Discovery of practical production processes for arylsulfur pentafluorides and their higher homologues, bis- and tris(sulfur pentafluorides): Beginning of a new era of “super-trifluoromethyl” arene chemistry and its industry

Abstract

SummaryVarious arylsulfur pentafluorides, ArSF5, have long been desired in both academic and industrial areas, and ArSF5 compounds have attracted considerable interest in many areas such as medicines, agrochemicals, and other new materials, since the highly stable SF5 group is considered a “super-trifluoromethyl group” due to its significantly higher electronegativity and lipophilicity. This article describes the first practical method for the production of various arylsulfur pentafluorides and their higher homologues, bis- and tris(sulfur pentafluorides), from the corresponding diaryl disulfides or aryl thiols. The method consists of two steps: (Step 1) treatment of a diaryl disulfide or an aryl thiol with chlorine in the presence of an alkali metal fluoride, and (step 2) treatment of the resulting arylsulfur chlorotetrafluoride with a fluoride source, such as ZnF2, HF, and Sb(III/V) fluorides. The intermediate arylsulfur chlorotetrafluorides were isolated by distillation or recrystallization and characterized. The aspects of these new reactions are revealed and reaction mechanisms are discussed. As the method offers considerable improvement over previous methods in cost, yield, practicality, applicability, and large-scale production, the new processes described here can be employed as the first practical methods for the economical production of various arylsulfur pentafluorides and their higher homologues, which could then open up a new era of “super-trifluoromethyl” arene chemistry and its applications in many areas.

Effects of substitution on the reactivity of alkyl aryl tetrafluoro-λ6-sulfanes

“…Chloroform-d (D, 99.8%) + (0.05% v/v TMS) was purchased from Cambridge Isotope Laboratories, Inc. The known compounds 3a, b and d were synthesized according to published methods [17]. Compound 1c was generously provided by UBE America, Inc. All reactions were carried out under an inert atmosphere.…”

“…The reactivity of arene tetrafluoro-l 6 -sulfanyl chlorides can be modulated by the selection of arene substituents [17]. The preparation and characterization of alkenyl aryl tetrafluoro-l 6 -sulfanes have only been recently reported [18].…”

Exploration of fluorination reagents starting from FITS reagents

“…However, there had been no practically useful preparative methods. Our extensive studies accomplished the first practical industrial method for the production of ArSF 5 46, which consisted of two-step processes; (1) treatment of a diaryl disulfide 40 or an aryl thiol with chlorine in the presence of an alkali metal fluoride and (2) treatment of the resulting ArSF 4 Cl 45 with a fluoride source such as ZnF 2 , HF, and Sb(III/V) fluorides [115] (Scheme 19). By means of this method, a wide range of ArSF 5 containing electron-donating or withdrawing substituents were prepared.…”

“…By means of this method, a wide range of ArSF 5 containing electron-donating or withdrawing substituents were prepared. This method was also successfully applied to the preparation of bis and tris(SF 5 ) aromatic compounds [115].…”

Synthetic chemistry and biological activity of pentafluorosulphanyl (SF5) organic molecules

“…Subsequent treatment with a fluoride source such as ZnF 2 or Sb(III/V) fluorides effectively produced a displacement of the chlorine atom by fluoride affording the target SF 5 -aryl compounds. Bis-SF 5 -aromatics could be also prepared from the corresponding thiols [72].…”