- Method for co-producing methyl chloropropene and 2-chloro-2-methylpropane by chlorination of isobutene
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The invention discloses a method for co-producing methyl chloropropene and 2-chloro-2-methylpropane by chlorination of isobutene. According to the method, a chlorination reaction is carried out on chlorine or a mixture of chlorine and inert gas and excessive isobutene to obtain products, namely methyl chloropropene and 2-chloro-2-methylpropane. The method can reduce influence of micro-mixing on arapid chlorination reaction of isobutene, decarburization and coking do not occur easily, and 2-chloro-2-methylpropane can be co-produced while the yield of methyl chloropropene is improved.
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Paragraph 0025; 0026
(2020/01/12)
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- METHOD OF CONVERTING ALCOHOL TO HALIDE
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The present invention relates to a method of converting an alcohol into a corresponding halide. This method comprises reacting the alcohol with an optionally substituted aromatic carboxylic acid halide in presence of an N-substituted formamide to replace a hydroxyl group of the alcohol by a halogen atom. The present invention also relates to a method of converting an alcohol into a corresponding substitution product. The second method comprises: (a) performing the method of the invention of converting an alcohol into the corresponding halide; and (b) reacting the corresponding halide with a nucleophile to convert the halide into the nucleophilic substitution product.
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Page/Page column 53; 132; 139; 140
(2017/01/02)
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- Synthesis of chlorothioformates from xanthates
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The Vilsmeier reagent derived from N-formylmorpholine produces chlorothioformates from primary and secondary alkyl xanthates. The major side products are the corresponding alkyl chlorides. Secondary alkyl chlorothioformates give lower yields due to their instability. Treating xanthates with other common chlorinating agents (oxalyl chloride, thionyl chloride) gives only dialkyl thiodicarbonates. Georg Thieme Verlag Stuttgart.
- Fikse, Megan A.,Bylund, William E.,Holubowitch, Nicolas E.,Abelt, Christopher J.
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p. 4118 - 4120
(2008/03/13)
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- PROCESS FOR MAKING HALOORGANOALKOXYSILANES
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A haloorganoalkoxysilane is prepared by reacting an olefinic halide with an alkoxysilane in which the alkoxy group(s) contain at least two carbon atoms in a reaction medium to which has been added a catalytically effective amount of ruthenium-containing catalyst and a reaction-promoting effective amount of an electron-donating aromatic compound promoter. The process can be used to prepare, inter alia, chloropropyltriethoxysilane, which is a key intermediate in the manufacture of silane coupling agents.
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Page/Page column 24
(2008/06/13)
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- Process for making haloorganoalkoxysilanes
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A haloorganoalkoxysilane is prepared by reacting an olefinic halide with an alkoxysilane in which the alkoxy group(s) contain at least two carbon atoms in a reaction medium to which has been added a catalytically effective amount of ruthenium-containing catalyst and a reaction-promoting effective amount of an electron-donating aromatic compound promoter. The process can be used to prepare, inter alia, chloropropyltriethoxysilane, which is a key intermediate in the manufacture of silane coupling agents.
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- Oxidative alkoxylation of zinc phosphide in alcoholic solutions of copper(II) chloride
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Oxidative alkoxylation of Zn3P2 with the formation of valuable phosphoric and phosphorous acid esters occurred at a high rate and with a high selectivity in alcoholic solutions of CuCl2 under the action of oxygen at 30-60°C. Depending on the nature of the alcohol, two products were formed, namely, trialkyl phosphates (RO)3PO and dialkyl phosphites (RO)2HPO. Water favored the formation of dialkyl phosphates (RO)2(HO)PO. The kinetics and mechanism of the new catalytic reaction were studied, and the optimal conditions for conducting this reaction were found. The reaction proceeded in a topochemical mode by a separate redox mechanism.
- Dorfman,Ibraimova,Polimbetova
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- Gas-phase reactions of Cl atoms with propane, n-butane, and isobutane
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Using the relative kinetic method, rate coefficients have been determined for the gas-phase reactions of chlorine atoms with propane, n-butane, and isobutane at total pressure of 100 Torr and the temperature range of 295-469 K. The Cl2 photolysis (λ = 420 nm) was used to generate Cl atoms in the presence of ethane as the reference compound. The experiments have been carried out using GC product analysis and the following rate constant expressions (in cm3 molecule-1 s-1) have been derived: (7.4 ±0.2) × 10-11 exp [-(70 ± 11)/T], Cl + C3H8 → HCl + CH3CH2CH2; (5.1 ± 0.5) × 10-11 exp [(104±32)/T], Cl + C3H8 → HCl + CH3CHCH3; (7.3±0.2) × 10-11 exp [-(68 ± 10)/T], Cl + n-C4H10 → HCl + CH3 CH2CH2CH2; (9.9 ± 2.2) × 10-11 exp [(106 ± 75)/T], Cl + n-C4H10 → HCl + CH3CH2CHCH3; (13.0 ± 1.8) × 10-11 exp [-(104 ± 50)/T], Cl + i-C4H10 → HCl + CH3CHCH3 CH2; (2.9 ± 0.5) × 10-11 exp [(155 ± 58)/T], Cl + i-C4H10 → HCl + CH3CCH3CH3 (all error bars are ±2ρ precision). The studies provide a set of reaction rate constants allowing to determine the contribution of competing hydrogen abstractions from primary, secondary, or tertiary carbon atom in alkane molecule.
- Sarzynski, Dariusz,Sztuba, Barbara
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p. 651 - 658
(2007/10/03)
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- Generation of alkyl hypochlorites in oxidation of alcohols with carbon tetrachloride catalyzed by vanadium and manganese compounds
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Primary alcohols and diols with various structures were subjected to transformations into esters, aldehydes, ketones, and lactones under the action of carbon tetrachloride in the presence of manganese compounds (MnCl 2, MnO2, Mn(OAc)2, Mn(acac)3) and vanadium compounds (VCl5, V2O5, VO(acac) 2) as catalysts. These transformation proceeded with the involvement of alkyl hypochlorites, which were generated in the course of oxidation of alcohols with carbon tetrachloride catalyzed by manganese or vanadium compounds. The optimum molar ratios between the catalyst and reagents were determined, and the reaction conditions for the highly selective synthesis of esters, aldehydes, ketones, and lactones from alcohols were found.
- Khusnutdinov,Shchadneva,Baiguzina,Lavrentieva,Dzhemilev
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p. 2074 - 2079
(2007/10/03)
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- Catalytic decomposition of alkyl chloroformates by hexabutylguanidinium chloride
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Hexabutylguanidinium chloride (0.5 molar %) efficiently decomposes alkyl chloroformates into chlorides, with low alkenes formation, via a S(N)2 mechanism as demonstrated from substituents effects and asymmetric chloride synthesis.
- Foulon, Frederique,Fixari, Bernard,Picq, Dominique,Le Perchec, Pierre
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p. 3387 - 3390
(2007/10/03)
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- REACTION OF ORGANIC COMPOUNDS WITH THE SF4-HF-HALOGENATING AGENT SYSTEM. X. REACTIONS OF ALKANES AND HALOALKANES WITH THE SF4-HF-Cl2 SYSTEM
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In the reaction of the SF4-HF-Cl2 system with alkanes and haloalkanes there are formed chlorofluoroalkanes with both linear and iso-structure.As the result of the electrophilic attack on the sp3-hybridized carbon atom of the C-H bond by a halogen cation, a pentacoordinated carbonium ion is formed with various modes of stabilization, depending on the structure of the starting haloalkane.
- Kunshenko, B. V.,Ostanin, Yu. A.,Yagupol'skii, L. M.
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p. 1603 - 1610
(2007/10/02)
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- CHLORINATION OF PHOSPHINE IN ALCOHOLS
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Trialkyl phosphates are rapidly and selectively formed when dilute gaseous PH-Ar and Cl2-Ar mixtures are passed into alcohols (ROH, R=Bu, i-Bu, Am, i-Am, Oct) at 50-70 deg C.Analogous results are obtained in the presence of pyridine at 8-25 deg C.The reaction was studied by gas chromatography, 31P NMR spectroscopy, and potentiometry.The reaction was shown to pass successively through the stages of the chlorination of phosphine to PCl5, the alcoholysis of phosphorus pentachloride to phosphoryl chloride, and finally by the esterification of phsophoryl chloride to trialkyl and dialkyl phosphates.Pyridine, excess af alcohol, and high temperature accelerate the stage of the esterification of phosphoryl chloride to the trialkyl phosphate.
- Dorfman, Ya. A.,Polimbetova, G. S.,Aibasov, E. Zh.,Borangazieva, A. K.,Kokpanbaeva, A. O.,Faizova, F. Kh.
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p. 1860 - 1864
(2007/10/02)
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- ORGANOBORANES FOR SYNTHESIS. 12. THE REACTION OF ORGANOBORANES WITH NITROGEN TRICHLORIDE. A CONVENIENT PROCEDURE FOR THE CONVERSION OF ALKENES INTO ALKYL CHLORIDES VIA HYDROBORATION
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Trialkylboranes are readily converted to the corresponding alkyl chlorides by a free radical reaction with nitrogen trichloride (NCl3).Compared to many other chlorinating agents examined, NCl3 is a superior reagent for the effective conversion of organoboranes into alkyl chlorides.Combined with the high regioselectivity inherent in the hydroboration reaction, the treatment with NCl3 allows alkenes to be transformed into pure alkyl chlorides of predictable structure.This process constitutes valuable method for the anti-Markovnikov hydrochlorination of alkenes in 66-94percent yield.Experimental evidence indicates that this reaction proceeds via free radical intermediates.The reaction of organoboranes with NCl3 is comparable to or better than other methods, such as those requiring refluxing aqueous cupric or ferric chloride, or those producing hydrogen chloride as a by-product.Consequently, this procedure could be very useful for the conversion of acid-sensitive (e.g., certain bicyclic) alkenes into alkyl chlorides where extensive skeletal rearrangements occur in hydrogen chloride additions.
- Brown, Herbert C.,de Lue, Norman R.
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p. 2785 - 2792
(2007/10/02)
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- A Functionalized Alkyldiphenylphosphine as an Efficient and Mild Reagent in CCl4-Promoted Substitution Reactions: Kinetics and Mechanism of the Reaction in CHCl3
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(Pyrid-2-ylethyl)diphenylphosphine can be used at 35-45 deg C in carbon tetrachloride-chloroform to give high yields of primary and secondary alkyl chlorides from the corresponding alcohols. The isolation of products is simplified by removal of the phosphorus-containing products by extraction into a dilute aqueous acid solution.The complex reaction was studied by 31P NMR.The rate constants based on the decay of phosphine are reported.The rapid conversion of alcohols proceeds equally via chlorination by CCl3 (path A) and by Cl (path B).The rates of formation and decay of an isobutoxyphosphonium intermediate, Cl, have been measured with 31P NMR.
- Toto, Susan D.,Doi, Joyce Takahashi
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p. 4999 - 5003
(2007/10/02)
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- The Free Radical Reaction between Alkanes and Carbon Tetrachloride
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Product studies and kinetic electron paramagnetic resonance methods were used to investigate the free radical reaction between alkanes and carbon tetrachloride in solution.Trichloromethyl radicals abstracted hydrogen from simple alkanes with rate constants of ca. 60 M-1 s-1 at 300 K. in good agreement with gas-phase data.However, rate constants for chlorine abstraction by alkyl radicals from carbon tetrachloride were ca.E4 M-1 s-1 and were therefore ca. 2 orders of magnitude higher in solution than in the gas phase.Possibilities for the origin of this effect are discussed.
- Hawari, J. A.,Davis, S.,Engel, P. S.,Gilbert, B. C.,Griller, D.
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p. 4721 - 4724
(2007/10/02)
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- SN2 Reactions in the Gas Phase. Temperature Dependence of the Rate Constants and Energies of the Transition States. Comparison with Solution
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The rate constants for the gas-phase reactions Cl- + RBr = ClR + Br-, where R = Me, Et, n-Bu, i-Pr, and i-Bu, were determined for temperatures between 25 and 390 deg C with a pulsed electron beam high ion source pressure mass spectrometer.The rate constants for Me decreased with an increase of temperature (negative temperature dependence).Et and n-Bu had almost no temperature dependence while i-Pr and i-Bu had positive temperature dependence.An analysis of the data on the basis of theory provides approximate values for ΔE0, the energy of the transition state relative to the energy of the reactants.These ΔE0 values are as follows: Me, -2.5; Et, 0.8; n-Bu, -0.5; i-Pr, +5.1; i-Bu, +5.7 kcal/mol.The δΔE0 are compared with relative activation energies: δEa in solution (C.K.Ingold and A.J.Parker) and calculated strain energies δΔEstrain due to steric repulsions in the transition state (C.K.Ingold and D.F.DeTar).An approximate agreement between the three sets of data is found.This finding supports the assumption of Ingold that steric effects in the transition state dominate the relative rates of this reaction series.The temperature dependence of the rate constants in the gas phase is of interest to ion-molecule reaction theory.It provides a graphic demonstration for the effect of the central barrier in the double-well reaction coordinate.When ΔE0 is negative, negative temperature dependence is observed.When -ΔE0 is small (Me, n-Bu) the reaction proceeds with chemical activation at the very low pressures used in ion cyclotron resonance but with near Boltzmann transition-state distribution at the higher pressures used in high-pressure mass spectrometry.When ΔE0 is positive, the reaction proceeds with positive temperature dependence and boltzmann transition-state distribution.
- Caldwell, Gary,Magnera, Tom F.,Kebarle, Paul
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p. 959 - 966
(2007/10/02)
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- Hydrocarbon Functionalization by the (Iodosylbenzene)manganese(IV) Porphyrin Complexes from the (Tetraphenylporphinato)manganese(III)-Iodosylbenzene Catalytic Hydrocarbon Oxidation System. Mechanism and Reaction Chemistry
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The two types of complexes isolated from the reaction of (tetraphenylporphinato)manganese(III) derivatives, XMnIIITPP, with iodosylbenzene - IVTPP(OIPh)>2O, 1, X = Cl- or Br-, and IVTPP>2O, 2, X = N3- - are capable of oxidizing alkane substrates in good yields at room temperature.Several lines of evidence establish the intermediacy of free alkyl radicals in the reactions of 1 and 2 with alkanes.Oxygen exchange with water in both the iodosyl (Mn-O-I) and μ-oxo (Mn-O-Mn) moieties of 1 suggests the formation of oxo manganese porphyrin complexes from these moieties.Hydrogen abstraction from the alkane substrate by an oxo manganese porphyrin intermediate is postulated to be mechanism for reaction of 1 and 2 with alkanes.Observation of a monomeric manganese(IV) porphyrin intermediate by EPR spectroscopy during the reactions of 1 with alkanes is consistent with the formation of a hydroxymanganese(IV) porphyrin complex resulting from substrate hydrogen abstraction by an oxo intermediate.The formation of RX product from oxidation of RH by 1 has been determined to result from ligand-transfer oxidation of free alkyl radicals by the porphyrin complexes in solution.Through competition reactions and time-dependent product formation studies, ligand-transfer oxidation by XMnIIITPP was found to be the major pathway for RX production.Observation of MnIITPP by EPR spectroscopy during the reactions of 1 with alkanes supports this conclusion.Formation of ROH product may result from ligand-transfer oxidation of free radicals or from the collapse of an intermediate caged radical pair.The mechanism of ROH product formation in the caged radical pair is postulated to be an outer-sphere electron-transfer process due to the expected slow rate of inner-sphere ligand transfer for the high-spin d3 hydroxymanganese(IV) porphyrin complex.Thus the ability of the substrate radical to undergo electron-transfer oxidation determines the ratio of radicals that undergo cage escape to give free radicals to radicals that undergo oxidation and subsequent formation of alcohol product in the caged species.Studies with tertiary substrates support these conclusions.
- Smegal, John A.,Hill, Craig L.
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p. 3515 - 3521
(2007/10/02)
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- Catalytic Replacement of Unactivated Alkane Carbon-Hydrogen Bonds with Carbon-X Bonds (X = Nitrogen, Oxygen, Chlorine, Bromine, or Iodine). Coupling of Intermolecular Hydrocarbon Activation by MnIIITPPX Complexes with Phase-Transfer Catalysis
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A simple system has been devised to facilitate the first processes for the catalytic replacement of unactivated alkane C-H bonds with C-X bonds, X = nitrogen and iodine.The system also enables alkane C-H bonds to be replaced by C-X bonds, X = chlorine, bromine, and oxygen.The system is composed of two liquid phases and the oxidant iodosylbenzene (iodosobenzene).The alkane substrate, the MnIIITPPX catalyst, and the organic solvent (dichloromethane, chlorobenzene, or other aromatic hydrocarbon) constitute one phase, a saturated aqueous solution of the sodium salt of the anion to be incorporated into the alkane, NaX, X = N3(1-), NCO(1-), I(1-), Br(1-), or Cl(1-), constitutes the second phase, and the sparingly soluble oxidant iodosylbenzene constitutes a third phase.When the two liquid phases and the oxidant iodosylbenzene are stirred under an inert atmosphere, both RX and ROH products are produced catalytically based on MnTPP and in reasonable yield based on iodosylbenzene.The MnTPP moiety functions as a catalyst for C-H bond cleavage and for phase transfer of X(1-) from the aqueous phase to the organic phase where the functionalization chemistry takes place.The oxidant hypochlorite can be used in place of, but is less effective than, iodosylbenzene, and the oxidants hydrogen peroxide, periodate, and persulfate are ineffective.Product distributions obtained from the oxidation of cyclohexane, isobutane, 2,3-dimethylbutane, and tert-butylbenzene are most consistent with a product-determining step that involves transfer of X from manganese to a free alkyl radical intermediate.
- Hill, Craig L.,Smegal, John A.,Henly, Timothy J.
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p. 3277 - 3281
(2007/10/02)
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- Relative Bond Dissociation Energies for Two-Ligand Complexes of Cu+ with Organic Molecules in the Gas Phase
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Ralative two-ligand dissociation enthalpies, δD(Cu+-2L), for Cu+ with 43 organic molecules are determined.A pulsed-laser volatilization/ionization sourse is used to generate Cu+ which reacts with EtCl and/or other molecules to give Cu(ligand)2+ species.Equilibrium constants are measured for the ligand-exchange reactions which occur when pairs of ligand molecules are present.Free energies for two-ligand exchange are obtained from the equilibrium constant for the reaction Cu(A)2+ + 2B ->/+ + 2A.The free-energiy differences are added to give a scale of relative free energies for ligand exchange.These are converted to enthalpies to give δD(Cu+-2L) scale with the assumption that enthropy changes are small and can be neglected except for symmetry corrections which are made in appropriate cases.Dependence of δD(Cu+-2L) on functional group and substituent effects is analyzed.These results for Cu+ are compared to available results for other reference acids: H+, Al+, Mn+, Li+, and CpNi+.These comparisons show that Cu+ is a softer acid than the other reference acids.This is apparent from the relative preference of Cu+ for mercaptans and HCN compared to alcohols and other oxygen bases.
- Jones, Roger W.,Staley, Ralph H.
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p. 2296 - 2300
(2007/10/02)
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- Studies on Sulphochlorination of Paraffins. IX. Regularities of the Sulphochlorination of Branched-chain Paraffins
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In the cases of 2-methylbutane and 2-methylpentane the formation of tertiary sulphochlorides in the sulphochlorination of the parent hydrocarbons could be established by means of 13C-n.m.r.-spectroscopy.The relative rates of the various C-H-bonds in 2-methylbutane, 2-methylpentane and 3-methylpentane in the sulphochlorination reaction were determined.The relative rates of the tertiary C-H-bonds in the sulphochlorination were considerably lower than the corresponding values for the chlorination of the branched-chain paraffins.
- Estel, D.,Mateew, K.,Pritzkow, W.,Schmidt-Renner, W.
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p. 262 - 268
(2007/10/02)
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- POLARISATION NUCLEAIRE INDUITE CHIMIQUEMENT: ETUDE COMPARATIVE DE LA DECOMPOSITION THERMIQUE ET PHOTOCHIMIQUE DE PEROXYDES D'ACYLE BENZOYLE
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A comparative CIDNP study of the thermal and photochemical decomposition of acyl benzoyl peroxides PhCO2O2CR (R=methyl and isobutyl) has provided an explanation of the effect of the mode of initiation on the course of the decomposition of this class of peroxides and on the product distribution.The observed variations result from an important decrease (from 1E-8 sec to less than 1E-10 sec) in the lifetime of the benzoyloxy radical on changing from thermal to photochemical initiation.
- Nedelec, J. Y.,Lefort, D.
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p. 3199 - 3204
(2007/10/02)
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- Bisphosphinic acid anhydrides and process for their preparation
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Bisphosphinic acid anhydrides of the formula STR1 in which R is a saturated open chain or cyclic alkylene radical, an arylene or aralkylene radical, and R1 and R2, which may be identical or different, represent optionally halogen substituted alkyl, aryl or aralkyl radicals, and m represents an integer ≥1, preferably ≥2 and a process for their preparation which comprises reacting bisphosphinic acid derivatives of the formula STR2 in which R3 and R4, are hydrogen, monovalent cations, the ammonium group or optionally halogen-substituted alkyl groups, with inorganic acid chlorides and/or with phosgene and/or with oxalyl chloride and/or with the corresponding bromine compounds in a molar ratio of about 1:1 at a temperature up to 250° C.
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- Carbon-Halogen Bonding Studies. Halogen Redistribution Reactions between Alkyl or Acetyl Halides and Tri-n-butyltin Halides
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The equilibrium positions have been determined for the halogen redistribution reactions of tri-n-butyltin halides with a variety of structurally different types of alkyl halides and with acetyl halides.These have been related through the reaction ΔGo values to carbon-halogen bond dissociation energy differences.It is suggested that the trends observed in the latter may provide evidence for the existence of a small steric bond weakening effect in the order C-I > C-Br > C-Cl bonds on going from methyl to primary, secondary, and tertiary alkyl halides.On the other hand, with the 2,3-? bond containing allyl, benzyl, and propargyl halides , α-haloacetones, and haloacetonitriles, there may be some type of electronic carbon-halogen bond strengthening effect which lies in order C-I > C-Br > C-Cl.Finally, for the acetyl halides, the data are in agreement with increases in bond strengths resulting from ? contributions being in the order C-Cl > C-Br > C-I.
- Friedrich, Edwin C.,Abma, Charles B.
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p. 1367 - 1371
(2007/10/02)
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- Synthesis and transformations of phosphorus imidazolidines (1,3-diaza-2-phospholidines)
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Four new derivatives of the phosphorus imidazolidine ring system have been prepared by animation of dichlorophosphines with variously N,N′-disubstituted ethylenediamines. The nmr spectra of the N-CH3 substituted rings show a sharp doublet for these protons and a multiplet for the methylene bridge protons, while the N-phenyl derivatives show a sharp doublet for the methylene bridge protons at 60 and 100 MHz contrary to expectations on the basis of the pyramidal stereochemistry of phosphorus(III). These observations are interpreted in terms of the stereochemistry and dynamics of the diazaphos-pholidine heterocycles. The phosphorus imidazolidines are transformed to their boron analogs in an exothermic reaction with phenylboron dichloride with the release of dichlorophosphine, but the reaction is not reversible. Treatment of the phosphorus ring with arsenic trichloride yields a solid whose mass spectrum shows a peak at the highest mass corresponding to the ten-membered ring dimer of the known arsenic imidazolidine.
- Das,Zuckerman
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p. 1028 - 1030
(2007/10/08)
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