- Facile and systematic access to the least-coordinating WCA [(RFO)3Al-F-Al(ORF)3]- and its more Lewis-basic brother [F-Al(ORF)3]- (RF = C(CF3)3)
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By reaction of the Lewis acid Me3Si-F-Al(ORF)3 with a series of [PF6]- salts, gaseous PF5 and Me3Si-F are liberated and salts of the anion [F-Al(ORF)3]- ([f-al]-; RF = C(CF3)3) can be obtained. By addition of another equivalent of Me3Si-F-Al(ORF)3 to [f-al]-, gaseous Me3Si-F is released and salts of the least coordinating anion [(RFO)3Al-F-Al(ORF)3]- ([al-f-al]-) are formed. Both procedures work for a series of synthetically useful cations including Ag+, [NO]+, [Ph3C]+ and in very clean reactions with 5 g batch sizes giving excellent yields typically exceeding 90%. In addition, the synthesis of Me3Si-F-Al(ORF)3 has been optimized and scaled up to 85 g batches in an one-pot procedure. These anions could previously only be obtained by difficult to control decomposition reactions of [Al(ORF)4]- or by halide abstraction reactions with Me3Si-F-Al(ORF)3, generating relatively large countercations that are unsuited for further use as universal starting materials. Especially [al-f-al]- is of interest for the stabilization of reactive cations, since it is even weaker coordinating than [Al(ORF)4]- and more stable against strong electrophiles. This bridged anion can be seen as an adduct of [f-al]- and Al(ORF)3. Thus, it is similarly Lewis acidic as BF3 and eventually reacts with nucleophiles (Nu) from the reaction environment to yield Nu-Al(ORF)3 and [f-al]-. This prevents working with [al-f-al]- salts in ethereal or other donor solvents. By contrast, the [f-al]- anion is no longer Lewis acidic and may therefore be used for reactions involving stronger nucleophiles than the [al-f-al]- anion can withstand. Subsequently it may be transformed into the [al-f-al]- salt by simple addition of one equivalent of Me3Si-F-Al(ORF)3.
- Martens, Arthur,Weis, Philippe,Krummer, Michael Christian,Kreuzer, Marvin,Meierh?fer, Andreas,Meier, Stefan C.,Bohnenberger, Jan,Scherer, Harald,Riddlestone, Ian,Krossing, Ingo
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- Ruthenium-Catalyzed C?H Arylation of Benzoic Acids and Indole Carboxylic Acids with Aryl Halides
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Herein we report the first Ru-catalyzed C?H arylation of benzoic acids with readily available aryl (pseudo)halides. The reaction, which does not require the use of silver salt additives, allows the arylation of previously challenging hindered benzoic acids and the use of generally unreactive ortho-substituted halorarenes. Furthermore, our new protocol can efficiently be applied to indole carboxylic acids, thus allowing access to C7-, C6-, C5- and C4-arylated indole compounds, a departure from the classical enhanced reactivity of the C2 and C3 positions of indole.
- Simonetti, Marco,Cannas, Diego M.,Panigrahi, Adyasha,Kujawa, Szymon,Kryjewski, Michal,Xie, Pan,Larrosa, Igor
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- Syntheses of "phosphine-Free" Molybdenum Oxo Alkylidene Complexes through Addition of Water to Alkylidyne Complexes
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Addition of 1 equiv of water to Mo(CArp)(ORF9)3 (Arp = p-methoxyphenyl; ORF9 = OC(CF3)3) in the presence of 5percent NEt3 (vs Mo) in THF led to the formation of Mo(O)(CHArp)(ORF9)2(THF)2 in good yield. Mo(O)(CHArp)(ORF9)2(THF)2 reacts with 2 equiv of LiOH
- Zhai, Feng,Schrock, Richard R.,Hoveyda, Amir H.,Müller, Peter
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- Three-coordinate late transition metal fluorinated alkoxide complexes
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Homoleptic fluorinated alkoxide complexes have been prepared from KOC 4F9, 1, via salt metathesis routes. One four-coordinate K{K(18C6)}[Co(OC4F9)4], 2, and four three-coordinate complexes: {K(18C6)}[Fe(OC4F9) 3], 3, {K(18C6)}[Co(OC4F9)3], 4, {K(18C6)}[Cu(OC4F9)3], 5, and {K(18C6)}[Zn(OC4F9)3], 6, have been prepared and all except 5 have been characterized crystallographically. Compounds 3, 4, and 6 are very rare examples of monomeric, trigonal alkoxide complexes. All compounds have been characterized with UV-vis and IR spectroscopy, solution magnetic susceptibility, and elemental analysis. In solution, compound 2 exists in an equilibrium with 4 and 1, which has been probed with cyclic voltammetry, supporting energetically different Co2+/Co3+ potentials in the three-coordinate (Ep,a = ~1.2 V vs Fc/Fc+) and four-coordinate (Ep,a = ~0.9 V) geometries. The ligand field engendered by the perfluoro-t-butoxide ligand has been studied with DFT calculations on 4 and the hypothetical [Co(OC4H9) 3]- as well as the previously reported [Co(mes) 3]- and [Co{N(TMS)2}3]- showing significant π-type interactions in the xy plane as well as above and below for the two alkoxide species. The Royal Society of Chemistry.
- Cantalupo, Stefanie A.,Lum, June S.,Buzzeo, Marisa C.,Moore, Curtis,DiPasquale, Antonio G.,Rheingold, Arnold L.,Doerrer, Linda H.
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- PERFLUORINATED ALLYL ETHERS AND PERFLUORINATED ALLYL AMINES AND METHODS OF MAKING AND USING THE SAME
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Described herein is a method to synthesize a perfluorinated allyl ether compound of formula (I) or a perfluorinated allyl amine compound of formula (II) Where Rf1 and Rf2 are (i) independently selected from a perfluorinated alkyl group comprising 1-7 carbon atoms, a perfluorinated aryl group comprising a 5- or 6-membered ring, or combinations thereof, and optionally comprising one or more catenated heteroatoms selected from N or O; or (ii) bonded together to form a perfluorinated ring structure having 4-8 ring carbon atoms, optionally comprising at least one catenated O or N atom; and Rf3 is a perfluorinated alkyl group comprising 1-3 carbon atoms. The resulting perfluorinated allyl ether compounds disclosed herein may be used in polymer synthesis.
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Paragraph 0080-0081
(2021/09/26)
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- Syntheses of Molybdenum Oxo Benzylidene Complexes
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The reaction between Mo(O)(CHAro)(ORF6)2(PMe3) (Aro = ortho-methoxyphenyl, ORF6 = OCMe(CF3)2) and 2 equiv of LiOHMT (OHMT = O-2,6-(2,4,6-Me3C6H2)2C6H3) leads to Mo(O)(CHAro)(OHMT)2, an X-ray structure of which shows it to be a trigonal bipyramidal anti benzylidene complex in which the o-methoxy oxygen is coordinated to the metal trans to the apical oxo ligand. Addition of 1 equiv of water (in THF) to the benzylidyne complex, Mo(CArp)(OR)3(THF)2 (Arp = para-methoxyphenyl, OR = ORF6 or OC(CF3)3 (ORF9)) leads to formation of {Mo(CArp)(OR)2(μ-OH)(THF)}2(μ-THF) complexes. Addition of 1 equiv of a phosphine (L) to Mo(CArp)(ORF9)3(THF)2 in THF, followed by addition of 1 equiv of water, all at room temperature, yields Mo(O)(CHArp)(ORF9)2(L) complexes in good yields for several phosphines (e.g., PMe2Ph (69% by NMR), PMePh2 (59%), PEt3 (69%), or P(i-Pr)3 (65%)). The reaction between Mo(O)(CHArp)(ORF9)2(PEt3) and 2 equiv of LiOHMT proceeds smoothly at 90 °C in toluene to give Mo(O)(CHArp)(OHMT)2, a four-coordinate syn alkylidene complex. Mo(O)(CHArp)(OHMT)2 reacts with ethylene (1 atm in C6D6) to give (in solution) a mixture of Mo(O)(CHArp)(OHMT)2, Mo(O)(CH2)(OHMT)2, and an unsubstituted square pyramidal metallacyclobutane complex, Mo(O)(CH2CH2CH2)(OHMT)2, along with ethylene and ArpCH=CH2. Mo(O)(CHArp)(OHMT)2 also reacts with 2,3-dicarbomethoxynorbornadiene to yield syn and anti isomers of the "first-insertion" products that contain a cis C=C bond.
- Zhai, Feng,Bukhryakov, Konstantin V.,Schrock, Richard R.,Hoveyda, Amir H.,Tsay, Charlene,Müller, Peter
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supporting information
p. 13609 - 13613
(2018/10/20)
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- Fluorinated Tertiary Alcohols and Alkoxides from Nucleophilic Trifluoromethylation of Carbonyl Compounds
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(CH3)3SiCF3 reacts with fluoro ketones in the presence of excess KF in CH3CN to produce alkoxides derived from formal addition of CF3(1-) to the carbonyl carbon.These alkoxides may be isolated as such or acidified to the corresponding alcohols.Ketones to which this technique was applied include (CF3)2C=O, CF3C(O)CF2Cl, CF3C(O)CF2H, and 2C=O.The last compound reacts with replacement of one of its perfluoroisopropyl groups by CF3.With 2 equiv of TMS-CF3, the acid fluorides RC(O)F (R = CF3CF2, n-C3F7, n-C7F15) yield products of the form RC(CF3)2OX (X = K, H) due to both substitution and addition of CF3 at the carbonyl.Similarly, F2C=O with 3 equiv of TMS-CF3 provides a novel and high-yield synthesis of the perfluoro-tert-butoxide group.Phosgene does not appear to react directly with the TMS-CF3/KF system, but is converted first to CF2C=O.The intermediate ketone CF3CF2C(O)CF3 is observed in reactions of equimolecular amounts of CF3CF2C(O)F and TMS-CF3.
- Kotun, Stefan P.,Anderson, John D. O.,DesMarteau, Darryl D.
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p. 1124 - 1131
(2007/10/02)
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