cas 421-07-8, 1,1,1-TRIFLUOROPROPANE | Articles data

Articles about 421-07-8Total 34 be found

Article title
Article abstract
Author
Journal number and time
Download

Reactivity of 3,3,3-Trifluoropropyne at Rhodium Complexes: Development of Hydroboration Reactions
The rhodium compounds [Rh(C≡CCF3)(PEt3)3] (2), fac-[RhH(C≡CCF3)2(PEt3)3] (3), and fac-[Rh{(E)-CH=CHCF3}(C≡CCF3)2(PEt3)3] (4) were synthesized by reactions of the rhodium(I) complexes [Rh(H)(PEt3)3] (1) and [Rh(Bpin)(PEt3)3] (5, HBpin=pinacolborane) with the alkyne 3,3,3-trifluoropropyne. Reactivity studies of [Rh(C≡CCF3)(PEt3)3] (2) were performed with CO and 13CO to form [Rh(C≡CCF3)(CO)(PEt3)3] (7) and subsequently trans-[Rh(C≡CCF3)(CO)(PEt3)2] (8) as well as the labeled derivatives. Using 1–4 as catalysts, hydroboration reactions selectively afforded borylated building blocks.
von Hahmann, Cortney N.,Talavera, Maria,Xu, Conghui,Braun, Thomas
p. 11131 - 11138
(2018)
Read Online

The monofluorination of hydrofluorocarbons over cobalt trifluoride
Hydrofluorocarbons (HFCs) have been fluorinated via the high-valency metal fluorides CoF3, MnF3 and KCoF4.The fluorinating powers of these reagents for the monofluorination of 2,2-difluoropropane are in the order CoF3>MnF3>KCoF4.The fluorinations of fluorinated ethanes with CoF3 have been examined in detail.The effects of temperature and the distribution products are described.Furthermore, regioselective monofluorination of gem-difluoro compounds (C3-C5) with CoF3 was achieved at the methylene position adjacent to the gem-difluoro group.The trifluoro compounds were obtained in good yield at low reaction temperatures.
Kurosawa, Shigeru,Sekiya, Akira,Arimura, Takashi,Yamada, Toshiro
p. 69 - 76
(1993)
Read Online

Versatile Reaction Pathways of 1,1,3,3,3-Pentafluoropropene at Rh(I) Complexes [Rh(E)(PEt3)3] (E=H, GePh3, Si(OEt)3, F, Cl): C-F versus C-H Bond Activation Steps
The reaction of the rhodium(I) complexes [Rh(E)(PEt3)3] (E=GePh3 (1), H (6), F (7)) with 1,1,3,3,3-pentafluoropropene afforded the defluorinative germylation products Z/E-2-(triphenylgermyl)-1,3,3,3-tetrafluoropropene and
Braun, Thomas,Talavera, Maria
supporting information
p. 11926 - 11934
(2021/07/06)

Activation of pentafluoropropane isomers at a nanoscopic aluminum chlorofluoride: Hydrodefluorination versus dehydrofluorination
The hydrofluorocarbon 245 isomers, 1,1,1,3,3-pentafluoropropane, 1,1,1,2,2- pentafluoropropane, and 1,1,1,2,3-pentafluoro-propane (HFC-245fa, HFC-245cb, and HFC-245eb) were activated through C-F bond activations using aluminium chlorofluoride (ACF) as a catalyst. The addition of the hydrogen source Et3SiH is necessary for the activation of the secondary and tertiary C-F bonds. Multiple C-F bond activations such as hydrodefluorinations and dehydrofluorinations were observed, followed by hydroarylation and Friedel-Crafts-type reactions under mild conditions.
Ahrens, Mike,Braun, Thomas,Kemnitz, Erhard,Kervarec, Ma?va-Charlotte
supporting information
p. 2623 - 2635
(2020/11/26)

C?H and C?F Bond Activation Reactions of Fluorinated Propenes at Rhodium: Distinctive Reactivity of the Refrigerant HFO-1234yf
The reaction of [Rh(H)(PEt3)3] (1) with the refrigerant HFO-1234yf (2,3,3,3-tetrafluoropropene) affords an efficient route to obtain [Rh(F)(PEt3)3] (3) by C?F bond activation. Catalytic hydrodefluorinations were achieved in the presence of the silane HSiPh3. In the presence of a fluorosilane, 3 provides a C?H bond activation followed by a 1,2-fluorine shift to produce [Rh{(E)-C(CF3)=CHF}(PEt3)3] (4). Similar rearrangements of HFO-1234yf were observed at [Rh(E)(PEt3)3] [E=Bpin (6), C7D7 (8), Me (9)]. The ability to favor C?H bond activation using 3 and fluorosilane is also demonstrated with 3,3,3-trifluoropropene. Studies are supported by DFT calculations.
Talavera, Maria,von Hahmann, Cortney N.,Müller, Robert,Ahrens, Mike,Kaupp, Martin,Braun, Thomas
supporting information
p. 10688 - 10692
(2019/07/10)

Consecutive Transformations of Tetrafluoropropenes: Hydrogermylation and Catalytic C?F Activation Steps at a Lewis Acidic Aluminum Fluoride
Functionalization reactions of the refrigerants HFO-1234yf (2,3,3,3-tetrafluoropropene) and HFO-1234ze (1,3,3,3-tetrafluoropropene) were developed. The selectivity and reactivity towards CF3 groups of C?F activation reactions can be controlled by employing either a germane or a silane as the hydrogen source. Unique transformations were designed to accomplish consecutive hydrogermylation and C?F activation steps. This allowed for an unprecedented transformation of an olefinic C?F bond into a C?H bond by heterogeneous catalysis. These reactions are catalyzed by nanoscopic aluminum chlorofluoride (ACF) under very mild conditions.
Mei?ner, Gisa,Kretschmar, Konrad,Braun, Thomas,Kemnitz, Erhard
supporting information
p. 16338 - 16341
(2017/11/29)

Trifluoromethylation of Alkyl Radicals in Aqueous Solution
The copper-mediated trifluoromethylation of alkyl radicals is described. The combination of Et3SiH and K2S2O8 initiates the radical reactions of alkyl bromides or iodides with BPyCu(CF3)3 (BPy = 2,2′-bipyridine) in aqueous acetone at room temperature to afford the corresponding trifluoromethylation products in good yield. The protocol is applicable to various primary and secondary alkyl halides and exhibits wide functional group compatibility. A mechanism involving trifluoromethyl group transfer from Cu(II)-CF3 intermediates to alkyl radicals is proposed.
Shen, Haigen,Liu, Zhonglin,Zhang, Pei,Tan, Xinqiang,Zhang, Zhenzhen,Li, Chaozhong
p. 9843 - 9846
(2017/08/02)

Silver-Catalyzed Decarboxylative Trifluoromethylation of Aliphatic Carboxylic Acids
The silver-catalyzed decarboxylative trifluoromethylation of aliphatic carboxylic acids is described. With AgNO3 as the catalyst and K2S2O8 as the oxidant, the reactions of aliphatic carboxylic acids with (bpy)C
Tan, Xinqiang,Liu, Zhonglin,Shen, Haigen,Zhang, Pei,Zhang, Zhenzhen,Li, Chaozhong
p. 12430 - 12433
(2017/09/25)

Competing reaction pathways of 3,3,3-trifluoropropene at rhodium hydrido, silyl and germyl complexes: C-F bond activation: Versus hydrogermylation
The reaction of the silyl complex [Rh{Si(OEt)3}(PEt3)3] (1) with 3,3,3-trifluoropropene afforded the rhodium complex [Rh(CH2CHCF3){Si(OEt)3}(PEt3)2] (2) which features a bonded fluorinated olefin. In contrast the rhodium hydrido complex [Rh(H)(PEt3)3] (3) yielded on treatment with 3,3,3-trifluoropropene in the presence of a base the fluorido complex [Rh(F)(PEt3)3] (4) together with 1,1-difluoro-1-propene by C-F bond activation. At low temperature the intermediate fac-[Rh(H)(CH2CHCF3)(PEt3)3] (5) was detected by NMR spectroscopy. The germyl complex [Rh(GePh3)(PEt3)3] (6) reacted also with 3,3,3-trifluoropropene by C-F bond activation affording again the fluorido complex [Rh(F)(PEt3)3] (4) as well as the (3,3-difluoroallyl)triphenylgermane 7. The catalytic hydrogermylation of 3,3,3-trifluoropropene in the presence of various germanium hydrides under mild conditions was developed by employing complex 6 as a catalyst. The molecular structures of both germane derivatives (3,3-difluoroallyl)triphenylgermane 7 and 1,1,1-trifluoropropane-3-triphenylgermane 8 were determined by X-ray crystallography.
Ahrens, Theresia,Teltewskoi, Michael,Ahrens, Mike,Braun, Thomas,Laubenstein, Reik
p. 17495 - 17507
(2016/11/13)

PROCESS FOR 1-CHLORO-3,3,3-TRIFLUOROPROPENE FROM TRIFLUOROPROPENE
The present invention provides routes for making 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) from commercially available raw materials. More specifically, this invention provides several routes for forming HCFO-1233zd from 3,3,3-trifluoropropene (FC-1234zf).
-
Paragraph 0072

(2015/02/25)

Process for the Preparation of 1,1,1-Trifluoropropane
The invention provides a process comprising contacting (1243zf) or (253fb) with hydrogen in the presence of a hydrogenation catalyst to produce a composition comprising 1,1,1-trifluoropropane (263fb).
-
Paragraph 0048-0050

(2015/05/13)

Highly selective hydroformylation of 3,3,3-trifluoropropene to 4,4,4-trifluorobutanal using Rh/Xantphos catalyst
Synthesis of 4,4,4-trifluorobutanal by Rh-catalyzed hydroformylation of 3,3,3-trifluoropropene with bis(4,5-diphenylphosphino)xanthene as a ligand was investigated. The uses of [Rh(OH)(cod)]2 (cod = 1,5-cyclooctadinene) and dimethylformamide in CO/H2 = 75/25 mixed gas under atmospheric pressure at 80 C for 15 h provided the highest aldehyde yield 90%. The molar ratio of linear aldehyde (4,4,4-trifluorobutanal) to branched aldehyde (3,3,3-trifluoro-2-methylpropanal) was 99/1. The successive addition of dimethylformamide solution of 3,3,3-trifluoropropene under atmospheric pressure revealed that 4,4,4-trifluorobutanal formation increased linearly with the reaction time and the total turnover number reached 500 after 10 h retaining 99% selectivity of 4,4,4-trifluorobutanal at 80 C.
Ohtsuka, Yuhki,Kobayashi, Osamu,Yamakawa, Tetsu
p. 34 - 40
(2014/04/03)

PROCESS FOR THE PREPARATION OF 1, 1, 1 - TRIFLUOROPROPANE
The invention provides a process comprising contacting (1243zf) or (253fb) with hydrogen in the presence of a hydrogenation catalyst to produce a composition comprising 1,1,1-trifluoropropane (263fb).
-
Page/Page column 9

(2013/03/26)

Titanium-catalyzed vinylic and allylic C-F bond activation-scope, limitations and mechanistic insight
The hydrodefluorination (HDF) of fluoroalkenes in the presence of a variety of titanium catalysts was studied with respect to scope, selectivity, and mechanism. Optimization revealed that the catalyst requires low steric bulk and high electron density; secondary silanes serve as the preferred hydride source. A broad range of substrates yield partially fluorinated alkenes, such as previously unknown (Z)-1,2-(difluorovinyl)ferrocene. Mechanistic studies indicate a titanium(III) hydride as the active species, which forms a titanium(III) fluoride by H/F exchange with the substrate. The HDF step can follow both an insertion/elimination and a σ-bond metathesis mechanism; the E/Z selectivity is controlled by the substrate. The catalysts' ineffieciency towards fluoroallenes was rationalized by studying their reactivity towards Group 6 hydride complexes. The broad application of the catalytic hydrofluorination of fluoroalkenes by the system [Cp2TiF 2]/silane is demonstrated. Isolated yields up to 79 % could be obtained for various substrates. Mechanistic studies indicate two competing reaction mechanisms. Copyright
Kuehnel, Moritz F.,Holstein, Philipp,Kliche, Meike,Krueger, Juliane,Matthies, Stefan,Nitsch, Dominik,Schutt, Joseph,Sparenberg, Michael,Lentz, Dieter
supporting information
p. 10701 - 10714
(2013/01/14)

USE OF COPPER-NICKEL CATALYSTS FOR DEHLOGENATION OF CHLOROFLUOROCOMPOUNDS
The disclosure describes a process for dehalogenation of chlorofluorocompounds. The process comprises contacting a saturated chlorofluorocompound with hydrogen in the presence of a catalyst at a temperature sufficient to remove chlorine and/or fluorine substituents to produce a fluorine containing terminal olefin.
-
Page/Page column 4

(2012/05/07)

METHOD FOR PRODUCING 3,3,3-TRIFLUORO PROPENE
A production method of 3,3,3-trifluoropropene includes the step of hydrogenating 1-chloro-3,3,3-trifluoropropene with hydrogen (H2) in a gas phase in the presence of either of: (A) a catalyst having carried on a carrier at least one kind of transition metal selected from the group consisting of ruthenium, nickel, rhodium, iridium, iron, osmium and cobalt, or an oxide of said transition metal; (B) an oxide catalyst of copper and manganese; and (C) a catalyst having carried on a carrier palladium and at least one kind of element selected from the group consisting of bismuth, zinc, copper, silver, lanthanum, lead, zirconium, niobium, hafnium, magnesium, tin and arsenic.
-
Page/Page column 9

(2012/11/07)

Titanium-catalyzed C-F activation of fluoroalkenes
(Figure Presented) Detox: Air-stable titanocene difluoride efficiently catalyzes the chemoselective hydrodefluorination of fluoroalkenes at room temperature leading to hydrofluoroalkenes in high yields (see scheme: Cp = cyclopentadienyl). This is a rare example of the catalyzed conversion of fluoroalkenes into less-fluorinated compounds, which have a lower climatic impact, and is a potential method for breaking down toxic perfluoroalkenes.
Kuehnel, Moritz F.,Lentz, Dieter
scheme or table
p. 2933 - 2936
(2010/07/05)

1,2,3,3,3-PENTAFLUOROPROPENE PRODUCTION PROCESSES
A process is disclosed for making CF3CF=CHF. The process involves reacting CF3CCIFCCI2F with H2 in a reaction zone in the presence of a catalyst to produce a product mixture comprising CF3CF=CHF. The catalyst has a catalytically effective amount of palladium supported on a support selected from the group consisting of alumina, fluorided alumina, aluminum fluoride and mixtures thereof and the mole ratio of H2 to CF3CCIFCCI2F fed to the reaction zone is between about 1 :1 and about 5:1.. Also disclosed are azeotropic compositions of CF3CCIFCCI2F and HF and azeotropic composition of CF3CHFCH2F and HF.
-
Page/Page column 14

(2008/06/13)

Transition state for alkyl group hydrogenation on Pt(111)
Substituent effects have been used to probe the characteristics of the transition state to hydrogenation of alkyl groups on the Pt(111) surface. Eight different alkyl and fluoroalkyl groups have been formed on the Pt(111) surface by dissociative adsorption of their respective alkyl and fluoroalkyl iodides. Coadsorption of hydrogen and alkyl groups, followed by heating of the surface, results in hydrogenation of the alkyl groups to form alkanes, which then desorb into the gas phase. Temperature-programmed reaction spectroscopy was used to measure the barriers to hydrogenation, ΔEH≠, which are dependent on the size of the alkyl group (polarizability) and the degree of fluorination (field effect). This example is one of only two surface reactions for which the influence of the substituents on ΔE H? has been correlated with both the field and the polarizability substituent constants of the alkyl groups in the form of a linear free energy relationship. Increasing both the field and the polarizability constants of the alkyl groups increases the value of ΔEH ?. The substituent effects are quantified by a field reaction constant of ρF = 27 ± 4 kJ/mol and a polarizability reaction constant of ρα = 19 ± 3 kJ/mol. These suggest that the transition state for hydrogenation is slightly cationic with respect to the alkyl group on the Pt(111) surface, RC + H ←{RC δ+ ...H)?.
Ye, Pingping,Gellman, Andrew J.
supporting information; body text
p. 8518 - 8526
(2009/02/03)

PROCESSES FOR PRODUCING 2,3,3,3-TETRAFLUOROPROPENE, A PROCESS FOR PRODUCING 1-CHLORO-2,2,3,3,3-PENTAFLUOROPROPANE AND AZEOTROPIC COMPOSITIONS OF 1-CHLORO-2,3,3,3-TETRAFLUOROPROPENE WITH HF
A process is disclosed for making CH2=CFCF3. The process involves contacting CH2CICF2CF3 with H2 in a reaction zone in the presence of a catalyst including a catalytically effective amount of palladium supported on a support selected from chromium oxide, fluorinated chromium oxide, chromium fluoride, aluminum oxide, aluminum fluoride and/or fluorinated alumina, to produce CH2=CFCF3. The mole ratio of H2 to the CH2CICF2CF3 fed to the reaction zone is between about 1 :1 and about 4:1. Also disclosed is another process for making CH2=CFCF3 that involves (a) reacting CH2CICF2CF3 with H2 in the presence of a catalytically effective amount of hydrogenation catalyst to form CH3CF2CF3; and (b) dehydrofluorinating CH3CF2CF3 from (a) to form CH2=CFCF3;and another process for making CH2=CFCF3 that involves (1 ) dehydrofluorinating CH2CICF2CF3 in the presence of a catalytically effective amount of dehydrofluorination catalyst to form CHCI=CFCF3; and (2) hydrogenating CHCI=CFCF3 from (1 ) in the presence of a hydrogenation catalyst including a catalytically effective amount of palladium supported on a support selected from chromium oxide, fluorinated chromium oxide, chromium fluoride, aluminum oxide, aluminum fluoride and/or fluorinated alumina to form CH2=CFCF3. Also disclosed is a process for making CH2CICF2CF5. This process involves reacting CH2CIF with CF2=CF2 in a reaction zone in the presence of a catalytically effective amount of an aluminum halide composition having a bulk formula of AICIxBryF3-x-y wherein the average value of x is O to 3, the average value of y is O to 3-x, provided that the average values of x and y are not both O. Also disclosed is an azeotropic composition including CF3CF=CHCI and HF.
-
Page/Page column 14-15

(2008/12/05)

PROCESS FOR THE SYNTHESIS AND SEPARATION OF HYDROFLUOROOLEFINS
A process for the synthesis of fluorinated olefins of the formula CF3CF=CHX, wherein X is F or H comprising contacting hexafluoropropene with hydrogen chloride in the vapor phase, in the presence of a catalyst, at a temperature in the range from about 200 °C to about 350 °C, wherein the mole ratio of hydrogen chloride to hexafluoropropene is from about 2:1 to about 4:1, separating the 1-chloro-1,2,3,3,3-pentafluoro-1-propene, 1,1-dichloro-2,3,3,3-tetrafluoro-1-propene and hydrogen fluoride products from unreacted hexafluoropropene, and hydrogen chloride by distillation, hydrogenating either the 1-chloro-1,2,3,3,3-pentafluoro-1-propene, 1,1-dichloro-2,3,3,3-tetrafluoro-1-propene or mixture thereof over a catalyst, and dehydrochlorinating the said hydrogenation product to produce either 1225ye or 1234yf.
-
Page/Page column 17-18

(2008/12/07)

PROCESSES FOR PRODUCING AND COMPOSITIONS COMPRISING 2,3,3,3-TETRAFLUOROPROPENE AND/OR 1,2,3,3-TETRAFLUOROPROPENE
A process is disclosed for making CF3CF=CH2 or mixtures thereof with CHF=CFCHF2. The process involves contacting CCI3CF2CF3 and optionally CCI2FCF2CCIF2 with H2 in the presence of a catalyst including a catalytically effective amount of palladium supported on a support of alumina, fluorided aluminaand/or aluminum fluoride, to produce a product mixture including CH2=CFCF3 (and when CCI2FCF2CCIF2 is present, CHF=CFCHF2); recovering CH2=CFCF3 or a mixture thereof with CHF=CFCHF2 from the product mixture; and optionally, separating at least a portion of any CHF=CFCHF2 in the product mixture from the CH2=CFCF3 in the product mixture. The mole ratio of H2 to the total of CCI3CF2CF3 and CCI2FCF2CCIF2 fed to the reaction zone is between about 1 :1 and about 5:1. The present invention also provides another process for making CH2=CFCF3 Or mixtures thereof with CHF=CFCHF2 This process involves (a) reacting CCI3CF2CF3 and optionally CCI2FCF2CCIF2 with H2 in the presence of a catalytically effective amount of a hydrogenation catalyst to form CH3CF2CF3 (and when CCI2FCF2CCIF2 is present, CH2FCF2CHF2); (b) dehydrofluorinating CH3CF2CF3 and optionally any CH2FCF2CHF2 from (a) to form a product mixture including CH2=CFCF3, and if CH2FCF2CHF2 is present, CHF=CFCHF2; (c) recovering CH2=CFCF3 or a mixture thereof with CHF=CFCHF2 from the product mixture formed in (b); and optionally (d) separating at least a portion of any CHF=CFCHF2 in the product mixture formed in (b) from the CH2=CFCF3 in the product mixture formed in (b). The present invention also provides compositions involving CH2=CFCF3 and/or CHF=CFCHF2, including compositions useful as refrigerants, foam blowing agents, cleaning agents and aerosols and azeotropic compositions involving (a) CF2HCF=CFH and (b) HF.
-
Page/Page column 21-22

(2008/12/05)

PROCESSES FOR PRODUCING 2,3,3,3-TETRAFLUOROPROPENE AND/OR 1,2,3,3-TETRAFLUOROPROPENE
A process is disclosed for making CF3CF=CH2 or mixtures thereof with CHF2CF=CHF. This process involves (a) reacting CHCI2CF2CF3, and optionally CHCIFCF2CCIF2, with H2 in the presence of a catalytically effective amount of a hydrogenation catalyst to form CH3CF2CF3 and, when CHCIFCF2CCIF2 is present, CH2FCF2CHF2; (b) dehydrofluorinating CH3CF2CF3, and optionally any CH2FCF2CHF2, from (a) to form a product mixture including CF3CF=CH2 and, if CH2FCF2CHF2 Js present, CHF2CF=CHF; and optionally (c) recovering CF3CF=CH2, or a mixture thereof with CHF2CF=CHF from the product mixture formed in (b) and/or (d) separating at least a portion of any CHF2CF=CHF in the product mixture formed in (b) from the CF3CF=CH2 in the product mixture formed in (b).
-
Page/Page column 10-11

(2008/12/05)

Activation of aromatic, aliphatic, and olefinic carbon-fluorine bonds using Cp*2HfH2
The hafnium hydride Cp*2HfH2 is reacted with a series of fluorocarbons to examine the scope of C-F bond activation. Aromatic, vinylic, and aliphatic C-F bonds all show some degree of reactivity, and possible mechanisms are discussed. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Rieth, Ryan D.,Brennessel, William W.,Jones, William D.
p. 2839 - 2847
(2008/02/10)

Fluoride-mediated selective cross-coupling reactions of alkyl halides and trimethyl(perfluoroalkyl)silanes, Me3SiRf (Rf = CF3, C2F5) in the absence of any catalysts
A temperature range of -18 °C to room temperature was found to be effective for selective fluoride-mediated cross-coupling reactions of trimethyl(perfluoroalkyl)silanes, Me3SiCF3 and Me3SiC2F5, and alkyl halides, RX (X = Br, I) in the absence of any catalyst.
Tyrra, Wieland,Naumann, Dieter,Quadt, Silke,Buslei, Sigrid,Yagupolskii, Yurii L.,Kremlev, Mikhail M.
p. 813 - 817
(2008/03/14)

PROCESS FOR THE PREPARATION OF 1,1,1,3,3-PENTAFLUOROPROPANE AND 1,1,1,2,3-PENTAFLUOROPROPANE
A process is disclosed for the manufacture of CF3CH2CHF2 and CF3CHFCH2F. The process involves (a) reacting hydrogen fluoride, chlorine, and at least one halopropene of the formula CX3CCl=CClX (where each X is independently F or Cl) to produce a product including both CF3CCl2CClF2 and CF3CClFCCl2F; (b) reacting CF3CCl2CClF2 and CF3CClFCCl2F produced in (a) with hydrogen to produce a product including both CF3CH2CHF2, and CF3CHFCH2F; and (c) recovering CF3CH2CHF2 and CF3CHFCH2F from the product produced in (b). In (a), the CF3CCl2CClF2 and CF3CClFCCl2F are produced in the presence of a chlorofluorination catalyst including a ZnCr2O4/crystalline α-chromium oxide composition, a ZnCr2O4/crystalline α-chromium oxide composition which has been treated with a fluorinating agent, a zinc halide/α-chromium oxide composition and/or a zinc halide/α-chromium oxide composition which has been treated with a fluorinating agent.
-
Page/Page column 17; 19

(2008/06/13)

Conversion of hexafluoropropene into 1,1,1-trifluoropropane by rhodium-mediated C-F activation
Rapid and regioselective C-F bond activation of hexafluoropropene occurs on reaction with 1. Treatment of the resulting complex 2 with hydrogen yields the rhodium fluoro complex 3 and 1,1,1-trifluoropropane (4).
Braun, Thomas,Noveski, Daniel,Neumann, Beate,Stammler, Hans-Georg
p. 2745 - 2748
(2007/10/03)

Substituent effects on the disproportionation-combination rate constant ratios for gas-phase halocarbon radicals. II. Reactions of · CF3 + CF3CH2CH2 · and CF3CH2CH2· + CF3CH2CH2·
Disproportionation/combination rate constant ratios, kd/kc. have been measured for the collision between CF3CH2CH2 and CF3 radicals to be 0.022 ± 0.002 and for CF3CH2CH2 and CF3CH2CH2 radicals to be 0.100 ± 0.002. Comparison to previous work from this laboratory for the reaction of CF3CH2CHCl with CF3 radicals shows that substitution of Cl for H increases the kd/kc by about 50%; however, for the auto disproportionation-combination of CF3CH2CH2 radicals the chlorine substituent decreases the observed rate constant ratio by a factor of two. The chlorine substituent effect on the observed kd/kc ratios is compared to predictions from molecular orbital calculations.
McDowell, Derek R.,Weston, Jennie,Holmes, Bert E.
p. 61 - 68
(2007/10/03)

Hydroformylation of Fluoro Olefins, RfCH=CH2, Catalyzed by Group VIII Transition-Metal Catalysts. Crucial Factors for Extremely High Regioselectivity
Hydroformylations of fluoro olefins, trifluoroprop-1-ene (TFP), pentafluorobut-1-ene (PFB), heptafluoropent-1-ene (HPFP), heptadecafluorodec-1-ene (HPDFD), vinyl fluoride (VF), pentafluorostyrene (PFS), and allylpentafluorobenzene (4a), promoted by transition-metal catalysts were studied.Remarkable dependency of the regioselectivity of the reaction on the catalyst metal species (Co, Pt, Ru, and Rh) was found in the reactions of TFP and PFS; e.g., n-aldehyde was obtained with >93percent selectivity by a cobalt catalyst whereas iso-aldehyde was obtained with >96percent selectivity by a rhodium catalyst for the reaction of TFP.On the contrary, the reaction of VF gave 2-fluoropropanal (2-FPA) exclusively, regardless of the metal catalyst species.The effects of temperature and carbon monoxide pressure on the regioselectivity were investigated.Possible mechanisms for the uniquely regioselective hydroformylations are discussed on the basis of the results obtained, and a mechanism that involves an initial formation of isoalkyl-metal species followed by isomerization to n-alkyl-metal species and/or followed by carbon monoxide insertion to form isoacyl-metal intermediate was proposed to be the one operating in these reactions.
Ojima, Iwao,Kato, Koji,Okabe, Masami,Fuchikami, Takamasa
p. 7714 - 7720
(2007/10/02)

Nucleophilic Reactions of F3C- at sp2 and sp3 Carbon in the Gas Phase. Characterization of Carbonyl Addition Adducts
The reactions of F3C- with CH3Br and CH3Cl established the medium kinetic nucleophilicity of F3C- on Bohme's reactivity scale for gas-phase SN2 reactions.The reactions of F3C- with (CH3)2C=O and CH3CO2CH3 proceeded by competitive bimolecular H+ transfer and termolecular carbonyl addition giving the corresponding adducts anions m/z 127 and 143, respectivaly.F3C- reacted with esters C6H5CO2CH3, CF3CO2CH3, and (CH3O)2C=O both by SN2 displacement forming the corresponding carboxylate anions and by carbonyl addition yielding the adduct anions; with CF3CO2C2H5 and CF3CO2C(CH3)3, the competitive bimolecular reaction channel involved E2 elimination giving CF3CO2-.The major reaction channel of F3C- with HCO2CH3 was the Riveros reaction that produced the series of cluster ions F3C-(HOCH3), F3C-(HOCH3)2, CH3O-(HOCH3), and CH3O-(HOCH3)2, along with a minor amount of carbonyl addition.The fast termolecular reaction of F3C- with (CF3)2C=O exclusively formed the adduct (CF3)3CO- (m/z 235) which was characterized as the bound, tetrahedral structure by bracketing its proton affinity.The reaction of F3C- with CO2 giving CF3CO2- was established as a termolecular process when the "apparent" bimolecular rate constant was shown to be PHe dependent.These results demonstrate unequivocally that the reactions of gas-phase nucleophiles with the carbonyl group of ketones and esters proceed by addition yielding the corresponding adduct oxyanions which is analogous to the related process in the condensed phase.
McDonald, Richard N.,Chowdhury, A. Kasem
p. 7267 - 7271
(2007/10/02)

KINETICS OF REACTIONS OF C3., C5. AND C7. ALKYL RADICALS FORMED IN THE CF3. + C2H4 SYSTEM, I. DETERMINATION OF THE RATE COEFFICIENTS
n-Propyl, n-pentyl and n-heptyl free radicals (with perfluorinated methyl groups) were generated by the photolysis of perfluoroacetic anhydride (PFAA) in the presence of ethylene.Reaction products up to dodecanes were identified and measured under various experimental conditions, i.e. at different ethylene concentrations, / ratios, reaction temperatures and incident light intensities.Disproportionation/combination ratios were obtained for the n-propyl, n-pentyl and s-heptyl free radicals.The rates of addition of the C3. and C5. radicals were studied at 300 and 362 K.The rate coefficient ratios kaddition/kcombination1/2 of (4.04+/-0.69)E-3 and (2.72+/-0.66)E-3 dm3/2 mol-1/2 s-1/2 were determined at room temperature for the n-propyl and n-pentyl radicals, respectively.The activation energies obtained were 27.8 kJ mol-1 for C3. addition and 26.8 kJ mol-1 for C5. addition.Isomerisation of the n-heptyl radical by 1,5-hydrogen shift was observed to occur and the isomerization rate coefficient relative to that of C7. self-combination, kisomeriz/kcomb1/2=(5.8+/-1.0)E-5 mol1/2 dm-3/2 s-1/2, was determined at room temperature.The kinetic results for addition and isomerization reactions are discussed in the light of available literature data.
Dobe, Sandor,Berces, Tibor,Marta, Ferenc
p. 43 - 58
(2007/10/02)

Remarkable Dependency of Regioselectivity on the Catalyst Metal Species in the Hydroformylation of Trifluoropropene and Pentafluorostyrene
-
Fuchikami, Takamasa,Ojima, Iwao
p. 3527 - 3529
(2007/10/02)

ORGANOPHOSPHORUS CHEMISTRY. PART 21. INSERTION OF OLEFINS INTO P-CF3 BONDS
Tris(trifluoromethyl)phosphine and ethylene reacted efficiently under u.v. irradiation to give 3,3,3-trifluoropropylbis(trifluoromethyl)phosphine in good yield.With vinyl fluoride, vinylidene fluoride, and propene the reaction was regioselective rather than regiospecific, and the yield of 1:1 adduct was low.In these reactions, and in those with vinyl chloride, but-1-ene, and hexafluoropropene, in which only traces of 1:1 adduct could be detected, the bulk of the olefin and of the phosphine was recovered, and numerous by-products consistent with radical intermediates were identified.With propyne, 1,1,1-trifluoro-3-bis(trifluoromethyl)phospino-cis-but-2-ene was obtained in moderate yield, but no reaction occured between the phosphine and either but-2-yne or hexafluorobut-2-yne.Tris(trifluoromethyl)phosphine oxide did not form an adduct with ethylene, tetrafluoroethylene, or propyne.Bis(trifluoromethyl)phosphine and dimethylphosphine both reacted readily under u.v. irradiation with 3,3,3-trifluoropropene, the phosphinyl radical attacking the terminal carbon in each case.
Cooper, Peter,Fields, Roy,Haszeldine, Robert N.,Mitchell, Gordon H.,Nona, Shmaiel N.
p. 317 - 328
(2007/10/02)

Fluorine substitution in 1,1,1-trihalomethanes
Fluorine is substituted for other halogen atoms on the 1-carbon atom of a compound which contains a 1,1,1-trihalomethyl group (trichloromethyl) by contacting said compound or a precursor thereof with liquid HF in the presence of a mixture of antimony pentahalide with at least an approximately equimolar amount of antimony trihalide. The antimony halides may be added as the chlorides and in situ converted to fluorides and/or chlorofluorides, which are believed to be the essential agents. Additional starting material and antimony pentahalide may be added in the course of the reaction which proceeds stepwise. When the reactant is 1,1,1,3-tetrachloropropane the reaction can be continued to produce 3-chloro-1,1,1-trifluoropropane which, upon reaction with alkali, yields 3,3,3-trifluoropropane, of known utility in making fluorosilicones. The reaction is also useful in the production of 2-chloro-1,1,1-trifluoroethane from 2-chloro-1,1,1-trihaloethanes and/or precursors thereof such as trichloroethylene, as well as in the production of trifluoromethane and chlorotrifluoromethane from chloroform and carbon tetrachloride, respectively.
-
(2008/06/13)