C_(sp~3)—F Bond Formation: A Free-Radical Approach

摘要

The importance of fluorine-containing compounds in pharmaceutical and agrochemical industries has significantly grown in recent years because the unique properties of fluorine. The use of ~(18)F-labeled compounds in molecular imaging using positron emission tomography (PET) has also stimulated efforts to find new and selective methods to introduce fluorine onto a carbon framework. While many approaches have been devised to incorporate atomic fluorine using electrophilic and nucleophilic fluorine sources, the formation of a C—F bond by reaction of a C-centered radical with a fluorine source has been restricted to molecular F2, hypofluorites, and XeF2. Although XeF2 has a very efficient fluorine-transfer rate constant (k_(abs) = 1.1 × 10~6m~(-1) s~(-1) for a primary radical) , it is an expensive noble gas, and F2 and hypofluorites are hazardous and exhibit uncontrollable reactivities.