- TETRAKIS(DIMETHYLAMINO)ETHYLENE/TRIFLUOROIODOMETHANE, A SPECIFIC NOVEL TETRAFLUOROMETHYLATING AGENT
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At low temperatures tetrakis(dimethylamino)ethylene (I) and CF3I form a charge transfer complex, which can act as a nucleophilic trifluoromethylating agent in polar solvents according to eqn. (1): The applicability of eqn.(1) to various silicon and boron halides R-X was tested and the following trifluoromethyl-silicon and boron derivatives were obtained in resonable yields: Me3SiCF3 (II), Me2Si(CF3)2 (III), (F3C)3BNHEt2 (IV).
- Pawelke, G.
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- An efficient inexpensive electrochemical preparation of Ruppert's reagent
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The electrochemical reduction of CF3Br in N,N-dimethylformamide (DMF) in the presence of Me3SiCl and a sacrificial aluminum anode provides Me3SiCF3 in ca 90% faradaic yields.
- Aymard, Frederic,Nedelec, Jean-Yves,Perichon, Jacques
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- SYNTHESIS AND PROPERTIES OF (TRIFLUOROMETHYL)TRICHLOROSILANE, A VERSATILE PRECURSORFOR CF3Si COMPOUNDS
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(Trifluoromethyl)trichlorosilane (I) has been prepared for the first time by the reaction of CF3SiH(NMe2)2 (III) with HCl in dibutyl ether and, as a solution in CH2Cl2, by nucleophilic trifluoromethylation of SiCl4 with CF3Br/P(NEt2)3.From this solution, I mey be isolated by HCl cleavage of its insoluble bis(pyridine) adduct (II).The aminosilane III was obtained from the reaction of HSi(Cl)(NMe2)2 with CF3Br/P(NEt2)3.Selective substitution of I without attack on the CF3Si moiety was achieved in high yields with SbF3 (-> CF3SiF3), Ag(OCN) (-> CF3Si(NCO)3 (IV)), MeOH (-> CF3Si(OMe)3 (V)), HNMe2 (CF3Si(NMe2)3 (VI)), LiAlH4 (-> CF3SiH3), MeMgBr (-> CF3SiMe3) and LiPh (-> CF3SiPh3 (VII)).With 2,2'-bipyridyl a 1/1complex (VIII) was formed.The novel compounds I to VIII have been characterized by their IR, NMR and mass spectra, and for I a vibrational analysis including a normal coordinate treatment has been performed.
- Beckers, H.,Buerger, H.,Bursch, P.,Ruppert, I.
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- Preparation method of trifluoromethyltrimethylsilane
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The invention provides a preparation method of trifluoromethyltrimethylsilane. The preparation method comprises the following steps: (1) synthesizing a Grignard reagent by taking magnesium metal and trifluorohalomethane as raw materials; and (2) enabling the Grignard reagent to react with trimethyl halogenosilane, so as to prepare the trifluoromethyl trimethyl silane. The preparation method of trifluoromethyltrimethylsilane provided by the invention has the advantages of high yield, simple process, low cost and the like.
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Paragraph 0040-0063
(2021/07/14)
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- Generation and Applications of the Hydroxide Trihydrate Anion, [OH(OH2)3]?, Stabilized by a Weakly Coordinating Cation
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The reaction of a strongly basic phosphazene (Schwesinger base) with water afforded the corresponding metastable hydroxide trihydrate [OH(OH2)3]? salt. This is the first hydroxide solvate that is not in contact with a cation and furthermore one of rare known water-stabilized hydroxide anions. Thermolysis in vacuum results in the decomposition of the hydroxide salt and quantitative liberation of the free phosphazene base. This approach was used to synthesize the Schwesinger base from its hydrochloride salt after anion exchange in excellent yields of over 97 %. This deprotonation method can also be used for the phosphazene-base-catalyzed preparation of the Ruppert–Prakash reagent Me3SiCF3 using fluoroform (HCF3) as the trifluoromethyl building block and sodium hydroxide as the formal deprotonation agent.
- Weitkamp, Robin F.,Neumann, Beate,Stammler, Hans-Georg,Hoge, Berthold
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supporting information
p. 14633 - 14638
(2019/11/05)
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- Borazine-CF3? Adducts for Rapid, Room Temperature, and Broad Scope Trifluoromethylation
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A fluoroform-derived borazine CF3? transfer reagent is used to effect rapid nucleophilic reactions in the absence of additives, within minutes at 25 °C. Inorganic electrophiles spanning seven groups of the periodic table can be trifluoromethylated in high yield, including transition metals used for catalytic trifluoromethylation. Organic electrophiles included (hetero)arenes, enabling C?H and C?X trifluoromethylation reactions. Mechanistic analysis supports a dissociative mechanism for CF3? transfer, and cation modification afforded a reagent with enhanced stability.
- Geri, Jacob B.,Wade Wolfe, Michael M.,Szymczak, Nathaniel K.
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supporting information
p. 1381 - 1385
(2018/01/15)
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- Recyclable Trifluoromethylation Reagents from Fluoroform
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We present a strategy to rationally prepare CF3- transfer reagents at ambient temperature from HCF3. We demonstrate that a highly reactive CF3- adduct can be synthesized from alkali metal hydride, HCF3, and borazine Lewis acids in quantitative yield at room temperature. These nucleophilic reagents transfer CF3- to substrates without additional chemical activation, and after CF3 transfer, the free borazine is quantitatively regenerated. These features enable syntheses of popular nucleophilic, radical, and electrophilic trifluoromethylation reagents with complete recycling of the borazine Lewis acid.
- Geri, Jacob B.,Szymczak, Nathaniel K.
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supporting information
p. 9811 - 9814
(2017/08/03)
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- COMPLEXES FOR NUCLEOPHILIC, RADICAL, AND ELECTROPHILIC POLYFLUOROALKYLATION
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Disclosed herein are borazine complexes and use of the same in perfluoroalkylation reactions.
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Paragraph 00157; 00159; 00160
(2018/04/11)
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- Oxidative trifluoromethylation and fluoroolefination of unactivated olefins
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Fluorine-containing organic compounds are gaining increasing importance in medicinal chemistry. Described herein is a mild and efficient method for the radical addition of olefins with TMSCF3 and TMSCF2R (R = COOEt or CF3) to deliver various α-trifluoromethylated ketones and α-fluoroolefinated ketones.
- Wu, Ye-Bin,Lu, Guo-Ping,Yuan, Tao,Xu, Zhu-Bing,Wan, Li,Cai, Chun
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p. 13668 - 13670
(2016/11/29)
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- Preparation method of trifluoromethyl (trimethyl) silane
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The invention discloses a preparation method of trifluoromethyl (trimethyl) silane. The preparation method comprises the following steps that (a) under the argon gas protection, metal potassium, styrene and hexamethyl disilazane take a reaction in methylbenzene until the metal potassium completely dissolves, and reaction liquid is obtained; (b) at -45 to -110 DEG C, trimethylchlorosilane is added into the reaction liquid obtained in the step (a); fluoform is introduced for reaction; after the reaction is finished, the temperature is raised to room temperature; washing and standing layering are performed; an obtained organic layer is rectified to obtain the product of the trifluoromethyl (trimethyl) silane. The preparation method has the advantages of simple process, low cost, high yield, safety and environment-friendly effect.
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Paragraph 0024; 0025; 0026; 0027; 0028; 0029-0035
(2017/07/20)
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- DIRECT TRIFLUOROMETHYLATIONS USING TRIFLUOROMETHANE
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A direct trifluoromethylation method preferably using a trifluoromethane as a fluoro-methylating species. In particular, the present method is used for preparing a trifluoromethylated substrate by reacting a fluoromethylatable substrate with a trifiuoromethylating agent in the presence of an alkoxide or metal salt of silazane under conditions sufficient to trifluoromethylate the substrate; wherein the fluoromethylatable substrate includes chlorosilanes, carbonyl compounds such as esters, aryl halides, aldehydes, ketones, chalcones, alkyl formates, alkyl halides, aryl halides, alkyl borates, carbon dioxide or sulfur.
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Paragraph 0057
(2014/03/25)
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- Taming of fluoroform: Direct nucleophilic trifluoromethylation of Si, B, S, and C centers
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Fluoroform (CF3H), a large-volume by-product of the manufacture of Teflon, refrigerants, polyvinylidene fluoride (PVDF), fire-extinguishing agents, and foams, is a potent and stable greenhouse gas that has found little practical use despite the growing importance of trifluoromethyl (CF3) functionality in more structurally elaborate pharmaceuticals, agrochemicals, and materials. Direct nucleophilic trifluoromethylation using CF3H has been a challenge. Here, we report on a direct trifluoromethylation protocol using close to stoichiometric amounts of CF3H in common organic solvents such as tetrahydrofuran (THF), diethyl ether, and toluene. The methodology is widely applicable to a variety of silicon, boron, and sulfur-based electrophiles, as well as carbon-based electrophiles.
- Surya Prakash,Jog, Parag V.,Batamack, Patrice T. D.,Olah, George A.
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p. 1324 - 1327
(2013/02/22)
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- Reagent And Method For Preparing A Fluorinated and Silylated Derivative
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The invention relates to a method for preparing a fluorinated and silylated derivative having a bond between the bearing carbon of at least one fluorine and one silicon. This method comprises at least one step during which a derivative of formula (I) Rf-CO—O-D, in which D is selected among silylated radicals, is placed in the presence of a base. The inventive method is used for synthesizing fluorinated derivatives.
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Page/Page column 5-6
(2008/06/13)
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- The synthesis of tris(perfluoroalkyl)phosphines
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Tris(perfluoroalkyl)phosphines, of interest as turtable alternatives to the carbon monoxide ligand, can be synthesised by the nucleophile mediated reaction of perfluoroalkyltrimethylsilanes with triphenylphosphite; the method can be extended to diphosphines. The Royal Society of Chemistry 2005.
- Murphy-Jolly, Makeba B.,Lewis, Lesley C.,Caffyn, Andrew J. M.
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p. 4479 - 4480
(2007/10/03)
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- Preparation of tri- and difluoromethylsilanes via an unusual magnesium metal-mediated reductive tri- and difluoromethylation of chlorosilanes using tri- and difluoromethyl sulfides, sulfoxides, and sulfones
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A new and efficient method for the preparation of tri- and difluoromethylsilanes using magnesium metal-mediated reductive tri- and difluoromethylation of chlorosilanes is reported using tri- and difluoromethyl sulfides, sulfoxides, and sulfones. The byproduct of the process is diphenyl disulfide. Since phenyl trifluoromethyl sulfone, sulfoxide, and sulfide are readily prepared from trifluoromethane (CF3H) and diphenyl disulfide, the method can be considered to be catalytic in diphenyl disulfide for the preparation of (trifluoromethyl)trimethylsilane (TMS-CF3) from non-ozone-depleting trifluoromethane.
- Prakash, G.K. Surya,Hu, Jinbo,Olah, George A.
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p. 4457 - 4463
(2007/10/03)
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- Electrochemical synthesis of fluoro-organosilanes
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The electrochemical reduction of some fluorohalocarbons in the presence of trimethylchlorosilane is followed by formation of the corresponding fluoroalkyltrimethylsilanes. CF3SiMe3, CFCl2SiMe3, CF3CCl2SiMe3 and (EtO)2P(O)CF2SiMe3 were obtained with current efficiency 20-50%. Voltammetric data are presented.
- Martynov,Stepanov
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p. 127 - 128
(2007/10/03)
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- Synthesis and Solvolysis of 7-(Perfluoroalkyl)-7-bicycloheptyl Derivatives
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Several α-(trifluoromethyl)- and α-(pentafluoroethyl)carbinols were synthesized by the addition of perfluoroalkylating agent (TMSCF3, TMSC2F5, and/or C2F5Li) to polycyclic ketones.An improved procedure for the preparation of α-(perfluoroalkyl)trimethylsilyl ethers from (perfluoroalkyl)trimethylsilanes and ketones was developed to facilitate the synthesis of the compounds of interest.All of the alcohols featured the bicycloheptyl skeleton or some analog of this structure containing double bonds or cyclopropyl groups.Sulfonate esters of the carbinols were prepared, and these sulfonates were solvolyzed in different solvents to examine the competition between destabilization of the carbocationic intermediates by perfluoroalkyl groups and stabilization by neighboring-group participation.The extent of the destabilization of the cations was gauged by the difference in rates of solvolysis of the α-hydrogen and α-(perfluoroalkyl) derivatives.The kα-H/kα-RF ratios ranged from 8 to ca. 1E4, and the extent of anchimeric assistance that occurred in each system influenced the difference in rates.The pentafluoroethyl group exerted a slightly smaller rate-retarding effect when compared to the trifluoromethyl group (kα-C2F5/kα-CF3 = 1.1-8.0).The products of the solvolysis reactions revealed a general trend of destabilization of both localized and delocalized cations by perfluoroalkyl groups.
- Nelson, Derek W.,O'Reilly, Neil J.,Speier, Jon,Gassman, Paul G.
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p. 8157 - 8171
(2007/10/02)
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- Inhibition of human leukocyte elastase (HLE) by N-substituted peptidyl trifluoromethyl ketones
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A series of tripeptides possessing trifluoromethyl or aryl ketone residues at P1 were prepared and evaluated both in vitro and in vivo as potential inhibitors of human leukocyte elastase (HLE). Tripeptides containing non naturally occurring N-substituted glycine residues at the P2-position have been demonstrated to be potent in vitro inhibitors of HLE, with IC50 values in the submicromolar range. Sterically demanding substituents on the P2- nitrogen have no detrimental effect on in vitro potency. The inhibition process presumably acts via hemiketal formation with the active site Ser195 of HLE, and is facilitated by the strongly electron withdrawing trifluoromethyl functionality. Deletion of the amino acid at the P3-subsite region affords inactive compounds. Valine is the preferred residue at the P1-position, whereas the corresponding glycine, alanine, α,α- dimethylglycine, or phenylalanine analogues are all inactive. The compounds described herein all confer a high degree of in vitro specificity when tested against representative cysteine, aspartyl, metallo, and other serine proteases. One of the most potent in vitro inhibitors is (3RS)-N-[4[[[(4- chlorophenyl)sulfonyl]amino]carbonyl]phenyl]oxomethyl]-L-valyl-N-(2,3- dihydro-1H-inden-2-yl)glycine N-[3-(1,1,1-trifluoro-4-methyl-2- oxopentyl)amide (20i; BI-RA-260) (IC50 = 0.084 μM). Compound 20i was also tested in hamsters in an elastase-induced pulmonary hemorrhage (EPH) model. In this model, intratracheal (it.) administration of 20i, 5 min prior to HLE challenge, effectively inhibited hemorrhage in a dose-dependent manner with an ED50 of 4.8 μg. The inhibitor 20i, 20 μg administered it. 24, 48, and 72 h prior to HLE challenge, exhibits significant inhibition against hemorrhage at all time points (97%, 64% and 49%, respectively). In a 21-day chronic model of emphysema in hamsters, 200 μg of HLE administered it. caused an elastase-induced emphysema in the lungs which can be quantitated histologically utilizing image analysis. In this assay, 20i significantly inhibited pulmonary lesions associated with septal destruction and increased alveolar spaces, when dosed at 20 μg it. 5 min prior to challenge with HLE.
- Skiles,Fuchs,Miao,Sorcek,Grozinger,Mauldin,Vitous,Mui,Jacober,Chow,Matteo,Skoog,Weldon,Possanza,Keirns,Letts,Rosenthal
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p. 641 - 662
(2007/10/02)
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- Preparation of Trifluoromethyl and Other Perfluoroalkyl Compounds with (Perfluoroalkyl)trimethylsilanes
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The preparation of a variety of novel perfluoroalkyl-substituted compounds in high yields using easily prepared (perfluoroalkyl)trimethylsilanes (1a - c) is described. (Trifluoromethyl)-, (pentafluoroethyl)-, and (heptafluoropropyl)trimethylsilane, 1a - c, respectively, react readily with carbonyl compounds, such as aldehydes and ketones, by a fluoride-initiated catalytic process.Fluoride-initiated addition of 1 to a carbonyl group generates an oxyanionic species which then further catalyzes the reaction.Even enolizable carbonyl compounds react cleanly under the reaction conditions.A study of the scope of the reactivity of 1a toward other carbonyl groups in esters, lactones and an acid chloride was also carried out.Thus 1a reacts cleanly with five- and six-membered ring lactones.However, unactivated esters do not react under the reaction conditions.The acid chloride reacts with 1a to give a mixture of products.
- Krishnamurti, Ramesh,Bellew, Donald R.,Prakash, G. K. Surya
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p. 984 - 989
(2007/10/02)
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- DIE ERSTEN CF3-SUBSTITUIERTEN ORGANYL(CHLOR)SILANE
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The three component reaction (Et2N)3P/CF3Br/R(n)SiCl(4-n) ( n= 1, 2, 3; R=CH3, Ph) gives CF3-substituted organyl (chloro)silanes for the first time.Their genesis will be elucidated.
- Ruppert, Ingo,Schlich, Klaus,Volbach, Wolfgang
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p. 2195 - 2198
(2007/10/02)
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- aFUTHER STUDIES ON REACTIONS OF ORGANIC HALIDES WITH DISILANES CATALYSED BY TRANSITION METAL COMPLEXES
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The interaction of a range of organic halides with (Cl3Si)2 or (Me3Si)2 in the presence of a variety of transition metal catalysts (very predominantly Pd0 or PdII complexes) have been examined.PhSiMe3 was formed from PhCl (m.y. = maximum yield), PhBr (m.y., 92percent, with as catalyst (L=PPh3)), and (contrary to earlier reports) PhI (m.y. 51percent, with ).MeSiCl3 was formed from MeBr (m.y., 78percent with ) and MeI (m.y., 91percent with ), and EtSiCl3 from EtBr (m.y., 49percent, with ; L''=P(C6H4OMe-p)3) and EtI (m.y. 45percent, with ).Me4Si was satisfactorily formed from MeBr (m.y. 42percent, with ).Evidence was obtained for the formation of Me3SiCF3 from CF3I.Very poor yields of XC6H4CH2SiMe3 were obtained from XC6H4CH2Br (X=H or p-Me) (with X=H some PhSiMe3 was formed), but p-O2NC6H4CH2SiMe3 was formed in 48percent yield from p-O2NC6H4CH2Cl with as catalyst.PhCOSiMe3 was formed from PhCOCl (m.y. 52percent with ).The nickel complex was moderately effective as a catalyst for reactions between (Cl3Si)2 and MeBr, EtBr, or PhCH2Br.The new complex was prepared by treatment of with (Cl3Si)2 or Cl3SiH, and shown to catalyse the reaction between MeBr and (Cl3Si)2.
- Eaborn, Colin,Griffiths, Robert W.,Pidcock, Alan
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p. 331 - 342
(2007/10/02)
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