Late‐Stage C‐H Functionalization with 2,3,7,8–Tetrafluorothianthrene: Preparation of a Tetrafluorothianthrenium‐Salt

<jats:title>Abstract</jats:title> <jats:p>The C–H functionalization of arenes using 2,3,7,8–tetrafluorothianthrene‐S‐oxide accesses a versatile synthetic lynchpin (aryl tetrafluorothianthrenium salt) in a highly selective manner. This chapter describes the procedure for late‐stage C‐H functionalization with 2,3,7,8–tetrafluorothianthrene and preparation of a tetrafluorothianthrenium‐salt. It presents some of the important points to be considered, the conditions that need to be maintained, characterization data, and the reagents required, as well as the techniques used and the equipment setup that are vital to carrying out the process. The chapter also describes the hazards associated with working with chemicals and the ways to deal with these hazards.</jats:p>