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1.
Molecules labeled with fluorine‐18 are used as radiotracers for positron emission tomography. An important challenge is the labeling of arenes not amenable to aromatic nucleophilic substitution (SNAr) with [18F]F?. In the ideal case, the 18F fluorination of these substrates would be performed through reaction of [18F]KF with shelf‐stable readily available precursors using a broadly applicable method suitable for automation. Herein, we describe the realization of these requirements with the production of 18F arenes from pinacol‐derived aryl boronic esters (arylBPin) upon treatment with [18F]KF/K222 and [Cu(OTf)2(py)4] (OTf=trifluoromethanesulfonate, py=pyridine). This method tolerates electron‐poor and electron‐rich arenes and various functional groups, and allows access to 6‐[18F]fluoro‐L ‐DOPA, 6‐[18F]fluoro‐m‐tyrosine, and the translocator protein (TSPO) PET ligand [18F]DAA1106.  相似文献   

2.
Treatment of bis(fluoroalkyl) phosphites (RFCH2O)2P(O)H, where RF was CF3 or C2F5 with sulfur in pyridine at 80 °C gave salts of structure [(RFCH2O)2P(O)SH]NC5H5 in 90 and 88% yield, respectively. The salts reacted with alkyl iodides in acetonitrile at 50 °C to furnish bis(fluoroalkyl) S-alkyl phosphorothiolates (RFCH2O)2P(O)SR, where R was Me, Et, n- and i-Pr (when RF = CF3) and Me (when RF = C2F5). Yields ranged from 21 to 57%. Bis(trifluoroethyl) S-methyl phosphorothiolate (CF3CH2O)2P(O)SMe underwent fluorination by silver(I) fluoride in acetonitrile at room temperature to yield the phosphorofluoridate (CF3CH2O)2P(O)F in 75% yield. Tris(fluoroalkyl) phosphorothionates (RFCH2O)3P = S, where RF was CF3, C2F5 and C3F7, were prepared in 30-34% yield by heating the tris(fluoroalkyl) phosphites (RFCH2O)3P and sulfur to 200 °C in a sealed tube for 8 h.  相似文献   

3.
The reaction of H2PtCl6 with fluorobenzene, σ-chlorofluorobenzene and m-chlorofluorobenzene in CF3COOH/H2O affords anionic σ-aryl complexes of platinum(IV). The first two compounds give rise to mixtures of two isomers (meta and para), the latter forms only one isomer (1,3,5-substituted). The 19F NMR spectrum shows that [PtCl4NH3]? group, when bound to fluorobenzene, is an electron donor in both the inductive and resonance senses.  相似文献   

4.
A series of previously unknown asymmetrical fluorinated bis(aryl)bromonium, alkenyl(aryl)bromonium, and alkynyl(aryl)bromonium salts was prepared by reactions of C6F5BrF2 or 4-CF3C6H4BrF2 with aryl group transfer reagents Ar′SiF3 (Ar′ = C6F5, 4-FC6H4, C6H5) or perfluoroorganyl group transfer reagents RF′BF2 (RF = C6F5, trans-CF3CFCF, C3F7C≡C) preferentially in weakly coordinating solvents (CCl3F, CCl2FCClF2, CH2Cl2, CF3CH2CHF2 (PFP), CF3CH2CF2CH3 (PFB)). The presence of the base MeCN and the influence of the adducts RF′BF2·NCMe (RF = C6F5, CF3C≡C) on reactions aside to bromonium salt formation are discussed. Reactions of C6F5BrF2 with AlkF′BF2 in PFP gave mainly C6F5Br and AlkF′F (AlkF′ = C6F13, C6F13CH2CH2), presumably, deriving from the unstable salts [C6F5(AlkF′)Br]Y (Y = [AlkF′BF3]). Prototypical reactivities of selected bromonium salts were investigated with the nucleophile I-and the electrophile H+. [4-CF3C6H4(C6F5)Br][BF4] showed the conversion into 4-CF3C6H4Br and C6F5I when reacted with [Bu4N]I in MeCN. Perfluoroalkynylbromonium salts [CnF2n+1C≡C(RF)Br][BF4] slowly added HF when dissolved in aHF and formed [Z-CnF2n+1CFCH(RF)Br][BF4].  相似文献   

5.
The reactions of the fluoride-ion donor, XeF6, with the fluoride-ion acceptors, M′OF4 (M′=Cr, Mo, W), yield [XeF5]+ and [Xe2F11]+ salts of [M′OF5] and [M2O2F9] (M=Mo, W). Xenon hexafluoride and MOF4 react in anhydrous hydrogen fluoride (aHF) to give equilibrium mixtures of [Xe2F11]+, [XeF5]+, [(HF)nF], [MOF5], and [M2O2F9] from which the title salts were crystallized. The [XeF5][CrOF5] and [Xe2F11][CrOF5] salts could not be formed from mixtures of CrOF4 and XeF6 in aHF at low temperature (LT) owing to the low fluoride-ion affinity of CrOF4, but yielded [XeF5][HF2]⋅CrOF4 instead. In contrast, MoOF4 and WOF4 are sufficiently Lewis acidic to abstract F ion from [(HF)nF] in aHF to give the [MOF5] and [M2O2F9] salts of [XeF5]+ and [Xe2F11]+. To circumvent [(HF)nF] formation, [Xe2F11][CrOF5] was synthesized at LT in CF2ClCF2Cl solvent. The salts were characterized by LT Raman spectroscopy and LT single-crystal X-ray diffraction, which provided the first X-ray crystal structure of the [CrOF5] anion and high-precision geometric parameters for [MOF5] and [M2O2F9]. Hydrolysis of [Xe2F11][WOF5] by water contaminant in HF solvent yielded [XeF5][WOF5]⋅XeOF4. Quantum-chemical calculations were carried out for M′OF4, [M′OF5], [M′2O2F9], {[Xe2F11][CrOF5]}2, [Xe2F11][MOF5], and {[XeF5][M2O2F9]}2 to obtain their gas-phase geometries and vibrational frequencies to aid in their vibrational mode assignments and to assess chemical bonding.  相似文献   

6.
The partial fluorination of polycyclic aromatic hydrocarbons often produces a layered crystal packing, where fluorinated aromatic surfaces are stacked over nonfluorinated aromatic surfaces. Herein, we report the synthesis and crystal packing of partially fluorinated [4]helicenes with steric congestion resulting from H and F atoms in the fjord region. F6‐[4]Helicene forms head‐to‐tail columnar stacks consisting of an alternate arrangement of perfluorinated and nonfluorinated naphthalene moieties. With decreasing fluorine content, aromatic stacking switched from arene?fluoroarene (ArH?ArF) hetero‐stacking to ArH?ArH/ArF?ArF homo‐stacking with the help of intermolecular C?H???F contacts in the fjord region. As a result, head‐to‐head columnar stacks appear. Therefore, the conventional ArH?ArF stacking motif is not always applicable to Fn‐[4]helicenes with twisted π‐surfaces.  相似文献   

7.
The influence of CF3COONa on the acidity function (H 0) and IR spectra of the CF3COOH-N,N-dimethylformamide (DMF)-CF3COONa system ([CF3COOH] ≤ [DMF], [CF3COONa] = 0–3 M) and H 0 of solutions of the salt in 100% CF3COOH ([CF3COONa] = 0–1.2 M) was studied. The addition of the salt to 100% CF3COOH insignificantly changed solution acidity; H 0 passed a minimum at [CF3COONa] = 0.7 M because of the formation of (CF3COO…H…OOCCF3)? anions and destruction of acid associates in the presence of the salt. Changes in the acidity of solutions of CF3COOH in DMF caused by the addition of the salt depended on the n = [CF3COOH]/[DMF] ratio. At n = 1, the salt almost did not influence H 0. At n < 1, a substantial decrease in the acidity of solutions was observed, because the salt increased the degree of proton transfer in CF3COO…H…OC(H)N(CH3)2 quasi-ion pairs solvated by DMF molecules.  相似文献   

8.
The fluorination using TbF4 as fluorinating agent was successfully performed on poly(p-phenylene). The method allows the fluorine content of the polymer to be controlled and the formation of structural defects, such as dangling bonds, to be significantly decreased by comparison with the direct fluorination using pure F2 gas. The aromatic character of the phenyl ring is partly maintained through the fluorination contrary to the direct fluorination (using pure F2 gas), for which a quasi-perfluorination and a partial decomposition of the polymer occur. Complementary analytical techniques have been used, such as 19F and 13C solid state NMR, FT-IR and EPR to compare the samples as a function of the reaction conditions.  相似文献   

9.
The use of 5H-3-oxa-octafluoropentanesulfonyl fluoride (HCF2CF2OCF2CF2SO2F) as a novel and efficient condensing reagent for esterification of carboxylic acids with alcohols and amidation of carboxylic acids with amines in the presence of 1,3-diazabicyclo[5.4.0]-undec-7-ene (DBU) is reported. HCF2CF2OCF2CF2SO2F cannot serve as a condensing agent for anhydridization of carboxylic acids, however, HCF2CF2OCF2CF2SO2F/(CH3)3SiCN system can mediate anhydridization of some aromatic carboxylic acids.  相似文献   

10.
A simple and rapid method for 18F radiolabelling of [GaF3(BnMe2‐tacn)] by 18F/19F isotopic exchange is described. The use of MeCN/H2O or EtOH/H2O (75:25) and aqueous [18F]F? (up to 200 MBq) with heating (80 °C, 10 min) gave 66±4 % 18F incorporation at a concentration of 268 nm , and 37±5 % 18F incorporation at even lower concentration (27 nm ), without the need for a Lewis acid promoter. A solid‐phase extraction method was established to give [Ga18F19F2(BnMe2‐tacn)] in 99 % radiochemical purity in an EtOH/H2O mixture.  相似文献   

11.
The dissolution of (perfluoroorgano)difluoroboranes RFBF2 in anhydrous HF (aHF) resulted in equilibrium mixtures of the starting borane and different kinds of acid‐base products: [H2F] [RFBF2(F · HF)] (RF = C6F5, cis‐C2F5CF=CF, trans‐C4F9CF=CF) or [H2F] [RFBF3] (RF = C6F13). In aHF the aryl compounds C6F5BF2 and K [C6F5BF3] showed two parallel reactivities with XeF2: xenodeborylation (formation of the [C6F5Xe]+ cation) and fluorine addition to the aryl group. In aHF perfluoroalk‐1‐enyldifluoroboranes RFBF2 as well as potassium perfluoroalk‐1‐enyltrifluoroborates K [RFBF3] (RF = cis‐C2F5CF=CF, trans‐C4F9CF=CF) underwent only fluorine addition across the carbon‐carbon double bond under the action of XeF2. Potassium perfluorohexyltrifluoroborate K [C6F13BF3] did not react with XeF2 in aHF.  相似文献   

12.
To evaluate the suitability of [18F]perchorylfluoride [18F]FClO3 as an electrophilic fluorination agent for the preparation of radiopharmaceuticals, the reactivity non-radioactive FClO3 towards 4-substituted trimethyltin aromatic compounds was studied. Contrary to the expectation, an electrophilic fluorination of the aromatic nucleus did not occur. The reaction of perchlorylfluoride with aromatic trimethylstannyl compounds resulted in the formation of trimethyltin fluoride and the respective destannylated aromatics in variable yields.  相似文献   

13.
Electron-impact studies of diazadiphosphetidines,[YF2PNMe]2(Y? F,Me, Ph, MeO,2,5-Me2C6H3, and m-CF3C6H4) are reported, the most abundant fragments corresponding to m/e [M/2–1]+, [M/2]+ and [M/2–1]+. It is concluded from metastable data that formation of the noval rearrangement ion, [M]+→[M/2+1]+is predominantly due to an electron-impact process. Variable temperature spectra of(F3PNMe)2, (i.e. for Y=F), suggest that ions of m/e [M/2-1]+are formed, in part, by a thermal process. For the compound [(m-CF3C6H4)F2PNMe]2 a well resolved negative ion spectrum has been obtained, with the molecular ion present in 100% abundance.  相似文献   

14.
The molecules ArFXeF (ArF=C6F5, 2,4,6-C6H2F3) with a more polar Xe-F bond than XeF2 are versatile starting materials for substitution reactions. Fluorine-aryl substitutions with Cd(ArF)2, C6F5SiMe3/[F], and C6F5SiF3 formed symmetric and/or asymmetric diarylxenon compounds. Applying C6F5BF2, with a higher F-affinity than the corresponding aryltrifluorosilane, in contrast gave the salt [RXe] [ArFBF3]. Using the alkenyl and alkyl compounds CF2=CFSiMe3/[F], CF3SiMe3/[F], and Cd(CF3)2 in reactions with C6F5XeF, the perfluoroalkenyl or -alkyl transfer reagents were consumed without observing C6F5XeCF=CF2 or C6F5XeCF3 but the formation of Xe(C6F5)2 (dismutation product) and in the latter case C6F5CF3 (coupling product), gave hints of the desired intermediates.  相似文献   

15.
Bis(fluorbenzoyloxy)methyl phosphane oxides CH3P(O)[OC(O)R]2 [R = C6H42F (1), C6H43F (2), C6H44F (3), C6H32,6F2 (4), C6H2,3,5,6F4 (5)] were prepared by treating silver salts of carboxylic acids AgOC(O)R with CH3P(O)C?2 (IR-, 1H-, 19?F-and 31P{1H}-NMR-data). The mixed anhydrides 1–5 show unusual thermal stability at room temperature. Stability against hydrolysis decreases with increasing number of fluorine-atoms. The reaction of R′P(O)C?2 [R′ = CH3, C6H5, (CH3)3C] with MIOC(O)RF [RF = CF3, C2F5, C6F5; MI = AgI, NaI T?I] was investigated.  相似文献   

16.
Molten mixtures of XeF6 and CrVIOF4 react by means of F2 elimination to form [XeF5][Xe2F11][CrVOF5] ⋅ 2 CrVIOF4, [XeF5]2[CrIVF6] ⋅ 2 CrVIOF4, [Xe2F11]2[CrIVF6], and [XeF5]2[CrV2O2F8], whereas their reactions in anhydrous hydrogen fluoride (aHF) and CFCl3/aHF yield [XeF5]2[CrV2O2F8] ⋅ 2 HF and [XeF5]2[CrV2O2F8] ⋅ 2 XeOF4. Other than [Xe2F11][MVIOF5] and [XeF5][MVI2O2F9] (M=Mo or W), these salts are the only Group 6 oxyfluoro-anions known to stabilize noble-gas cations. Their reaction pathways involve redox transformations that give [XeF5]+ and/or [Xe2F11]+ salts of the known [CrVOF5]2− and [CrIVF6]2− anions, and the novel [CrV2O2F8]2− anion. A low-temperature Raman spectroscopic study of an equimolar mixture of solid XeF6 and CrOF4 revealed that [Xe2F11][CrVIOF5] is formed as a reaction intermediate. The salts were structurally characterized by LT single-crystal X-ray diffraction and LT Raman spectroscopy, and provide the first structural characterizations of the [CrVOF5]2− and [CrV2O2F8]2− anions, where [CrV2O2F8]2− represents a new structural motif among the known oxyfluoro-anions of Group 6. The X-ray structures show that [XeF5]+ and [Xe2F11]+ form ion pairs with their respective anions by means of Xe- - -F–Cr bridges. Quantum-chemical calculations were carried out to obtain the energy-minimized, gas-phase geometries and the vibrational frequencies of the anions and their ion pairs and to aid in the assignments of their Raman spectra.  相似文献   

17.
Four new [H3tren]3+ or [H4tren]4+ fluoride zirconates and two new [H3tren]3+ fluoride tantalates are evidenced in the (ZrF4 or Ta2O5)-tren-HFaq.-ethanol systems at 190 °C: the structurally related phases [H4tren]·(Zr2F12)·H2O and α-[H4tren]·(Zr2F12) (P212121), β-[H4tren]·(Zr2F12) (P21/c), [H3tren]4·(ZrF8)3·4H2O (I23), β-[H3tren]2·(Ta3O2F16)·(F) (R32) and its monoclinic distortion α-[H3tren]2·(Ta3O2F16)·(F) (C2/m). α and β-[H4tren]·(Zr2F12) and [H4tren]·(Zr2F12)·H2O are built up from (Zr2F12) dimers of edge sharing ZrF7 polyhedra while isolated ZrF8 dodecahedra are found in [H3tren]4·(ZrF8)3·4H2O. Linear (Ta3O2F16) trimers build α and β-[H3tren]2·(Ta3O2F16)·(F); they consist of two (TaOF6) pentagonal bipyramids that are linked to two opposite oxygen atoms of one central (TaO2F4) octahedron. A disorder affects the equatorial fluorine atoms of the trimers and eventually carbon or nitrogen atoms of [H3tren]3+ cations.  相似文献   

18.
Dimethyl phosphorochloridate reacted with RFCH2NH2 in ether in the presence of Et3N to afford (MeO)2P(O)NHCH2RF, where RF = CF3 and C2F5, in 39 and 47% yield, respectively. Similar reactions with di-n-propyl and diisopropyl phosphorochloridates could be effected only with H2NCH2CF3 when 4-dimethylaminopyridine catalyst was added and (n-PrO)2P(O)NHCH2CF3 and (i-PrO)2P(O)NHCH2CF3 were isolated in 49 and 25% yield, respectively. Treatment of POCl3 with one molar equivalent each of H2NCH2CF3 and Et3N permitted the synthesis of Cl2P(O)NHCH2CF3 in 43% yield. Bis(fluoroalkyl) phosphorochloridates (RFO)2P(O)Cl, where RF = C2F5CH2, C3F7CH2 and (CF3)2CH, reacted with 2,2,2-trifluoroethylamine and 2,2,3,3,3-pentafluoropropylamine to furnish phosphoramidates (RFO)2P(O)NHCH2R, where R = CF3 or C2F5, in yields of 32-67%.  相似文献   

19.
K3InF6 is synthesized by a sol-gel route starting from indium and potassium acetates dissolved in isopropanol in the stoichiometry 1:3, with trifluoroacetic acid as fluorinating agent. The crystal structures of the organic precursors were solved by X-ray diffraction methods on single crystals. Three organic compounds were isolated and identified: K2InC10O10H6F9, K3InC12O14H4F18 and K3InC12O12F18. The first one, deficient in potassium in comparison with the initial stoichiometry, is unstable. In its crystal structure, acetate as well as trifluoroacetate anions are coordinated to the indium atom. The two other precursors are obtained, respectively, by quick and slow evaporation of the solution. They correspond to the final organic compounds, which give K3InF6 by decomposition at high temperature. The crystal structure of K3InC12O14H4F18 is characterized by complex anions [In(CF3COO)4(OHx)2](5−2x)− and isolated [CF3COOH2−x](x−1)− molecules with x=2 or 1, surrounded by K+ cations. The crystal structure of K3InC12O12F18 is only constituted by complex anions [In(CF3COO)6]3− and K+ cations. For all these compounds, potassium cations ensure only the electroneutrality of the structure. IR spectra of K2InC10O10H6F9 and K3InC12O12F18 were also performed at room temperature on pulverized crystals.  相似文献   

20.
Syntheses and NMR Spectroscopic Ivestigations of Salts containing the Novel Anions [PtXn(CF3)6‐n]2— (n = 0 ‐ 5, X = F, OH, Cl, CN) and Crystal Structure of K2[(CF3)2F2Pt(μ‐OH)2PtF2(CF3)2]·2H2O The first syntheses of trifluoromethyl‐complexes of platinum through fluorination of cyanoplatinates are reported. The fluorination of tetracyanoplatinates(II), K2[Pt(CN)4], and hexacyanoplatinates(IV), K2[Pt(CN)6], with ClF in anhydrous HF leads after working up of the products to K2[(CF3)2F2Pt(μ‐OH)2PtF2(CF3)2]·2H2O. The structure of the salt is determined by a X‐ray structure analysis, P21/c (Nr. 14), a = 11.391(2), b = 11.565(2), c = 13.391(3)Å, β = 90.32(3)°, Z = 4, R1 = 0.0326 (I > 2σ(I)). The reaction of [Bu4N]2[Pt(CN)4] with ClF in CH2Cl2 generates mainly cis‐[Bu4N]2[PtCl2(CF3)4] and fac‐[Bu4N]2[PtCl3(CF3)3], but in contrast that of [Bu4N]2[Pt(CN)6] with ClF in CH2Cl2 results cis‐[Bu4N]2[PtX2(CF3)4], [Bu4N]2[PtX(CF3)5] (X = F, Cl) and [Bu4N]2[Pt(CF3)6]. In the products [Bu4N]2[PtXn(CF3)6‐n] (X = F, Cl, n = 0—3) it is possibel to exchange the fluoro‐ligands into chloro‐ and cyano‐ligands by treatment with (CH3)3SiCl und (CH3)3SiCN at 50 °C. With continuing warming the trifluoromethyl‐ligands are exchanged by chloro‐ and cyano‐ligands, while as intermediates CF2Cl and CF2CN ligands are formed. The identity of the new trifluoromethyl‐platinates is proved by 195Pt‐ and 19F‐NMR‐spectroscopy.  相似文献   

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