Progress in C—N Bond Formation Involving C(sp2)—H Bond through Transition-Metal-Free Radical Reactions

The C-N bond is widely found in medicinal molecules, natural products and functional materials.Therefore, it has great significance to develop simple and efficient methods for the construction of C-N bond.Recently, remarkable progress has been made in construction of C-N bond involving C(sp 2 )-H bond through transition-metal-free radical reactions.Due to the relatively mild reaction condition and high reactivity, it provides a novel approach to construct C-N bond.In this review, the recent developments in this area are summarized on the basis of different nitrogen sources.