Recent Advances in Radical-Initiated C(sp3)–H Bond Oxidative Functionalization of Alkyl Nitriles

Chemoselective functionalizations of intrinsically less reactive C(sp3)–H bonds of alkyl nitriles are of particular interest to the chemical community because these strategies provide opportunities for the introduction of important cyanoalkyl groups onto target frameworks in a step-economical fashion. In recent years, the introduction of nitrile-containing alkyl radicals in tandem radical additions and oxidative couplings has inarguably brought chemists a new radical reaction platform for the diverse synthesis of natural products and pharmaceuticals. Compared with the wide applications of various C-centered radicals adjacent to a heteroatom, however, nitrile-containing alkyl radicals remain largely unexplored. New methods for C(sp3)–H bond oxidative functionalization of alkyl nitriles and new mechanistic manifolds would result in the development of a broad range of novel reactions. Therefore, this review will give an overview of various types of radical cyanoalkylation using the key alkyl nitrile reactants, which lie beyond traditional coupling chemistry.