- The reaction of perfluoro-2,5-diazahexane 2,5-dioxyl with aromatic compounds and perfluoroiodoalkanes
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Treatment of perfluoro-2,5-diazahexane 2,5-dioxyl (1) with the fluoroarenes C6F5X (X = F or Br at c. 20 deg C; X = CF3 at 50 deg C) and pentafluoropyridine (50 deg C) gives 2:1 copolymers in high yield, but pentachloropyridine is unreactive at 50 deg C.Copolymers are also formed between 1 and the arenes C6F5I, C6F5H and C6H6 which did not analyse correctly for 2:1 copolymers; in the latter case, hydrogen abstraction is taking place as shown by the presence of N-OH and C=O groups in the polymer.Hexafluorobenzene is not incorporated in the polymer formed by treatment of 1 with a mixture of vinylidene fluoride and hexafluorobenzene.Photochemical reaction of trifluoroiodomethane with 1 affords the bishydroxylamine CF3ON(CF3)CF2CF2N(CF3)OCF3 in quantitative yield, while the di-iodides I(CF2)nI (n = 2 and 4) give copolymers of 1 and the units (CF2)n (n = 2 and 4), which contain (CF2)nI end-groups.
- Green, Michael J.,Tipping, Anthony E.
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p. 237 - 242
(2007/10/02)
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- The synthesis of -substituted dialkyldichlorosilanes and their conversion into polysiloxanes
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Attack of the oxyl (CF3)2NO. (1) on an ethyl group of the silane Et2SiCl2 occurs at both the α- and β-positions relative to silicon (ratio 31:45), whereas with the silane PrnSiMeCl2 attack takes place at the β-position of the propyl group.With the disilane Me3SiCH2SiMe3, the mojor silicon-containing products formed from treatment with oxyl 1 are Me3SiF, (CF3)2NOSiMe3 and Me3SiSiMe3.Speier-catalysed (H2PtCl6) addition of the silane HSiCl2X (X = Me and Cl) to the alkene (CF3)2NOCH2CH=CH2 gives the adducts (CF3)2NOCH2CH2CH2SiCl2X (29, X = Me) and (28, X = Cl)in high yield.The substituted dichlorosilanes (CF3)2NOCH2CH2SiEtCl2 (9), (CF3)2NOCHMeCH2SiMeCl2 (14) and (CF3)2NOCH2CH2CH2SiMeCl2 (29) are converted into corresponding polysiloxanes ("prepolymers" of low molecular weight) by reaction with reagents including water, acid, base and metal oxides; equilibration of the polysiloxane "prepolymer" 38, derived from dichlorosilane 29 by heating with powdered KOH, affords a solid rubbery polysiloxane.
- Ducker, Graham E.,Tipping, Anthony E.
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p. 253 - 262
(2007/10/02)
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- The reaction of perfluoro-2,5-diazahexane 2,5-dioxyl with alkenes
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The liquid-phase reaction at room temperature of the title dioxyl (1) with an excess of the alkenes CH2=CHR (R = H, F, COCl), CF2=CHF, CHCl=CCl2 and cis-CHCl=CHCl gives 1:1 copolymers 3 in high yield, although with the alkenes CH2=CH2, CH2=CHF and CF2=CHF cyclic 1:1 adducts 2 are also formed in low yield.The reactions with the alkenes CH2=CMe2, CH2=CHEt, CH2=CHCO2H, and cis-HO2CCH=CHCO2H produce copolymers which are not 1:1 copolymers.The 1:1 copolymer 3f from acryloyl chloride is hydrolysed readily by water to the acrylic acid/dioxyl 1 1:1 copolymer 3j.Gas-phase reaction at room temperature of 1 with an excess of the alkenes CH2=CHR (R=Cl, Br, COCl, COF), CH2=CXCH3 (X = Cl, Br), CHCl=CCl2, cis- and trans-CHCl=CHCl, CH2=CCl2, CF2=CCl2, CF2=CFCl and CF2=CFBr affords cyclic 1:1 adducts 2 (11.5-78percent) and copolymers 3 (18.5-76.5percent): hydrolysis of the acryloyl fluoride 1:1 adduct 2j gives the acrylic acid 1:1 adduct 2s in high yield.
- Green, Michael J.,Tipping, Anthony E.
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p. 115 - 126
(2007/10/02)
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- Fluoride-promoted competitive reactions of cyanogen fluoride, perfluoromethanimine, and pentafluoro-2-azapropene
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Competitive reactions of cyanogen fluoride (FC≡N), perfluoromethanimine (CF2=NF), and pentafluoro-2-azapropene (CF3N=CF2) were performed by combining pairs of the substrates over KF or CsF. These reactions establish the order of reactivity with fluoride ion as CF2=NF > CF3N=CF2 ? F - C≡N. Subsequent reactions of the addition products with fluoride ion, CIF, and Br2/CsF are discussed. Seven new compounds, including a novel diaziridine, were characterized by IR, NMR, MS, and physical properties.
- Bauknight Jr., Charles W.,DesMarteau, Darryl D.
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p. 728 - 733
(2007/10/02)
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- Cycloaddition and Oxygen-Transfer Reactions of 2-(Trifluoromethyl)-3,3-difluorooxaziridine
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The oxaziridine CF3-cyclo-NCF2O (1) cycloadds to various 1,1-difluoroolefins under mild conditions, forming perhalo-1,3-oxazolidines, and dialkyl ketones, forming the corresponding 1,3,4-dioxazolidines.Reaction of 1 with trimethylsilyl cyanide results in the formation of (CH3)3SiN=C=NCF3 and COF2, but 1 is unreactive with other alkyl nitriles and isocyanides.With 2,5-dimethylfuran and 2,3-dimethylbutene, 1 reacts rapidly and under mild conditions ( ca. - 50 deg C) to yield CF3N=CF2 and organic products derived from the transfer of a single oxygen atom.
- O'Brien, Brian A.,Lam, William Y.,DesMarteau, Darryl D.
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p. 4466 - 4470
(2007/10/02)
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- EXCHANGE REACTIONS BETWEEN O-NITROSOBIS(TRIFLUOROMETHYL)HYDROXYLAMINE AND M(CF3)3 (M=P, As and Sb)
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O-Nitrosobis(trifluoromethyl)hydroxylamine gives novel reactions with tris(trifluoromethyl)-phosphine, -arsine and -stibine to afford mainly the corresponding bis(trifluoromethyl)nitroxyl derivatives.Tris(trifluoromethyl)phosphine affords (CF3)2NOP(O)(CF3)2 and (CF3)2NNO.Tris(trifluoromethyl)arsine also gives (CF3)2NNO in high yield, together with smaller amounts of (CF3)2NOAs(CF3)2, CF3N=CF2, COF2 and a polymeric white solid.With tris(trifluoromethyl)stibine, no oxidation nor addition reactions occurred.Instead, 3Sb and 2SbCF3 were obtained in high yields.The stoichiometry of the reactions suggests that the additional amounts of bis(trifluoromethyl)nitroxyl groups bonded to antimony are derived from the trifluoromethyl groups bonded to antimony.Mechanisms to rationalise these reactions are proposed.
- ANG, H. G.,SO, K. K.
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p. 411 - 432
(2007/10/02)
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- REACTIONS OF TRIFLUORONITROSOMETHANE WITH BISTRIFLUOROMETHYLPHOSPHORUS COMPOUNDS, (CF3)2PX (WHERE X = H, Cl, CF3)
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Trifluoronitrosomethane reacts with bis(trifluoromethyl)phosphine to give (CF3)P(O)N(OH)CF3 and a small amount of (CF3)2NOH.On the other hand, the reactions with tris(trifluoromethyl)phosphine and bis(trifluoromethyl)chlorophosphine afford (CF3)2NOP(O)CF3N(CF3)2 and (CF3)2NP(O)(CF3)Cl respectively.Isomerisation of =N-O-P= to =N-P(O)= may be involved as found for the isomerisation of the phosphine, (CF3)2NOP(CF3)2, to the phosphoryl compound, (CF3)2NP(O)(CF3)2.Mechanisms for the above reactions are discussed.
- ANG, H. G.,SO, K. K.
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p. 451 - 460
(2007/10/02)
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- Reactions of Perfluoronitroxides with Sulphur Dioxide
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Perfluoro-2,5-diazahexane 2,5-dioxyl reacts with sulphur dioxide and with sulphur tetrafluoride to give the 1 : 1 cyclic adducts perfluoro(4,7-dimethyl-1,3-dioxa-2-thia-4,7-diazacycloheptane 2,2-dioxide) and perfluoro(4,7-dimethyl-1,3-dioxa-2-tetrafluorothia-4,7-diazacycloheptane), respectively.Perfluoro(4,7-dimethyl-1,3-dioxa-2-thia-4,7-diazacycloheptane 2,2-dioxide) which oxidises iodide ion to iodine at room temperature, is stable to hydrolysis by aqueous potassium hydroxide at 120 deg C.It is stable to u.v. irradiation, but flow pyrolysis at 350 deg C and ca. 1 mmHg pressure gives trifluoronitrosomethane, perfluoro(2-methyl-1,2-oxazetidine), carbonyl fluoride, perfluoro(N-methylenemethylamine), and sulphur dioxide.It reacts with triphenylphosphine to give perfluoro(3,6-dimethyl-1-oxa-2-thia-3,6-diazacyclohexane 2,2-dioxide), perfluoro(2,5-dimethyl-1-thia-2,5-diazacyclopentane 1,1-dioxide) and triphenylphosphine oxide.Bis(trifluoromethyl) nitroxide reacts with sulphur dioxide to give the 2 : 1 adduct perfluoro(2,6-dimethyl-3,5-dioxa-4-thia-2,6-diazaheptane 4,4-dioxide), flow pyrolysis of which at 350 deg C and ca. 1 mmHg gives only bis(trifluoromethyl) nitroxide and sulphur dioxide.Perfluoro(2,4-dimethyl-3-oxa-2,4-diazapentane) reacts with sulphur dioxide giving perfluoro(2,5-dimethyl-3-oxa-4-thia-2,5-diazahexane 4,4-dioxide).
- Arfaei, Ahmad,Smith, Sydney
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p. 1791 - 1794
(2007/10/02)
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- NOVEL REACTIONS INVOLVING 0-NITROSOBIS(TRIFLUOROMETHYL)HYDROXYLAMINE WITH M(CF3)3 (M=P, As AND Sb) AND SOME OLEFINS
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O-nitrosobis(trifluoromethyl)hydroxylamine gives novel reactions with tris(trifluoromethyl)phosphine, -arsine and -stibine to afford mainly the corresponding bis(trifluoromethyl)nitroxy derivatives.Tris(trifluoromethyl)phosphine affords (CF3)2NOP(O)(CF3)2 and (CF3)2NNO.Tris(trifluoromethyl)arsine also gives (CF3)2NNO in high yield, together with smaller amounts of (CF3)2NOAs(CF3)2, CF3N=CF2, COF2 and a polymeric white solid.With tris(trifluoromethyl)stibine, no oxidation nor addition reactions occured.Instead, 3Sb and SbCF3 were obtained in high yields.The stoichiometry of the reactions suggests that the additional amounts of bis(trifluoromethyl)nitroxy groups bonded to antimony are derived from the trifluoromethyl groups bonded to antimony.However, O-nitrosobis(trifluoromethyl)hydroxylamine gives addition products at room temperature with 1,1-difluoro-2,2-dichloroethylene and 1,1-difluoro-2-fluoro-2-bromoethylene.Mechanism to rationalise the above reactions involving Group V compounds are proposed.
- Ang, H. G.,So, K. K.
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- Nitroxide Chemistry. Part 18. Reaction of Bistrifluoromethyl Nitroxide with Some Ethers
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Treatment of the methyl ethers MeOX (X = Me, Ph) with a stoicheiometric amount of bistrifluoromethyl nitroxide . = R.> at room temperature converts them efficiently into their bistrifluoromethylamino-oxymethyl counterparts, RCH2OX; the bis-derivative (RCH2)2O is a minor by-product in the case of dimethyl ether (X = Me).Multiple hydrogen-abstraction increases in importance with diethyl ether as substrate, the expected products RCHMeOEt and (RCHMe)2O being accompanied by a bis-derivative (RCH2CHROEt) arguably produced via the αβ-dehydrogenation 2R. + Et2O -> 2RH + CH2=CHOEt.The halogeno-ether MeOCF2CHFCl reacts slowly with the nitroxide at 50 deg C to yield a 7 : 1 mixture of the derivatives RCH2OCF2CHFCl and RCFClCF2OMe, hydrolysis of which gives the esters RCH2OCOCHFCl and RCFClCO2Me, respectively.The latter ester is best obtained via treatment of methyl chlorofluoroacetate with bistrifluoromethyl nitroxide.
- Banks, Ronald E.,Brown, Alan K.,Haszeldine, Robert N.,Jefferson, John
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p. 1068 - 1070
(2007/10/02)
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- Heterocyclic Polyfluoro-compounds. Part 30. Perfluoroalkylation of Trifluoro-1,2,4-triazine
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Reaction of trifluoro-1,2,4-triazine with hexafluoropropene and caesium fluoride in the absence of solvent leads to successive replacement of fluorine by perfluoroisopropyl groups to give 5-mono-, 3,5- and possibly 3,6-di, and tri-substituted derivatives.Similarly, perfluoro-2-azapropene yields 5- and some 6-, 3,6-bis, and tris-perfluorodimethylamino-derivatives. Pyrolysis of trifluoro-1,2,4-triazine at 500 deg C/ 42 h yields trifluoro-1,3,5-triazine (32percent); of perfluoro(tri-isopropyl-1,2,4-triazine) at 560 deg C/ 0.26 s yields perfluorobutyronitrile and perfluoro-2,5-dimethylhex-3-yne; and of perfluoro(trisdimetylamino-1,2,4-triazine) at 620 deg C/ 2.4 s yields N,N-bis(trifluoromethyl)cyanamide and perfluorobis(dimethylamino)acetylene.
- Barlow, Michael G.,Haszeldine, Robert N.,Simon, Charles
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p. 2254 - 2257
(2007/10/02)
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- Polyfluoroalkyl Derivatives of Nitrogen. Part 48. The Addition of N-Halogenoamines (CF3)2NX to Cyclohexa-1,3- and -1,4-dienes; a New Synthesis of NN-Bistrifluoromethylaniline.
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Treatment of cyclohexa-1,3-diene with the N-halogenoamines (CF3)2NX (X=Cl or Br) at -78 deg C gives a mixture of the 1:1 adducts, trans- and cis- and trans-; in contrast (CF3)2NI affords the former adduct exclusively.All three amines react with cyclohexa-1,4-diene under analogous conditions to yield the 1:1 adduct trans- only.Dehydrohalogenation of the 1,3-diene adducts (X=Cl or Br) with various bases (KOH powder, PriONa, ButOK) affords a mixture of 1-and 2-(NN-bistrifluoromethylamino)cyclohexa-1,3-diene.The latter diene forms a Diels-Alder adduct with trifluoronitrosomethane and the diene mixture dehydrogenates readily over a Pd-C catalyst at 180-190 deg C to give NN-bistrifluoromethylaniline exclusively in high yield.
- Hart, Terence W.,Haszeldine, Robert N.,Tipping, Anthony E.
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p. 1544 - 1550
(2007/10/02)
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