Aryl trifluoromethyl sulfides

An alumina-supported trifluoromethylthiocopper reagent gave improved yields of trifluoromethyl aryl sulfides in coupling reactions with this reagent [26 ] (equation 184). 

Silver(I) trifluoromethanethiolate (AgSCF3) has been used to prepare trifluoromethyl aryl sulfides by reaction with iodide.996 A mixed silver-zinc thiolate complex [Ag4Zn2(SC6H2-Pr -2,4,6)6(OTf)2] has been prepared by reaction of AgOTf with Zn[N(TMS)2]2 in the presence of the thiol.99 Solid-state 109Ag NMR can be a sensitive environment probe for silver thiolates,998 overall for biological thiolates ligands as cysteine,999 or proteins such as metallothionein.1000,1001... 

The reaction of trifluoromethyl iodide with arene thiolates provides trifluoromethyl aryl sulfides via a single electron transfer (SET) reaction rather than the SN2 reaction, which is the only formal mechanism (Scheme 2.31). In general, perfluoroalkyl (Rf—X), ferf-alkyl, and vinyl and aromatic halides are strongly deactivated for the replacement of halogens with... 

Trifluoromethyl aryl sulfides. The preparation of these substances from aryl halides requires a Cu(I)-catalyzed reaction with sulfur and methyl fluorosulfonyldi-fluoroacetate in HMPA or A(-methylpyrrolidinone. 

Clark JH, Tavener SJ (1997) The preparation of trifluoromethyl aryl sulfides using KF and thiophosgene. J Fluorine Chem 85 169-172. doi 10.1016/S0022-1139(97)00057-2... 

Quiclet-Sire B, Saicic RN, Zard SZ (1996) Convenient synthesis of trifluoromethyl aryl sulfides. Tetrahedron Lett 37 9057-9058. doi 10.1016/80040-4039(96)02127-2... 

Another way to prepare fluorinated sulfides is the photochemical alkylation of sulfides or disulfides by perfluoroalkyl iodides [69, 70, 71] (equations 62-64). Reaction of trifluoromethyl bromide with alkyl or aryl disulfides in the presence of a sulfur dioxide radical anion precursor, such as sodium hydroxymethanesulfi-nate, affords trifluoromethyl sulfides [72] (equation 65). 

Bromination of the enol ether product with two equivalents of bromine followed by dehydrobromination afforded the Z-bromoenol ether (Eq. 79) which could be converted to the zinc reagent and cross-coupled with aryl halides [242]. Dehydrobromination in the presence of thiophenol followed by bromination/dehydrobromination affords an enol thioether [243]. Oxidation to the sulfone, followed by exposure to triethylamine in ether, resulted in dehydrobromination to the unstable alkynyl sulfone which could be trapped with dienes in situ. Alternatively, dehydrobromination of the sulfide in the presence of allylic alcohols results in the formation of allyl vinyl ethers which undergo Claisen rearrangements [244]. Further oxidation followed by sulfoxide elimination results in highly unsaturated trifluoromethyl ketonic products (Eq. 80). 

In contrast to aryl trichloromethyl ethers (see Section 12.1.2.), the replacement of chlorine atoms by fluorine in aryl trichloromethyl sulfides using antimony(III) fluoride (or hydrogen fluoride) proceeds under milder conditions, without a catalyst. Various substituents in the aromatic ring have little effect on the halogen exchange. The yields of aryl trifluoromethyl sulfides are 60 to 90% (see Table 1). 

An oxygen bound to a trifluoromethyl group has much less effect upon its chemical shift than a chlorine substituent. Thus, the fluorines of trifluoromethyl ethers (—58 ppm) are not as deshielded as those of CF3C1 (—28 ppm). Those of CF3 sulfides and selenides are deshielded still further (—42 and -37 ppm, respectively). Also, aryl and alkyl trifluoromethyl ethers have similar fluorine chemical shifts, as do aryl and alkyl trifluoromethyl sulfides. 

Aryl trichloromethyl sulfides are readily fluorinated with antimony(Ill) fluoride or hydrogen fluoride to give the corresponding trifluoromethyl sulfides in good yield (Tabic 17) 00-zo ... 

Table 17. Aryl Trifluoromethyl Sulfides by Fluorination of Aryl Trichloromethyl Sulfides Using Antimony(lll) Fluoride...

Alkyl, aryl, and uiisaturated aldehydes can be transformed to the corresponding (x-trifluoro-mcthylated alcohols in 86-96% yield by trifluoromethylation of the aldehydes with sodium triethylgermanidc/phenyl trifluoromethyl sulfide. ... 

A new preparation of aryl trifluoromclhyl sulfides, e.g. 35, has been described from 4-nilro-benzenesulfenyl chlorides and trimethyl(trifluoromethyl)silanc in the presence of a source of anhydrous fluoride anions. 

Thermal reaction of potassium trifluoroacetate with diaryl disulfides 30 is a useful method for effecting the synthesis of aryl trifluoromethyl sulfides 31 (see Table 3), ... 

Table 4. Aryl Trifluoromethyl Sulfides 3 from Copper Trifluoromethanethiolate and Aryl Halides "...

Trifluoromethyl sulfides. The reagent (1) reacts with aryl and heteroaryl iodides in N-methylpyrrolidone, quinoline, or DMF to form trifluoromethyl sulfides ... 

Aryl trifluoromethyl sulfides. Heating mixtures of CFjCOOK and diaryl disulfides constitutes a simple preparation of the sulfides. 

Aryl triftuoromethyl sulfides, The reagent, which can be prepared in situ, reacts with aryl bromides and iodides to form aryl trifluoromethyl sulfides (DMF, HMPT 100-160°) in about 80-100% yield. 

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