Perfluoroalkyl Halides as Fluorine-Containing Building Blocks for the Synthesis of Fluoroalkylated Heterocycles

Abstract

The unique chemical and physical advantages conferred by incorporation of F-atoms/perfluoroalkyl groups (Rf) into organic compounds have gained widespread recognition throughout drug discovery, crop protection, polymer chemistry, and materials science. The past decades have witnessed a boom in organofluorine chemistry and heterocyclic chemistry mainly owing to the importance of fluorine-containing heterocycles. As a result, the exploitation of readily available fluorinated building blocks to attach Rf groups to various heterocycles has become an important topic in synthetic chemistry. On the other hand, perfluoroalkyl halide, as a low-toxic and environmentally friendly perfluoroalkyl building block, has been extensively utilized as a unique reagent in the heterocycle construction. Considering the great influence and synthetic potential of these novel avenues, we summarize the recent advances for the synthesis of fluoroalkylated heterocycles by using perfluoroalkyl halides as key fluorine-containing building blocks. One or three C-X bonds of perfluoroalkyl halides are cleaved/functiona- lized during the perfluoroalkylation and cyclization process, and a series of perfluoroalkylated heterocycles such as quinoxalines, phenanthridines, hydrazones, thiazoles, pyrimidines, aza-tricycles, isoxazoles,etc. were synthesized in moderate to good yields. With a specific emphasis on their proposed mechanism, we hope this review will be useful for medicinal and synthetic organic chemists who are interested in radical-mediated perfluoroalkylation.