Synthetic Methods for Compounds Having CF3–S Units on Carbon by Trifluoromethylation, Trifluoromethylthiolation, Triflylation, and Related Reactions

XeF+MF6− (M As, Sb) reagiert mit (C6F5)2S in HF zu (C6F5)2SF+MF6−/. Die beiden tiefvioletten Sulfoniumsalze sind bei Raumtemperatur bis zu 24 Stunden unzersetzt haltbar.



Das Hexafluoroantimonat kristallisiert in der monoklinen Raumgruppe P21/n mit a = 1056,4(7) pm, b = 1446,3(10) pm, c = 1102,9(8) pm, β = 91,29(6)° und Z = 4. Der SF-Bindungsabstand ist mit 158,4(3) pm ausergewohnlich lang. Kationen und Anionen werden durch interionische Fluor-Kontakte zu einer unendlichen Kette verknupft, in der Kationen und Anionen in einer ABAB-Folge angeordnet sind.



Preparation of (C6F5)2SF+MF6− (M As, Sb) and Crystal Structure of (C6F5)2SF+SbF6−



XeF+MF6− (M As, Sb) reacts with (C6F5)2S in HF to form (C6F5)2SF+MF6−. The deeply violet sulfonium salts can be kept without decomposition up to 24 h at room temperature.



The hexafluoroantimonate salt crystallizes in the monoclinic space group P21/n with a = 1056.4(7) pm, b = 1446.3(10) pm, c = 1102.9(8) pm, β = 91.29(6)° und Z = 4. The SF-bond distance with 158.4(3) pm is of unusual length. Cations and anions are connected via interionic fluorine contacts to an infinite chain, in which cations and anions form to ABAB sequence along the chain.

Synthese von (C6F5)2SF+MF6− (M As, Sb) und Kristallstruktur von (C6F5)2SF+SbF6− [1]

Es werden mehrere Synthesewege fur die Darstellung der Iodsulfonium(IV)-Salze, (CH3)2SI+AsF6− und (CH3)2SI+SbCl6−, angegeben. Diese Salze sind bis −20°C stabil, und sie werden Raman- und NMR-spektroskopisch charakterisiert. \n \n \n \nContributions to the Chemistry of Sulfur Halides. 16. Dimethyliodosulfonium(IV) Salts \n \n \n \nSome preparative methods of iodosulfonium(IV) salts, (CH3)2SI+AsF6− and (CH3)2SI+SbCl6−, are reported. These salts are stable up to −20°C and they are characterized by Raman and n.m.r. spectroscopy.

Beiträge zur Chemie der Schwefelhalogenide. XVI: Dimethyliodsulfonium(IV)-Salze

NMR-Untersuchungen zeigen, das Sulfoniumsalze [(CF3)nSF3−n]+ AsF6− (1−3, n = 0−2) CH3CN addieren unter Bildung ψ-pentakoordinierter Sulfuranoniumionen [(CF3)nSF3−n · NCCH3]+ mit axialstandigem Donor. NSF3 (4,) bildet in Losung die analogen Salze [(CF3)n SF3−n · NSF3]+ AsF6− (1b-3b,) mit schwacherer Donor-Akzeptor-Wechselwirkung. Bei Umsetzungen mit NSF2NMe2 (5,), wird die Stufe der Primarprodukte sehr schnell durchlaufen; unter Fluoridwanderung kommt es mit 1, und 2, zur Bildung von Persulfuranonium-Ionen ([(CH3)2NSF3NSF2]+ (6,) bzw. [(CH3)2NSF3NSFCF3]+ (7,)), wahrend aus der Umsetzung mit 3, nur Zersetzungsprodukte (Me2NSF2+, CF3SSCF3, CF4) erhalten wurden.



On the Lewis Acidity of Fluorinated Sulfonium Ions



NMR investigations show, that sulfonium salts [(CF3)nSF3−n]+ AsF6− (1–3, n = 0–2) add CH3CN under formation of ψ-pentacoordinated sulfuranonium ions [(CF3)nSF3−n · NCCH3]+ (1a – 3a,) with the donor in an axial position. In solution NSF3 (4,) forms similar salts [(CF3)nSF3−n · NSF3]+ AsF6− (1b-3b,) with weaker donor-acceptor interactions. With NSF2NMe2 (5,) the step of the primary addition products is passed very quickly, by fluoride-migration from 1, and 2, persulfuranonium ions [(CH3)2NSF3NSF2]+ (6,) and [(CH3)2NSF3NSFCF3]+ (7,), respectively, are formed, while from 3, only decomposition products (Me2NSF2+, CF3SSCF3, CF4) were obtained.

Untersuchungen zur Lewis-Acidität fluorierter Sulfonium-Ionen†

Synthesis and Reactions of Bis(fluorosulfinyl)difluoromethane, F2C(SOF)2



From F2C(SF3)2 (1) and AsF5 the thermally labile monosulfonium salt F3SCF2SF2+ AsF6− (2) is prepared in SO2 as a solvent, while under the same conditions the corresponding tetrafluoroborate is solvolyzed to give an isomeric mixture of F2C(SOF)2 (5a,b). In the reaction of 5a,b with N-silylated amines F2C[S(O)NMe2]2 (7a,b), 






(8a,b), and 






(9a,b) are formed. The structure of the cis derivative 8b has been determined by X-ray diffraction. From 5a,b and HCl the rather unstable F2C[S(O)Cl]2 (10a,b) is obtained, which is hydrolyzed to F2C[S(O)OH]2 (11a,b).

Synthese und Reaktionen von Bis(fluorsulfinyl)difluormethan, F2C(SOF)2

(Perfluoroalkyl)(dimethylamino)sulfonium Hexafluoroarsenates



MeN = S(CF3)2 (5) is alkylated by Me3O⊕ AsF⊖6 to Me2N-S(CF3)⊕2 AsF⊖6 (4). From 5 and MeOSO⊕ AsF⊖6 (6) MeOS(O)-N(Me)S(CF3)⊕2 AsF⊖6 (7) is formed as a relatively stable primary product. Decomposition of 7 gives the expected 4 only in poor yield. Nucleophilic substitution of the sulfur-bonded fluorine in CF3SF⊕2 AsF⊖6 (8) by Me3SiNMe2 yields CF3S(NMe2)⊕2 AsF⊖6 (9). Similarly, (CF3)2CFSF⊕2 AsF⊖6 (10) reacts with dimethyl(trimethylsilyl)amine to give (CF3)2CFS(NMe2)⊕2 AsF⊖6 (11). The structures of 4 and 9 are elucidated by X-ray analyses, and the influence of the substituents on the bonding is discussed.

Rüdiger

Papers

(Perfluoralkyl)(dimethylamino)sulfonium-hexafluoroarsenate