate scope. Preliminary mechanistic studies indicate that the reaction proceeds via photo-induced homolytic cleavage of the peroxide followed by hydrogen atom transfer leading to the formation of N-centered radicals.