- The stereospecific preparation of two perfluoro-1,3-butadiene synthons; (E)-1-trimethylsilyl-1,2,3,4,4-pentafluoro-1,3-butadiene and (E)-1-tributylstannyl-1,2,3,4,4-pentafluoro-1,3-butadiene
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(E)-1-Trimethylsilyl-1,2,3,4,4-pentafluoro-1,3-butadiene (1) can be stereospecifically prepared by Pd(0)/CuI catalyzed cross-coupling of (Z)-1-tributylstannyl-1,2-difluoro-2-trimethylsilylethene with iodotrifluoroethene. The corresponding (E)-1-tributylst
- Lim, Chongsoo,Burton, Donald J.,Wesolowski, Craig A.
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- Preparative-scale one-pot syntheses of hexafluoro-1,3-butadiene
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Hexafluoro-1,3-butadiene, with its negligible global warming potential, is required in quantities for application in plasma dielectric etching in semiconductor industry and as gaseous microbubble suspension contrast agents in diagnostic ultrasound imaging. Three efficient protocols for the preparation of perfluoro-1,3-butadiene in 62-70% overall yields have been described. They involve the coupling of (1) iodotrifluoroethylene (ITFE) with activated copper, (2) trifluorovinylzinc bromide in the presence of copper (II) or iron (III) salts and (3) trifluorovinylzinc chloride, prepared from 1,1,1,2-tetrafluorethane (HFC 134a) in the presence of copper (II) or iron (III) salts.
- Ramachandran, P. Veeraraghavan,Reddy, G. Venkat
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- The stereoselective synthesis of (E)-octafluoro-1,3,5-hexatriene and (3E,5E,7E)-dodecafluoro-1,3,5,7,9-decapentaene
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(E)-(1,2-Difluoro-1,2-ethenediyl)bis[tributylstannane], 3, readily undergoes a Pd(PPh3)4/CuI-catalyzed cross-coupling reaction with iodotrifluoroethene to yield (E)-octafluoro-1,3,5-hexatriene, 4, in high isomeric purity. (1Z,3E,5Z)-
- Liu, Qibo,Burton, Donald J.
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- Trifluorovinylxenon(II) tetrafluoroborate
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The first acyclic alkenylxenon(II) compound, trifluorovinylxenon(II) tetrafluoroborate, was prepared from XeF2 and trifluorovinylboron difluoride and characterized by 13C, 19F and 129Xe NMR spectroscopy.
- Frohn,Bardin
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- Reaction of organylxenonium(II)salts, [RXe][Y], with organyl iodides, R'I, in anhydrous HF: Scope and limitation of a new synthetic approach to iodonium salts, [RR'I][Y]
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Perfluoroalkynylxenonium salts, [RXe][BF4] (R = CF 3C≡C, (CF3)22CFC≡C), reacted with organyl iodides, R'I (R' = 3-FC6H4, C6F 5, CF2 ≡CF, CF3CH2; no reaction with R' = CF3CF2CF2)in anhydrous HF to yield the corresponding asymmetric polyfluorinated iodonium salts, [RR'I][Y]. The action of the arylxenonium salt, [C6F5Xe]-[BF4], and the cycloalkenylxenonium salt, [cyclo-1,4-C6F7Xe]-[AsF6], on 4-FC6H4I gave [C6F5(4-FC 6H4)I][BF4] and [cyclo-1,4-C 6F7(4-FC6H4)I][AsF6], respectively, besides the symmetric iodonium salt, [(4-FC6H4)2 2I][Y]. But the aryl-, as well as the cycloalkenylxenonium salt, did not react with C6F5I, CF2 =CFI, and CF 3CH2I.
- Frohn, Hermann-Josef,Bardin, Vadim V.
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experimental part
p. 2616 - 2620
(2012/05/31)
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- Reactions of perfluorinated alkenyl-, alkynyl-, alkyltrifluoroborates, and selected hydrocarbon analogues with the halogenating agents Hal2 (Hal = F, Cl, Br), "brF" (BrF3-Br2 1:1), and ICl
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Reactions of [Bu4N][RBF3] [R = CnF 2n+1CF=CF (cis, trans), CF2=CF, CF2=C(CF 3), trans-C4H9CF=CF, trans-C6H 5CF=CF, C4H9CH=CH (cis, trans), CF 3C≡C, and C4H9C≡C] with chlorine, bromine, BrF3 + Br2 (as equivalent of "BrF"), and ICl in solution (CH2Cl2, CHCl3, CF 3CH2CF2CH3) led to 1, 2-addition of halogen and/or replacement of boron by halogen (halodeboration). The reaction of [Bu4N][CF3C≡CBF3] with less than equimolar amounts of diluted fluorine (5 %) in 1, 1, 1, 3, 3-pentafluorobutane (PFB) showed only [Bu4N][CF3CF2CF 2BF3] as fluorine addition product besides extensive fluorodeboration. Suspensions of the insoluble K[CF2=CFBF 3] salt reacted with Cl2 and Br2 in CH 2Cl2 giving preferentially products of halogen addition across the C=C bond. In reactions with ICl iododeboration with formation of CF2=CFI occurred besides 1, 2-addition with formation of [CF 2I-CFClBF3]-. The halodeboration reaction of[Bu4N][trans-C4H9CF=CFBF3] with Br2, "BrF", and ICl, of K[trans-C6H 5CF=CFBF3] with Br2, and of [Bu 4N][trans-C4F9CF=CFBF3] with ICl proceeded stereospecifically. Copyright
- Bardin, Vadim V.,Adonin, Nicolay Yu.,Frohn, Hermann-Josef
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experimental part
p. 565 - 579
(2012/05/20)
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- CHEMICAL PRODUCTION PROCESSES AND SYSTEMS
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Chemical production processes are provided that include reacting a metal comprising olefin to form a conjugated olefin; reacting a heterohalogenated olefin to form a conjugated olefin; reacting a halogenated alkane to form a conjugated olefin; and/or reacting a hydrohalogenated olefin to form a conjugated olefin. Chemical production systems are also provided that can include: a first reactant reservoir configured to house a perhalogenated olefin; a second reactant reservoir configured to house a catalyst mixture; a first reactor coupled to both the first and second reservoirs, the first reactor configured to house a metal-comprising mixture and receive both the perhaloganated olefin form the first reactant reservoir and the reactant mixture from the second reactant reservoir; and a product collection reservoir coupled to the first reactor and configured to house a conjugated olefin.
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(2008/06/13)
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- The hydrofluorocarbon 1,1,1,2-tetrafluoroethane (HFC-134a) as a ready source of trifluorovinyllithium
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Trifluorovinyllithium has been synthesised in high yield from 1,1,1,2-tetrafluoroethane (HFC 134a) by treatment with butyllithium at -78°C, and then treated with a variety of electrophiles in one-pot reactions.
- Burdon, James,Coe, Paul L.,Haslock, Iain B.,Powell, Richard L.
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- SYNTHESE ET REACTIVITE D'ENYNES FLUORES
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Several fluoroenynes have been prepared by palladium-catalyzed cross-coupling reactions.Cycloaddition reactions of these enynes give substituted cyclobutanes, whereas treatment with sulfuric acid leads to α-fluoro-α-allenic acid fluorides, lactones, α-fluoro-β-diketones or cyclic α-fluoroenones, according to the nature of the starting enyne.The cyclisation process is discussed.
- Tellier, Frederique,Sauvetre, Raymond,Normant, Jean-F.
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