Читать книгу Methodologies in Amine Synthesis - Группа авторов - Страница 32

The most familiar pathway for C—N bond formation is via the addition of in situ generated N‐radical species to unsaturated carbon‐centered moieties. Visible light photoredox catalysis has provided a large array of methodologies for C—N bond construction, and in major cases, the active N‐radical species are produced by the reductive cleavage of N—X (X = N, O, S, Cl, and Br) bonds via single‐electron transfer (SET) processes, which have already been comprehensively summarized by Xiong and Zhang [6], Xiao and coworkers [7], and Kärkäs [8]. However, unlike the reductive cleavage of weak N—X bonds, direct oxidative scission of strong N—H bonds to form N‐radical species is far more challenging because of their higher bond dissociation energies, which usually requires harsh conditions or strong stoichiometric oxidants.