Aryltrifluoromethylsulfoxides: Sulfinylation or Aromatics by Triflinate Salts in Acid Medium

Abstract

Direct sulfinylation reaction of simple aromatic compounds by triflinate salts in triflic acid led to aryltrifluoromethyl sulfoxides. The para isomer was the major one. The regioselectivity of the reaction was very high when the substituent on the aromatic ring was a halogen atom, a trifluoromethoxy group or an acetanilide function.

One-pot synthesis of arylfluoroalkylsulfoxides and study of their anomalous 19F NMR behavior

“…Triflic anhydride and triflic acid were employed as activated reagents instead of commonly used acyl chloride or phosphoryl chloride. According to the literature, this method was effective for trifluoromethanesulfinylation of substituted aromatic compounds [10]. Application of this method to benzene itself, however, resulted in polymeric reactions.…”

“…Wakselman et al consequently improved the method through the preparation of aryltrifluoromethyl sulfoxides from substituted benzenes and triflinates in the triflic acid medium [10]. Triflic anhydride and triflic acid were employed as activated reagents instead of commonly used acyl chloride or phosphoryl chloride.…”

“…These fluorinated sulfoxides were usually synthesized by the oxidation of corresponding sulfides with peracids, a process that is hard to control because a mixture of sulfoxide and sulfone compounds plus the initial sulfide was often obtained. In 2001, Wakselman et al reported that aryltrifluoromethyl sulfoxides could directly be yielded from substituted benzenes and triflinates in the triflic acid medium [10]. Nevertheless, the preparation of other kinds of arylfluoroalkyl sulfoxides by this method is still undocumented.…”

Benchmark and Solvent‐Free Preparation of Sulfonium Salt Based Electrophilic Trifluoromethylating Reagents

“…In this area, we first described the one-pot preparation of aryl trifluoromethyl sulfoxides 6, involving treatment of an aromatic compound with potassium trifluoromethanesulfinate in the presence of trifluoromethanesulfonic acid. [16] In a further improvement, we showed that the simple replacement of the acid by trifluoromethanesulfonic anhydride gave rise directly to sulfonium salts 5 instead of sulfoxides 6 (Scheme 1). [17] Scheme 1.…”

Selective oxidation and chlorination of trifluoromethylsulfide using trichloroisocyanuric acid in ionic liquid

“…For example, electrophilic reaction of substrates with the poorly stable trifluoromethanesulfinate/phosphoryl chloride mixture was limited to electron-rich heterocyclic compounds [11,12]. Expensive triflic acid and triflic anhydride are wasted in the reaction of simple aromatic compounds by triflinate salts [13]. Obviously, to develop a simple and efficient route to synthesis of aryltrifluoromethylsulfoxide under neutral conditions is still a goal.…”