Visible-light-driven α-Oxidation of Amide C(sp3)-H Bonds to Imides via N-Bromosuccinimide and Water

An efficient, metal-free oxidation method of the N-ortho C(sp(3))-H bond of amide via visible-light irradiation has been developed. A broad range of imides can be facilely obtained at room temperature and this protocol is showcased in the gram-scale synthesis. Preliminary mechanistic studies revealed that a hydrogen atom transfer (HAT) process was involved and H2O offered the main oxygen source to achieve greener photochemical C(sp(3))-H oxidation.

Automated summary

A highly efficient metal-free visible-light irradiation oxidation method for N-ortho C(sp(3))-H bonds of amides has been developed. A broad range of imides can be easily obtained at room temperature, and the scalability of this protocol has been demonstrated in gram-scale synthesis. Preliminary mechanistic studies indicate the involvement of a hydrogen atom transfer (HAT) process, where H2O serves as the main oxygen source for greener photochemical C(sp(3))-H oxidation.