- Catalytic Hydrodefluorination via Oxidative Addition, Ligand Metathesis, and Reductive Elimination at Bi(I)/Bi(III) Centers
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Herein, we report a hydrodefluorination reaction of polyfluoroarenes catalyzed by bismuthinidenes, Phebox-Bi(I) and OMe-Phebox-Bi(I). Mechanistic studies on the elementary steps support a Bi(I)/Bi(III) redox cycle that comprises C(sp2)-F oxidative addition, F/H ligand metathesis, and C(sp2)-H reductive elimination. Isolation and characterization of a cationic Phebox-Bi(III)(4-tetrafluoropyridyl) triflate manifests the feasible oxidative addition of Phebox-Bi(I) into the C(sp2)-F bond. Spectroscopic evidence was provided for the formation of a transient Phebox-Bi(III)(4-tetrafluoropyridyl) hydride during catalysis, which decomposes at low temperature to afford the corresponding C(sp2)-H bond while regenerating the propagating Phebox-Bi(I). This protocol represents a distinct catalytic example where a main-group center performs three elementary organometallic steps in a low-valent redox manifold.
- Cornella, Josep,Katzenburg, Felix,Leutzsch, Markus,N?thling, Nils,Pang, Yue
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supporting information
p. 12487 - 12493
(2021/08/30)
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- Method for preparing 2, 3, 5-trichloropyridine on basis of layered manganese oxide catalysts with nanometer zinc
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The invention provides a method for preparing 2, 3, 5-trichloropyridine on the basis of layered manganese oxide catalysts with nanometer zinc. The method includes steps of dissolving manganese nitrateand zinc acetate in water, uniformly mixing the manganese nitrate and the zinc acetate with each other to obtain first liquid, dropwise adding alkali liquor into the first liquid to obtain second liquid, stirring and precipitating the second liquid to obtain manganese/iron mixed precipitates, adding the manganese/iron mixed precipitates into potassium permanganate solution to obtain third liquid,oxidizing the third liquid, filtering and washing the third liquid, adding carbon powder into the third liquid to obtain mixtures and calcining the mixtures at the high temperatures to obtain the layered manganese oxide catalysts with the nanometer zinc; carrying out reaction on pentafluoropyridine, DMF (dimethyl formamide) and active potassium fluoride powder under the effects of the layered manganese oxide catalysts with the nanometer zinc under strong-alkali conditions, filtering reaction products, and adding filter cake into calcium fluoride solution to obtain the 2, 3, 5-trichloropyridine on the basis of the layered manganese oxide catalysts with the nanometer zinc. The pentafluoropyridine is used as a raw material, the DMF is used as a solvent, and the active potassium fluoride powder is used as fluorinating agent. The method for preparing the 2, 3, 5-trichloropyridine on the basis of the layered manganese oxide catalysts with the nanometer zinc has the advantages that the reaction is mild and is high in efficiency, and the 2, 3, 5-trichloropyridine which is a product prepared by the aid of the method is high in purity.
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Paragraph 0025; 0029; 0033; 0037; 0039; 0041; 0045; 0048
(2018/05/16)
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- BORON OR ALUMINUM COMPLEXES
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The present invention relates to boron and aluminum complexes, to the preparation thereof, and to the use thereof for solubilizing ionic compounds. The complexes have one of the following formulae: in which D represents B or Al; R1 represents R, RF, NO2, CN, C(═O)OR, RSO2, or RFSO2; —X1—, —X2—, —X3— and X4 each represent a divalent group >C═O, >C═NC≡N, >C═C(C≡N)2, >CR2R3 or >SO2; —Y1—, —Y2— and —Y3— each represent a divalent group —O—, >N(C≡N), >N(CORF), >N(SO2R4), >NR4, >N(COR4) or >N(SO2RF); R, R2 and R3 each represent H, an alkyl group, an aryl group, an alkylaryl group, an arylalkyl group, an oxaalkyl group or an alkenyl group; R4 represents an alkyl group, an aryl group, an alkylaryl group, a heteroaryl group, an arylalkyl group, an oxaalkyl group, an alkenyl group or an RFCH2— group; RF is a perfluoroalkyl group, a partially fluorinated alkyl group, or a partially or totally fluorinated phenyl group; each of the R′2 and R′3 groups represents R or F.
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Page/Page column 23
(2011/08/02)
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- From hypervalent xenon difluoride and aryliodine(III) difluorides to onium salts: Scope and limitation of acidic fluoroorganic reagents in the synthesis of fluoroorgano xenon(II) and iodine(III) onium salts
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Fluorinated organodifluoroboranes RfBF2 are in general suitable reagents to transform XeF2 and RIF2 into the corresponding onium tetrafluoroborate salts [RfXe][BF4] and [R(Rf)I][BF4], respectively. (4-C5F4N)BF2 and trans-CF3CF{double bond, long}CFBF2 which represent boranes of high acidity form no Xe-C onium salts in reactions with XeF2 but give the desired iodonium salts with RIF2 (R = C6F5, o-, m-, p-C6FH4). The reaction of (4-C5F4N)BF2 with XeF2 ends with a XeF2-borane adduct. C6F5Xe(4-C5F4N), the first Xe-(4-C5F4N) compound, was obtained when C6F5XeF was reacted with Cd(4-C5F4N)2. We describe the synthesis of (4-C5F4N)IF2 and reactions of (4-C5F4N)IF2 and C6F5IF2 with (4-C5F4N)BF2. Analogous to [(4-C5F4N)2I][BF4] and [C6F5(4-C5F4N)I][BF4] aryl(perfluoroalkenyl)iodonium salts [R(R′)I][BF4] were obtained from RIF2 (R = C6F5, o-, m-, p-C6FH4) and R′BF2 (R′ = trans-CF3CF{double bond, long}CF, CF2{double bond, long}CF). The gas phase fluoride affinities pF- of selected fluoroorganodifluoroboranes RfBF2 and their hydrocarbon analogs are calculated (B3LYP/6-31+G*) and discussed with respect to their potential to introduce Rf-groups into hypervalent EF2 bonds. Four aspects which influence the transformation of hypervalent EF2 bonds (E = Xe, R′I) under the action of Lewis acidic reagents RAFn-1 (A = B, P; n = 3, 5) into the corresponding [RE][AFn+1] salts are presented and the important role of the acidity is emphasized. Fluoride affinities may help to plan the introduction of organo groups into EF2 moieties and to expand the types of acidic reagents. Thus C6H5PF4 with a pF- value comparable to that of RfBF2 compounds is able to introduce the C6H5 group into RIF2 (R = C6F5, p-C6FH4).
- Abo-Amer, Anwar,Frohn, Hermann-Josef,Steinberg, Christoph,Westphal, Ulrich
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p. 1311 - 1323
(2008/12/21)
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- PHOSPHAZENIUM SALT MIXTURES CONTAINING HEXAKIS(AMINO)DIPHOSPHAZENIUM, TETRAKIS(AMINO)-PHOSPHONIUM AND POLYAMINOPHOSPAZENIUM SALTS
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The invention relates to mixtures containing 5 99.5 wt. % of a compound of formula (I), 95 0.5 wt. % of a compound of formula (II) and a maximum of 10 wt. % of one of several compounds of general formula (III a), wherein A - A which are independent from each other are equal or different and represent a straight-chained or branched alkyl or alkenyl having 1 - 12 carbon atoms, cycloalkyl having 4 8 carbon atoms, an aryl having 6 -12 carbon atoms, an aralkyl having 7 - 12 carbon atoms, or A-A, A-A, A-A etc. - A-A which are independent from each other and are equal or different and are connected together directly or via O or N-A to a ring having 3 - 7 ring members, A represents an alkyl having 1 - 4 carbon atoms. X1 and/or X2 and/or X3 which are independent from each other represent a radical of formula (III b), or the radical X1 and/or X2 and/or X3 as well as a straight-chained or branched alkyl or alkenyl having 1 - 12 carbon atoms, cycloalkyl having 4 - 8 carbon atoms represent an aryl having 6 - 12 carbon atoms, an aralkyl having 7 - 12 carbon atoms, or respectively the radicals which are disposed on an identically bound nitrogen atom, e.g. A and A, A and A, A and A etc. - A and A which are independent from each other are equal or different and are connected together directly or via O or N-A to a ring having 3 - 7 ring members and A represents an alkyl having 1 - 4 carbon atoms and B represents a single-valent organic or inorganic acid radical or the equivalent of a multi-valent acid radical. The mixtures can be used as catalysts and co-catalysts for phase transfer reactions, nucleophilic substitution reactions or halogen-fluoro-exchange reactions.
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Page/Page column 13-14
(2010/02/08)
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- METHOD FOR PRODUCING A COMPOUND CONTAINING FLUORINE VIA FLUORINE-HALOGEN EXCHANGE BY SPECIAL POLYAMINO PHOSPHAZENE CATALYSTS
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The invention relates to a method for producing compounds containing fluorine by reacting a compound, which contains hydrogen that can be exchanged for fluorine, with a fluoride or with a mixture of fluorides of general formula (I): MeF, wherein Me represents an alkaline earth metal ion, an NH4+ ion or an alkali metal ion, in the presence or absence of a solvent at a temperature ranging from 60 to 260 °C. The invention is characterized in that the reaction is carried out in the presence of a compound or of a mixture of compounds of general formula (IIa) and/or (IIb), whereby X1 and/or X2 and/or X3, independent of one another, have groups of formula (llc) or other groups cited in the claims.
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- Preparation and reactions of 2,3,4,6-tetrafluoropyridine and its derivatives
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A reliable route to 2,3,4,6-tetrafluoropyridine has been established starting from the readily available 3,5-dichlorotrifluoropyridine by halogen exchange under controlled conditions to give 3-chlorotetrafluoropyridine and its subsequent hydrodechlorination using hydrogen over palladium on alumina at 250-270°C. The formation and reactions of the 3-lithio derivative have been studied with the aim of obtaining 3,4-disubstituted trifluoropyridines. Routes to such materials have been developed and their conversion to deazapurine derivatives as potential substrates for the generation of anti-sense nucleosides are reported.
- Coe, Paul L.,Rees, Anthony J.
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- Reactivity of Negative Ions with Trifluoromethyl Halides
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The kinetics of the reactions of selected anions (A(-)) with the trifluoromethyl halides CF3X (X = F, Cl, Br, I) in the gas phase were measured at 300 K.Reaction rate constants and product branching fractions were determined using a selected ion flow tube (SIFT) instrument.The chosen anions were C5F5N(-), o-, m-, and p-CF3C6H4CN(-), C6F5Br(-), C6F5Cl(-), C6F5CF3(-), C6F5COCH3(-), Fe(-), FeCO(-), SF6(-), SO(-), SO2(-), NO(-), NO2(-), and NO3(-).The reactivity of these systems varies from unreactive to collisional, and a variety of reaction types was found.The results of our present and previous measurements on A(-) + CF3X reactions show that, in cases where nondissociative electron transfer (NDET) is energetically allowed, the total reactivity tends to be high, approaching collisional.This suggests that reactivity in these cases is initiated and controlled by electron transfer from the anion.In addition, association reactions tend to be preempted when NDET is energetically allowed.A few exceptions to these tendencies were found and are discussed.
- Morris, Robert A.,Viggiano, A. A.,Miller, Thomas M.,Seeley, John V.,Arnold, Susan T.,et al.
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p. 10641 - 10645
(2007/10/03)
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- FLUORINATIONS WITH COMPLEX METAL FLUORIDES. PART 6. FLUORINATION OF PYRIDINE AND RELATED COMPOUNDS WITH CAESIUM TETRAFLUOROCOBALTATE(III)
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Pyridine has been fluorinated over caesium tetrafluorocobaltate(III) (CsCo(III)F4) at 300-400 deg C to give a mixture of undecafluoro-N-methyl-pyrrolidine, bis(trifluoromethyl)amine, pentafluoropyridine and several polyfluoropyridines; the product composition depend to some extent on the geometry of the reactor.The fluorinations of pentafluoropyridine, piperidine and undecafluoropiperidine were also investigated.
- Plevey, Raymond G.,Rendell, Richard W.,Tatlow, John Colin
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p. 159 - 170
(2007/10/02)
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- FLUORINATIONS WITH POTASSIUM TETRAFLUOROCOBALTATE(III) PART VII. FURTHER INVESTIGATIONS ON THE FLUORINATION OF PYRIDINE
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The product from the fluorination of pyridine by KCoF4 at ca. 220 deg C contains eleven fluoropyridines, two fluoro-2-azahex-enes, three azahexadienes, and two fluoro-N-methylpyrrolidines, besides an azacyclohexa-1,3-diene.Four products were isolated from fluorination of pyridine by CoF3 at ca. 150 deg C, a 2-azahexene, two N-methylpyrrolidines, and 4H-nonafluoropiperidine.
- Coe, Paul L.,Holton, Andrew G.,Tatlow, John Colin
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p. 171 - 190
(2007/10/02)
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- FLUORINATIONS WITH COMPLEX METAL FLUORIDES. PART 7. FLUORINATIONS OF THE METHYL PYRIDINES WITH CAESIUM TETRAFLUOROCOBALTATE
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4-Methylpyridine passed over caesium tetrafluorocobaltate at 330-340 deg gave tridecafluoro(1,3-dimethylpyrrolidine) (1) and its 3-difluoromethyl analogue (2), together with a range of polyfluoro-4-picolines (4-10) with -CF3, -CHF2 or -CH2F groups in the 4-position. 3-Methylpyridine similarly gave 1 and its 1,2-isomer (11) together with several polyfluoro-3-picolines (14-18). 2-Methylpyridine at 270 deg gave tridecafluoro(1-ethylpyrrolidine) (13), a trace of 11 and 2-trifluoromethyl- (22), 2-difluoromethyl- (23) and 2-fluoromethyl-tetrafluoropyridine (24); there were also products arising by loss of methyl.Other unidentified fluoroalkylpyridines besides those isolated were present in each case.
- Plevey, Raymond G.,Rendell, Richard W.,Tatlow, John Colin
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p. 265 - 286
(2007/10/02)
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- HIGHLY FLUORINATED HETEROCYCLES PART XV . THE METAL CATALYSED DEFLUORINATIVE REARRANGEMENT OF POLYFLUORINATED PYRROLIDINES TO POLYFLUOROPYRIDINES
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Pyrolysis of a number of polyfluoro-1-alkyl pyrrolidines over iron gauze at 500-525o affords a small conversion to polyfluoropyridines.
- Coe, P. L.,Sleigh, J. H.
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p. 403 - 408
(2007/10/02)
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- LA FLUORATION DE L'HEXACHLOROBENZENE ET DE LA PENTACHLOROPYRIDINE EN MILIEU DE FLUORURE DE POTASSIUM SOLIDE
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The fluorinations of hexachlorobenzene and pentachloropyridine were carried out in sealed tubes with KF in presence of inert gas; the fluorinated derivatives C6FxCly x + y = 6 0 - are investigated and compared; the molar yield varied from 45percent to 90percent.It is possible to get directly and selectively some fluorinated drivatives as C5Cl2F3N.The fluorinations in liquid KF-KCl and solid KF are compared.
- Hitzke, J.
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p. 103 - 128
(2007/10/02)
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- 2,4-Diaryl[1,3,4H]thiadiazines fused to quinoxalines
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Compounds are provided which have the formula: STR1 WHERE Ar1 and Ar2 are aromatic radicals and X and Y are 1 to 2 nitrogen atoms and conversely 3 to 2 carbon atoms which may have selected substitutes. Preferably, 2 adjacent carbon atoms (usually the 2 Y's) have a butadienyl or a substituted butadienyl attached thereto. The compounds are useful as dyes.
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