Katrin Lummer

• The limitation of pentafluoro-λ6-sulfanyl (SF5) sources and building blocks stimulates great interest for investigating new approaches for synthesizing of SF5-containing compounds. The properties of the SF5-group often are compared with those of the CF3-group and the “advantages” of the SF5-group were hence referred to as a “super CF3-function”. In this work, new synthetic routes towards SF5 and CF3 containing aromatics are presented. The first route is the radical addition of SF5Cl and CF3I to double bonds of 7-oxabicyclo[2.2.1]hept-2-ene derivatives, the second approach shows an improved method for the synthesis and followed by fluorination of arylsulfur chlorotetrafluorides to give arylsulfur pentafluorides. Key steps of the synthetic sequence for the first approach were based upon radical addition reactions of SF5Cl or CF3I as sources of SF5- and CF3-groups, to the double bond of different 7-oxabicyclo[2.2.1]hept-2-ene derivatives. Dehydrohalogenation followed by aromatization leads to pentafluorosulfanyl and trifluoromethyl aromatics, respectively. The second synthetic route is the fluorination of arylsulfur chlorotetrafluorides to yield arylsulfur pentafluorides. Treatment of different aryl thiols and diaryl disulfides with chlorine and potassium fluoride provides the corresponding arylsulfur chlorotetrafluorides. The application of new conditions using KHF2 and TFA converts these compounds to arylsulfur pentafluorides.