Recent Progress in Transition Metal-Free C-Heteroatom Bond Formation by Functionalization of C-H Bond in Imidazole-Fused Heterocycles

Recently, the direct incorporation of heteroatom into imidazole-fused heterocycles through transition metal-free C-H functionalization has rapidly been advanced and become an eco-friendly synthetic tool for the synthesis of functionalized natural or bioactive molecules such as (hetero)arenes, olefins, carbonyl compounds. In particular, the C-H functionalization of imidazole-fused heterocycles has been considered to be the most important since it can lead to a new class of biologically active compounds. The recent progress in the incorporation of heteroatom into imidazole-fused heterocycles through transition metal-free C-H functionalization is introduced, and their mechanisms from a new perspective are also elaborated.