Xn:Harmful;106-35-4Relevant articles and documents
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Spektor,S.S. et al.
, (1979)
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Oxidations by the reagent O2-H2O2-vanadium complex - Pyrazine-2-carboxylic acid. Part 7. Hydroperoxidation of higher alkanes
Shul'pin, Georgiy B.,Guerreiro, Mario C.,Schuchardt, Ulf
, p. 13051 - 13062 (1996)
Alkanes (n-heptane, 2- and 3-methylhexane, cis- and trans-decalin) are readily oxidized under air in acetonitrile by the O2-H2O2-PCA-VO3- reagent at room temperature to produce alkyl hydroperoxides as main products as well as minor amounts of the corresponding alcohols and carbonyl compounds. The site selectivities of the reactions are very similar to those observed with hydroxylation of the alkanes with hydrogen peroxide under UV irradiation. The proposed mechanism involves the catalytic formation of hydroxyl radicals from hydrogen peroxide which abstract hydrogen atoms from the alkanes. The alkyl radicals react rapidly with molecular oxygen to produce peroxyl radicals which are transformed mainly into the hydroperoxides.
Synergistic hydrogen atom transfer with the active role of solvent: Preferred one-step aerobic oxidation of cyclohexane to adipic acid by N-hydroxyphthalimide
Liang, Futong,Zhong, Wenzhou,Xiang, Liping,Mao, Liqiu,Xu, Qiong,Kirk, Steven Robert,Yin, Dulin
, p. 256 - 269 (2019)
In this work, we developed an one-step aerobic oxidation of cyclohexane to prepare adipic acid, catalyzed by N-hydroxyphthalimide (NHPI) under promoter- and metal-free conditions. A significant beneficial solvent effect for synergistic reaction is observed with varying polarity and hydrogen-bonding strength: detailed study reveals that the solvent environments manipulate catalytic activity and adipic acid selectivity. Cyclic voltammetry measurements and UV–visible spectra of the NHPI catalyst are examined in various solvent environments to understand the active role of solvent in influencing the catalytic-site structure (>NOH) of the molecule. Analysis of the UV–visible spectra reveals that these differences can be rationalized by considering hydrogen-bonding with solvent molecules, which modifies the catalytic-site structure. This observation is in agreement with cyclic voltammetry results: the different reversibility of the catalytic-site (>NOH/>NO[rad]) wave shows that the catalytic activity of NHPI is related to the formation of hydrogen bonds with the active participation of solvents. Computational studies presented herein have furnished mechanistic insights into the effect of solvent environments. Specifically, we present the structures, dissociation energies, and reaction barriers from DFT studies of the reactants and reaction intermediates involved in the two types of H-abstraction on >NO[rad] catalytic-sites for the rate-determining step. The results of modeling the solvent effects using the PCM continuum solvent method predict that the resulting reaction barrier of the rate-controlling H-abstraction for cyclohexane and cyclohexanone is modified significantly: the transition state barrier of H-abstraction for cyclohexane decreases from 22.36 (in benzene) to 20.78 kcal?mol?1 (in acetonitrile); the α-H-abstraction barrier for cyclohexanone decreases from 21.45 to 20.53 kcal?mol?1. The active participation of solvent molecule results in a strong interaction between pre-reaction complex (PINO???H???C NO[rad] catalytic-sites at the transition state. The lower calculated barriers of H-abstraction for cyclohexanone oxidation approximate more closely the experimental results of the higher adipic acid selectivity. Our work provides a dimension of sustainable chemistry for the metal-free preparation of adipic acid: a conversion of 27% with 79% adipic acid selectivity is achieved over use of NHPI catalysts in CH3CN solvent.
Effect of cis/trans isomerism on selective oxidation of olefins with nitrous oxide
Ivanov, Dmitry,Babushkin, Dmitry,Semikolenov, Sergey,Malykhin, Sergey,Kharitonov, Alexander,Dubkov, Konstantin
, p. 2501 - 2506 (2016)
Liquid phase oxidation of olefins with nitrous oxide is a promising synthetic route to ketones. The effect of cis/trans isomerism on the reactivity of olefins towards N2O and on the reaction mechanism was studied for the first time using 3-heptene oxidation as an example. Our experimental study revealed that cis- and trans-isomers of 3-heptene have similar reactivity and yield the same set of products. However, the cis/trans isomerism of the olefin has a pronounced effect on the reaction route involving the cleavage of the initial C=C bond and, accordingly, on the products ratio. The yield of ketones is lower for the trans-isomer due to higher contribution of the cleavage route.
Redox isomerization of allylic alcohols into carbonyl compounds catalyzed by the ruthenium(IV) complex [Ru(η3:η3-C 10H16)Cl(κ2 O,O -CH3CO 2)] in water and ionic liquids: Highly efficient transformations and catalyst recycling
Garcia-Alvarez, Joaquin,Gimeno, Jose,Suarez, Francisco J.
, p. 2893 - 2896 (2011)
Isomerization reactions of allylic alcohols into carbonyl compounds can be efficiently performed in both water and in ionic liquids using [Ru(η3:η3-C10H16) Cl(κ2O,O-CH3CO2)] as catalyst. In both cases, the catalytic system could be recycled up to five times.
In vitro double oxidation of n-heptane with direct cofactor regeneration
Mueller, Christina A.,Akkapurathu, Beneeta,Winkler, Till,Staudt, Svenja,Hummel, Werner,Groeger, Harald,Schwaneberg, Ulrich
, p. 1787 - 1798 (2013)
A novel concept for the direct oxidation of cycloalkanes to the corresponding cyclic ketones in a one-pot synthesis in water with molecular oxygen as sole oxidizing agent was reported recently. Based on this concept we have developed a new strategy for the double oxidation of n-heptane to enable a biocatalytic resolution for the direct synthesis of heptanone and (R)-heptanols in a one-pot reaction. The bicatalytic cascade employs an NADH driven P450 BM3 monooxygenase variant (WTNADH, 19A12NADH or CM1 NADH) and an (S)-enantioselective alcohol dehydrogenase (RE-ADH). In the initial step n-heptane is hydroxylated under consumption of NADH to produce (R/S)-heptanol. In the second oxidation step the (S)-heptanol enantiomers are transformed to the corresponding ketones, reducing and thereby regenerating the cofactor. Characterization of initial hydroxylation step revealed high turnover frequencies (TOF) of up to 600 min-1, as well as high coupling efficiencies using NADH as cofactor (up to 44%). In the cascade reaction a nearly 2-fold improved product formation was achieved, compared to the single hydroxylation reaction. The total product concentration reached 1.1 mM, corresponding to a total turnover number (TTN) of 2500. Implementation of an additional cofactor regeneration system (D-glucose/glucose dehydrogenase) enabled a further enhancement in product formation with a total product concentration of 1.8 mM and a TTN of 3500. Copyright
Mild homogeneous oxidation of alkanes and alcohols including glycerol with tert-butyl hydroperoxide catalyzed by a tetracopper(II) complex
Kirillova, Marina V.,Kirillov, Alexander M.,Mandelli, Dalmo,Carvalho, Wagner A.,Pombeiro, Armando J.L.,Shul'Pin, Georgiy B.
, p. 9 - 17 (2010)
The homogeneous catalytic system composed of the aqua-soluble tetracopper(II) triethanolaminate complex [O?Cu4{N(CH2CH2O)3}4(BOH)4][BF4]2 (1), t-BuOOH (TBHP), water and acetonitrile solvent (optional) has been applied for the mild oxidation of (i) linear and cyclic alkanes to the corresponding alkyl peroxides, alcohols and ketones, (ii) secondary or primary alcohols to ketones or aldehydes, respectively and (iii) glycerol (GLY) to dihydroxyacetone (DHA). Unusual regio-, bond and stereoselectivity parameters have been determined for the alkane oxygenations and discussed in terms of possible steric, hydrophobic and electronic effects. In alcohol oxidations, secondary alcohols are the most reactive substrates. Yields and TONs up to 82% and 1200, respectively, have been obtained in the oxidation of isopropanol to acetone. The selective oxidation of GLY to DHA by the 1/TBHP system has been also achieved, although providing lower conversions. The 1/H2O2 system for the GLY oxidation is particularly advantageous in terms of selectivity and oxidant efficiency. These systems constitute one of the first examples of a metal-catalyzed oxidation of glycerol under homogeneous conditions.
A NEW SYNTHESIS OF KETONES FROM 1,2-DIMETHOXYETHENYLLITHIUM, ORGANOBORANES, AND ALKYL FLUOROSULFONATES
Yogo, Toshinobu,Koshino, Junji,Suzuki, Akira
, p. 1059 - 1060 (1981)
The reaction of alkyl fluorosulfonates with lithium 1,2-dimethoxyethenyltrialkylborates readily prepared from organoboranes gives corresponding ketones in good yields.
Oxidation with the "O2-H2O2-VO3 --pyrazine-2-carboxylic acid" reagent: 6. * Oxidation of n-heptane and cyclohexane. Direct determination of alkyl hydroperoxides by gas-liquid chromatography
Guerreiro,Schuchardt,Shul'pin
, p. 749 - 754 (1997)
n-Heptane is readily oxidized in acetonitrile under the action of H2O2 with a "vanadate anion-pyrazine-2-carboxylic acid" system as the catalyst in air to form isomeric heptyl hydroperoxides (detected by GLC) along with isomeric heptanols and heptanones. Heptyl hydroperoxides slowly decompose at low temperature yielding the corresponding alcohols and ketones (aldehyde). The values of the parameter of the relative normalized reactivity of the H atoms at the carbon atoms in positions 1, 2, 3, and 4 depend on the reaction time and concentrations of the reagents. The value of the parameter of selectivity C(1) : C(2) : C(3) : C(4) varies in the range from 1.0 : 2.8 : 2.9 : 1.8 to 1.0 : 5.6 : 5.9 : 5.3. The low selectivity of the reaction shows that the key role is played by the attack of highly reactive radical particles on the C-H bond of the alkane molecule.
Water and catalytic isomerization of linear allylic alcohols by [RuCp(H2O-κO)(PTA)2]+ (PTA = 1,3,5-triaza-7-phosphaadamantane)
Scalambra, Franco,Serrano-Ruiz, Manuel,Romerosa, Antonio
, p. 5864 - 5871 (2017)
A new water soluble complex [RuCp(H2O-κO)(PTA)2]+ (1) (PTA = 1,3,5-triaza-7-phosphaadamantane) has been synthesized and fully characterized by NMR and IR. The crystal structure of 1(CF3SO3)·3.5H2O was characterized by single crystal X-ray determination. The catalytic activity of this complex was evaluated for the isomerisation of linear allylic alcohols from 3-buten-2-ol to 1-octen-3-ol into the correspondent ketones under both an inert atmosphere and in air, using as solvents: water, the substrate, mixtures of water/substrate, MeOH and mixtures of MeOH/water. An isomerization experiment on a mixture of all the studied allylic alcohols was also carried out.
Oxidation catalysis in air with CpIr: Influence of added ligands and reaction conditions on catalytic activity and stability
Gunay, Ahmet,Mantell, Mark A.,Field, Kathleen D.,Wu, Wenbo,Chin, Michael,Emmert, Marion H.
, p. 1198 - 1205 (2015)
We describe the systematic evaluation of CpIr catalysts for the aerobic oxidation of alcohols. Our results demonstrate turnover numbers up to 270 per [CpIrCl2]2 which have not been previously achieved for this reaction. Using air as the sole oxidant under base-free conditions, the effects of solvent systems and additives on the catalytic activity are documented systematically. We further elucidate the role of additives in catalyst decomposition processes and establish a novel buffer system which results in significant catalyst stabilization upon prolonged reaction times.
Reaction of Alkyl Peroxides and Hydroperoxides with Iron Pentacarbonyl and Dicobalt Octacarbonyl
Lee, Kang-Wook,Filippo, Joseph San
, p. 259 - 261 (1983)
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On the Isolation and Characterization of Methyl(trifluoromethyl)dioxirane
Mello, Rossella,Fiorentino, Michele,Sciacovelli, Oronzo,Curci, Ruggero
, p. 3890 - 3891 (1988)
The title dioxirane 1f, generated by the reaction of CF3COCH3 with potassium peroxomonosulfate, has been isolated and fully characterized spectroscopically; it displays a remarkable reactivity in oxygen transfer reactions.
Mononuclear Ruthenium and Osmium Complexes with a Bicyclic Guanidinate Ligand: Synthesis and Catalytic Behavior in Olefin Isomerization Processes
Gámez-Rivera, Sebastián A.,Francos, Javier,Borge, Javier,Cadierno, Victorio
, p. 4138 - 4146 (2017)
The preparation of the first mononuclear RuII, RuIV, and OsII complexes containing the anion of the bicyclic guanidine 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (Hhpp) as a chelating ligand, namely [RuX{κ2-(N,N′)-hpp}(η6-arene)] [arene = p-cymene, X = Cl (2a), Br (2b), I (2c); arene = C6Me6, X = Cl (7)], [RuCl{κ2-(N,N′)-hpp}(η3:η3-C10H16)] (9; C10H16 = 2,7-dimethylocta-2,6-diene-1,8-diyl), and [OsCl{κ2-(N,N′)-hpp}(η6-p-cymene)] (11), is described. Compounds 2a–c, 7, 9, and 11 have been fully characterized by elemental analysis, HRMS, IR and NMR spectroscopy. In addition, the structure of 2a has been unequivocally confirmed by single-crystal X-ray diffraction methods. The catalytic behavior of these metal guanidinate complexes in the base-free redox isomerization of allylic alcohols is explored, with the ruthenium(IV) derivative 9 showing the best performance (TOF up to 5940 h–1). All of the synthesized complexes have also proven to be active in the isomerization of the allylbenzene estragole into the industrially relevant 1-propenylbenzene anethole, with a trans selectivity of up to 95 %.
Cationic and anionic metalloporphyrins simultaneously immobilized onto raw halloysite nanoscrolls catalyze oxidation reactions
Machado, Guilherme Sippel,Ucoski, Geani Maria,Lima, Omar José De,Ciuffi, Kátia Jorge,Wypych, Fernando,Nakagaki, Shirley
, p. 124 - 131 (2013)
We simultaneously immobilized an anionic iron(III) porphyrin (FePor) and a cationic manganese(III) porphyrin (MnPor) onto raw halloysite nanoscrolls. The positive and negative residual charges at the edges of the halloysite nanoscrolls and the negative residual charges on the surface of this support favored FePor and MnPor immobilization. We characterized the material containing simultaneously immobilized FePor and MnPor (FeMn-Hallo) by powder X-ray diffraction, Fourier transform infrared spectroscopy, textural analysis, and UV-vis spectroscopy (solid sample); these techniques confirmed that both FePor and MnPor were present on the support. We also investigated whether FeMn-Hallo catalyzed cyclooctene epoxidation as well as cyclohexane and n-heptane oxidation. FeMn-Hallo was an effective catalyst for oxidation reaction, attesting the efficiency and versatility of both immobilized metalloporphyrins in the same support. The simultaneous immobilization of metalloporphyrins paves the way for chemists to develop multifunctional catalysts that can simultaneously promote distinct reactions.
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Kabasakalian,P. et al.
, p. 2718 - 2722 (1962)
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Robust Mn(iii): N -pyridylporphyrin-based biomimetic catalysts for hydrocarbon oxidations: heterogenization on non-functionalized silica gel versus chloropropyl-functionalized silica gel
Pinto, Victor Hugo A.,Falc?o, Nathália K. S. M.,Mariz-Silva, Bárbara,Fonseca, Maria Gardennia,Rebou?as, Júlio S.
, p. 16404 - 16418 (2020)
Two classes of heterogenized biomimetic catalysts were prepared and characterized for hydrocarbon oxidations: (1) by covalent anchorage of the three Mn(iii) meso-tetrakis(2-, 3-, or 4-pyridyl)porphyrin isomers by in situ alkylation with chloropropyl-functionalized silica gel (Sil-Cl) to yield Sil-Cl/MnPY (Y = 1, 2, 3) materials, and (2) by electrostatic immobilization of the three Mn(iii) meso-tetrakis(N-methylpyridinium-2, 3, or 4-yl)porphyrin isomers (MnPY, Y = 4, 5, 6) on non-modified silica gel (SiO2) to yield SiO2/MnPY (Y = 4, 5, 6) materials. Silica gel used was of column chromatography grade and Mn porphyrin loadings were deliberately kept at a low level (0.3% w/w). These resulting materials were explored as catalysts for iodosylbenzene (PhIO) oxidation of cyclohexane, n-heptane, and adamantane to yield the corresponding alcohols and ketones; the oxidation of cyclohexanol to cyclohexanone was also investigated. The heterogenized catalysts exhibited higher efficiency and selectivity than the corresponding Mn porphyrins under homogeneous conditions. Recycling studies were consistent with low leaching/destruction of the supported Mn porphyrins. The Sil-Cl/MnPY catalysts were more efficient and more selective than SiO2/MnPY ones; alcohol selectivity may be associated with hydrophobic silica surface modification reminiscent of biological cytochrome P450 oxidations. The use of widespread, column chromatography, amorphous silica yielded Sil-Cl/MnPY or SiO2/MnPY catalysts considerably more efficient than the corresponding, previously reported materials with mesoporous Santa Barbara Amorphous No 15 (SBA-15) silica. Among the materials studied, in situ derivatization of Mn(iii) 2-N-pyridylporphyrin by covalent immobilization on Sil-Cl to yield Sil-Cl/MnP1 showed the best catalytic performance with high stability against oxidative destruction and reusability/recyclability.
Pincer and diamine Ru and Os diphosphane complexes as efficient catalysts for the dehydrogenation of alcohols to ketones
Baratta, Walter,Bossi, Gianluca,Putignano, Elisabetta,Rigo, Pierluigi
, p. 3474 - 3481 (2011)
The ruthenium and osmium complexes [MCl2(diphosphane)(L)] (M=Ru, Os; L=bidentate amino ligand) and [MCl(CNN)(dppb)] (CNN=pincer ligand; dppb=1,4-bis- (diphenylphosphino)butane), containing the N-H moiety, have been found to catalyze the acceptorless dehydrogenation of alcohols in tBuOH and in the presence of KOtBu. The compounds trans-[MCl2(dppf)(en)] (M=Ru 7, Os 13; dppf=1,1′-bis(diphenylphosphino)ferrocene; en=ethylenediamine) display very high activity and different substrates, including cyclic and linear alcohols, are efficiently oxidized to ketones by using 0.8-0.04mol% of catalyst. The effect of the base and the comparison of the catalytic activity of the Ru versus Os complexes are reported. The ruthenium complex 7 generally leads to a faster conversion into ketones with respect to the osmium complex 13, which displays better activity in the dehydrogenation of 5-en-3β-hydroxy steroids. The synthesis of new Ru and Os complexes [MCl2(PP)(L)] (PP=dppb, dppf; L=(±)-trans-1,2-diaminocyclohexane, 2-(aminomethyl) pyridine, and 2-aminoethanol) of trans and cis configuration is also reported. Alcohol breakdown: Ruthenium and osmium phosphane complexes containing nitrogen ligands with the N-H functionality efficiently catalyze the acceptorless dehydrogenation of alcohols. With [MCl2(dppf)(en)] (M=Ru, Os; dppf=1,1′-bis(diphenylphosphino)ferrocene; en=ethylenediamine) in the presence of KOtBu several alcohols have been converted into ketones (see scheme), including sterols for which Os displays a better activity than Ru. Copyright
One-pot dialkylation of allylphenylsulfide induced by aminoalkoxides- activated NaNH2. Application to the synthesis of unsymmetrical ketones
Choppin, Sabine,Gros, Philippe,Fort, Yves
, p. 9261 - 9268 (1999)
It is shown that the activation of NaNH2 by sodium aminoalkoxides, leading to new superbases, induced an efficient one-pot dialkylation of allylphenylsulfide. The regioselectivity of the reaction (α,α' vs α,γ) was found as strongly dependent on the nature of the alkyl halide. As an application, α,γ dialkylated products were efficiently converted Into the corresponding unsymmetrical ketones.
Epoxldation of terminal alkenes with oxygen and 2-ethyl hexanal, without added catalyst or solvent
Lehtinen, Christel,Brunow, C?sta
, p. 101 - 103 (1999)
Two terminal alkenes, 1-decene and methyl 10-undecenoate, were epoxidized with oxygen using 2-ethyl hexanal as coreactant without any added solvent. Under optimal conditions, the yield of methyl 10, 11-epoxyundecanoate was 98.7%. 2-Ethyl hexanal was oxidized mainly to 2-ethyl hexanoic acid and also formed some byproducts. The tested metal complexes retarded the epoxidation reaction slightly and increased the amount of byproducts of 2-ethyl hexanal.
Copper-catalyzed aerobic oxidative functionalization of C-H bonds of alkanes in the presence of acetaldehyde under mild conditions
Hayashi, Yukiko,Komiya, Naruyoshi,Suzuki, Ken,Murahashi, Shun-Ichi
, p. 2706 - 2709 (2013)
Copper-catalyzed oxidative functionalization of C-H bonds of alkanes with molecular oxygen has been performed in the presence of Cu(OAc)2 catalyst and acetaldehyde in acetonitrile at 70 C with extremely high turn-over numbers.
Immobilization of anionic metalloporphyrins on zinc hydroxide nitrate and study of an unusual catalytic activity
MacHado, Guilherme S.,Arizaga, Gregorio G.C.,Wypych, Fernando,Nakagaki, Shirley
, p. 130 - 141 (2010)
This paper is the first report on the immobilization of an anionic iron(III) porphyrin family on zinc hydroxide nitrate (ZHN), a layered hydroxide salt. ZNH was prepared by means of a precipitation reaction between a zinc nitrate solution and ammonium hydroxide. Two immobilization systems were investigated, namely magnetic stirring at room temperature and stirring/reflux in an ethanolic solution. The solids were characterized by powder X-ray diffraction (XRD), electron paramagnetic resonance (EPR), thermogravimetric and derivative thermogravimetric (TGA/DTG), transmission electron microscopy (TEM), as well as ultraviolet-visible (UV-Vis) and Fourier transform infrared (FTIR) spectroscopic analyses. The catalytic activity of the materials was investigated in the oxidation of cyclooctene, cyclohexane, and n-heptane using iodosylbenzene as oxygen donor. The oxidation products were analyzed by gas chromatography. The results revealed an unusual selectivity for cyclohexanone in the reactions of cyclohexane oxidation catalyzed by the anionic iron(III) porphyrins immobilized onto ZHN. These results suggest that the structure of the ZHN support influences the catalytic mechanism and that cyclohexane oxidation occurs via a radicalar pathway.
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Smith
, p. 453 (1960)
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Dialkylation of Ketone Dianions
Bates, Robert B.,Taylor, Stuart R.
, p. 245 - 246 (1994)
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Ponzio,de Gaspari
, p. 271 (1898)
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The Application of 1,2-Oxazinanes as Chiral Cyclic Weinreb Amide-Type Auxiliaries Leading to a Three-Component, One-Pot Reaction
F?hrmann, Jan,Hermann, Ludmila,Hilt, Gerhard
, (2021/12/17)
1,2-Oxazines were synthesised via a copper-catalysed aerobic acyl nitroso Diels-Alder reaction from 1,4-disubstituted 1,3-dienes and N-Boc-hydroxylamine. From this, 1,2-oxazinanes were obtained in a novel follow-up reaction path. The stability of several 1,2-oxazines and 1,2-oxazinanes towards organometallic compounds was tested to rate their operability as cyclic chiral Weinreb amide auxiliaries. 3,6-Di-tertbutyl-1,2-oxazinane gave the best results and was introduced as a chiral Weinreb amide-type auxiliary to yield chiral α-substituted ketones in a diastereomeric ratio of up to 98:2. The removal of the auxiliary can be performed with BuLi to form unsymmetrical α-chiral ketones. Thereafter, the chiral auxiliary can be re-isolated and purified by sublimation under vacuum.
OZONE-FACILITATED SELECTIVE OXIDATION OF ALKANES IN LIQUID CARBON DIOXIDE
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Paragraph 0037, (2018/03/06)
A process for the ozonolysis of an alkane may comprise combining an alkane and ozone in a liquid phase medium comprising CO2 under conditions sufficient to oxidize the alkane to produce one or more non-combustion products. The liquid phase medium may be free of a super acid.
