- Insights into the mechanism of cumene peroxidation using supported gold and silver nanoparticles
-
Due to the considerable industrial implications, an in-depth study of cumene peroxidation using supported gold and silver nanoparticles was carried out to gain more insight into the mechanism of this reaction. Supported gold nanoparticles were found to ef
- Crites, Charles-Oneil L.,Hallett-Tapley, Geniece L.,Frenette, Mathieu,Gonzalez-Bejar, Maria,Netto-Ferreira,Scaiano
-
-
Read Online
- The Initiation Properties of 2-Cyano-2-propyl Hydroperoxide in Oxidation Processes
-
The initiating ability of 2-cyano-2-propyl hydroperoxide in the oxidation reaction of cumene by molecular oxygen has been investigated and compared with the initiating ability of cumene hydroperoxide. - Keywords: Autoxidation; Cumene; Initiation ability;
- Burghardt, Aleksandra,Kulicki, Zdzislaw
-
-
Read Online
- Oxidation of cumene in the presence of high concentrations of ascorbic acid
-
Initiated oxidation of cumene by oxygen in the presence of ascorbic acid was studied.
- Smirnova,Efimova,Opeida
-
-
Read Online
- Aerobic oxidation of cumene to cumene hydroperoxide catalyzed by metalloporphyrins
-
A protocol for the aerobic oxidation of cumene to cumene hydroperoxide (CHP) catalyzed by metalloporphyrins is reported herein. Typically, the reaction was performed in an intermittent mode under an atmospheric pressure of air and below 130°C. Several imp
- Yang, Wei-Jun,Guo, Can-Cheng,Tao, Neng-Ye,Cao, Jun
-
-
Read Online
- A highly efficient transformation from cumene to cumyl hydroperoxide via catalytic aerobic oxidation at room temperature and investigations into solvent effects, reaction networks and mechanisms
-
Cumyl hydroperoxide (CHP) is an important intermediate for the production of phenol/acetone, but suffers from severe reaction conditions and a low yield industrially. Here, an efficient transformation from cumene to CHP was developed. Different solvents were modulated for cumene oxidation catalyzed by NHPI/Co, and reaction network and mechanisms were investigated methodically. Hexafluoroisopropanol (HFIP) markedly promoted the transformation from cumene to CHP compared to other solvents at room temperature. A cumene conversion high up to 64.3% were observed with a selectivity to CHP of 71.7%. The solvent HFIP exhibited a significant promotion on cumene oxidation due to its contribution to the enhancement of the concentration of PINO radicals. Moreover, cumyl, cumyl oxyl and methyl radicals were captured by TEMPO and analyzed by HRMS, and the reaction paths and mechanisms from cumene to products were inferred. The preparation method discovered in this work may open an access to the production of CHP.
- Chen, Chong,Ji, Lijun,Lu, Qiuting,Shi, Guojun,Yuan, Enxian,Zhou, Hongyu
-
-
- LIGHT INDUCED CATALYTIC C-H OXYGENATION OF ALKANES
-
A method of oxygenating a benzylic C-H bond is provided. The method comprises light induced activation of an initiator and subsequent reaction with oxygen, resulting in the formation of free radicals. Subsequently, free radicals catalyze the reaction of the benzylic C-H bond with oxygen, thereby forming an oxygenated compound.
- -
-
Paragraph 00201; 00207; 00211-00217
(2021/04/02)
-
- A new highly active La2O3-CuO-MgO catalyst for the synthesis of cumyl peroxide by catalytic oxidation
-
In this study, different magnesium, copper, lanthanide single metal, and composite multimetal oxide catalysts were preparedviathe coprecipitation route for the aerobic oxidation of cumene into cumene hydroperoxide. All catalysts were characterized using several analytical techniques, including XRD, SEM, EDS, FT-IR, BET, CO2-TPD, XPS, and TG-DTG. La2O3-CuO-MgO shows higher oxidation activity and yield than other catalysts. The results of XRD and SEM studies show that the copper and magnesium particles in the catalyst are smaller in size and have a distribution over a larger area due to the introduction of the lanthanum element. The CO2-TPD results confirmed that the catalyst has more alkali density and alkali strength, which can excite active sites and prevent the decomposition of cumene hydroperoxide. XPS results show that due to the promotional effect of La2O3, there are more lattice and active oxygen species in the catalyst, which can effectively utilize the lattice defects under the strong interaction between metal oxides for rapid adsorption and activation, thus improving the oxidation performance. Besides, La2O3-CuO-MgO exhibits good stability and crystalline structure due to its high oxygen mobility inhibiting coking during the cycle stability test. Finally, the possible reaction pathway and promotional mechanism on La2O3-CuO-MgO in cumene oxidation are proposed. We expect this study to shed more light on the nature of the surface-active site(s) of La2O3-CuO-MgO catalyst for cumene oxidation and the development of heterogeneous catalysts with high activity in a wide range of applications.
- Liu, HanShuang,Wang, KaiJun,Cao, XiaoYan,Su, JiaXin,Gu, Zhenggui
-
p. 12532 - 12542
(2021/04/14)
-
- Room Temperature Aerobic Peroxidation of Organic Substrates Catalyzed by Cobalt(III) Alkylperoxo Complexes
-
Room temperature aerobic oxidation of hydrocarbons is highly desirable and remains a great challenge. Here we report a series of highly electrophilic cobalt(III) alkylperoxo complexes, CoIII(qpy)OOR supported by a planar tetradentate quaterpyridine ligand that can directly abstract H atoms from hydrocarbons (R′H) at ambient conditions (CoIII(qpy)OOR + R′H → CoII(qpy) + R′?+ ROOH). The resulting alkyl radical (R′?) reacts rapidly with O2to form alkylperoxy radical (R′OO?), which is efficiently scavenged by CoII(qpy) to give CoIII(qpy)OOR′ (CoII(qpy) + R′OO?→ CoIII(qpy)OOR′). This unique reactivity enables CoIII(qpy)OOR to function as efficient catalysts for aerobic peroxidation of hydrocarbons (R′H + O2→ R′OOH) under 1 atm air and at room temperature.
- Chen, Yunzhou,Shi, Huatian,Lee, Chi-Sing,Yiu, Shek-Man,Man, Wai-Lun,Lau, Tai-Chu
-
supporting information
p. 14445 - 14450
(2021/09/18)
-
- Low-temperature oxidation of isopropylbenzene mediated by the system of NHPI, Fe(acac)3 and 1,10-phenanthroline
-
Highly efficient oxidation of isopropylbenzene mediated by the system of NHPI/Fe(acac)3/Phen has been carried out at temperature as low as 60 °C. Significant improvement of catalysis by NHPI was associated with an enhanced oxidizing ability of Fe(III) tandem with Phen, which caused the intense generation of PINO. Furthermore, NMR observations revealed formation of a hydrogen-bonded NHPI-Phen adduct soluble in acetonitrile and isopropylbenzene. Based on this phenomenon, the system was applicable for the oxidation of solvent-free isopropylbenzene. The promise of the system of NHPI/Fe(acac)3/Phen for the selective synthesis of isopropylbenzene hydroperoxide was demonstrated by oxidation at a low content of Fe(acac)3.
- Babushkin, D. E.,Koscheeva, O. S.,Kuznetsova, L. I.,Kuznetsova, N. I.,Zudin, V. N.
-
-
- The influence of Fe(III) acetylacetonate and o-phenanthroline towards improvement of NHPI-catalyzed cumene oxidation
-
Cumene hydroperoxide (CHP) is the most important product or intermediate in the oxidative processing of cumene. In the present study, cooperative action of NHPI catalyst with Fe(acac)3/Phen additives in oxidation of cumene has been described in terms of oxidation rate and selectivity for products, notably CHP, under variable conditions. The oxidation characteristics were influenced by promoting additives, the main function of which was to generate an active PINO radical. An abundance of the additives might enhance the non-selective conversion of intermediates and decomposition of CHP, which led to a decrease in CHP selectivity. The addition of 0.0003 mol% Fe(acac)3 was sufficient to initiate NHPI catalyzed fast cumene oxidation and very selective CHP production at 50 °°C. Phen showed an impressive multifaceted effect, as the increase in its amount initially lowered the CHP selectivity and then increased to 95% with a large excess of Phen over Fe(acac)3. That was due to the different ability of iron complexes of various compositions to react to NHPI and to CHP. UV-VIZ spectroscopy and DFT calculation was used to elucidate assistance of Phen in reduction of Fe(acac)3 with NHPI and creation of FeII/FeIII –Phen2or3 complexes as reversible single-electron carriers upon catalysis by NHPI. In addition, the selective formation of CHP contributes to the resistance of NHPI to degradation during catalysis.
- Babushkin, D. E.,Karmadonova, I. E.,Kuznetsova, L. I.,Kuznetsova, N. I.
-
-
- Hydroperoxidations of Alkenes using Cobalt Picolinate Catalysts
-
Hydroperoxides were synthesized in one step from various alkenes using Co(pic)2as the catalyst with molecular oxygen and tetramethyldisiloxane (TMDSO). The hydration product could be obtained using a modified catalyst, Co(3-mepic)2, with molecular oxygen and phenylsilane. Formation of hydroperoxides occurred through a rapid Co-O bond metathesis of a peroxycobalt compound with isopropanol.
- Peralta-Neel, Zulema,Woerpel
-
supporting information
p. 5002 - 5006
(2021/06/30)
-
- Method for synthesizing tertiary alcohol by catalytically oxidizing benzyl tertiary C-H bonds of aromatic hydrocarbon through metalloporphyrin
-
The invention discloses a method for synthesizing tertiary alcohol by catalytically oxidizing benzyl tertiary C-H bonds of aromatic hydrocarbon through metalloporphyrin. The method comprises the following steps: dispersing metalloporphyrin (1*10-1%, mol/mol) into aromatic hydrocarbon; sealing the reaction system, heating to 40-120 DEG C while stirring, introducing an oxidant (0.10-1.0 MPa), keeping the set temperature and pressure, carrying out reactions for 3.0-24.0 hours under stirring, and carrying out after-treatment on the reaction solution to obtain the product aromatic benzyl tertiary alcohol. The method has the advantages of shortest conversion path, highest atom economy, lower reaction temperature, lower environmental influence and the like, and the selectivity of aromatic benzyl tertiary alcohol is high. In addition, the content of aromatic hydrocarbon hydroperoxide is low, and the safety coefficient is high. The invention provides an efficient, feasible and safe method for synthesizing aromatic benzyl tertiary alcohol through selective catalytic oxidation of benzyl tertiary C-H bonds of aromatic hydrocarbon.
- -
-
Paragraph 0100-0105
(2020/09/30)
-
- Efficient and selective oxidation of tertiary benzylic C[sbnd]H bonds with O2 catalyzed by metalloporphyrins under mild and solvent-free conditions
-
The direct and efficient oxidation of tertiary benzylic C[sbnd]H bonds to alcohols with O2 was accomplished in the presence of metalloporphyrins as catalysts under solvent-free and additive-free conditions. Based on effective inhibition on the unselective autoxidation and deep oxidation, systematical investigation on the effects of porphyrin ligands and metal centers, and apparent kinetics study, the oxidation system employing porphyrin manganese(II) (T(2,3,6-triCl)PPMn) with bulkier substituents as catalyst, was regarded as the most promising and efficient one. For the typical substrate, the conversion of cumene could reach up to 57.6% with the selectivity of 70.5% toward alcohol, both of them being higher than the current documents under similar conditions. The superiority of T(2,3,6-triCl)PPMn was mainly attributed to its bulkier substituent groups preventing metalloporphyrins from oxidative degradation, its planar structure favoring the interaction between central metal with reactants, and the high efficiency of Mn(II) in the catalytic transformation of hydroperoxides to alcohols.
- Hu, Meng-Yun,Liu, Lei,Qi, Bei,She, Yuan-Bin,Shen, Hai-Min,Ye, Hong-Liang
-
-
- Cobalt(II) Bipyrazolate Metal-Organic Frameworks as Heterogeneous Catalysts in Cumene Aerobic Oxidation: A Tag-Dependent Selectivity
-
Three metal-organic frameworks with the general formula Co(BPZX) (BPZX2- = 3-X-4,4′-bipyrazolate, X = H, NH2, NO2) constructed with ligands having different functional groups on the same skeleton have been employed as heterogeneous catalysts for aerobic liquid-phase oxidation of cumene with O2 as oxidant. O2 adsorption isotherms collected at pO2 = 1 atm and T = 195 and 273 K have cast light on the relative affinity of these catalysts for dioxygen. The highest gas uptake at 195 K is found for Co(BPZ) (3.2 mmol/g (10.1 wt % O2)), in line with its highest BET specific surface area (926 m2/g) in comparison with those of Co(BPZNH2) (317 m2/g) and Co(BPZNO2) (645 m2/g). The O2 isosteric heat of adsorption (Qst) trend follows the order Co(BPZ) > Co(BPZNH2) > Co(BPZNO2). Interestingly, the selectivity in the cumene oxidation products was found to be dependent on the tag present in the catalyst linker: while cumene hydroperoxide (CHP) is the main product obtained with Co(BPZ) (84% selectivity to CHP after 7 h, pO2 = 4 bar, and T = 363 K), further oxidation to 2-phenyl-2-propanol (PP) is observed in the presence of Co(BPZNH2) as the catalyst (69% selectivity to PP under the same experimental conditions).
- Nowacka, Anna,Vismara, Rebecca,Mercuri, Giorgio,Moroni, Marco,Palomino, Miguel,Domasevitch, Kostiantyn V.,Di Nicola, Corrado,Pettinari, Claudio,Giambastiani, Giuliano,Llabrés I Xamena, Francesc X.,Galli, Simona,Rossin, Andrea
-
supporting information
p. 8161 - 8172
(2020/06/08)
-
- Benzylic Hydroperoxidation via Visible-Light-Induced Csp3-H Activation
-
A highly efficient benzylic hydroperoxidation has been realized through a visible-light-induced Csp3-H activation. We believe that this reaction undergoes a direct HAT mechanism catalyzed by eosin Y. This approach features the use of a metal-free catalyst (eosin Y), an energy-economical light source (blue LED), and a sustainable oxidant (molecular oxygen). Primary, secondary, and tertiary hydroperoxides as well as silyl, benzyl, and acyl peroxides were successfully prepared with good yields and excellent functional group compatibility.
- Inoa, Joan,Patel, Mansi,Dominici, Grecia,Eldabagh, Reem,Patel, Anjali,Lee, John,Xing, Yalan
-
p. 6181 - 6187
(2020/05/22)
-
- Method for synthesizing cumene hydroperoxide by catalytic oxidation of cumene with copper (II) porphyrin
-
A method for synthesizing cumene hydroperoxide through catalytic oxidation of cumene with copper (II) porphyrin comprises the steps of: dispersing copper (II) porphyrin in cumene, wherein the amount of substance of the copper (II) porphyrin is 1 * 10 -4
- -
-
Paragraph 0024-0051; 0056-0127
(2020/12/10)
-
- Strain-Promoted Oxidation of Methylenecyclopropane Derivatives using N-Hydroxyphthalimide and Molecular Oxygen in the Dark
-
The hydroperoxidation of alkylidenecyclopropanes and other strained alkenes using an N-hydroxylamine and molecular oxygen occurred in the absence of catalyst, initiator, or light. The oxidation reaction proceeds through a radical pathway that is initiated by autoxidation of the alkene substrate. The hydroperoxides were converted to their corresponding alcohols and ketones under mild conditions.
- Anderson, T. E.,Woerpel, K. A.
-
supporting information
(2020/07/30)
-
- Method for selectively oxidizing cumene compounds
-
The invention relates to a method for selectively oxidizing cumene compounds, and the method comprises the following steps: placing cumene compounds shown in a formula (I), an iron porphyrin catalyst,an oxidant and a dispersant into a ball milling tank, sealing the ball milling tank, performing ball milling for 3 to 24 hours at a rotating speed of 100 to 800 rpm at room temperature, stopping ballmilling once every 1 to 3 hours in the ball milling process, discharging gases in the ball milling tank, finishing the reaction, and performing post-treatment on a reaction mixture to obtain product2-phenyl-2-propanol compound shown in a formula (II); according to the invention, the oxidation conversion of the cumene and derivatives thereof is realized through solid-phase ball milling, the reaction mode is novel, the operation is convenient, and the energy consumption is low; the method needs no organic solvent, thus effectively avoiding the use of toxic and harmful organic solvents and being green and environment-friendly; has low peroxide content and high safety factor, and high 2-phenyl-2-propanol and derivative selectivity and meets the social requirements of the current green chemical process, environmental compatibility chemical process and biological compatibility chemical process.
- -
-
Paragraph 0043-0044; 0057-0058; 0065-0066
(2019/11/21)
-
- Method for preparing alpha, alpha-dimethyl benzyl alcohol under dual catalyst and solvent-free conditions
-
The present invention relates to a method for preparing alpha, alpha-dimethyl benzyl alcohol under dual catalyst and solvent-free conditions. The method comprises the following steps of 1) preparing an ionic liquid catalyst; 2) adding cumene, the ionic liquid catalyst and an inorganic salt catalyst into a reactor with a reflux device, introducing a certain amount of air into the reactor as an oxygen source, and enabling cumene to perform an oxidation reaction under a solvent-free condition; and 3) after the reaction is finished, performing standing, wherein after the material in the reactor islayered, the upper-layer material is a reaction product alpha-dimethyl benzyl alcohol and the lower-layer material is a mixed catalytic system formed by the ionic liquid catalyst and the inorganic salt catalyst; and 4) separating the upper-layer material to obtain the reaction product alpha-dimethyl benzyl alcohol. The method is a brand-new synthesis mechanism, is low in cost and is suitable forlarge-scale industrial production.
- -
-
Page/Page column 6-9
(2019/12/31)
-
- {[Cu3Lu2(ODA)6(H2O)6]·10H2O}: N: The first heterometallic framework based on copper(II)/lutetium(III) for the catalytic oxidation of olefins and aromatic benzylic substrates
-
The catalytic performance of the novel framework {[Cu3Lu2(ODA)6(H2O)6]·10H2O}n was tested in the oxidation of alkenes and benzylic hydrocarbons, using tert-butyl hydroperoxide (TBHP) and molecular oxygen (O2) as oxidants. Excellent conversions were obtained with O2 under solvent-free conditions, in the absence of a co-catalyst, for cyclohexene (95%) and for cumene (91%).
- Cancino,Paredes-García,Torres,Martínez,Kremer,Spodine
-
p. 4929 - 4933
(2017/11/09)
-
- A novel copper(II)-lanthanum(IIi) metal organic framework as a selective catalyst for the aerobic oxidation of benzylic hydrocarbons and cycloalkenes
-
The synthesis and structure of a novel heteronuclear CuII and LaIII metal organic framework (MOF) having pyridinedicarboxylic acid (CuLa-MOF) is reported. The obtained MOF with the formula {[Cu0.5La2(HPDC)(PDC)2(SO4)(H2O)2]H2O}n (PDC: 3,5-pyridinedicarboxylate) has a 3D non-porous lattice with a single type of octahedrally coordinated CuII and two distinct nonacoordinated LaIII ions, with sulphate being a linker between the CuII and LaIII centers. CuLa-MOF exhibits catalytic activity to promote the aerobic autooxidation of benzylic hydrocarbons and the aerobic oxidation of cycloalkenes. Compared with a homogenous catalyst, Cu(OAc)2, CuLa-MOF, as a heterogeneous catalyst, exhibits similar activity, but the solid is recyclable with some minor decrease in activity from the first to the second catalytic cycle; after which, a steady activity is observed, as determined by the coincidence of temporal evolution of the reaction upon reuse.
- Cancino,Vega,Santiago-Portillo, Andrea,Navalon, Sergio,Alvaro, Mercedes,Aguirre,Spodine,García, Hermenegildo
-
p. 3727 - 3736
(2016/06/13)
-
- The effect of surface oxygenated groups of carbon nanotubes on liquid phase catalytic oxidation of cumene
-
It is of particular interest to reveal the influence of surface oxygenated groups and surface defects of carbon catalysts on liquid phase oxidation reactions. Herein, surface oxygenated groups and defects were introduced on the surface of carbon nanotubes (CNTs) using a gas-phase oxidation method with O2 and a liquid-phase oxidation method with concentrated HNO3. The results strongly confirm that the surface oxygenated groups on CNTs have a negative effect on catalytic activity for cumene oxidation. To the best of our knowledge, for the first time, we have distinguished experimentally that the factor responsible for the decrease in catalytic activity of the oxidized CNTs for the liquid phase aerobic oxidation reaction is the surface oxygenated groups instead of the surface defects. Meanwhile, the mechanism that drives the decrease in catalytic activity of the oxidized CNTs has also been revealed. It has been proven that the oxidized CNTs serve as free radical quenchers, capturing the free radical intermediates of the reaction and inhibiting the free radical chain transfer, thereby reducing the catalytic activity of the free radical reaction in the liquid phase. This study gains a new insight into the effect of surface structures on carbon-catalyzed liquid phase oxidation, and further pushes forward the research on carbon catalysis.
- Chi, Yumei,Zhu, Mingli,Li, Yuhang,Yu, Hao,Wang, Hongjuan,Peng, Feng
-
p. 2396 - 2402
(2016/04/26)
-
- SYNTHESIS OF FUNCTIONALIZED CARBON MICROSPHERES AND THEIR CATALYST ACTIVITY IN C-O AND C-N BOND FORMATION REACTIONS
-
Disclosed herein is a simple process for functionalization/grafting of carbon microspheres obtained from bagasse with various active functional groups onto it and use of the same as catalyst for various organic reactions, having very high selectivity and conversion rate.
- -
-
-
- MIL-101 as reusable solid catalyst for autoxidation of benzylic hydrocarbons in the absence of additional oxidizing reagents
-
Materiaux de l'Institute Lavosier-101 (MIL-101) promotes benzylic oxidation of hydrocarbons exclusively by molecular oxygen in the absence of any other oxidizing reagent or initiator. Using indane as model compound, the selectivity toward the wanted ol/one mixture is higher for MIL-101(Cr) (87% selectivity at 30% conversion) than for MIL-101(Fe) (71% selectivity at 30% conversion), a fact that was associated with the preferential adsorption of indane within the pore system. Product distribution and quenching experiments with 2,2,6,6-tetramethyl-1-piperidinyloxy, benzoic acid, and dimethylformamide show that the reaction mechanism is a radical chain autoxidation of the benzylic positions by molecular oxygen, and the differences in selectivity have been attributed to the occurrence of the autoxidation process inside or outside the metal organic framework pores. MIL-101 is reusable, does not leach metals to the solution, and maintains the crystal structure during the reaction. The scope of the benzylic oxidation was expanded to other benzylic compounds including ethylbenzene, n-butylbenzene, iso-butylbenzene, 1-bromo-4-butylbenzene, sec-butylbenzene, and cumene.
- Santiago-Portillo, Andrea,Navalón, Sergio,Cirujano, Francisco G.,Xamena, Francesc X. Llabrés I,Alvaro, Mercedes,Garcia, Hermenegildo
-
p. 3216 - 3224
(2015/06/16)
-
- Carbon nanotubes as catalyst for the aerobic oxidation of cumene to cumene hydroperoxide
-
The effective oxidation reaction system using the commercial carbon nanotubes (CNTs) as catalysts for the liquid aerobic oxidation of cumene to cumene hydroperoxide (CHP) under low temperature is reported in this paper. Several reaction parameters, including the temperature, catalyst content, oxygen flow rate and reaction time were carefully studied. Under optimal conditions, cumene conversion of 24.1% with CHP selectivity of 88.4%, close to that of metal catalyst, was obtained. Cumene oxidation catalyzed by CNTs was proved a radical-involved reaction, and the outstanding catalytic performance was attributed to CHP decomposition catalyzed by CNTs to produce free radicals. Oxygenated functional groups on the surface of catalyst showed a negative effect on cumene oxidation due to the localization of electrons after the introducing of defects and oxygenated functional groups. CNTs as catalysts also showed desirable recyclability after five cycling tests. This study not only provides an applicable method for selective oxidation of cumene to CHP, but also gives some useful information on catalytic role of CNTs-catalyzed liquid-phase oxidation reactions of aromatic hydrocarbons.
- Liao, Shixia,Peng, Feng,Yu, Hao,Wang, Hongjuan
-
-
- Cu-MOFs as active, selective and reusable catalysts for oxidative C-O bond coupling reactions by direct C-H activation of formamides, aldehydes and ethers
-
MOFs with Cu2+ centers linked to four nitrogen atoms from azaheterocyclic compounds, i.e., pyrimidine [Cu(2-pymo)2] and imidazole [Cu(im)2], are active, stable and reusable catalysts for oxidative C-O coupling reactions by direct C-H activation of formamides, aldehydes and ethers. The measured catalytic activities are clearly superior to other homogeneous cupric salts, especially for the [Cu(im)2] MOF. The previously reported activity of the Cu2+ centers for cumene oxidation allows the use of the MOF as a bifunctional catalyst for olefin epoxidation with O2. The overall catalytic process consists of a cascade reaction in which the Cu-MOF first produces cumyl hydroperoxide and then the same Cu2+ centers catalyze the oxidative C-O coupling reaction using the generated hydroperoxide as the oxidant. This journal is the Partner Organisations 2014.
- Luz,Corma,Llabres I Xamena
-
p. 1829 - 1836
(2014/06/09)
-
- Epoxidation of stilbene using supported gold nanoparticles: Cumyl peroxyl radical activation at the gold nanoparticle surface
-
The catalytic epoxidation of cis-stilbene using cumene as a solvent in the presence of supported gold nanoparticles (AuNP) yields a mixture of cis and trans-stilbene oxides. EPR and product distribution studies support a new mechanistic proposal where oxygen centred radicals activate the AuNP surface and form active surface oxygen species responsible for the epoxidation products. The Royal Society of Chemistry 2014.
- Crites, Charles-Oneil L.,Hallet-Tapley, Geniece L.,Gonzalez-Bejar, Maria,Netto-Ferreira,Scaiano, Juan C.
-
p. 2289 - 2291
(2014/03/21)
-
- Aerobic oxidation of cumene catalysed by 4-Alkyloxycarbonyl-N- Hydroxyphthalimide
-
4-Hexyloxycarbonyl-, 4-dodecyloxycarbonyl- and 4-hexadecyloxycarbonyl-N- hydroxyphthalimides were synthesised using trimellitic anhydride chloride as the starting material. The obtained lipophilic derivatives of N-hydroxyphthalimide were applied as catalysts of the cumene oxidation reaction with oxygen performed in polar acetonitrile, in non-polar tert-butylbenzene and in the absence of a solvent. The courses of reactions catalysed by N-hydroxyphthalimide and its derivatives were compared. Versita Sp. z o.o.
- Kasperczyk, Kornela,Orlinska, Beata,Zawadiak, Jan
-
p. 1176 - 1182
(2014/06/09)
-
- Mechanistic insights into the oxidation of substituted phenols via hydrogen atom abstraction by a cupric-superoxo complex
-
To obtain mechanistic insights into the inherent reactivity patterns for copper(I)-O2 adducts, a new cupric-superoxo complex [(DMM-tmpa)CuII(O2?-)]+ (2) [DMM-tmpa = tris((4-methoxy-3,5-dimethylpyridin-2-yl)methyl)amine] has been synthesized and studied in phenol oxidation-oxygenation reactions. Compound 2 is characterized by UV-vis, resonance Raman, and EPR spectroscopies. Its reactions with a series of para-substituted 2,6-di-tert-butylphenols (p-X-DTBPs) afford 2,6-di-tert-butyl-1,4-benzoquinone (DTBQ) in up to 50% yields. Significant deuterium kinetic isotope effects and a positive correlation of second-order rate constants (k2) compared to rate constants for p-X-DTBPs plus cumylperoxyl radical reactions indicate a mechanism that involves rate-limiting hydrogen atom transfer (HAT). A weak correlation of (kBT/e) ln k 2 versus Eox of p-X-DTBP indicates that the HAT reactions proceed via a partial transfer of charge rather than a complete transfer of charge in the electron transfer/proton transfer pathway. Product analyses, 18O-labeling experiments, and separate reactivity employing the 2,4,6-tri-tert-butylphenoxyl radical provide further mechanistic insights. After initial HAT, a second molar equiv of 2 couples to the phenoxyl radical initially formed, giving a CuII-OO-(ArO') intermediate, which proceeds in the case of p-OR-DTBP substrates via a two-electron oxidation reaction involving hydrolysis steps which liberate H2O2 and the corresponding alcohol. By contrast, four-electron oxygenation (O-O cleavage) mainly occurs for p-R-DTBP which gives 18O-labeled DTBQ and elimination of the R group.
- Lee, Jung Yoon,Peterson, Ryan L.,Ohkubo, Kei,Garcia-Bosch, Isaac,Himes, Richard A.,Woertink, Julia,Moore, Cathy D.,Solomon, Edward I.,Fukuzumi, Shunichi,Karlin, Kenneth D.
-
p. 9925 - 9937
(2014/08/05)
-
- Tuning the selectivity in the aerobic oxidation of cumene catalyzed by nitrogen-doped carbon nanotubes
-
In this study it is demonstrated that carbon nanotubes (CNTs) with doped nitrogen atoms in graphitic domains (NCNTs) can act as a new class of metal-free catalysts exhibiting excellent activity in the aerobic oxidation of cumene. We proved that NCNTs can promote the decomposition of hydroperoxide cumene with exceptionally high activity, resulting in strongly increased cumene conversion and extraordinarily high selectivity to acetophenone and 2-benzyl-2-propanol. The incorporation of nitrogen altered the surface electron structure of the CNTs and tuned the reactivity and selectivity. DFT calculations revealed that the remarkable improvement of catalytic performance of NCNTs is caused by the strong interaction between hydroperoxide cumene and the NCNTs. NCNTs also exhibited desirable recyclability after four cycling tests. This study not only provides a novel method for the cumene oxidation to high-value-added products at moderate reaction temperatures and oxygen atmospheric pressure, but also gives new insights into the effect of surface nitrogen doping on carbon-catalyzed liquid-phase oxidation of aromatic hydrocarbons. b Copyright
- Liao, Shixia,Chi, Yumei,Yu, Hao,Wang, Hongjuan,Peng, Feng
-
p. 555 - 560
(2014/03/21)
-
- Nanosized ruthenium particles decorated carbon nanofibers as active catalysts for the oxidation of p-cymene by molecular oxygen
-
Highly dispersed, nanosized ruthenium (Ru) particles anchored on carbon nanofibers (CNFs) with varying Ru loadings (1-7 wt.%) showed effective catalytic activity in the aerobic oxidation of p-cymene using molecular oxygen. The activity of the Ru catalysts was influenced by the structural properties that resulted from the different metal loadings and by various reaction variables, such as the temperature, the amount of catalyst and the type of radical-initiator substrate. Under optimized reaction conditions, the 3%Ru/CNF catalyst exhibited excellent performance with a selectivity of 42% toward primary cymene hydroperoxide (PCHP) and 33% toward tertiary cymene hydroperoxide (TCHP) at 55% p-cymene conversion achieved within 5 h at 90 °C. The results demonstrated that the direct participation of the catalyst in p-cymene CH bond activation occurred via catalytic decomposition of tertiary-butyl hydroperoxide (TBHP), which was added as an initiator, into a free-radical chain initiator rather than the direct H-atom abstraction by the catalyst itself. The catalytic efficacy displayed by the Ru/CNF catalysts provides encouraging results for the activation of CH bonds of liquid-phase alkyl aromatic hydrocarbons, such as p-cymene, toward the introduction of an oxygen atom. The catalyst was reusable for five consecutive reaction cycles without appreciable loss of activity. Moreover, Ru/CNF catalyst was active for extended substrate scope application in the oxidation of other alkyl-substituted aromatics.
- Makgwane, Peter R.,Ray, Suprakas Sinha
-
-
- Selective aerobic oxidation of activated alkanes with MOFs and their use for epoxidation of olefins with oxygen in a tandem reaction
-
MOFs with Cu2+ centers linked to four nitrogen atoms from azaheterocyclic compounds, i.e., pyrimidine [Cu(2-pymo)2] and imidazole [Cu(im)2], are active catalysts for aerobic oxidation of activated alkanes, such as tetralin, cumene and ethylbenzene. Differences in activity among the two MOFs appear to be related to differences in their ability to decompose the hydroperoxide and to coordinate to the resulting radical OH species. Copper ions in [Cu(im)2] can coordinate by expanding their coordination sphere from 4 to 5 in a reversible way, while in the case of [Cu(2-pymo)2] it results in a displacement of one of the pyrimidine ligands. The MOFs can be used in combination with a silylated Ti-MCM-41 to catalyze the epoxidation of olefins with oxygen by means of a tandem reaction in which the MOF produces cumene hydroperoxide, which is used by Ti-MCM-41 to epoxidize the olefin. The Royal Society of Chemistry 2013.
- Luz,Leon,Boronat,Llabres I Xamena,Corma
-
p. 371 - 379
(2013/03/14)
-
- Rhodium acetate-catalyzed aerobic Mukaiyama epoxidation of alkenes
-
Mukaiyama epoxidation of alkenes under oxygen catalyzed by rhodium acetate with isobutyraldehyde as the reducing agent is as or more effective than previously reported procedures. A variety of alkenes, including terpenes and cholesterol derivatives, were oxidized. And high regioselectivity for monoepoxidation was observed with neryl, geranyl, and linalyl acetates.
- Shabashov, Dmitry,Doyle, Michael P.
-
supporting information
p. 10009 - 10013
(2013/11/06)
-
- PROCESS FOR THE PRODUCTION OF ALKYLBENZENE HYDROPEROXIDES UNDER MILD CONDITIONS AND IN THE PRESENCE OF NEW CATALYTIC SYSTEMS
-
Process for the preparation of hydroperoxides of alkylbenzenes characterized by the fact that the alkylbenzene reacts with oxygen in the presence of a catalytic system which includes an N-hydroxyimide or an N-hydroxysulfamide and a polar solvent.
- -
-
Page/Page column 2-3
(2011/10/19)
-
- GAS-LIQUID DISPERSION DEVICE AND METHOD FOR PRODUCING GAS-LIQUID DISPERSION
-
The present invention relates to a gas-liquid dispersion device which is used in a column wherein a gas-liquid mixed fluid flows upward which comprises a liquid as a continuous phase and a gas as a dispersed phase, characterized in that the gas is dispersed effectively into the liquid, so that a sufficient contact between the gas and the liquid can be attained. The device is characterized in that (A) the plate has at least one hole through which the gas and the liquid pass, (B) one end of the conduit is connected to the hole at a lower surface of the plate so that the conduit extends downward from the plate, (C) at least one passage for the gas is provided through a side surface of the conduit, and (D) at least one passage for the liquid is provided in a lower part of the conduit.
- -
-
Page/Page column 8
(2011/01/12)
-
- PROCESS FOR THE PREPARATION OF PHENOL BY MEANS OF NEW CATALYTIC SYSTEMS
-
The invention relates to a process for the preparation of phenol which comprises the aerobic oxidation of cumene to hydroperoxide with high conversions and selectivities, in the presence of new catalytic systems, extremely mild conditions and the subsequent acid decomposition of the hydroperoxide to phenol and acetone.
- -
-
Page/Page column 2
(2011/05/05)
-
- Hydroperoxidation of tertiary alkylaromatics catalyzed by N-hydroxyphthalimide and aldehydes under mild conditions
-
A metal-free catalytic system consisting of an aldehyde and N-hydroxyphthalimide (NHPI) for the selective oxidation of tertiary alkylaromatics with molecular oxygen has been developed. Cumene was oxidized efficiently to the corresponding hydroperoxide under mild conditions. The molecule-induced homolysis between peracids generated in situ and NHPI ensured the formation of the phthalimide N-oxyl (PINO) radical even at room temperature. Investigations on aldehyde, solvent and temperature effects allowed us to achieve good conversions with high selectivity in hydroperoxide. The optimized procedure was successfully extended to phenylcyclohexane, a valuable alternative for the production of phenol. The mechanism is discussed in detail.
- Melone, Lucio,Gambarotti, Cristian,Prosperini, Simona,Pastori, Nadia,Recupero, Francesco,Punta, Carlo
-
experimental part
p. 147 - 154
(2011/04/22)
-
- Water as efficient medium for mild decarbonylation of tertiary aldehydes
-
Decarbonylation of the tertiary aldehydes 4-ethyl-4-formyl-hexanenitrile (2) and 2-methyl-2-phenylpropanal (4) promoted by dioxygen occurs at room temperature only if suspended in water probably via the sequential acyl radical-CO liberation-tertiary radical that is promoted by an 'on water' process originating preferentially from the corresponding tertiary hydroperoxide.
- Rodrigues, Catarina A.B.,De Matos, Marta Norton,Guerreiro, Bruno M.H.,Gon?alves, Ana M.L.,Rom?o, Carlos C.,Afonso, Carlos A.M.
-
experimental part
p. 2803 - 2807
(2011/06/19)
-
- Process for Producing Alkylbenzene Hydroperoxides
-
In a process for producing alkylbenzene hydroperoxides, a feed comprising (i) sec-butylbenzene, (ii) cumene in an amount greater than 10 wt % of the total feed and (iii) at least one of iso-butylbenzene and tert-butylbenzene in an amount up to 20 wt % of the total feed is contacted with an oxygen-containing gas in the presence of a catalyst comprising a cyclic imide of the general formula (I): wherein each of R1 and R2 is independently selected from hydrocarbyl and substituted hydrocarbyl radicals having 1 to 20 carbon atoms, or from the groups SO3H, NH2, OH, and NO2 or from the atoms H, F, Cl, Br, and I, provided that R1 and R2 can be linked to one another via a covalent bond; each of Q1 and Q2 is independently selected from C, CH, N and CR3; each of X and Z is independently selected from C, S, CH2, N, P and elements of Group 4 of the Periodic Table; Y is O or OH; k is 0, 1, or 2; l is 0, 1, or 2; m is 1 to 3; and R3 can be any of the entities listed for R1. The contacting is conducted under conditions to convert the sec-butylbenzene and cumene to their associated hydroperoxides.
- -
-
Page/Page column 6-7
(2011/05/03)
-
- N-Hydroxyphthalimide in combination with Cu(II), Co(II) or Mn(II) salts as catalytic systems for the oxidation of isopropyl-aromatic hydrocarbons with oxygen
-
Catalytic systems consisting of N-hydroxyphthalimide in combination with copper(II), cobalt(II) and manganese(II) acetylacetonate, acetate or chloride were applied to the oxidation of cumene with oxygen. The use of these catalytic systems decreases cumyl hydroperoxide selectivity as a result of the decomposition reaction of hydroperoxide to 2-phenyl-2-propanol and acetophenone. It has been demonstrated that the use of N-hydroxyphthalimide in combination with copper salts at 60 °C results in high alcohol content whereas ketone is the major product at 90 °C. The results can be used to develop a method for alcohol or ketone synthesis from other isopropyl-aromatic hydrocarbons.
- Orlińska, Beata
-
experimental part
p. 4100 - 4102
(2010/08/19)
-
- Catalytic activity of iron-substituted polyoxotungstates in the oxidation of aromatic compounds with hydrogen peroxide
-
The tetrabutylammonium (TBA) salts of Keggin-type polyoxotungstates of the general formula [XW11FeIII(H2O)O39] n-, where X = P, B or Si, were evaluated as catalysts in the oxidation, under mild conditions, of ethylbenzene, cumene, p-cymene and sec-butylbenzene with aqueous H2O2 in CH3CN at 80 °C. The influence of various factors, such as the substrate/catalyst molar ratio, the amount of oxidant added or the reaction time, was investigated in a systematic way. Generally, the system exhibited moderate conversion, with good selectivity towards the corresponding acetophenone and hydroperoxide. In order to understand the reaction pathways, the oxidation of several products and presumed intermediates was also carried out in the presence of TBA 4[PW11Fe(H2O)O39]?2H 2O. Under the conditions used, the oxidation of styrene and styrene derivatives gave rise mainly to carbon-carbon double-bond cleavage, affording the corresponding products in very high yields (81-87%). Possible reaction pathways are presented.
- Estrada, Ana C.,Simoes, Mario M. Q.,Santos, Isabel C. M. S.,Neves, M. Graca P. M. S.,Cavaleiro, Jose A. S.,Cavaleiro, Ana M. V.
-
experimental part
p. 1223 - 1235
(2011/09/12)
-
- PROCESS FOR PRODUCING PHENOL
-
Disclosed is a process for producing phenol or a substituted phenol and a co-product comprising the steps of (i) contacting a first stream comprising an alkylaromatic compound with a second stream comprising an oxygen-containing gas in the presence of a first catalyst comprising a cyclic imide under conditions to convert at least a portion of said alkylaromatic compound to an alkylaromatic hydroperoxide, (ii) producing an effluent stream comprising said cyclic imide, said alkylaromatic hydroperoxide, and said alkylaromatic compound wherein said effluent stream has an alkylaromatic hydroperoxide concentration of from 10 to 40 wt%; and (iii) contacting in a second reactor at least a portion of said effluent stream with a second catalyst to convert said alkylaromatic hydroperoxide to a product stream comprising phenol and said co-product.
- -
-
Page/Page column 20
(2010/09/17)
-
- Selective side-chain oxidation of alkyl aromatic compounds catalyzed by cerium modified silver catalysts
-
Silver supported on silica effectively catalyzes the aerobic side-chain oxidation of alkyl aromatic compounds under solvent-free conditions. Toluene, p-xylene, ethylbenzene and cumene were investigated as model substrates. Typically, the reaction was performed at ambient pressure; only for toluene an elevated pressure was required. Carboxylic acids, such as benzoic acid or p-toluic acid, additionally increased the reaction rate while CeO2 could act both as a promoter and an inhibitor depending on the substrate and the reaction conditions. Silver catalysts were prepared both by standard impregnation and flame spray pyrolysis. Addition of a Ce precursor to the FSP catalyst resulted in significantly smaller silver particles. Ce-doped FSP catalysts in general exhibited a superior catalytic performance with TONs up to 2000 except for cumene oxidation that appeared to proceed mainly by homogeneous catalysis. In addition, flame-made catalysts were more stable against silver leaching compared to the impregnated catalysts. The structure of the silver catalysts was studied in detail both by X-ray absorption spectroscopy and transmission electron microscopy suggesting metallic silver to be required for catalytic activity. Catalytic studies point to a radical mechanism which differs depending on the type of substrate.
- Beier, Matthias J.,Schimmoeller, Bjoern,Hansen, Thomas W.,Andersen, Jens E.T.,Pratsinis, Sotiris E.,Grunwaldt, Jan-Dierk
-
experimental part
p. 40 - 49
(2010/12/25)
-
- 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)
-
- PROCESS FOR PRODUCING ALKYLBENZENE HYDROPEROXIDE
-
ABSTRACT A process for producing an alkylbenzene hydroperoxide from an alkylbenzene solution containing 0.01 to 10 mmol/kg of phenols by subjecting the solution to oxidation with an oxygen-containing gas, including allowing a compound represented by formu
- -
-
Page/Page column 9-13
(2009/06/27)
-
- OXIDATION OF HYDROCARBONS
-
In a process for oxidizing a hydrocarbon to the corresponding hydroperoxide, alcohol, ketone, carboxylic acid or dicarboxylic acid, a reaction medium comprising a hydrocarbon is contacted with an oxygen-containing gas in the presence of a catalyst comprising a cyclic imide of the general formula (I): wherein each of R1 and R2 is independently selected from hydrocarbyl and substituted hydrocarbyl radicals having 1 to 20 carbon atoms, or from the groups SO3H, NH2, OH and NO2, or from the atoms H, F, Cl, Br and I provided that R1 and R2 can be linked to one another via a covalent bond; each of Q1 and Q2 is independently selected from C, CH, N, and CR3; each of X and Z is independently selected from C, S, CH2, N, P and an element of Group 4 of the Periodic Table; Y is O or OH; k is O, 1, or 2; 1 is 0, 1, or 2; m is 1 to 3; and R3 can be any of the entities listed for R1. The contacting is conducted under conditions such as to maintain the concentration of both water and organic acids in the reaction medium below 50 ppm.
- -
-
Page/Page column 22-23; 25
(2009/06/27)
-
- PROCESS FOR THE PRODUCTION OF ALKYLBENZENE HYDROPEROXIDES UNDER MILD CONDITIONS AND IN THE PRESENCE OF NEW CATALYTIC SYSTEMS
-
Process for the preparation of hydroperoxides of alkylbenzenes characterized by the fact that the alkylbenzene reacts with oxygen in the presence of a catalytic system which includes an N-hydroxyimide or an N-hydroxysulfamide and a polar solvent.
- -
-
Page/Page column 9-10
(2009/10/22)
-
- Autooxidation of hydrocarbons with oxygen in ionic liquids as solvents
-
The results of hydrocarbons autooxidation process carried out using several ionic liquids (IL) as solvents are demonstrated. Test studies to check the influence of ILs on this process showed that most ILs can accelerate the initiation rate of autooxidation. The results could be very useful for choosing an IL not only for autooxidation processes but also for catalytic oxidation systems.
- Baj, Stefan,Chrobok, Anna
-
p. 287 - 293
(2008/09/21)
-
- PROCESS FOR THE PREPARATION OF PHENOL BY MEANS OF NEW CATALYTIC SYSTEMS
-
The invention relates to a process for the preparation of phenol which comprises the aerobic oxidation of cumene to hydroperoxide with high conversions and selectivities, in the presence of new catalytic systems, extremely mild conditions and the subsequent acid decomposition of the hydroperoxide to phenol and acetone.
- -
-
Page/Page column 11-12
(2008/06/13)
-
- Method for production of cumene hydroperoxide
-
A continuous method of cumene oxidation in a gas-liquid system is provided, where the liquid phase is represented by cumene and its oxidation products and the gas phase is represented by air. The oxidation process can be carried out either in a reactor se
- -
-
Page/Page column 12-15
(2008/12/06)
-
- METHOD FOR PRODUCING PROPYLENE OXIDE
-
A method for producing propylene oxide in which the concentration of an organic peroxide in a reaction solution after an epoxidation step is from 20 to 5,000 ppm by weight based on the amount excluding propylene in the reaction solution, the method comprising an epoxidation step of reacting an organic peroxide with propylene in the presence of a catalyst to obtain propylene oxide and an alcohol, a propylene recovery step of recovering the unreacted propylene in the epoxidation step and recycling the resulting propylene as a raw material of the epoxidation step, and a propylene oxide purification step of distilling the propylene oxide obtained in the epoxidation step to obtain purified propylene oxide.
- -
-
Page/Page column 25-26
(2008/12/04)
-