Application of the Pentafluorosulfanyl Group as a Bioisosteric Replacement

The success of fluorinated molecules in drug design has led medicinal chemists to search for new fluorine‐containing substituents. A major recently developed group is the pentafluorosulfanyl group. This group is stable under physiological conditions and displays unique physical and chemical properties. There are currently few synthetic methods to install the SF5 group, yet efforts to integrate this group into lead optimization continue unabated. Typically, the SF5 group has been used as a replacement for trifluoromethyl, tert‐butyl, halogen, or nitro groups. In this review, the use of the SF5 group as a bioisosteric replacement for each of these three functionalities is compared and contrasted across various groups of biologically active molecules. The organization and presentation of these data should be instructive to medicinal chemists considering to design synthetic strategies to access SF5‐substituted molecules. The distinctive properties of the pentafluorosulfanyl group (SF5) and its metabolic stability have prompted many recent pharmaceutical applications. Owing to its relative novelty, a closer look at the potential uses of the SF5 group in medicinal chemistry is fully warranted. This review focuses on the potential of the SF5 group as a bioisosteric replacement of CF3, tert‐butyl, NO2, and halide groups.