Visible-light-driven photochemical activation of sp³ C-H bond for hemiaminal formation

Photochemical synthesis of organic chemicals has attracted a massive revitalized research interest. A metal-free photochemical system with carbon tetrabromide (CBr4) is here developed for the synthesis of hemiaminal compounds. In this reaction system, the sp3 C-H bond of the N-alkyl group in the amide is photochemically activated, producing an ionic iminium species. The hemiaminal compounds are produced by nucleophilic attack of the iminium ion by alcohol in the presence of base. This photochemical conversion system shows high yield and broad substrate scope