- Determination of the hydrogen-bond basicity of weak and multifunctional bases: The case of lindane (γ-hexachlorocyclohexane)
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We made use of four methods for determining the hydrogen-bond (HB) basicity of lindane (λ-hexachlorocyclohexane): (i) experimental Fourier transform IR measurement of a sum of individual 1:1 equilibrium constants for the formation of 1:1 4-fluorophenol-lindane hydrogen-bonded complexes in CCl4; (ii) calculation of the overall HB basicity from octanol-water partition coefficients; (iii) correlation of the HB basicity of chloroalkanes with the electrostatic potentials around chlorine atoms; and (iv) correlation of the HB basicity of chloroalkanes with the computed enthalpy of their complexes with hydrogen fluoride. It is consistently found that lindane remains a weak HB base because multifunctionality cannot fully compensate for the electron-withdrawing inductive effects that chlorine atoms exert over one another. Actually, only five chlorine atoms behave as HB acceptors, one axial chlorine being deactivated by inductive effects. Stereoelectronic effects lead to the formation of three-centered hydrogen bonds. Copyright
- Ouvrard, Carole,Lucon, Maryvonne,Graton, Jerome,Berthelot, Michel,Laurence, Christian
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- POLAR RADICALS XVIII. ON THE MECHANISM OF CHLORINATION BY N-CHLOROAMINES: INTERMOLECULAR AND INTRAMOLECULAR ABSTRACTION.
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The photochlorinations of the n-butyl, n-pentyl, and n-hexyltrimethylammonium chlorides, using molecular chlorine in hexachloroacetone or 15percent CD3CO2D/85percent H2SO4, or using N-chlorodimethylamine in the acid solvent are described.The ammonium group exerted a strong polar directing effect upon the site of substitution.This effect was found to be more pronounced in the more polar protic solvent.The reagent, N-chlorodimethylamine, generated the dimethylamminium radical, whose reaction showed a polar sensitivity toward hydrogen abstraction similar to that of the chlorine atom, but exhibiting a much greater secondary/primary selectivity.Comparison of the isomer distributions obtained from the self photochlorination reactions of N-chloro-n-hexylmethylamine and N-chloro-n-pentylmethylamine in the acid solvent, with the distribution pattern obtained for the chlorinations of the ammonium salts with N-chlorodimethylamine, suggested that the self chlorinations of the N-chloroamines proceed by the intramolecular hydrogen abstraction mechanism suggested previously.
- Tanner, Dennis D.,Arhart, Richard,Meintzer, Christian P.
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- Fragmentation of alkoxychlorocarbenes in the gas phase
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In contrast to photolysis or thermal decomposition in solution, which is dominated by ionic reactions, flash vacuum pyrolysis of alkylchlorodiazirines in the gas phase generates radicals. The cyclopropylcarbinyl system is re-examined and the l-norbornylca
- Blake, Michael E,Jones Jr., Maitland,Zheng, Fengmei,Moss, Robert A
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- Diels-Alder Reactions of Trichlorophosphaethene
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The Diels-Alder reactions of trichlorophosphaethene (3), generated in situ from dichloro(dichloromethyl)phosphine (2), with 1-vinylnaphthalene (6), 1-(1-methylethenyl)cyclohexene (4), and 1-cyclohexene (13) at 60-75 deg C, are described.The reactions of 3 with 4 and 6 afforded, after aromatization of the primary Diels-Alder adducts 5 and 8 under the influence of triethylamine, the 2-chlorophosphinines 9 and 11, respectively.The reaction with 13, however, led to the formation of the "double adduct" 16, which could not be isolated in pure form.The formation of the "double adduct" is explained by a subsequent Diels-Alder reaction of 13 with dihydrophosphinine 15, which is formed after HCl elimination from the primary Diels-Alder adduct 14.The reaction of 13 with 23, the pentacarbonyltungsten complex of 2, furnished 27, the pentacarbonyltungsten complex of 16, which was isolated in pure form.The regiochemistry of the Diels-Alder reactions described above is discussed on the basis of MNDO/PM3 calculations of the frontier molecular orbital coefficients.The Diels-Alder reactions proceed with normal electron demand, and the experimentally observed regiochemistry is in accordance with theoretical predictions.The formation of the "double adducts" 16 and 27 is rationalized as a consequence of the high HOMO energy of 13 compared with that of 4.
- Teunissen, Herman T.,Hollebeek, Jan,Nieuwenhuizen, Peter J.,Baar, Ben L. M. van,Kanter, Frans J. J. de,Bickelhaupt, Friedrich
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- Solid-phase reactions of alkanedicarboxylic acids with the Pb(OAc) 4-NH4Cl system
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The title reactions of HOOC(CH2)nCOOH acids afford α,ω-dichloroalkanes (n = 3, 4, 6) and lactones (n = 3, 4) as the main products.
- Nikishin, Gennady I.,Sokova, Lyubov L.,Makhaev, Viktor D.,Kapustina, Nadezhda I.
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- Ethers as Oxygen Donor and Carbon Source in Non-hydrolytic Sol–Gel: One-Pot, Atom-Economic Synthesis of Mesoporous TiO2–Carbon Nanocomposites
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Mesoporous TiO2–carbon nanocomposites were synthesized using an original non-hydrolytic sol–gel (NHSG) route, based on the reaction of simple ethers (diisopropyl ether or tetrahydrofuran) with titanium tetrachloride. In this atom-economic, solvent-free process, the ether acts not only as an oxygen donor but also as the sole carbon source. Increasing the reaction temperature to 180 °C leads to the decomposition of the alkyl chloride by-product and to the formation of hydrocarbon polymers, which are converted to carbon by pyrolysis under argon. The carbon–TiO2 nanocomposites and their TiO2 counterparts (obtained by calcination) were characterized by nitrogen physisorption, XRD, solid state 13C NMR and Raman spectroscopies, SEM, and TEM. The nanocomposites are mesoporous with surface areas of up to 75 m2 g?1 and pore sizes around 10 nm. They are composed of aggregated anatase nanocrystals coated by an amorphous carbon film. Playing on the nature of the ether and on the reaction temperature allows control over the carbon content in the nanocomposites. The nature of the ether also influences the size of the TiO2 crystallites and the morphology of the nanocomposite. To further characterize the carbon coating, the behavior of the carbon-TiO2 nanocomposites and bare TiO2 samples toward lithium insertion–deinsertion was investigated in half-cells. This simple NHSG approach should provide a general method for the synthesis of a wide range of carbon–metal oxide nanocomposites.
- Escamilla-Pérez, Angel Manuel,Louvain, Nicolas,Boury, Bruno,Brun, Nicolas,Mutin, P. Hubert
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- Preparation method of dichloroalkane
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The invention discloses a preparation method of dichloroalkane, which comprises the following steps: mixing diol, a catalyst and a solvent, stirring and heating the components, introducing HCl gas into the mixture, and carrying out reflux reaction for 3-5 hours; and after the reaction is finished, treating the reaction solution to obtain dichloroalkane. According to the preparation method providedby the invention, the catalyst ammonium chloride is added, so that the reaction speed is obviously increased, and side reactions are reduced. In the invention, a large amount of solvent water is added in the reaction process, so that on one hand, the formation of monochloro ether by-products can be effectively inhibited, a water phase can be directly and repeatedly used, and basically no sewage is discharged; besides, by using the oil-water separator, the dichloroalkane product can be effectively separated, the product purity is high, and the yield is high.
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Paragraph 0020
(2021/02/10)
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- Continuous method for preparation of dihalogenated alkane from diol compound
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The invention discloses a continuous method for preparation of dihalogenated alkane from a diol compound. A diol compound and haloid acid are used as the substrate, a microchannel reactor is utilizedto synthesize dihalogenated alkane continuously. Synthesis of the dihalogenated alkane includes the steps of: inputting the diol compound and haloid acid into a mixer respectively by a metering pump at room temperature, conducting premixing, then sending the mixture into a high-temperature section of the microchannel reactor at for reaction, and controlling the reaction temperature by an externalcirculating heat exchange system; at the end of the reaction, letting the product flow out from an outlet of the microchannel reactor and enter a cooling section, letting the cooled material enter a liquid separation kettle for standing and liquid separation, and collecting an organic layer; and preheating the organic layer, then feeding the preheated organic layer into a rectifying tower by a metering pump, controlling the temperature and reflux ratio of a reboiler, and collecting fractions at a specific temperature, thus obtaining the target product in a product collecting tank. The method provided by the invention has the characteristics of high reaction efficiency, safety, environmental protection, convenience and rapidity.
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Paragraph 0051-0054; 0069-0075
(2020/03/16)
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- Quinoline derivatives and its preparation method and in the application of neural protection in
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The invention discloses a quinoline derivative and its preparation method and in the application of neural protection in, quinoline derivatives of the formula is Wherein R1 , R2 , R3 , R4 Independently selected from - H, - F or - OCH3 . Anti-A β25 - 35 Induced PC12 cell protective action of injury the experimental results show that, in the dosage is 100μmol/L under the condition of, KL201, KL202 and KL208 with the survival rate of the model set of differences are statistical significance (p25 - 35 Induced neurotoxicity, obviously improve the survival rate of the cells, with nerve protection function, can be used as neuroprotective agents for more in-depth research.
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Paragraph 0024-0027
(2019/02/19)
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- 1,4-dichlorobutane production technology
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The invention provides a 1,4-dichlorobutane production technology. The technology comprises the following steps: 1, preparing 1,4-butanediol, triphosgene, a catalyst and a reaction kettle with an elevated tank, wherein a molar ratio of the 1,4-butanediol to triphosgene is 1:(0.66-0.70); 2, pumping 60-90% of the 1,4-butanediol weighed in step 1 into the reaction kettle, heating the 1,4-butanediol to 40-70 DEG C, adding the triphosgene, and performing stirring until complete dissolving is achieved; 3, pumping the 1,4-butanediol remained the after step 1 and the catalyst into the elevated tank ofthe reaction kettle, performing dissolving until clarity in the reaction kettle, slowly dropwise adding a solution obtained in the elevated tank into the reaction kettle, and collecting a gas generated by a reaction; and 4, lowering the temperature to 0-30 DEG C after the reaction is finished, standing for layering, and collecting the obtained lower yellowish oily liquid to complete the preparation of 1,4-dichlorobutane. The 1,4-dichlorobutane production technology has the advantages of simplicity in operation, mild reaction conditions, greenness, no pollution, low carbon, environmental protection, and realization of large-scale production.
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Paragraph 0026-0036
(2019/10/23)
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- 2-furan aldehyde compounds and application to Alzheimer's disease drugs thereof
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The invention discloses a 2-furan aldehyde compound and application to Alzheimer's disease drugs thereof. The structural formula of the 2-furan aldehyde compound is shown in the specification, and inthe structural formula, R1, R2, R3 and R4 are each independently selected from the group consisting of -H, -F or -OCH3. A protective effect experiment result of A[beta][25-35]-induced PC12 cell injuryshows that the differences between the survival rate of a model group and the survival rates of FN201, FN202, FN208 and FN209 are statistically significant(p0.01) at a dose of 50 [mu]mol/L. Therefore, the experiment result proves that compared with the model group, the compound of the present invention can significantly reduce the neurotoxicity induced by A[beta][25-35], the cell survival rate is obviously improved, and the compound has a neuroprotective effect, can be used as a neuroprotective agent for further research, and can also be used as a therapeutic and/or a more in-depth study ofdrugs to prevent Alzheimer's disease.
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Paragraph 0025; 0026; 0027; 0028
(2019/01/05)
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- Quinoline derivative with neuroprotective effect and preparation method of quinoline derivative
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The invention discloses a quinoline derivative with a neuroprotective effect and a preparation method of the quinoline derivative. The quinoline derivative has a structural formula as shown in the specification. In the formula, R1, R2, R3 and R4 are respectively independently selected from -H, -F or -OH. Experimental results of protective effects on anti-Abeta 25-35 induced PC12 cellular damage show that under the condition that the dosage of compounds in an experimental group is 50umol/L, the survival rate differences of KL301, KL303 and KL306 and the model group have statistical significance(p0.01). Compared with the model group, the compound disclosed by the invention has the advantages that the Abeta 25-35 induced neurotoxicity can be obviously reduced, the cell survival rate is obviously improved, and the compound has the neuroprotective effect, can serve as a neuroprotective agent for in-depth study, and can serve as a medicine for treating and/or preventing Alzheimer's diseasefor more in-depth study.
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Paragraph 0024-0027
(2019/01/08)
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- Solid-state chlorodecarboxylation of mono- and dicarboxylic acids with the Pb(OAc)4-MCl system
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Solid state reactions of acids RCOOH (R = n-C7H15, BuC(Et)H, n-C9H19, PhCH2, PhCH 2CH2, H2C=CH(CH2)8, or MeOOC(CH2)3) with Pb(OAc)4 combined with KCl, NaCl, CdCl2, or NH4Cl in the absence of a solvent and without mechanical activation afford chlorohydrocarbons RCl. The corresponding reactions of acids HOOC(CH2)nCOOH (n = 3-6) give dichloroalkanes Cl(CH2)nCl and γ-butyrolactone (n = 3).
- Nikishin,Sokova,Chizhov,Makhaev,Kapustina
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p. 2200 - 2204
(2007/10/03)
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- Methods for synthesizing ether compounds and intermediates therefor
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The present invention relates to novel ether compounds, compositions comprising ether compounds, and methods useful for treating and preventing cardiovascular diseases, dyslipidemias, dysproteinemias, and glucose metabolism disorders comprising administering a composition comprising an ether compound. The compounds, compositions, and methods of the invention are also useful for treating and preventing Alzheimer's Disease, Syndrome X, peroxisome proliferator activated receptor-related disorders, septicemia, thrombotic disorders, obesity, pancreatitis, hypertension, renal disease, cancer, inflammation, and impotence. In certain embodiments, the compounds, compositions, and methods of the invention are useful in combination therapy with other therapeutics, such as hypocholesterolemic and hypoglycemic agents.
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- Group 5 and group 6 metal halides as very efficient catalysts for acylative cleavage of ethers
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Group 5 and 6 metal chlorides such as MoCl5, WCl6, NbCl5 and TaCl5 were found as very efficient catalysts for acylative cleavage of the C-O bond of ethers. Compared with conventional Lewis acid catalysts such as ZnCl2, AlCl3, SnCl4 and TiCl4, group 5 and 6 metal chlorides showed better results in the catalytic C-O bond cleavage of dibutyl ether with benzoyl chloride.
- Guo, Qiaoxia,Miyaji, Taichi,Hara, Ryuichiro,Shen, Baojian,Takahashi, Tamotsu
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p. 7327 - 7334
(2007/10/03)
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- A safe and efficient procedure to prepare alkyl and alkoxyalkyl chlorides and dichlorides by catalytic decomposition of the corresponding alkyl and alkoxyalkyl chloroformates and bischloroformates with hexabutylguanidinium chloride
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Small amounts of hexabutylguanidinium chloride (0.01 mol%) decomposes pure chloroformates or bischloroformates with different lengths of carbon chains by a semicontinuous process to diminish run-away risk, leading to chloride compounds with high yield and purity.
- Violleau,Thiebaud,Borredon,Le Gars
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p. 367 - 373
(2007/10/03)
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- New aspect of nucleophilic reactivity of tertiary phosphine oxides. R3PO-POCl3 binary system
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The reaction of tertiary phosphine oxides with phosphorus oxychloride was found to give triorganylphosphonium dichlorophosphates R3PCl+PO2Cl-2 rather than phosphorylphosphonium salts R3P · OPOCl2. Mixtures of the reagents, called binary system, possess a considerable synthetic potential. They are capable of converting alcohols to the corresponding alkyl chlorides.
- Kazantseva,Timokhin,Rokhin,Blazhev,Golubin,Rybakova
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p. 1233 - 1235
(2007/10/03)
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- Side products in the syntheses of vinylsilanes and vinylsiloxanes using vinylmagnesium chloride
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Impurity of moisture in the solvent (tetrahydrofuran) alters the, normal scheme of formation of vinylmagnesiumm chloride and gives rise to several unexpected products: benzene, toluene, and methyl chloride. Side products forming in alkali hydrolysis of trivinylsilane and hydrochlorination of tetravinylsilane were isolated and identified.
- Zhun
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p. 1746 - 1748
(2007/10/03)
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- The versatile behavior of the PdCl2/Et3SiH system. Conversion of alcohols to the corresponding halides and alkanes
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The versatility of the palladium(II) chloride/triethylsilane system has been tested in the transformation of alcohols. The conversion to the corresponding halides and alkanes has been achieved in good yields and in the absence of solvent for a variety of substrates.
- Ferreri,Costantino,Chatgilialoglu,Boukherroub,Manuel
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p. 135 - 137
(2007/10/03)
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- Dimethylformamide-Catalyzed Chlorination with Pentavalent Phosphorus Chlorides
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It is found that the chlorinating activity of pentavalent phosphorus chlorides is much increased by DMF. Treatment with phosphorus oxychloride in the presence of DMF was used to prepare 1,4-dichlorobutane from THF in 85% yield and carboxylic acid chlorides from the corresponding acids in ~92% yield.
- Kaabak,Baranov,Kalitina,Orlov
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p. 117 - 119
(2007/10/03)
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- Fungicidal 1-aryl-1-[α-(triazolyl)alkyl]-1-silacycloalkanes and their preparation methods
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The novel compounds of 1-aryl-1-[α-(triazolyl]alkyl]-1-silacycloalkanes of the following formula I and their preparation are provided. The compounds of the present invention are useful in controlling fungal diseases of living plants. STR1 wherein R1 can be 4- or 2,4-substituted phenyl such as 4-fluorophenyl, 4-chlorophenyl, 4-ethoxyphenyl, 4-methoxyphenyl, 4-trifluoromethylphenyl, biphenyl, 2,4-difluorophenyl, and 2,4-dichlorophenyl and R2 can be hydrogen or methyl and n is 4 or 5.
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- Preparation of alkyl, alkenyl, and alkynyl chlorides
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The preparation of an alkyl, alkenyl, or alkynyl chloride by the reaction of a corresponding alcohol with phosgene or thionyl chloride in the presence of a phosphine oxide acting as catalyst, wherein the catalyst used is an aliphatic, cycloaliphatic, or cyclic/aliphatic phosphine oxide.
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- Versatility of Zeolites as Catalysts for Ring or Side-Chain Aromatic Chlorinations by Sulfuryl Chloride
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Zeolites catalyze chlorination of aromatics by sulfuryl chloride SO2Cl2.It is possible by an appropriate choice of the catalyst to effect at will, with very high selectivity, either the ring or the side-chain chlorination.Zeolite ZF520 is the choice catalyst for the former, because of its high Broensted acidity.Zeolite NaX (13X) is a fine catalyst for the latter, free-radical chlorination; the reaction is best effected in the presence of a light source; the catalyst can be reused many times with no loss in activity.Both reaction modes, the ionic (ring chlorination)and the radical (side-chain substitution), are likely to occur outside of the channel network in the microporous solid.The effects of various experimental factors - such as the nature of the solvent, the reaction time and temperature, the Broensted acidity of the solid support, the presence of radical inhibitors, and the quantity of catalysts - were investigated.The procedures resulting from this study are very easy to implement in practice and are quite effective.
- Delaude, Lionel,Laszlo, Pierre
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p. 5260 - 5269
(2007/10/02)
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- MECHANISMS OF FREE-RADICAL REACTIONS. XXIV. QUANTITATIVE DESCRIPTION OF THE POLAR EFFECTS OF SUBSTITUENTS ON THE KINETICS OF THE FREE-RADICAL CHLORINATION OF ALIPHATIC COMPOUNDS BY N-CHLOROPIPERIDINE
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The free-radical chlorination of 1-substituted alkanes with electron-withdrawing substituents by N-chloropiperidine in trifluoroacetic acid was studied by the method of competing reactions, and the relative rate constants were obtained for all positions of the substrates.The data on the position selectivity can be described satisfactorily by means of an electrostatic model of the polar effect of the substituent, calculated according to the Kirkwood-Westheimer equation.The obtained characteristics of the electrostatic effect can be successfully applied to calculation of the substrate selectivity and the intermolecular relative rate constants for all the positions, beginning with the third.The Taft equation is unsuitable for description of the effect of substituents on the reaction rate.
- Dneprovskii, A. S.,Mil'tsov, S. A.,Arbuzov, P. V.
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p. 1826 - 1835
(2007/10/02)
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- THE LONG-RANGE ACTION OF THE POLAR EFFECT OF SUBSTITUENTS ON THE ABSTRACTION OF HYDROGEN IN FREE-RADICAL CHLORINATION PROCESSES
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The free-radical chlorination of 1-chloroalkanes between C3 and C6 at 263 deg K was studied under conditions with wide variation in the concentrations of the substrates in benzene.By analysis of the products from chlorination of the pure substrates it was shown that the deactivating effect of the polar substituent does not extend beyond the third carbon atom and is mainly determined by the inductive effect.In the transition to an aromatic solvent the deactivating effect on the substituent extends to the fourth carbon atom.The results are substantiated in terms of a contribution from dipole-dipole interaction between the substituent and the polar form of the transition state to the polar effect of the substituents.
- Aver'yanov, V. A.,Ruban, S. G.,Klykova, M. B.,Golubev, V. E.
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p. 435 - 439
(2007/10/02)
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- Metal-assisted Reactions. Part 17. Ring-opening and Dimerization of Cyclic Ethers by Titanium Halides
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Reaction of TiCl4 or TiBr4 with a variety of cyclic ethers gives, predominantly, products resulting from simple ring-opening or from ring-opening with simultaneous condensation to dimeric species.The variations in yields of these two kinds of products might be correlated qualitatively with an initial formation of the complex TiX4*2E (X = Cl or Br; E = cyclic ether) in which the ethers were held in a cis or trans relationship.Although such a correlation might suggest that TiCl4 but not TiBr4 exerts a template effect on the condensation, stereochemical considerations of the reaction products indicate otherwise.TiCl3 and VCl3 do not give similar results and TiF4 gives no reaction.
- Delaney, Paul A.,Johnstone, Robert A. W.,Entwistle, Ian D.
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p. 1855 - 1860
(2007/10/02)
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- MECHANISMS OF FREE-RADICAL REACTIONS. XIX. SELECTIVITY OF THE FREE-RADICAL CHLORINATION OF 1-CHLOROALKANES BY N-CHLOROPIPERIDINE
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The free-radical chlorination of 1-chloroalkanes ClH2l+1Cl (l = 4-7) by N-chloropiperidine was studied by the method of competing reactions, and the relative constants for all the positions of the investigated substrates were determined.The chlorination is a highly electrophilic process, and the effect of the substituents is transmitted through at least six C-C bonds.The results can be described satisfactorily by means of an electrostatic model of the polar effect of the substituents according to the Kirkwood-Westheimer equation.At the same time an attempt to describe the obtained data by means of the Taft equation led to unsatisfactory results.
- Dneprovskii, A. S.,Mil'tsov, S. A.
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p. 265 - 269
(2007/10/02)
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- Silylaminyl Radicals. Part 2. Free Radical Chain Halogenation of Hydrocarbons using N-Halogenobis(trialkylsilyl)amines
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The liquid-phase halogenation of a number of hydrocarbons and of 1-chlorobutane by N-halogenobis(trialkylsilyl)amines has been studied using product analysis techniques.The reactions take place by free radical chain mechanisms which involve the propagation steps generalised in equations (A) and (B) (X=Br or Cl).At 353 K, the molar reactivities of toluene (benzylic C-H) and cyclohexane towards (R3Si)2N+RH(R3Si)2NH+R (A) R+(R3Si)2NXRX+(R3Si)2N (B) (Me3Si)2N are approximately equal and toluene is 5.2 times more reactive than perdeuteriotoluene.The relative rates of hydrogen abstraction by (Me3Si)2N and (ButMe2Si)2N from the primary, secondary, and tertiary C-H groups in 2-methylbutane show that the silylaminyl radicals are not only highly reactive but also sterically demanding.Thus, at 333 K the average primary C-H reactivity is 0.6 times that of the tertiary C-H towards attack by (Me3Si)2N, but 4.2 times that of the tertiary C-H towards attack by the more bulky (ButMe2Si)2N.Silylaminyl radicals are much more reactive in hydrogen abstraction than are analogous dialkylaminyl radicals and this difference is interpreted in terms of thermodynamic and polar effects which arise because of the ?-donor-?-acceptor nature of the trialkylsilyl substituent.
- Cook, Malcolm D.,Roberts, Brian P.,Singh, Karamjit
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p. 635 - 644
(2007/10/02)
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- EFFECT OF STRUCTURAL FACTORS ON THE REACTIVITY OF C-H BONDS IN CHLOROALKANES IN REACTION WITH A CHLORINE ATOM AND WITH THE COMPLEX OF THE CHLORINE ATOM WITH o-DICHLOROBENZENE
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The competition reaction of dichloroethanes, 1,1,2-trichloroethane, and 1-chlorobutane in o-dichlorobenzene was investigated over a wide range of temperature (-20 to +80 deg C) and solvent concentrations (0-7 M).The selective action of the solvent is consistent with a mechanism involving attack on the C-H bonds of the chloroalkanes by free chlorine atoms and by ArH -> Cl ? complexes.Equations were obtained for the selectivity of the investigated processes on the basis of the proposed mechanism.The parameters of the obtained equations reflect the relative reactivityof the C-H bonds during chlorination by chlorine atoms and ArH -> Cl complexes and also the capacity of the solvent for the complex formation.It was shown that the reactivities of the C-H bonds during attack by chlorine atoms and ArH -> Cl complexes are described by a correlation equation including the inductive effect of the substituents on the reaction center and also stabilization of the obtained radicals through conjugation and hyperconjugation effects.
- Aver'yanov, V. A.,Zarytovskii, V. M.,Shvets, V. F.
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p. 1832 - 1839
(2007/10/02)
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- Enhancement of Ring-Opening of Tetrahydrofuran by Trimethylsilyl Chloride in the Presence of Metal Oxides.
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Tetrahydrofuran was cleaved by trimethylsilyl chloride in the presence of metal oxides like alumina in hexane even at 50 deg C.
- Kawakami, Yuhsuke,Yamashita, Yuya
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p. 253 - 256
(2007/10/02)
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- Free Radical Substitution. Part 37. The Effect of Solvent on the Atomic Chlorination of 1-Substituted Butanes and Related Compounds
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Experimental results reported in this paper show that the relative selectivity of atomic chlorination of 1-substituted butanes and related compounds is greatly influenced by the phase and by solvents.Solvents can be divided into three classes: (a) inert, (b) solvents which decrease the selectivity, and (c) solvents which increase the selectivity.The second group solvate the transition state and the third group solvate the chlorine atoms.
- Potter, Alan,Tedder, John M.
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p. 1689 - 1692
(2007/10/02)
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- MECHANISMS OF FREE-RADICAL REACTIONS. XIV. SELECTIVITY OF FREE-RADICAL CHLORINATION OF VALERIC ACID DERIVATIVES WITH ARYLCHLOROIODONIUM CHLORIDES
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The free-radical chlorination of C4H9Y compounds with arylchloroiodonium chlorides was investigated.The reaction of the secondary C-H bonds increases as they become further from the electronegative substituent.The reaction parameters were calculated from the ratio of the β- and γ-monochlorides by means of the Taft equation.The absolute value of ρ increases with the introduction of electronwithdrawing substituents into the arylchloroiodonium chloride molecule.
- Dneprovskii, A. S.,Krainyuchenko, I. V.
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p. 324 - 328
(2007/10/02)
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- MECHANISM OF RADICAL TELOMERIZATION OF ETHYLENE WITH 1,1-DICHLOROETHANE
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The mechanism of the radical telomerization of ethylene with 1,2-dichloroethane was investigated. 1,2-Dichloroethane reacts with telomeric alkyl radicals with cleavage both of the C - H bond and of the C - Cl bond, and the ratio of the corresponding rate constants is 2.8 (100 deg C).It was shown that, in addition to the chlorine-containing telomers, the mixture of products from the reaction initiated by benzoyl peroxide contains alkyl- and dialkylbenzenes.
- Dzheiranishvili, M. S.,Levinskii, M. B.,Chkhubianishvili, N. G.,Afanas'ev, I. B.
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p. 445 - 447
(2007/10/02)
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