- AgBF4-Mediated Chlorine-Fluorine Exchange Fluorination for the Synthesis of Pentafluorosulfanyl (Hetero)arenes
-
We report a new protocol to form pentafluorosulfanyl (hetero)arenes via chlorine-fluorine exchange of (hetero)aryl tetrafluorosulfanyl chlorides by AgBF4. The method enables access to electron-deficient pentafluorosulfanyl(hetero)arenes, which are targets that are difficult to synthesize. Two advantages of AgBF4 are its ease of handling and stability. This would be a general transformation protocol.
- Tanagawa, Kazuhiro,Zhao, Zhengyu,Saito, Norimichi,Shibata, Norio
-
supporting information
p. 1682 - 1684
(2021/07/19)
-
- Preparation of (Pentafluorosulfanyl)benzenes by Direct Fluorination of Diaryldisulfides: Synthetic Approach and Mechanistic Aspects
-
Direct fluorination of ortho-, meta- and para-substituted aromatic thiols and disulfides using elemental fluorine afforded substituted (pentafluorosulfanyl)benzenes. This work thus represents the first study of the scope and limitation of direct fluorination for the synthesis of new SF5-containing building blocks. Fluorinations in batch and flow modes were compared. A comprehensive computational study was carried out employing density functional and wave function methods to elucidate the reaction mechanism of the transformation of ArSF3 into ArSF5. Eliminating various nonradical pathways, it has been shown that the reaction proceeds by a radical mechanism, initiated by the attack of the F. on the ArSF3 moiety, propagated via an almost barrierless F2+ArSF4 .→ArSF5+F. step and terminated by the ArSF4 .+F.→ArSF5. Most of the calculated data are in very good agreement with experimental observations concerning the ortho-substituent effect on the reaction rates and yields.
- Ajenjo, Javier,Klepetá?ová, Blanka,Greenhall, Martin,Bím, Daniel,Culka, Martin,Rulí?ek, Lubomír,Beier, Petr
-
supporting information
p. 11375 - 11382
(2019/08/20)
-
- Silver-induced self-immolative Cl-F exchange fluorination of arylsulfur chlorotetrafluorides: Synthesis of arylsulfur pentafluorides
-
A novel strategy for the synthesis of arylsulfur pentafluorides by silver carbonate-induced Cl-F exchange fluorination of arylsulfur chlorotetrafluorides is reported. This fluorination does not require any exogenous fluoride sources. Rather, the reaction proceeds via the self-immolation of the substrate Ar-SF4Cl.
- Cui, Benqiang,Jia, Shichong,Tokunaga, Etsuko,Saito, Norimichi,Shibata, Norio
-
p. 12738 - 12741
(2017/12/06)
-
- Synthesis of 4-(pentafluorosulfanyl)benzenediazonium tetrafluoroborate and analogs and their application for the preparation of SF5-aromatics
-
4-(pentafluorosulfanyl)benzenediazonium tetrafluoroborate salt was synthesized and isolated. The pentafluorosulfanyl salt was examined in a wide assortment of reactions to form novel SF5-bearing alkenes, alkynes, and biaryl derivatives using Heck-Matsuda, Sonogashira, and Suzuki coupling protocols. Dediazoniation of the salt furnished the corresponding p-SF5—C6H4X,C6H4OS(O)(CF3)═NSO2CF3, and p-SF5—C6H4-NTf2 derivatives. The azide derivative p-SF5—C6H4N3 entered into click chemistry with phenylacetylenes to furnish the corresponding triazoles. Various SF5-bearing alkenes were synthesized by coupling reactions using a metal catalyst. Fluorodediazoniation selectively furnished the fluoro derivative p-SF5—C6H4F. Homolytic dediazoniation gave the unsymmetrical biaryls, thus demonstrating the broad utility of pentafluorosulfanyl diazonium salts as building blocks of SF5-aromatics that are in high demand in many branches of chemistry including biomedicine and materials chemistry.
- -
-
-
- 4-(Pentafluorosulfanyl)benzenediazonium Tetrafluoroborate: A Versatile Launch Pad for the Synthesis of Aromatic SF5 Compounds via Cross Coupling, Azo Coupling, Homocoupling, Dediazoniation, and Click Chemistry
-
The reagent 4-(pentafluorosulfanyl)benzenediazonium tetrafluoroborate (1) was synthesized and isolated as a stable salt for the first time; its application in a wide assortment of transformations was subsequently investigated. A series of novel SF5-bearing alkenes, alkynes, and biaryl derivatives were synthesized by employing Heck-Matsuda, Sonogashira, and Suzuki coupling protocols. Dediazoniation with TMSX (X = Hal; N3; and CN) and NH4SCN in [BMIM][BF4] as solvent furnished the corresponding p-SF5-C6H4X derivatives. The azide derivative p-SF5-C6H4N3 entered into click chemistry with phenylacetylenes to furnish the corresponding triazoles. The 4,4′-bis(pentafluorosulfanyl)biphenyl was synthesized by homo-coupling using Pd(OAc)2. The corresponding azo compounds were obtained through azo-coupling with reactive aromatic nucleophiles (1,3-dimethoxybenzene, 1,3,5-trimethoxybenzene, 1,2,4-trimethoxybenzene, aniline and phenol). Fluorodediazoniation in [BMIM][PF6] and [BMIM][BF4] selectively furnished the fluoro derivative p-SF5-C6H4F. Dediazoniation in [BMIM][NTf2] gave p-SF5-C6H4OS(O)(CF3)=NSO2CF3 as the major and p-SF5-C6H4-NTf2 as the minor products. Homolytic dediazoniation in MeCN/NaI gave the unsymmetrical biaryls p-SF5-C6H4-Ar (ArH = mesitylene and p-xylene) along with p-SF5-C6H4I. Analysis of the dediazoniation product mixtures indicated that dediazoniation of p-SF5-C6H4N2+ BF4- in low nucleophilicity, highly ionizing, solvents (TfOH, TFE, HFIP, TFAH) is mainly heterolytic, while in MeOH it is mainly homolytic. The isodesmic reaction p-SF5-C6H4+ + R-C6H5 → SF5-C6H5 + p-R-C6H4+ (with R = NO2, CF3, H) was gauged by DFT at various levels and by PCM.
- Okazaki, Takao,Laali, Kenneth K.,Bunge, Scott D.,Adas, Sonya K.
-
p. 1630 - 1644
(2015/10/05)
-
- 4-(Pentafluorosulfanyl)benzenediazonium Tetrafluoroborate: A Versatile Launch Pad for the Synthesis of Aromatic SF5 Compounds via Cross Coupling, Azo Coupling, Homocoupling, Dediazoniation, and Click Chemistry
-
The reagent 4-(pentafluorosulfanyl)benzenediazonium tetrafluoroborate (1) was synthesized and isolated as a stable salt for the first time; its application in a wide assortment of transformations was subsequently investigated. A series of novel SF5-bearing alkenes, alkynes, and biaryl derivatives were synthesized by employing Heck-Matsuda, Sonogashira, and Suzuki coupling protocols. Dediazoniation with TMSX (X = Hal; N3; and CN) and NH4SCN in [BMIM][BF4] as solvent furnished the corresponding p-SF5-C6H4X derivatives. The azide derivative p-SF5-C6H4N3 entered into click chemistry with phenylacetylenes to furnish the corresponding triazoles. The 4,4′-bis(pentafluorosulfanyl)biphenyl was synthesized by homo-coupling using Pd(OAc)2. The corresponding azo compounds were obtained through azo-coupling with reactive aromatic nucleophiles (1,3-dimethoxybenzene, 1,3,5-trimethoxybenzene, 1,2,4-trimethoxybenzene, aniline and phenol). Fluorodediazoniation in [BMIM][PF6] and [BMIM][BF 4] selectively furnished the fluoro derivative p-SF 5-C6H4F. Dediazoniation in [BMIM][NTf 2] gave p-SF5-C6H4OS(O)(CF 3)=NSO2CF3 as the major and p-SF 5-C6H4-NTf2 as the minor products. Homolytic dediazoniation in MeCN/NaI gave the unsymmetrical biaryls p-SF 5-C6H4-Ar (ArH = mesitylene and p-xylene) along with p-SF5-C6H4I. Analysis of the dediazoniation product mixtures indicated that dediazoniation of p-SF 5-C6H4N2+ BF 4- in low nucleophilicity, highly ionizing, solvents (TfOH, TFE, HFIP, TFAH) is mainly heterolytic, while in MeOH it is mainly homolytic. The isodesmic reaction p-SF5-C6H 4+ + R-C6H5 → SF 5-C6H5 + p-R-C6H4 + (with R = NO2, CF3, H) was gauged by DFT at various levels and by PCM. Copyright
- Okazaki, Takao,Laali, Kenneth K.,Bunge, Scott D.,Adas, Sonya K.
-
p. 1630 - 1644
(2014/03/21)
-
- An improved method for the fluorination of arylsulfur chlorotetrafluorides to arylsulfur pentafluorides
-
A new method for the fluorination of arylsulfur chlorotetrafluorides to arylsulfur pentafluorides is described. The reaction is promoted by hydrogen fluoride generated from potassium hydrogen fluoride and trifluoroacetic acid which also serves as a solvent. The reaction is performed under mild conditions and uses substochiometric amounts of potassium hydrogen fluorides in certain cases. Recovery and reuse of trifluoroacetic acid was successfully demonstrated which makes this method safe, simple to use, and atom- and cost-effective.
- Lummer, Katrin,Ponomarenko, Maxim V.,R?schenthaler, Gerd-Volker,Bremer, Matthias,Beier, Petr
-
-
- 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
-
Various 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.
- Umemoto, Teruo,Garrick, Lloyd M.,Saito, Norimichi
-
supporting information; experimental part
p. 461 - 471
(2012/07/01)
-
- INDUSTRIAL METHODS FOR PRODUCING ARYLSULFUR PENTAFLUORIDES
-
Industrial methods for producing arylsulfur pentafluorides are disclosed. Methods include reacting arylsulfur halotetrafluoride with hydrogen fluoride in the absence or presence of one or more additives selected from a group of fluoride salts, non-fluoride salts, and unsaturated organic compounds to form arylsulfur pentafluorides.
- -
-
Page/Page column 21-24
(2012/09/10)
-
- METHODS FOR PRODUCING ARYLSULFUR PENTAFLUORIDES
-
Novel methods for preparing arylsulfur pentafluorides are disclosed. Arylsulfur halotetrafluoride is reacted with a fluoride source under hydrous conditions to form an arylsulfur pentafluoride. The purification method is also disclosed.
- -
-
Page/Page column 41
(2010/04/03)
-
- PROCESS FOR THE PRODUCTION OF FLUORINATED AROMATIC RINGS BY SIMULTANEOUS COOLING AND MICROWAVE HEATED HALOGEN EXCHANGE
-
Shown is an improved method of adding fluorine atoms to aromatic rings, using microwave energy application and simultaneous cooling to enhance the fluorination process. The result is an energy efficient method of microwave-assisted halogen exchange (HALEX) reactions involving chloroaromatics and fluorinating agents, with the result being the addition of fluorine atoms into aromatic rings.
- -
-
Page/Page column 7-8
(2010/02/17)
-
- PROCESS FOR PRODUCING ARYLSULFUR PENTAFLUORIDES
-
Novel processes for preparing arylsulfur pentafluorides are disclosed. Processes include reacting at least one aryl sulfur compound with a halogen and a fluoro salt to form an arylsulfur halotetrafluoride. The arylsulfur halotetrafluoride is reacted with a fluoride source to form a target arylsulfur pentafluoride.
- -
-
Page/Page column 16
(2008/12/07)
-