Direct C-H Functionalization of Heteroarenes via Redox-Neutral Radical Process: A Facile Route to C-C Bonds Formation

Aromatic heterocycles are an important class of compounds found in a wide range of natural products, pharmaceutically active molecules and organic materials. Recently, the direct radical functionalization of heteroaromatic C-H bonds has become an efficient and attractive method to access substituted heteroarenes. Especially, redox-neutral radical reactions have attracted much attention of chemists due to their potential advantages such as mild conditions, free of external oxidants, and good functional group tolerance. So far, a series of redox-neutral radical reactions have been developed. In this review, we mainly focus on the recent advance in direct redox-neutral radical C-H functionalization of heteroarenes. Herein, the direct C-H arylation, C-H alkylation, and C-H fluoroalkylation of heteroarenes are represented respectively, providing practical routes to C-C bond formation. 1 Introduction 2 C-H Arylation of Heteroarenes with Aryl Radicals 3 C-H Alkylation of Heteroarenes with Alkyl Radicals 4 C-H Fluoroalkylation of Heteroarenes with Fluorine-Containing Carbon Radicals 5 Concluding Remarks.