Light-Induced Dealkylation of Benzamides in Aqueous Solution

The N-dealkylation reactions of benzamides occur naturally in living organisms but chemical methods remain poorly developed. So far, light-induced variants of these processes have been restricted to amides containing secondary N-alkyl groups or required pre-functionalization of the starting material. Here, we present a direct, controllable N-dealkylation of tertiary and secondary benzamides possessing primary alkyl substituents at N-atom. The developed strategy operates in aqueous environment under mild conditions involving either blue LEDs or sunlight irradiation. Preliminary mechanistic studies indicate two-step oxidation and the intermediacy of radicals at α-position to N-atom. Selectivity in N-dealkylation of homo- and heterosubstituted tertiary benzamides is also investigated.

National Science Centre, Poland (SONATA 2018/31/D/ST5/00306)