- Selective Functionalization of Hydrocarbons Using a ppm Bioinspired Molecular Tweezer via Proton-Coupled Electron Transfer
-
An expanded porphyrin-biscopper hexaphyrin was introduced as a bioinspired molecular tweezer to co-catalyze functionalization of C(sp3)-H bonds. Theoretical and experimental investigations suggested that the biscopper hexaphyrin served as a molecular tweezer to mimic the enzymatic orientation/proximity effect, efficiently activating the N-hydroxyphthalimide (NHPI) via light-free proton-coupled electron transfer (PCET), at an exceptionally low catalyst loading of 10 mol ppm. The resulting N-oxyl radical (PINO) was versatile for chemoselective C-H oxidation and amination of hydrocarbons.
- Chen, Hongyu,Wang, Lingling,Xu, Sheng,Liu, Xiaohui,He, Qian,Song, Lijuan,Ji, Hongbing
-
p. 6810 - 6815
(2021/06/28)
-
- Synthesis and purification method of high-purity tert-butyl peroxy-2-ethylhexyl carbonate
-
The invention belongs to the fields of peroxidation, organic synthesis and peroxide purification, and particularly relates to a synthesis and purification method of tert-butyl peroxy-2-ethylhexyl carbonate, which comprises the steps of peroxidation reaction, substitution synthesis reaction, peroxide purification and the like. According to the method, the discharge of the waste liquid and the treatment cost of subsequent waste liquid are reduced, the reaction conditions are easy to control, the product yield is high, and the product purity is high and can reach 99% or above.
- -
-
Paragraph 0020; 0029-0031; 0034-0036; 0039-0041; 0044-0046
(2021/02/10)
-
- Waste liquid treatment process in TPO production process and device thereof
-
The invention relates to a waste liquid treatment process and device in a TPO production process, in particular to a waste liquid treatment process and device based on oxidant cyclic utilization in the TPO production process. The method comprises the following steps: mixing the synthetic waste liquid with sulfuric acid and water, carrying out esterification reaction to obtain a material phase, further carrying out mixing reaction on the material phase and hydrogen peroxide, carrying out liquid separation to obtain a tert-butyl hydroperoxide phase, and carrying out alkali washing to obtain tert-butyl hydroperoxide; tert-butyl hydroperoxide can return to a TPO synthesis section to be used as an oxidizing agent for preparing TPO; by adopting the process, the problem of high treatment cost ofthe synthetic waste liquid in the TPO production process is solved; and through the waste liquid treatment process, the resource utilization of the synthetic waste liquid is realized, the raw materialpurchasing and process production costs of the TPO production process are greatly reduced, and the economic value is obvious.
- -
-
Paragraph 0148-0169
(2021/03/31)
-
- Waste liquid treatment device in TPO production technology
-
The utility model relates to a waste liquid treatment device in TPO production technology, including be used for synthetic waste liquid. The bottom of the esterification reaction kettle is provided with first discharge outlets for discharging the material phase, first discharge ports are connected with the material-phase charging ports of the synthesis reaction kettle. In the device, the synthetic waste liquid in the esterification reaction kettle is subjected to esterification reaction and liquid separation to obtain the material phase. The material phase enters the synthesis reaction kettle, and is mixed with hydrogen peroxide to react, divide liquid and alkali to obtain tert-butyl peroxide. The waste liquid treatment device realizes resource utilization of the synthetic waste liquid, contains TPO synthesis section oxidant, greatly reduces raw material purchasing and process production cost TPO production technology, and has obvious economic value.
- -
-
Paragraph 0142; 0148-0162; 0169
(2021/09/29)
-
- PROCESS AND SYSTEM TO MAKE SUBSTITUTED LACTONES
-
A process for oxidizing iso-butane with oxygen to produce t-butyl hydroperoxide and t-butyl alcohol; dehydrating at least a portion of the t-butyl alcohol to produce di-tert-butyl ether and isobutylene; epoxidizing at least a portion of the isobutylene with the t-butyl hydroperoxide to produce isobutylene oxide and t-butyl alcohol; and carbonylating at least a portion of the isobutylene oxide with carbon monoxide to produce pivalolactone.
- -
-
Paragraph 0052-0053
(2021/02/05)
-
- ONLINE CONTINUOUS FLOW PROCESS FOR THE SYNTHESIS OF ORGANIC PEROXIDES USING HYDROGEN PEROXIDE AS RAW MATERIAL
-
An online continuous flow production process for directly preparing organic peroxides by using hydrogen peroxide as a raw material. This production process uses hydrogen peroxide, catalyst, and an oxidation substrate as a raw material. Substrate will be turned to designated peroxides sequentially through oxidation and workup. This process is performed in a plug-and-produce integrated continuous flow reactor, and the raw materials are continuously fed to the reactor. So, specified peroxide can be continuously obtained at the outlet of the plug-and-produce integrated continuous flow reactor.
- -
-
Paragraph 0289; 0293
(2020/06/29)
-
- Method for preparing tert-butyl hydroperoxide
-
The invention relates to a method for preparing tert-butyl hydroperoxide. The method comprises the following step that a contact reaction is carried out on tert-butyl alcohol, isopropanol and oxygen in the presence of a catalyst, wherein the catalyst contains a titanium-silicon molecular sieve. The method is simple in process, no additional solvent is needed, and the conversion rate of the raw materials and selectivity of products are high.
- -
-
Paragraph 0066-0101
(2019/02/13)
-
- Tert-butyl hydroperoxide preparation method
-
The invention relates to the field of production of tert-butyl hydroperoxide, and discloses a tert-butyl hydroperoxide preparation method, which comprises that a liquid mixture containing tert-butanoland an oxidizing agent flows through a catalyst bed layer under an oxidation reaction condition, wherein the catalyst bed layer comprises a first catalyst bed layer and a second catalyst bed layer, the first catalyst bed layer is positioned on the upstream of the second catalyst bed layer by using the flowing direction of the liquid mixture as the reference, the first catalyst bed layer is loadedwith a titanium-silicon molecular sieve, and the second catalyst bed layer is loaded with a titanium-silicon-aluminum molecular sieve. With the method of the present invention, the high tert-butanolconversion rate and the high tert-butyl hydroperoxide selectivity can be obtained.
- -
-
Paragraph 0141-0191
(2019/10/01)
-
- Synthetic method for drug intermediate tert-butyl hydroperoxide
-
The invention discloses a synthetic method for the drug intermediate tert-butyl hydroperoxide. The synthetic method comprises the following steps: adding 2-methyl-2-propylamine and a sodium sulfate solution into a reaction vessel, controlling a stirring speed to be 130-160 rpm, controlling a solution temperature to be 20-26 DEG C, adding lead tetraacetate and an ethylene glycol dibutyl ether solution, adding an oxalic acid solution in batches within 30-50 min, and continuing a reaction for 70-90 min; and then adding cobalt nitrate powder, raising the solution temperature to 40-45 DEG C, continuing the reaction for 2-4 h, lowering the temperature to 5-10 DEG C, subjecting the obtained solution to layering, carrying out washing with a potassium nitrate solution for 20-30 min, then carrying out washing with an ethyl bromide solution for 40-60 min, carrying out recrystallization in a 1-pentene solution, and then carrying out dehydration with a dehydrating agent so as to obtain the finishedtert-butyl hydroperoxide.
- -
-
Paragraph 0012; 0017; 0018; 0021-0026
(2018/07/30)
-
- Thioether oxidation method
-
The present invention discloses a thioether oxidation method, which comprises that (1-1) isobutane and oxygen are subjected to a contact reaction, wherein the tert-butyl hydroperoxide content in the reaction mixture obtained through the contact reaction is more than 1 wt% through the contact reaction condition; optional (1-2) the reaction mixture obtained in the step (1-1) is mixed with an inorganic acid; and (2) under conditions sufficient to oxidize thioether, a raw material mixture containing the reaction mixture obtained in the step (1-1) and thioether and a titanium-silicon molecular sieve are subjected to a contact reaction, or a raw material mixture containing the reaction mixture obtained in the step (1-2) and thioether and a titanium-silicon molecular sieve are subjected to a contact reaction. With the method of the present invention, the high through put of the apparatus can be obtained, and the high thioether conversion rate and the high target oxidation product selectivity can be obtained; and the method can be performed only by additionally arranging the thioether oxidation reaction apparatus on the material outlet end of the existing isobutane oxidation apparatus, such that the method is easy to perform.
- -
-
Paragraph 0092; 0093
(2017/08/28)
-
- A method of preparing di-tert-butyl peroxide
-
A method of preparing di-tert-butyl peroxide is disclosed and belongs to the technical field of organic synthesis. The method includes a step of adding tert-butyl alcohol and sulfuric acid into a first reaction device, reacting under stirring, and controlling the temperature and reaction time of the reaction under stirring in the first reaction device to obtain a tert-butyl hydrogen sulfate liquid, a step of adding a recovered mother liquor into a second reaction device, adding crude tert-butyl alcohol and the tert-butyl hydrogen sulfate liquid into the second reaction device, and controlling the temperature and reaction time of a reaction under stirring in the second reaction device to obtain a reaction product, a step of feeding the reaction product to a liquid separating tank, and performing liquid separating to obtain an upper oil phase that is the di-tert-butyl peroxide and a lower water phase that is a mother liquor adopted as a recovery mother liquor for a next turn of reactions. The method is simple and short in process steps, and can allow the content of the di-tert-butyl peroxide in the upper oil phase to be 97.5% or above, thus meeting requirements on industrial scaled-up production. The method avoids environment pollution, saves raw materials, reduces the cost and achieves circular economy.
- -
-
Paragraph 0020; 0022; 0024; 0026; 0028
(2017/02/24)
-
- Sodium difluoromethanesulfinate—A difluoromethylating agent toward protonated heterocyclic bases
-
Free radical difluoromethylation of protonated heteroaromatic bases was accomplished using sodium difluoromethanesulfinate in combination with tert-butyl hydroperoxide in a two-phase system (methylene chloride–water) at room temperature. The difluoromethylation products of methyl pyridine-4-carboxylate, pyridine-4-carbonitrile, and 2-amino-1,3,4-thiadiazole were isolated on a preparative scale.
- Lytkina,Eliseenkov,Boyarskii,Petrov
-
p. 539 - 546
(2017/06/06)
-
- A bionic catalytic isobutane method of oxidation process for preparing tertiary-butyl hydroperoxide
-
The invention discloses a method for preparing tert-butyl hydroperoxide employing biomimetic catalysis and isobutane oxidation. According to the method, with isobutene as a raw material, oxygen as an oxidant, and a metal porphyrin compound as a catalyst, under the condition of controlling the reaction temperature at 40-100 DEG C and the reaction pressure at 0.3-3.0MPa, catalytic reaction is carried out to obtain the tert-butyl hydroperoxide. Compared with other processes, the method disclosed by the invention has the advantages of being mild in reaction condition, good in catalytic effect, high in tert-butyl hydroperoxide selectivity, simple in process and the like.
- -
-
Paragraph 0020; 0021
(2017/04/29)
-
- Method for preparing tert-butyl hydroperoxide
-
The invention relates to a method for preparing tert-butyl hydroperoxide. According to the invention, the raw materials are isobutane and di-tert-butyl peroxide, and steps of catalysis, underpressure distillation and crystallization are carried out on the raw materials according to a certain proportion under high temperature and high pressure. According to the invention, the raw materials are isobutane and the di-tert-butyl peroxide with mass ratio being 1:1-3; the high temperature and high pressure condition are 140-160 DEG C and 1.5-2.5 atmospheric pressure; a catalyst is ferric potassium oxalate; the underpressure distillation condition is 0.1-0.3 atmospheric pressure, and temperature is 30-40 DEG C; the crystallization step is characterized in that the collected liquid is dissolved by distilled water at temperature of 20-40 DEG C, then is cooled to the temperature of 1-5 DEG C, is slightly stirred, and is stood for crystallization. The process flow is short, reaction byproduct is less, environment pollution and corrosion degree on production equipment are low, and product purity is high.
- -
-
Paragraph 0013
(2016/11/17)
-
- NMR study of the complex formation between tert-butyl hydroperoxide and tetraalkylammonium bromides
-
The interaction between tert-butyl hydroperoxide and tetraalkylammonium bromides was studied by NMR spectroscopy in acetonitrile-d 3 at 298 K. The complex formation between the hydroperoxide molecule and corresponding quaternary ammonium salt w
- Turovskij, Nikolaj A.,Berestneva, Yulia V.,Raksha, Elena V.,Zubritskij, Mikhail Yu.,Grebenyuk, Serhiy A.
-
p. 1443 - 1448
(2014/11/27)
-
- Binuclear iron complexes with acyclic Schiff bases based on 4-tert-butyl-2,6-diformylphenol: Synthesis, properties, and use in catalytic partial oxidation of isobutane
-
New binuclear iron complexes with acyclic Schiff bases based on 4-tert-butyl-2,6-diformylphenol and amino acids methionine and histidine were synthesized. The composition and inferred structure of the complexes were studied by elemental analysis, IR spectroscopy, Moessbauer spectroscopy, and electrochemical methods. The synthesized complexes were studied in catalytic reactions of partial oxidation of isobutane to tert-butyl alcohol and decomposition of tert-butyl hydroperoxide. The activity and selectivity of the complex depend on the nature of the bridging group between two iron ions and are independent of the amino acid environment.
- Rodionova,Borisova,Smirnov,Ordomsky,Moiseeva,Pankratov
-
p. 1201 - 1209
(2014/03/21)
-
- PROCESS FOR PREPARING AN EPOXIDE FROM AN OXYGENATE
-
The invention relates to an integrated process for preparing an epoxide from an oxygenate, wherein the production of a lower olefin from the oxygenate and the subsequent epoxidation of the lower olefin is combined and wherein isobutene, a by-product of the lower olefin production, is converted into a hydroperoxide that is used for the conversion of the lower olefin into the corresponding epoxide.
- -
-
Page/Page column 15; 16
(2013/05/09)
-
- PROCESS FOR PREPARING AN EPOXIDE FROM AN OXYGENATE
-
The invention relates to an integrated process for preparing an epoxide from an oxygenate, wherein the oxygenate is converted into a lower olefin and the lower olefin is subsequently epoxidised, and wherein isobutane obtained after hydrogenation and subsequent normal/iso separation of C4 hydrocarbons obtained as by-product of the oxygenate conversion, is converted into a hydroperoxide that is used for the conversion of the lower olefin into the corresponding epoxide.
- -
-
Page/Page column 14-15
(2013/05/09)
-
- Method for the manufacture of pressure sensitive adhesives
-
A method for the manufacture of an adhesive id described, comprising: (A) Providing an initial reaction product of a solution polymerization reaction, the initial reaction product comprising polymer, unreacted polymerizable reactant, non-polymerizable material, and solvent; and (B) Purifying the initial reaction product by adding an oxidizing agent and a reducing agent to the initial reaction product and allowing the unreacted polymerizable reactant in the initial reaction product to further react, thereby providing a second reaction product comprising additional polymer and a lower level of unreacted polymerizable reactant than was present in the initial reaction product. Optionally, the method of the invention may further comprise: Precipitating the polymer from the second reaction product to provide a precipitated polymer, and separating the precipitated polymer from the remainder of the second reaction product, the precipitated polymer comprising a lower level of non-polymerizable material or unreacted polymerizable reactant or both non-polymerizable material and unreacted polymerizable reactant than was present in the second reaction product.
- -
-
-
- Reactions of Mn(II) and Mn(III) with alkyl, peroxyalkyl, and peroxyacyl radicals in water and acetic acid
-
The kinetics of oxidation of Mn(II) with acylperoxyl and alkylperoxyl radicals were determined by laser flash photolysis utilizing a macrocyclic nickel complex as a kinetic probe. Radicals were generated photochemically from the appropriate ketones in the presence of molecular oxygen. In both acidic aqueous solutions and in 95% acetic acid, Mn(II) reacts with acylperoxyl radicals with k = (0.5-1.6) × 106 M-1 s-1 and somewhat more slowly with alkylperoxyl radicals, k = (0.5-5) x 10 5 M-1 s-1. Mn(III) rapidly oxidizes benzyl radicals, k = 2.3 × 108 M-1 s-1 (glacial acetic acid) and 3.7 × 108 M-1 s-1 (95% acetic acid). The value in 3.0 M aqueous perchloric acid is much smaller, 1× 107 M-1 s-1. The decarbonylation of benzoyl radicals in H2O has k = 1.2 × 106 s -1.
- Jee, Joo-Eun,Bakac, Andreja
-
p. 2136 - 2141
(2010/07/05)
-
- Product distributions from the OH radical-induced oxidation of n-Pentane and isopentane (2-Methylbutane) in Air
-
Hydroxyl radicals, generated by photolysis of H2O2. were reacted with n-pentane and isopentane in air in the absence of nitrogen oxides. The observed product distributions were compared with similar data derived by computer simulations, based on the known reaction mechanisms, to determine relative probabilities for hydrogen abstraction at different sites of the parent compounds and to estimate branching ratios and relative rate coefficients for cross-combination reactions between different peroxy radicals. For n-pentane. the distribution of the pentanols indicates probabilities for hydrogen abstraction, in percent, of q1= 9.1 ± 0.7. q 2 = 56.1 ± 1.8, and q3 = 34.8 ± 1.3. which agree with predictions based on the algorithm proposed by Atkinson. Branching ratios needed to harmonize calculated and observed product distributions are somewhat larger than, although still within the error ranges of. the values found by us previously Comparison between experimental and calculated data confirms the isomerization and decomposition constants recently established for the three pentoxyl radical isomers. The product distribution for isopentane. which is dominated by acetone, acetaldehyde. 2-methyl-butan-2-ol. and 2-methyl-butan-2-hydroperoxide, is in harmony with the predicted oxidation mechanism. Probabilities for hydrogen abstraction from isopentane were estimated to occur to 12% at the primary. 28% at the secondary, and 60% at the tertiary sites, again in agreement with predictions based on the algorithm of Atkinson.
- Heimann, Gerald,Warneck, Peter
-
p. 677 - 688
(2008/02/11)
-
- Hydrogen peroxide oxygenation of alkanes including methane and ethane catalyzed by iron complexes in acetonitrile
-
This paper describes an investigation of the alkane oxidation with hydrogen peroxide in acetonitrile catalyzed by iron(III) perchlorate (1), iron(III) chloride (2), iron(III) acetate (3) and a binuclear iron(III) complex with 1,4,7-triazacyclononane (4). The corresponding alkyl hydroperoxides are the main products. Nevertheless in the kinetic study of cyclohexane oxidation, the concentrations of oxygenates (cyclohexanone and cyclohexanol) were measured after reduction of the reaction solution with triphenylphosphine (which converts the cyclohexyl hydroperoxide to the cyclohexanol). Methane and ethane can be also oxidized with TONs up to 30 and 70, respectively. Chloride anions added to the oxidation solution with 1 activate the perchlorate iron derivative in acetonitrile, whereas the water as additive inactivates 2 in the H 2O2 decomposition process. Pyrazine-2-carboxylic acid (PCA) added to the reaction mixture decreases the oxidation rate if 1 or 2 are used as catalysts, whereas compounds 3 and 4 are active as catalysts only in the presence of small amount of PCA. The investigation of kinetics and selectivities of the oxidations demonstrated that the mechanisms of the reactions are different. Thus, in the oxidations catalyzed by the 1, 3+PCA and 4+ PCA systems the main oxidizing species is hydroxyl radical, and the oxidation in the presence of 2 as a catalyst has been assumed to proceed (partially) with the formation of ferryl ion, (FeIV=O)2+. In the oxidation catalyzed by the 4+PCA system (TONs attain 240) hydroxyl radicals were generated in the rate-determining step of monomolecular decomposition of the iron diperoxo adduct containing one PCA molecule. A kinetic model of the process which satisfactorily describes the whole set of experimental data was suggested. The constants of supposed equilibriums and the rate constant for the decomposition of the iron diperoxo adduct with PCA were estimated.
- Shul'pin, Georgiy B.,Nizova, Galina V.,Kozlov, Yuriy N.,Cuervo, Laura Gonzalez,Su?ss-Fink, Georg
-
p. 317 - 332
(2007/10/03)
-
- Dehydrogenation vs oxygenation in photosensitized oxidation of 9-substituted 10-methyl-9,10-dihydroacridine in the presence of scandium ion
-
Photooxidation of 9-substituted 10-methyl-9,10-dihydroacridine (AcrHR) with oxygen occurs efficiently in the presence of 9,10-dicyanoanthracene (DCA) and scandium triflate [Sc(OTf)3] under visible light irradiation in oxygen-saturated acetonitr
- Fukuzumi, Shunichi,Fujita, Shunsuke,Suenobu, Tomoyoshi,Imahori, Hiroshi,Araki, Yasuyuki,Ito, Osamu
-
p. 1465 - 1472
(2007/10/03)
-
- Preparation of di-t-alkyl peroxides and t-alkyl hydroperoxides from n-alkyl ethers
-
A process for production of a t-alkyl peroxide compound includes the steps of: a) reacting an n-alkyl t-alkyl ether with a reactant mixture comprising an acid catalyst and a compound of the formula RO2H??(I) ?where R is H or t-alkyl, provided that if R is t-alkyl the t-alkyl peroxide compound product is a di-t-alkyl peroxide, and b) isolating a reaction product comprising said t-alkyl peroxide compound from the mixture resulting from step a). The process can be used to prepare t-butyl hydroperoxide or di-t-butyl peroxide from methyl t-butyl ether. Sulfuric acid may be used as the acid catalyst.
- -
-
-
- Oxidations by the system 'hydrogen peroxide-manganese(IV) complex- acetic acid' - Part II: Hydroperoxidation and hydroxylation of alkanes in acetonitrile
-
Higher alkanes (cyclohexane, n-pentane, n-heptane, methylbutane, 2- and 3-methylpentanes, 3-methylhexane, cis- and trans-decalins) are oxidized at 20 °C by H2O2 in air in acetonitrile (or nitromethane) solution in the presence of the manganese(IV) salt [L2Mn2O3](PF6)2 (L = 1,4,7-trimethyl- 1,4-7-triazacyclononane) as the catalyst. An obligatory component of the reaction mixture is acetic acid. Turnover numbers attain 3300 after 2 h, the yield of oxygenated products is 46% based on the alkane. The oxidation affords initially the corresponding alkyl hydroperoxide as the predominant product, however later these compounds decompose to produce the corresponding ketones and alcohols. Regio- and bond selectivities of the reaction are high: C(1): C(2): C(3): C(4) ? 1: 40: 35: 35 and 1°: 2°: 3°is 1: (15-40): (180-300). The reaction with both isomers of decalin gives (after treatment with PPh3) alcohols hydroxylated in the tertiary positions with the cis/trans ratio of ~2 in the case of cis-decalin, and of ~30 in the case of trans-decalin (i.e. in the latter case the reaction is stereospecific). Light alkanes (methane, ethane, propane, normal butane and isobutane) can be also easily oxidized by the same reagent in acetonitrile solution, the conditions being very mild: low pressure (1-7 bar of the alkane) and low temperature (- 22 to +27°C). Catalyst turnover numbers attain 3100, the yield of oxygenated products is 22% based on the alkane. The yields of oxygenates are higher at low temperatures. The ratio of products formed (hydroperoxide: ketone: alcohol) depends very strongly on the conditions of the reaction and especially on the catalyst concentration (at higher catalyst concentration the ketone is predominantly produced).
- Shul'pin, Georgiy B.,Suess-Fink, Georg,Lindsay Smith, John R.
-
p. 5345 - 5358
(2007/10/03)
-
- Epoxidation of 2-Ethylallyl Ethylacrylate with tert-Butyl Hydroperoxide
-
The catalytic epoxidation of 2-ethylallyl ethylacrylate with tert-butyl hydroperoxide is studied. Of the two double bonds, only allylic double bond was found to be epoxidized yielding 2,3-epoxy-2-ethylpropyl ethylacrylate. A homogeneous catalyst was found ineffective in catalyzing the reaction. The most active catalyst was heterogeneous (NH4)6Mo7O24 · 4H2O.
- Trach,Chernyak,Nikipanchuk
-
p. 280 - 282
(2007/10/03)
-
- Di(tert-butylperoxy)triphenylbismuth and the triphenylbismuth - tert-butyl hydroperoxide system as efficient oxidants of alcohols
-
Di(tert-butylperoxy)triphenylbismuth and the triphenylbismuth - tert-butyl hydroperoxide system react with aliphatic alcohols and cyclohexanol to give carbonyl compounds in high yields. The oxidation occurs as the radical dehydrogenation of alcohols; Bi derivatives serve as the sources of free radicals.
- Zinov'eva,Dolganova,Dodonov,Prezhbog
-
p. 659 - 662
(2007/10/03)
-
- Evidence for divalent iodine (9-I-2) radical intermediates in the thermolysis of (tert-butylperoxy)iodanes. An unusually efficient deiodination of o-iodocumyl alcohols by cyclohexyl radicals
-
1-(tert-Butylperoxy)-3,3-dimethyl-1H-1,2-benziodoxoles (2a and 2b) and 1-(tert-butylperoxy)-3,3-bis(trifluoromethyl)-5-methyl-1H-1,2-benziodo xole (2c) were prepared from chloroiodanes 1a-c and tert-butylhydroperoxide in the presence of potassium tert-butoxide in tetrahydrofuran. Products, kinetic data for the decomposition of 2 in cyclohexane, benzene, toluene, and acetonitrile (E(a) = 31.0 ± 1.0 kcal/mol, log A = 17.0 ± 0.5; 35-70 °C), and the increased rate of decomposition of 2c in benzene-d6 in the presence of a magnetic field (7 T) indicate that homolytic cleavage of the I-O bond in 2 with the formation of iodanyl (9-I-2) and tert-butylperoxyl radicals is the primary decomposition step. The nearly quantitative formation of iodocyclohexane during the decomposition of 2c in cyclohexane is due to the unexpected reaction of cyclohexyl radicals with 2-(2-iodo-5-methylphenyl)-1,1,1,3,3,3-hexafluoro-2-propanol, a primary decomposition product of 2c. The results of a separate study of the deiodination of o-iodocumyl alcohols (3) by cyclohexyl radicals are consistent with an S(H)2 type mechanism.
- Dolenc, Darko,Plesni?ar, Bo?o
-
p. 2628 - 2632
(2007/10/03)
-
- Oxidations by the reagent 'O2-H2O2-vanadium complex-pyrazine-2-carboxylic acid' - VIII. Efficient oxygenation of methane and other lower alkanes in acetonitrile
-
Methane, ethane, propane, n-butane and isobutane can be readily oxidized in acetonitrile solution by air and H2O2 at 20-75°C using the catalytic system [n-Bu4N]VO3/pyrazine-2-carboxylic acid, Apart from alkyl hydroperoxides which are the primary oxidation products, more stable derivatives (alcohols, aldehydes or ketones and carboxylic acids) are obtained with high total turnover numbers (e.g., at 75°C after 4 h: 420 for methane and 2130 for ethane). It was shown in the case of ethane and cyclohexane that alkanes do not yield oxygenated products in the absence of air. The cyclohexane oxidation under an 18O2 atmosphere showed a high degree of 18O incorporation into the oxygenated products. Thus in the oxidation reaction described here H2O2 is only the promoter while O2 is the 'true' oxidant.
- Nizova, Galina V.,Suess-Fink, Georg,Shul'pin, Georgiy B.
-
p. 3603 - 3614
(2007/10/03)
-
- Catalytically active gel and a process for its preparation
-
A catalytically active gel is described consisting of a silica matrix with uniform porosity, monomodal pore distribution and high surface area, within which one or metal oxides possessing catalytic activity are dispersed. A process for preparing this catalytic gel is also described.
- -
-
-
- Functionally Substituted Organic Peroxides. XIX. Kinetics of the Reaction of Poly- and Perfluorinated Carbonyl Compounds with tert-Butyl Hydroperoxide
-
The kinetics of noncatalytic reaction of fluorinated aliphatic and aromatic aldehydes, alkyl, cycloalkyl, and aryl ketones, and β-ketoesters with tert-butyl hydroperoxide were studied by IR spectroscopy.
- Chapurkin
-
-
- Highly Selective Formation of tert-Butyl Hydroperoxide from the Reaction of Isobutane and O2 in a Zeolite under Visible Light
-
Isobutane and oxygen gas loaded into zeolite BaY react upon irradiation with green or blue light to yield tert-butyl hydroperoxide in a single-photon process.This was discovered when monitoring the reaction at room temperature in situ by FT-infrared spectroscopy.Selectivity was 98percent, even upon conversion of more than half of the reactants loaded into the zeolite.Diffuse reflectance spectra revealed a visible absorption tail which originates from an isobutane*O2 collision complex.It is attributed to the isobutane*O2 contact charge-transfer absorption, whose onset is shifted from the UV into the visible region by the high electrostatic field of the zeolite. - Keywords: hydroperoxides; isobutane; oxygen; photooxidations; zeolites
- Blatter, Fritz,Sun, Hai,Frei, Heinz
-
p. 385 - 389
(2007/10/03)
-
- Synthesis of MTBE from isobutane using a single catalytic system based on titanium-containing ZSM-5 zeolite
-
A new route for the synthesis of methyl tert-butyl ether (MTBE) from isobutane using a single catalytic system is developed in the liquid phase; the key of the process relies on the use of a bifunctional material, Al-TS-1, capable of catalysing the oxidation of isobutane with H2O2 and consequently etherification with methanol.
- Van Grieken,Ovejero,Serrano,Uguina,Melero
-
p. 1145 - 1146
(2007/10/03)
-
- Use of pentagonally supported palladium catalyst in the preparation of tertiary butyl alcohol from tertiary butyl hydroperoxide
-
A method for preparing tertiary butyl alcohol wherein a feedstock comprising a solvent solution of tertiary butyl hydroperoxide in tertiary butyl alcohol or a mixture of tertiary butyl alcohol with isobutane is charged to a hydroperoxide decomposition reaction zone containing a catalytically effective amount of a hydroperoxide decomposition catalyst consisting essentially of pentagonally cross-sectioned alumina having palladium deposited thereon and is brought into contact with the catalyst in liquid phase with agitation under hydroperoxide decomposition reaction conditions to convert the tertiary butyl hydroperoxide to decomposition products, principally tertiary butyl alcohol.
- -
-
-
- Halogenated Metalloporphyrin Complexes as Catalysts for Selective Reactions of Acyclic Alkanes with Molecular Oxygen
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We have shown that halogenation of the porphyrin ring of a metalloporphyrin complex can convert a catalytically inactive material into an exceptionally active catalyst for the selective reaction of an alkane with molecular oxygen.The greater the degree of halogenation of the ring, the greater is the catalytic activity of the metal complex.The product profile, while characteristic of radical reactions, is sensitive to the nature of the metal center.Iron complexes are generally more active than those of cobalt, manganese, or chromium.The activity of iron complexes is directly related to the Fe(III)/(II) reduction potential of the porphyrin complex.There is also a similar correlation between the F(III)/Fe(II) reduction potential and the rate at which iron haloporphyrin complexes decompose alkyl hydroperoxides.These iron perhaloporphyrin complexes are not only the most active known liquid phase alkane air-oxidation catalysts, they are also the most active hydroperoxide decomposition catalysts known to date.The nature of the products formed is dependent on the structure of the aliphatic substrate that is oxidized and can be rationalized by a catalytic pathway that very efficiently generates alkyl and alkoxy radicals at low temperatures.The relationship between the electrochemical properties of these complexes and the rates of alkane oxidation and hydroperoxide decomposition lends insight into possible mechanisms of catalytic activity.
- Lyons, James E.,Ellis, Paul E.,Myers, Harry K.
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- Tetraalkyl-4-(2,3-epoxypropoxy) piperidine compounds as stabilizers
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Esters or phenol ethers of the formula I or II STR1 in which m and n are each an integer from the range from 1 to 6; A1 is an m-valent hydrocarbon radical having 1 to 30 carbon atoms; or an m-valent hydrocarbon radical having 2 to 30 carbon atoms, which contains the heteroatoms oxygen, nitrogen and/or sulfur and the free valencies of which are located on carbon atoms; and in which A1, in the case where m=2, additionally is a direct bond; A2 is an n-valent aromatic or araliphatic hydrocarbon radical having 6 to 30 carbon atoms; or an n-valent aromatic or araliphatic hydrocarbon radical having 5 to 30 carbon atoms, which contains the heteroatoms oxygen, nitrogen and/or sulfur and n free valencies of which are located on those carbon atoms which are a constituent of aromatic rings; R1 is hydrogen; a hydrocarbon or hydrocarbonoxy radical having 1 to 36 carbon atoms, which is unsubstituted or substituted by --CO--N(R3)2 or interrupted by --CO--N(R3)-- or --N(R3)--CO-- or 1 to 6 oxygen or sulfur atoms; benzoyl or naphthoyl, each of which is substituted by 1 to 3 C1 -C4 alkyl or C1 -C4 alkoxy radicals; or --CO--R2 ; in which R2 is C1 -C18 alkyl; C5 -C8 cycloalkyl; phenyl; naphthyl; C7 -C9 phenylalkyl; or C11 -C14 naphthylalkyl; and R3 has the same meanings as R2 or is hydrogen, are described. The compounds are suitable for stabilizing organic material against the damaging influence of light, oxygen and/or heat.
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- Quantitative treatment of micellar effects upon nucleophilic substitution
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Cationic micelles of cetyltrimethylammonium surfactants increase first-order rate constants for the basic hydrolysis of tert-butyl perbenzoate and 2-naphthyl benzoate.Dealkylation of both butyl 4-nitrobenzenesulfonate and butyl 4-bromobenzenesulfonate by halide ions in micelles of CTACl, CTABr and CTAOMs, and by azide ion in micelles of cetyltrimethylammonium mesylate (CTAOMs) have been examined.The nucleophilic aromatic substitutions of 2-chloro-3,5-dinitropyridine by OH- and N3- ions in the presence of CTABr, CTACl and CTAOMs micelles have also been examined.The rate enhancements have been treated in terms of concentration of both substrates and nucleophilic anions at the micellar surface.The anionic concentrations depend upon specific and non-specific coulombic interactions, which were calculated by solving the Poisson-Boltzmann equation (PBE).The same parameters were used in fitting data for reactions of N3-, Br- or Cl- as nucleophiles and for systems with Cl-, Br- and OMs- as inert counter-anions in CTACl, CTABr and CTAOMs, respectively.
- Al-Lohedan, Hamad A.
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p. 1707 - 1714
(2007/10/02)
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- Aldehyde/Olefin Cooxidations: Parallel Epoxidation Pathways and Concerted Decomposition of the Peroxyacyl-Olefin Adduct
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Aldehyde-mediated olefin epoxidations appear to proceed by parallel peracid and radical addition pathways.For that portion of the reaction proceeding by radical addition, several lines of evidence favor an explanation in which the peroxyacyl-olefin adduct decomposes in a concerted manner to form alkyl radical, CO2, and epoxide.
- Lassila, Kevin R.,Waller, Francis J.,Werkheiser, Steven E.,Wressell, Amy L.
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p. 8077 - 8080
(2007/10/02)
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- Dynamics of the reactions of [meso-tetrakis(2,6-dimethyl-3-sulfonatophenyl)porphinato]-manganese(III) hydrate with various alkyl hydroperoxides in aqueous solution. Product studies and comparison of kinetic parameters
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The second-order rate constants (kly) for reactions of [meso-tetrakis(2,6-dimethyl-3-sulfonatophenyl)porphinato]manganese(III) hydrate [(1)MnIII(X)2, X = H2O or HO-] with t-BuOOH and (Ph)(Me)2COOH have been determined in aqueous solution in the pH range 7.3-12.6. The pH dependencies of kly were fitted to a kinetic expression (eq 2) that was similar to that shown previously to describe the pH dependence of the reaction of (1)MnIII(X)2 with (Ph)2(MeOCO)COOH. Comparison of the very similar pH-rate profiles for t-BuOOH, (Ph)(Me)2COOH, and (Ph)2(MeOCO)COOH (ROOH) showed that the log of the second-order rate constants exhibits only a modest dependency on the acidity of the ROH leaving group (-0.32 for the pH 7.3-10.0 range) as would be expected of a homolytic reaction. Product analysis on the reactions with t-BuOOH in the absence of the ABTS trapping agent provided (Me)2CO (60-70%) as the major product with the remainder of the oxidant recovered as t-BuOH (12%), t-BuOOMe, (t-BuO)2, MeOH, and HCHO. The product distributions showed no significant dependence on the pH of the reaction solutions. In the presence of ABTS (Me)2CO is formed in 5% yield, and the main product is t-BuOH (89%). These findings are consistent with a mechanism involving the homolytic (but not heterolytic) cleavage of the O-O bond of manganese(III)-coordinated alkyl hydroperoxide. Addition of imidazole to the reaction of (1)MnIII(X)2 with t-BuOOH resulted in a ~4-10-fold enhancement in the rate of reaction. The pH dependence of log klm for the reaction in the presence of imidazole, from pH 5.3 to 12.6, was found to be in accord with that determined previously for (Ph)2- (MeOCO)COOH. The product distribution for the reactions in the presence of imidazole showed significant dependence on the pH of the reaction mixtures. At pH 7.8 and 10.0 the product profiles were only consistent with a homolytic mechanism for the O-O bond cleavage where the major product was (Me)2CO (63-67%), with the remainder being t-BuOH (19%), t-BuOOMe (13-16%), (t-BuO)2, MeOH, and HCHO. At pH 12.6, the yield of t-BuOH (63%) increased dramatically with concomitant decreases in the yields of (Me)2CO (34%), t-BuOOMe (4%), (t-BuO)2, MeOH, and HCHO. The latter product distribution finds explanation in a change in mechanism of the O-O bond cleavage from homolysis to heterolysis as a result of the proton dissociation of the manganese(III)-coordinated ImH (i.e., (1)MnIII(OOR)(ImH) → [(1)MnIII(OOR)(Im)]-). The acidity dependences of the 1e- oxidation and reduction potentials of (1)MnIII(X)(ImH) have been used to determine the acid ionization constants for the mono-imidazole-ligated (1)MnII(H2O)(ImH), (1)MnIII(H2O)(ImH), and (1)MnIII(H2O)(ImH) species. The change in 1e- oxidation potentials with pH has also been compared to the change in rate constants with pH for reactions occurring in the presence and absence of imidazole.
- Arasasingham, Ramesh D.,Jeon, Seungwon,Bruice, Thomas C.
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p. 2536 - 2544
(2007/10/02)
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- Electron-transfer reactions of alkyl peroxy radicals
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One-electron-transfer reactions of alkyl peroxy radicals were studied by pulse radiolysis of aqueous solutions. At pH 13, the methyl peroxy radical was found to rapidly, k = 1 × 105-4.9 × 107 s-1, and quantitatively oxidize various organic substrates with E13 = 0.13-0.76 V vs NHE. On the other hand, this radical was unreactive with compounds with E13 ≥ 0.85 V. Consequently, E13 of the methyl peroxy radical is higher than 0.76 V and lower than 0.85 V, which means that E7 is in the range 1.02-1.11 V. At pH 8, the rate constants of the oxidation of four ferrocene derivatives by the alkyl peroxy radicals ranged from 7.1 × 104 M-1 s-1 for ferrocenedicarboxylate (E8 = 0.66 V) to 2.3 × 106 M-1 s-1 for (hydroxymethyl)ferrocene (E8 = 0.42 V). These rate constants were used to evaluate the reduction potential and self-exchange rate of alkyl peroxy radicals in neutral media from the Marcus equation. The calculated E7 = 1.05 V is in excellent agreement with the estimated E7 = 1.02-1.11 V and with one of the perviously published values E7 = 1.0 V, but the value is in excellent agreement higher than the other E7 ~ 0.6 V. It is suggested that the high reorganization energy, λ = 72 kcal mol-1 redox couple originates from the requirement for solvent reorganization due to the solvation of hydroperoxide anion in the transition state. In support of this are the activation parameters of the reaction of the methyl peroxy radical with uric acid. The activation entropy is 9 eu lower at pH 7.3 than it is at pH 13.2, whereas the activation enthalpies are unchanged. The importance of entropy control was verified in the reactions of cyclohexyl peroxy radicals with α- and δ-tocopherol in aerated cyclohexane (ΔH+ ≈ 0 kcal/mol, and ΔS+ = -25 and -26 eu). The implications of these findings on the inactivation of alkyl peroxy radicals in general are discussed.
- Jovanovic, Slobodan V.,Jankovic, Ivana,Josimovic, Ljubica
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p. 9018 - 9021
(2007/10/02)
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- EFFECT OF STERIC FACTORS ON THE EQUILIBRIUM IN THE FORMATION OF TERT-BUTYLPEROXY KETALS FROM ALIPHATIC KETONES
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The equilibrium in the formation of tert-butylperoxy ketals from aliphatic ketones and tert-butyl hydroperoxide is determined by the steric factors of the substituents at the carbonyl group of the ketones.The dependence of the equilibrium constant on the steric parameters of the substituents is described by the Taft equation log K/KO = δΣEs0 with δ = 1.37 (r = 0.970).
- Antonovskii, V. L.,Fedorova, E. V.,Shtivel', N. E.,Emelin, Yu. D.
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p. 704 - 706
(2007/10/02)
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- Dynamics of Reaction of [5,10,15,20-Tetrakis(2,6-dimethyl-3-sulfonatophenyl)porphinato]iron(III) Hydrate with t-BuOOH in Aqueous Solution. 3. Comparison of Refined Kinetic Parameters and D2O Solvent Isotope Effects to Those for [5,10,15,20-Tetrakis(2,6-dichloro-3-sulfonatophenyl)porphinato]iron(III) Hydrate and Iron(III) Hydrate
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The decomposition of t-BuOOH in the presence of added ferric ion has been studied in buffered H2O and D2O solutions between pH(D) 1 to 4, by using 2,2′-azinobis(3-ethylbenzthiazolinesulfonate) (ABTS) to trap the oxidizing products. The reaction is first-order in both [t-BuOOH] and [FeIII]total. The value of the second-order rate constants in H2O (k2H = 29 M-1 s-1) and in D2O (k2D = 15 M-1 s-1) is independent of H+(D+) and added buffer species but exhibits a solvent deuterium kinetic isotope effect (k2H/k2D) of 1.9. At pH(D) III(H2O)2] with t-BuOOH and the reaction of [5,10,15,20-tetrakis(2,6-dichloro-3-sulfonatophenyl)porphinato]iron(III) [(2)FeIII(H2O)2] with H2O2 exhibit the very same independence upon H+(D+) and kinetic isotope effects (klyH/klyD) of 2.7 and 3.0, respectively. Thus, below pH 3 the reactions of FeIII, (1)FeIII(H2O)2, and (2)FeIII(H2O)2 with t-BuOOH all display sizable deuterium solvent isotope effects and an independence of rate on [H+] suggesting a common mechanism. We suggest a homolytic mechanism with either H* or H+ transfer rate controlling. In the low pH region, the calculated second-order rate constant for the reaction of ferric ion with t-BuOOH exceeds that for the reaction of (1)FeIII(H2O)2 with t-BuOOH by 5-fold. Above pH 3, a plot of the second-order rate constant (kly) vs pH, for reaction of t-BuOOH with H2O and HO- ligated [(1)FeIII]+1, shows that kly increases and then decreases with increase in pH to form a bell-shaped plot with maximum kly at pH 7.0. In the mid pH range the decomposition of the critical intermediates to products is not associated with a deuterium solvent isotope effect. With further increase in pH, log kly again increases to reach a second maxima. The very same log kly vs pH profile has been seen for the reaction of t-BuOOH with H2O and HO- ligated [(2)FeIII]+. On the basis of the percentage yields of (CH3)2C=O and CH3OH the reactions above pH 3 must reflect rate-determining t-BuO-OH bond homolysis. Reaction mechanisms are discussed in terms of the structures of steady-state intermediates and the ground-state structures of oxidized iron porphyrin species as determined in the previous paper in this issue by Kaaret, Zhang, and Bruice. The pH-dependent second-order rate constants (kly) for the decomposition of t-BuOOH by [(2)FeIII(X)2, X = OH- or H2O] exceed kly values for the reaction of [(1)FeIII(X)2, X = OH- or H2O] with t-BuOOH by at most 2.5-3.8-fold across the entire pH range. The marked influence of ionic strength on the pKa associated with (1)FeIII(H2O)2 ? (1)FeIII(H2O)(HO) + H+ has been determined, and from the Debye-Huckel equation for a monobasic acid the thermodynamic pKa = 7.3 and the charge on the FeIII(H2O)(HO) moiety is 2-.
- Gopinath, Enona,Bruice, Thomas C.
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p. 4657 - 4665
(2007/10/02)
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- Mechanism of asymmetric epoxidation. 1. Kinetics
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The rate of titanium-tartrate-catalyzed asymmetric epoxidation of allylic alcohols is shown to be first order in substrate and oxidant, and inverse second order in inhibitor alcohol, under pseudo-first-order conditions in catalyst. The rate is slowed by substitution of electron-withdrawing substituents on the olefin and varies slightly with solvent, CH2Cl2 being the solvent of choice. Asymmetric induction suffers when the size of the alkyl hydroperoxide is reduced. Kinetic resolution of secondary allylic alcohols is shown to be sensitive to the size of the tartrate ester group and insensitive to the steric nature of inhibitor alcohol. Most importantly, the species containing equimolar amounts of Ti and tartrate is shown to be the most active catalyst in the reaction mixture, mediating reaction at much faster rates than titanium tetraalkoxide alone.
- Woodard, Scott S.,Finn,Sharpless, K. Barry
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p. 106 - 113
(2007/10/02)
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- Polymerization Mechanism of Styrene Initiated by 2,2-Bis(t-butyldioxy)alkanes
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The radical polymerization mechanism of styrene initiated by 2,2-bis(t-butyldioxy)alkanes (1) has been studied in benzene.The decomposition products of 1 are acetone, alkyl methyl ketone, t-butyl alcohol, and t-butyl peracetate.Styrene monomer converts to polystyrene along with styrene oxide.The peroxides 1 cleave homolytically at one of dioxy bonds to yield intermediate alkoxy radicals with α-t-butyldioxy group, which undergo β-scission to afford t-butyldioxy or alkyl radicals.The resulting t-butyldioxy radical reacts with styrene to form 2-(t-butyldiox)-1-phenylethyl radical, which decomposes subsequently to styrene oxide and t-butoxyl radical via γ-scission.Alternatively, a part of t-butyldioxy radical adds to styrene to afford polystyrene containing dioxy bond.
- Watanabe, Yasumasa,Ishigaki, Hideyo,Okada, Hiroshi,Suyama, Shuji
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p. 1231 - 1234
(2007/10/02)
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- KINETICS AND MECHANISM OF ACID HYDROLYSIS OF PEROXYKETALS
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The kinetics of hydrolysis of aliphatic ketone di-tert-butylperoxyketals R1R2, R1=CH3, CH3; CH3, C2H5; CH3, n-C3H7; CH3, n-C6H13; CH3, i-C5H10; CH3, i-C4H9; C2H5, i-C3H7; n-C4H9, n-C4H9; CH3, C6H5-CH2, in dioxane in the presence of H2SO4 were investigated by IR spectroscopy.It was found that the reaction is reversible and takes place according to the equation R1R2C(OOC(CH3)3)2 + H2O R1R2=O + 2 HOOC(CH3)3.The proposed mechanism of hydrolysis includes the fast, quasiequilibrium formation of protonated peroxyketal and subsequent formation of the alkylperoxycarbenium ion.A three-parameter correlation equation is proposed for describing the initial rates of hydrolysis of R1R2C(OO-t-Bu)2 peroxyketals.
- Antonovskii, V. L.,Fedorova, E. V.,Kislina, I. S.,Shtivel', N. E.,Emelin, Yu. D.
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p. 2261 - 2265
(2007/10/02)
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- Formation and Rearrangement of a Vinyl Peroxide Produced from the Reaction of 3-Bromo-2,3-dimethyl-2-t-butylperoxybutane with Silver Hyponitrite
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The reaction of 3-bromo-2,3-dimethylbutane-2-hydroperoxide 2 with t-butanol in the presence of sulfuric acid affords 3-bromo-2,3-dimethyl-2-t-butylperoxybutane 3.The latter reacts with silver hyponitrite to yield t-butoxypinacolone 9.The mechanism of formation of 9 from 3 possibly proceeds via the carbocations 6 and 7 arising from an intermediate vinyl peroxide 8.
- Schulz, Manfred,Goermar, Gerhard,Lukac, Ivan
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p. 491 - 495
(2007/10/02)
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- Quantitative Treatment and Micellar Effects in the Reaction of t-Butyl Perbenzoate and 2-Naphtyl Benzoate
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The basic hydrolysis of t-butyl perbenzoate and 2-naphtyl benzoate has been studied in cationic micelles of cetyltrimethylammonium chloride or hydroxide (CTACl or CTAOH, respectively).The increase in rate constants with surfactant concentration can be analysed in terms of the concentration of (1), (2) and hydroxide ion in the micellar pseudophase; the determined second order rate constants in the micellar pseudophase are smaller than the second order constants in water
- Al-Lohedan, Hamad A.
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p. 1181 - 1186
(2007/10/02)
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