New fluorinated polysiloxanes containing an ester function in the spacer. I. Synthesis and characterization

Unsaturated perfluoroalkyl esters derived from undecylenic acid: CH₂?CH? (CH₂)₈? COO? CH₂? CH₂? R_F (with R_F?C₆F₁₃, 2a and R_F?C₈F₁₇, 2b ) and C₈F₁₇? (CH₂)₁₀? COO? CH₂? CH?CH₂, 2c were prepared with excellent yields. Their hydrosilylation by methylhydrodimethylsiloxane copolymers of various Si? H contents gives new fluorinated polysiloxanes which were examined by ¹H- and ¹³C-NMR, GPC, differential scanning calorimetry, and optical polarizing microscopy. Polymers derived from compounds 2a and 2b exhibit mesomorphic structures. © 1994 John Wiley & Sons, Inc.     

Single‐Step Gas‐Phase Polyperfluoroalkylation of Naphthalene Leads to Thermodynamic Products

High‐temperature gas‐phase, solvent‐ and catalyst‐free reaction of naphthalene with an excess of R_FI reagent (R_F?CF₃, C₂F₅, n‐C₃F₇, and n‐C₄F₉) was used for the first time to produce a series of highly perfluoroalkylated naphthalene products NAPH(R_F)_n with n=2–5. Four 95+ % pure 1,3,5,7‐NAPH(R_F)₄ with R_F?CF₃, C₂F₅, n‐C₃F₇, and n‐C₄F₉ were isolated using a simple chromatography‐free procedure. These new compounds were fully characterized by ¹⁹F and ¹H NMR spectroscopy, X‐ray crystallography (for R_F?CF₃ and C₂F₅), atmospheric‐pressure chemical ionization mass spectrometry, and cyclic and square‐wave voltammetry. DFT calculations confirm that the proposed synthesis yields the most stable isomers that have not been accessed by alternative preparation techniques.     

Synthesis of symmetric and dissymetric bisperfluoroalkanesulfonylimides and evaluation of their inhibition on bovine carbonic anhydrase

This study describes a synthesis of symmetric and dissymmetric bis[(perfluoroalkane)‐sulfonyl]imides by the reaction of the sodium salt of perfluoroalkanesulfonamide R_FSO₂NH⁻Na⁺ (R_F = C₄F₉, C₆F₁₃, C₈F₁₇) with hexamethyldisilazane and perfluoroalkanesulfonylfluoride R_FSO₂F (R_F = C₄F₉, C₆F₁₃, C₈F₁₇). They are obtained, in two steps, in moderate overall yield. Moreover, this paper provides a study of their inhibition on bovine carbonic anhydrase. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:542–548, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20452     

Ein Neuer Syntheseweg für Perfluororganomangan- und -rhenium-Verbindungen

A New Synthesis of Perfluoroorgano Manganese and Rhenium Compounds Pentacarbonyl perfluoroorgano manganese and rhenium compounds M(CO)₅R_f (M = Mn, Re; R_f = CF₃, C₂F₅, C₃F₇, C₄F₉, C₆F₁₃, C₆F₅) are formed as colourless solids or liquids in good yields from the reactions of M(CO)₅Br with Cd(R_f)₂ complexes in CH₂Cl₂ either in the presence of stoichiometric amounts of Ag[BF₄] or catalytic amounts of CuI. In the presence of e. g. CH₃CN the mono or disubstituted complexes M(CO)₄(CH₃CN)R_f or M(CO)₃(CH₃CN)₂R_f are formed.     

Synthesis of block cotelomers involving a perfluorinated chain and a hydrophilic chain. II. Use of fluorinated telogens with iodine or thiol end groups

Radical acrylamide telomerization was carried out with three fluorinated telogens, C₆F₁₃C₂H₄I, C₆F₁₃I, and C₆F₁₃-C₂H₄SH with AIBN as initiator. Transfer constants were determined to be 40 × 10^?4, 550 × 10^?4, and 6500 × 10^?4, respectively. Reactions were carried out in butyronitrile, a solvent which also transfers to the growing chain. In the telomerization, the intervention of the solvent, whose transfer constant was also determined, is evaluated quantitatively. Thus the formation of side products, which may reach proportions on the order of 50% compared with the telomer expected, can be explained.     

Synthesen und Eigenschaften von Bis(perfluoralkyl)zink‐Verbindungen

Syntheses and Properties of Bis(perfluoroalkyl)zinc Compounds The conditions for the syntheses of bis(perfluoroalkyl)zinc compounds Zn(R_f)₂ · 2 D (R_f = C₂F₅, n‐C₃F₇, i‐C₃F₇, n‐C₄F₉, n‐C₆F₁₃, n‐C₇F₁₅, and n‐C₈F₁₇; D = CH₃CN, tetrahydrofurane, dimethylsulfoxide) are described. Mass spectra, thermal decompositions, ¹⁹F‐ and ¹³C‐NMR spectra are discussed.     

Synthesis and coordination chemistry of perfluoroalkyl-derivatised β-diketonates

A series of fluorinated β-diketones, R_fC(O)CH₂C(O)R_f′ (R_f=C₆F₁₃, R_f′=CF₃; R_f=R_f′=C₆F₁₃, C₇F₁₅), have been prepared in reasonable yields by a two-step synthesis. On reaction with appropriate metal substrates, deprotonation and concurrent coordination of the perfluoroalkyl-derivatised β-diketonate ligands affords a range of fluorous metal complexes which have been characterised by elemental analysis, mass spectrometry, IR and NMR spectroscopies. The structures of [Cu(L-L)₂(H₂O)₂] {L-L=CF₃C(O)CHC(O)C₆F₁₃, C₆F₁₃C(O)CHC(O)C₆F₁₃} and [Cu(PPh₃)₂{C₇F₁₅C(O)CHC(O)C₇F₁₅}] have been determined by single-crystal X-ray diffraction.     

Synthesen und Eigenschaften von Tetrakis(perfluoralkyl)tellur Te(Rf)4 (Rf = CF3, C2F5, C2F5, C3F7, C4F9)

Synthesis and Properties of Tetrakis(Perfluoroalkyl)Tellurium Te(R_f)₄ (R_f = CF₃, C₂F₅, C₃F₇, C₄F₉) Te(CF₃)₄ is obtained from the reaction of Te(CF₃)Cl₂ with Cd(CF₃)₂ complexes as a complex with e. g. CH₃CN, DMF. It is a light and temperature sensitive hydrolysable liquid. The reaction with fluorides yields the complex anion [Te(CF₃)₄F]⁻, with fluoride ion acceptors the complex cation [Te(CF₃)₃]⁺. With traces of water an acidic solution is formed. Te(CF₃)₄ acts as a trifluoromethylation reagent. The reaction with XeF₂ gives hints for the formation of Ye(CF₃)₄F₂. Properties and NMR spectra are discussed. The much more stable complexes of Te(R_f)₄ (R_f = C₂F₅, C₃F₇, C₄F₉) are formed from the reaction of TeCl₄ with the corresponding Cd(R_f)₂ complexes.     

The preparations and properties of tris(perfluoroorgano)bismuth compounds Bi(Rf)3 (Rf = CF3, C2F5, n-C3F7, n-C4F9, n-C6F13, n-C8 F17, C6F5)

Tris(perfluoroorgano)bismuth compounds Bi(R_f)₃ (R_f = CF₃, C₂F₅, n-C₃F₇, n-C₄F₉, n-C₆F₁₃, n-C₈F₁₇, C₆F₅) are easily prepared in high yields from the reactions of perfluoroorganocadmium complexes with BiCl₃, or BiBr₃ in aprotic solvents. The perfluoroorganobismuth halides intermediates in these reactions have been detected by NMR spectroscopy.     

New types of asymmetrical bromonium salts [RF(RF′)Br]Y where RF and/or RF′ represent perfluorinated aryl, alkenyl, and alkynyl groups

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 R_F′BF₂ (R_F = 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 R_F′BF₂·NCMe (R_F = C₆F₅, CF₃C≡C) on reactions aside to bromonium salt formation are discussed. Reactions of C₆F₅BrF₂ with Alk_F′BF₂ in PFP gave mainly C₆F₅Br and Alk_F′F (Alk_F′ = C₆F₁₃, C₆F₁₃CH₂CH₂), presumably, deriving from the unstable salts [C₆F₅(Alk_F′)Br]Y (Y = [Alk_F′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 [C_nF_2n+1C≡C(R_F)Br][BF₄] slowly added HF when dissolved in aHF and formed [Z-C_nF_2n+1CFCH(R_F)Br][BF₄].     

Bis(fluorbenzoyloxy)methylphosphanoxide

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 M^IOC(O)R_F [R_F = CF₃, C₂F₅, C₆F₅; M^I = Ag^I, Na^I T?^I] was investigated.     

Aryl(pentafluorphenyl)iodoniumtetrafluoroborate: allgemeine Synthesemethode,typische Eigenschaften und strukturelle Gemeinsamkeiten

Pentafluorophenyliodine(III) Compounds. 4 [1] Aryl(pentafluorophenyl)iodoniumtetrafluoroborates: General Method of Synthesis, Typical Properties, and Structural Features Aryl(pentafluorophenyl)iodoniumtetrafluoroborates [Ar′Ar″I][BF₄] (Ar′ = C₆F₅, Ar″ = C₆H₅, o‐C₆H₄F, m‐C₆H₄F, p‐C₆H₄F, 2,6‐C₆H₃F₂, 3,5‐C₆H₃F₂, 2,4,6‐C₆H₂F₃, 3,4,5‐C₆H₂F₃, C₆F₅) are prepared in good yields and high purity by the reaction of C₆F₅IF₂ with Ar″BF₂ in CH₂Cl₂. This convenient method can be applied generally to many iodonium compounds. Thermal and spectroscopic properties (¹H, ¹³C, ¹⁹F NMR, IR, Raman) are reported and discussed. The solid state structures of six iodonium compounds show significant cation‐anion interactions which result in two different arrangements: a dimer with a 8‐membered ring or polymers with infinite zigzag chains. Ab initio calculations on prototypes of aryliodonium cations show relations between the kind of the aryl group (C₆H₅ vs. C₆F₅) and structural parameters as well as charges. By means of ¹⁹F NMR the σ_I‐ and σ_R‐constants of the [C₆F₅I]⁺‐substituent are determined.     

New synthesis of polyfluoroalkanesulfonylureas

This study describes a new synthesis of F-alkanesulfonyl ureas by reaction of the sodium salt of perfluoroalkane sulfonamide (R_F = C₄F₉, C₆F₁₃) with some isocyanates in anhydrous THF. The perfluorinated sulfonylureas are obtained, in one step, from moderate to good yields.     

Magnitude and origin of the attraction and directionality of the halogen bonds of the complexes of C6F5X and C6H5X (X = I, Br, Cl and F) with pyridine

The geometries and interaction energies of complexes of pyridine with C₆F₅X, C₆H₅X (X=I, Br, Cl, F and H) and R_FI (R_F=CF₃, C₂F₅ and C₃F₇) have been studied by ab initio molecular orbital calculations. The CCSD(T) interaction energies (E_int) for the C₆F₅X–pyridine (X=I, Br, Cl, F and H) complexes at the basis set limit were estimated to be ?5.59, ?4.06, ?2.78, ?0.19 and ?4.37 kcal mol^?1, respectively, whereas the E_int values for the C₆H₅X–pyridine (X=I, Br, Cl and H) complexes were estimated to be ?3.27, ?2.17, ?1.23 and ?1.78 kcal mol^?1, respectively. Electrostatic interactions are the cause of the halogen dependence of the interaction energies and the enhancement of the attraction by the fluorine atoms in C₆F₅X. The values of E_int estimated for the R_FI–pyridine (R_F=CF₃, C₂F₅ and C₃F₇) complexes (?5.14, ?5.38 and ?5.44 kcal mol^?1, respectively) are close to that for the C₆F₅I–pyridine complex. Electrostatic interactions are the major source of the attraction in the strong halogen bond although induction and dispersion interactions also contribute to the attraction. Short‐range (charge‐transfer) interactions do not contribute significantly to the attraction. The magnitude of the directionality of the halogen bond correlates with the magnitude of the attraction. Electrostatic interactions are mainly responsible for the directionality of the halogen bond. The directionality of halogen bonds involving iodine and bromine is high, whereas that of chlorine is low and that of fluorine is negligible. The directionality of the halogen bonds in the C₆F₅I– and C₂F₅I–pyridine complexes is higher than that in the hydrogen bonds in the water dimer and water–formaldehyde complex. The calculations suggest that the C? I and C? Br halogen bonds play an important role in controlling the structures of molecular assemblies, that the C? Cl bonds play a less important role and that C? F bonds have a negligible impact.     

Reactions of 3-(Polyfluoroalkyl)propane-1,2,3-trione-2-oximes with Diaminoarenes

Novel quinoxaline derivatives have been synthesized via the reaction of 3-trifhioromethyl-1,2,3-propanetrione-2-oximes with 1,2-diaminobenzene or 2,3-diaminonaphthalene: 2-trifluoromethyl-3-aroylquinoxaline and 2-trifluoromethyl-3-aroylbenzo[g]quinoxaline. Under similar conditions, 3-R^F-1,2,3-propanetrione-2-oximes [R^F = C₃F₇, H(CF₂)₄, C₄F₉, and C₆F₁₃] with the same diaminoarenes have given a mixture of the condensation and fragmentation products in different ratios. The structure of (4-methylphenyl)[3-(tri-fluoromethyl)benzo[g]quinoxalin-2-yl]methanone has been elucidated by means of X-ray diffraction analysis.

     

Organothallium compounds : XVII. Halogenobis(polyfluorophenyl)thallium(III) complexes

The preparations, stabilities and structures of the complexes R₂TlX and R₂ LTlX (R = C₆F₅, p-HC₆F₄, or o-HC₆F₄; X = Br or Cl; L = Ph₃PO, 2,2′-bipyridyl (bpy) or Ph₃P) have been examined or (R = C₆ F₅) reinvestigated. The derivatives R₂TlX are monomeric in acetone, from which the complex (p-HC₆F₄)₂ Me₂COTIBr has been isolated. In this solvent, the complexes R₂LTlX (L = Ph₃PO, bpy, or Ph₃P) undergo partial dissociation by loss of L. When L = bpy, there is also slight ionization into R₂LTl⁺ and R₂TlX^?₂. The acceptor properties of R₂TlX compounds towards uncharged ligands decrease R = C₆F₅ ? p-HC₆F₄ > o-HC₆F₄ > Ph. Dimeric behaviour is observed for R₂TIX compounds in benzene, whilst R₂LTlX (L = Ph₃PO or bpy) derivatives show slight but significant association. In the solid state, R₂TlX compounds are considered to be polymeric with five coordinate thallium, and R₂LTlX derivatives to be dimeric with five (L = Ph₃PO) or six (L = bpy) coordinate thallium by contrast with four coordinate dimeric and four or five coordinate monomeric structures previously proposed for the respective pentafluorophenyl derivatives. Halogen bridging is unsymmetrical for R = C₆F₅ or p-HC₆F₄, but may be more symmetrical for R = o-HC₆F₄ when L = Ph₃PO or bpy. Reported structural data for the complexes (C₆F₅)LTlX (L = Ph₃AsO, Ph₃P, Ph₃As, or 1,10-phenanthroline; X = Br or Cl) and (C₆F₅)₂TlCl^?₂ are reinterpreted and the proposed structures revised.     

Synthesen und Eigenschaften von Tris(perfluoralkyl)arsen- und -antimon(III,V)-Verbindungen

Preparations and Properties of Tris(perfluoroalkyl) Arsenic and Antimony(III, V) Compounds As(R_f)₃ and Sb(R_f)₃ (R_f?C₂F₅, C₄F₉, C₆F₁₃) are prepared in good yields by the polar reactions of AsCl₃ and SbCl₃ with bis(perfluoroalkyl) cadmium compounds as colourless liquids or solids. The oxidation of As(C₂F₅)₃ and Sb(C₂F₅)₃ with XeF₂ gives the difluorides M(C₂F₅)₃F₂ (M?As, Sb). As(C₂F₅)₃Cl₂ is prepared by chlorination of As(C₂F₅)₃ in the presence of AlCl₃, while Sb(C₂F₅)₃Cl₂ is formed in the reaction of Sb(C₂F₅)₃F₂ with (CH₃)₃SiCl. During the reaction of M(C₂F₅)₃F₂ with (CH₃)₃SiBr ¹⁹F-NMR spectroscopic evidence is found for M(C₂F₅)₃ Br₂. The thermal decompositions of M(C₂F₅)₃F₂ mainly yield C₄F₁₀ and M(C₂F₅)F₂, while the thermal decompositions of M(C₂F₅)₃Cl₂ yield M(C₂F₅)₂Cl and C₂F₅Cl. The properties and spectroscopic data of the new compounds are described.     

Interaction of pentafluoropyridine with 4-nitrophenol and pentafluorophenol in the presence of potassium fluoride and 18-crown-6-ether

The reactions of 4-nitro- and pentafluorophenols with C₅F₅N, 4-ArOC₅F₄N and 2,4-(ArO)₂C₅F₃N (Ar = 4-NO₂C₆H₄, C₆F₅) in the presence of KF and catalitic amounts of 18-crown-6- -ether at various temperatures have been investigated. The leaving ability of the C₆F₅O-group is shown to be higher than that of the 4-NO₂C₆H₄O-group in the reactions of 4-ArOC₅F₄N, 2,4-(ArO)₂C₅F₃N and 2,4,6-(ArO)₃C₅F₂N with F^?-anion, which is in agreement with the order of the basicity of anions (C₆F₅O^?<4-NO₂C₆H₄O^?). The reaction pathways of pentafluoropyridine with ArO^?-anions are discussed.     

Borane‐Catalyzed Cross‐Metathesis Strategy for Facile Transformation of Cyclic (Alkyl)(Amino)Germylenes

A borane B(C₆F₅)₃‐catalyzed metathesis reaction between the Si?C bond in the cyclic (alkyl)(amino)germylene (CAAGe) 1 and the Si?H bond in a silane (R₃SiH; 2 ) is reported. Mechanistic studies propose that the initial step of the reaction involves Si?H bond activation to furnish an ionic species [ 1 ‐SiR₃]⁺[HB(C₆F₅)₃]^?, from which [Me₃Si]⁺[HB(C₆F₅)₃]^? and an azagermole intermediate are generated. The former yields Me₃SiH concomitant with the regeneration of B(C₆F₅)₃ whereas the latter undergoes isomerization to afford CAAGes bearing various silyl groups on the carbon atom next to the germylene center. This strategy allows the straightforward synthesis of eight new CAAGes starting from 1 .     

Organothallium compounds XII NMR spectra of some polyfluorophenylthallium (III) compounds

The PMR and ¹⁹F NMR spectra of the complexes R₂TlBr (R = C₆F₅, $\text{o}$-HC₆F₄, $\text{m}$-HC₆F₄, 3,5-H₂C₆F₃, or 3,6-H₂C₆F₃ and R₃Tl(diox) (R = C₆F₅, $\text{m}$-HC₆F₄, or 3,5-H₂C₆F₃; diox = 1,4-dioxan) have been recorded. Proton and fluorine chemical shifts, thallium-proton, thallium-fluorine, fluorine-fluorine, and fluorine-proton coupling constants, and thallium substituent chemical shifts are given and discussed