In recent years, the photochemical organic transformation promoted by visible light has aroused the interest of organic chemists. Compared with traditional methods, photoredox catalysis using visible light as renewable energy has been proved to be a mild and powerful tool, which can promote the activation of organic molecules by single electron transfer (SET) process. There are a lot of amino functional groups in the structures of many natural products, and amino groups are also important structural units of some drug molecules and functional materials. Therefore, by activating the C—N bond in these substances and carrying out some coupling reactions of C—C bond formation, the structure of these compounds can be effectively modified, so as to obtain compounds with various structures and functionalization. Therefore, this study has become an important research field of organic synthesis. The research results of C—N bond breaking promoted by visible light and its application in the study of C—C bond formation reaction in recent years are reviewed, and representative examples and reaction mechanisms are discussed.

Key words: diazonium salt, ammonium salt, Katritzky salt, photocatalysis, C—N bond fracture, C—C bond formation, research progress