5076-20-0Relevant articles and documents
Red light-induced reaction of NO2 with 2,3-dimethyl-2-butene in a low-temperature argon matrix
Nakata, Munetaka
, p. 1455 - 1466 (1994)
Red light-induced oxygen atom transfer from NO2 to 2,3-dimethyl-2-butene has been investigated in a low-temperature argon matrix.The IR spectra of a reaction intermediate identified as an alkyl nitrite radical and two final products, tetramethyloxirane and 3,3-dimethyl-2-butanone (pinacolone), were observed.From analysis of the absorbance growth of the IR bands, first-order rate constants were determined by least-square fitting.Based on these results and those of our earlier works on NO2 photoreactions with other alkenes, a reaction mechanism is proposed that involves oxygen atom transfer from NO2 to the C=C bond of 2,3-dimethyl-2-butene to give a short-lived singlet oxirane biradical.Alkyl nitrite radical is produced by a recombination of the transient biradical with NO trapped in the cage of the matrix.Tetramethyloxirane and pinacolone emerge from secondary photolysis of the trapped alkyl nitrite radical.
The Oxidation of Organic Compounds with Iodosylbenzene catalysed by Tetra(4-N-methylpyridyl)porphyrinatoiron(III) Pentacation: A Polar Model System for the Cytochrome P450 Dependent Mono-oxygenases
Smith, John R. Lindsay,Mortimer, David N.
, p. 410 - 411 (1985)
Replacing the tetraphenylporphyrinatoiron(III) chloride (Fe(III)TPPCl) catalyst, in Groves' model system (Fe(III)TPPCl-PhIO) for cytochrome P450 mono-oxygenases, with tetra(4-N-methylpyridyl)porphyrinatoiron(III) pentacation allows oxidations to be carried out in protic and dipolar aprotic solvents without significantly altering the mechanisms of the reactions.
METALLOPORPHYRIN-MEDIATED RADICAL CYCLOADDITIONS OF p-CYANO-N,N-DIMETHYLANILINE
Dicken, C. Michael,Lu, Fu-Lung,Bruice, Thomas C.
, p. 5967 - 5970 (1986)
Tetrahydroquinolines are formed via metalloporphyrin-catalyzed radical cycloadditions of olefins (2,3-dimethyl-2-butene and norbornene) and p-cyano-N,N-dimethylaniline; their synthesis, characterization and a mechanistic rationale of their formation are presented.
The reaction of permanganyl chloride with olefins: Intermediates and mechanism as derived from matrix-isolation studies and density functional theory calculations
Wistuba, Tobias,Limberg, Christian
, p. 4674 - 4685 (2001)
Density functional theory (DFT) calculations predict that the [2+3] addition of tetramethylethylene (TME) to the MnO2 moiety of MnO3Cl is thermodynamically favoured over [2+1] addition (epoxidation), while the kinetic barriers for bo
Reactions of Superoxide with Peroxides
Stanley, James P.
, p. 1413 - 1418 (1980)
The reactions of superoxide with tert-butyl hydroperoxide and 98percent H2O2 have been studied in aprotic solvents.In benzene solvent, the proton-catalyzed disproportionation of superoxide followed by the base-catalyzed disproportionation of H2O2 appear to be the only reactions to occur.In acetonitrile, peroxy anions react with the solvent to form, ultimately, acetamide.Reactions of superoxide with diacyl peroxides are rather complex, but this reacting system produces intermediates capable of epoxidation of a number of olefins.Reactions of superoxide with acid chlorides and anhydrides in the presence of olefins also produce epoxides.Plausible mechanisms for these reactions are discussed.
A Kinetic Study of the Epoxidation 2,3-Dimethyl-2-butene by tert-Butyl Hydroperoxide Catalyzed by Imidazole Ligated (meso-Tetraphenylporphinato)manganese(III)
Balasubramanian, P. N.,Sinha, Ashoke,Bruice, Thomas C.
, p. 1456 - 1462 (1987)
A kinetic study of the epoxidation of 2,3-dimethyl-2-butene (TME) by t-BuOOH in the presence of (mesotetraphenylporphinato)manganese(III) chloride (TPP)Mn(III)Cl) and imidazole (ImH) has been carried out (30 deg C, CH2Cl2 solvent).The rates of decrease in and increase in have been determined as a function of the initial concentrations of , , ImH>, and .As found previously, ImH ligation is required for the reaction of the manganese(III) porphyrin with t-BuOOH and thus for the epxidation of TME.Under the condition of i, i, and i >> i, it is found that the rate for disappearance of t-BuOOH is a;ways more than twofold greater than is the rate of epoxide formation regardlessof the ratios of , , and .This requires that in addition to an ImH ligated higher valent manganese oxo porphyrin there is the formation of an additional intermediate species capable of transferring oxygen.This must be so, because the total concentrations of (TPP)Mn(III)Cl is not sufficient to store the oxygen equivalents.Other pertinent observations are as follows: (i) Disappearance of t-BuOOH follows the first-order rate law in the absence of TME while in the presence of TME its disappearance follows two sequential first-order processes; (ii) formation of epoxide is always first-order; (iii) the maximum yield of epoxide is but 60percent; (iv) the percent yield of epoxide increases and then decreases with increase in i; and (v) there is formation of a small percentage of di-tert-butyl peroxide ((t-BuO)2).A proposed reaction sequence which competent in accounting for these observations is presented in Scheme I. the equilibrium constants for ligation of ImH with manganese(III) porphyrin and the rate constants for oxygen transfer from t-BuOOH to both (TPP)Mn(III)(ImH)Cl and (TPP)Mn(III)(ImH)2 were determined individually while the other constants of Scheme I were obtained as the best minimal values by computer simulation of the time dependence for the disappearance of t-BuOOH and the appearence of epoxide and (t-BuO)2.
Porphyrins in aqueous amphiphilic polymers as peroxidase mimics
Johnstone, Robert A. W.,Simpson, Anthony J.,Stocks, Paul A.
, p. 2277 - 2278 (1997)
Water-insoluble porphyrins dissolve in aqueous solutions of amphiphilic polymers to give systems which mimic the action of peroxidase enzymes.
Relative Rate Study of the Addition of HO2 Radicals to Ethylene and to Tetramethylethylene
Baldwin, Roy R.,Stout, David R.,Walker, Raymond W.
, p. 3481 - 3490 (1984)
Studies of the competitive oxidation of ethylene and tetramethylethylene in the presence and absence of tetramethylbutane as a source of HO2 radicals have been carried out between 400 and 500 deg C over a range of mixture composition and total pressure using aged boric-acid-coated Pyrex vessels.From measurements of the initial relative yields of oxirane and tetramethyloxirane, values of log10(A7/A5) = -0.77 +/- 0.09 and E5 - E7 = 36.5 +/- 0.9 kJ mol-1 have been obtained: HO2 + C2H4 -> C2H4O + OH (5), HO2 + (CH3)2C=C(CH3)2 -> (CH3)2C(O)C(CH3)2 + OH (7).Use of the published values of the Arrhenius parameters for reaction (5) gives log10(A7/dm3 mol-1 s-1) = 9.24 +/- 0.29 and E7 = 40.0 +/- 4.5 kJ mol1-.No other values are available in the literature, but the present results are consistent with the very limited data available for the addition of HO2 radicals to ethylene, propene and i-butene.Trends in the variation of the values of the rate constant and of the activation energy for HO2 addition with structure of the alkene are very similar to those observed for the addition of CH3O2 and i-C3H7O2 radicals.The relative rate of addition of i-C3H7O2, CH3O2 and HO2 radicals to any alkene at 130 deg C is ca. 1:4:30.
Synthesis and reaction of cyano-substituted 1,2,4-trioxolanes
Kuwabara, Hajime,Ushigoe, Yoshihiro,Nojima, Masatomo
, p. 871 - 874 (1996)
Carbonyl oxides, derived from the ozonolyses of vinyl ethers, readily undergo [3 + 2] cycloadditions with acyl cyanides affording the corresponding cyano-substituted 1,2,4-trioxolanes in isolated yields of 34-88%. In competition experiments, a relative order of reactivity of the carbonyl oxide trapping agents was tentatively deduced; trifluoroacetophenone > α,α-diphenyl-N-methylnitrone (N-methyldiphenyl-methylideneamine N-oxide) > benzoyl cyanide > methyl benzoylformate > α,α,N-triphenylimine [N-(diphenylmethylidene)aniline] ? benzaldehyde. As expected from the electron-withdrawing ability of the cyano group, 3-cyano-3-phenyl-1,2,4-trioxolane oxidized not only triphenylphosphine but also methyl p-tolyl sulfide and 2,3-dimethylbut-2-ene very easily.
Formation of β-Ga2O3nanorings from metal-organic frameworks and their high catalytic activity for epoxidation of alkenes
Wang, Wei Ping,Song, Le Xin,Li, Yao,Teng, Yue,Xia, Juan,Wang, Fang,Liu, Nan Ning
, p. 349 - 357 (2021/01/14)
Here we report a novel synthesis of hollow high-quality β-Ga2O3 nanorings based on an interesting structural evolution from concave Ga-MOF nanodisks. The concave low-crystallinity nanodisks were constructed by non-classical crystallization with particle a
