- Growth of Cu-BTC MOFs on dendrimer-like porous silica nanospheres for the catalytic aerobic epoxidation of olefins
-
The composition of metal-organic frameworks (MOFs) and porous carriers can be utilized for a variety of material applications. In this study, DPSNs@Cu-BTC nanocomposites are achieved utilizing Dendrimer-like Porous Silica Nanoparticles (DPSNs) as the support through a template-mediated self-assembly mechanism. The fabrication process is initiated from the controllable growth of Cu2O nanoparticles (NPs) in the center-radial porous channels of DPSNs, which forms DPSNs@Cu2O nanocomposites. Under the protection of DPSNs, the loaded Cu2O NPs gradually dissolved in the weak acid solution, thus providing copper ions to guide the formation and growth of Cu-BTC nanocrystals. Moreover, the Cu-BTC NPs were restricted in the center-radial porous channels of the DPSNs, thus resulting in small sizes and a uniform distribution. The formation of the DPSNs@Cu-BTC nanocomposites with adjustable amounts of Cu-BTC mainly depended on the amounts of Cu2O NPs loaded and the amount of organic ligands added. Furthermore, the nanocomposite exhibited high catalytic performance and good recyclability taking advantage of the uniform loading of small-sized Cu-BTC NPs in the accessible center-radial porous channels of the DPSNs. This new design of DPSNs@Cu-BTC provided a new approach for the synthesis of various MOF-based nanocomposites with improved performance.
- Zhou, Zihao,Li, Xiujuan,Wang, Yulin,Luan, Yi,Li, Xiaoyu,Du, Xin
-
-
Read Online
- An Organotin Vanadate with Sodalite Topology and Catalytic Versatility in Oxidative Transformations
-
The new coordination polymer formulated as [Et3SnVO3] (1) has been synthesized and shown by a combined single-crystal and synchrotron powder X-ray diffraction structural analysis, supported by solid-state NMR, to possess a three-dimensional network structure with the sodalite topology, formed by tetravanadate polyanions, [V4O12]4?, that are linked by Et3Sn+ spacers. The catalytic versatility of compound 1 for liquid phase organic reactions was demonstrated by applying it for the epoxidation of olefins, the oxidative dehydrogenation of alcohols, and the oxidation of benzyl alcohol to benzaldehyde and benzoic acid, using tert-butyl hydroperoxide (TBHP) as oxidant. Compound 1 acts a solid reservoir for soluble, catalytically active species, which promote high selectivities to the epoxide and carbonyl (aldehyde/ketone/acid) products. The epoxidation activity compares favorably with those reported for other organotin molybdate, tungstate and vanadate coordination polymers, and is superior to that displayed by the starting materials used for its synthesis (Et3SnBr and NH4VO3) and the metavanadate NBu4VO3.
- Gomes, Ana C.,Antunes, Margarida M.,Abrantes, Marta,Valente, Anabela A.,Paz, Filipe A. Almeida,Gon?alves, Isabel S.,Pillinger, Martyn
-
-
Read Online
- Molecular structure-activity relationships for the oxidation of organic compounds using mesoporous silica catalysts derivatised with bis(halogeno)dioxomolybdenum(VI) complexes
-
Mo K-edge XAFS spectra have been measured for ordered mesoporous silica MCM-41 grafted with the complexes [MoO2X2(thf) 2] (X = Cl, Br). For grafting reactions in the absence of triethylamine, materials with 1 wt.% Mo are obtained; the Mo K-edge EXAFS results indicate the co-existence of isolated surface-fixed monomeric species {MoO2[(-O)3SiO]2(thf)n} and {MoO2[(-O)3SiO]X(thf)n}. When Et3N is used in the grafting reactions, materials with 4 wt. % Mo are obtained. The EXAFS data for the material prepared using [MoO2Cl 2(thf)2] and Et3N indicate the presence of dinuclear species with two MoVI centres, each with two Mo=O groups and each linked by one or two oxo bridges (Mo...Mo 3.27 A). The molybdenum centres in the material prepared using the dibromo complex comprise mainly isolated four-coordinate dioxomolybdenum(VI) and trioxomolybdenum(VI) monomeric species, with a small contribution from dimeric acterised in the solid state by powder X-ray diffraction, N2 adsorption analysis, MAS NMR (13C, 29Si) and FTIR spectroscopy. The derivatised MCMs perform differently as catalysts in the liquid-phase oxidation of various olefins and alcohols with tert-butyl hydroperoxide. The highest alkene epoxidation activity was recorded for the catalysts with low metal loading, whereas the material containing oxo-bridged dimers had the highest activity for oxidation of alcohols. The recyclability of all the catalysts was tested: the catalytic activity of the derivatised materials tended to stabilize with ageing.
- Nunes, Carla D.,Valente, Anabela A.,Pillinger, Martyn,Rocha, Joao,Goncalves, Isabel S.
-
-
Read Online
- Synthesis and catalytic activity of organic-inorganic hybrid catalysts coordinated with cobalt(II) ions for aerobic epoxidation of styrene
-
New organic-inorganic hybrid materials (HM) containing 3-mercaptopropyl groups (-(CH2)3-SH) have been synthesized through a dry gel conversion (DGC) route. The complex catalyst Co-HM was prepared through a simple coordination of -SH with cobalt(II) ions, which was firstly applied in the aerobic epoxidation of alkenes to obtain good results. Co-HM-50 exhibited the highest activity for the epoxidation of styrene with air to achieve 95.8 mol% of conversion with the epoxide selectivity of 89.2%. Recycling and control tests showed high durability and heterogeneity of Co-HM-50 as a heterogeneous catalyst.
- Wei,Lu,Ma,Peng,Jiang,Zhou,Xia
-
-
Read Online
- Synthesis of a reusable polymer anchored cobalt(II) complex for the aerobic oxidation of alkyl aromatics and unsaturated organic compounds
-
Polymer anchored cobalt(II) catalyst was synthesized and characterized. The solid catalyst was characterized by fourier transform infrared spectroscopy (FT-IR), UV-vis diffuse reflectance spectroscopy (DRS), thermogravimetric analysis (TGA) and scanning electron microscope (SEM). The catalytic activity of the complex was investigated for the oxidative functionalization of alkyl aromatics to benzylic ketones using O2 (1 atm) with 1 mmol H2O2. The oxidation of organic compounds with carbon-carbon double bond with molecular oxygen under atmospheric pressure in the presence of this catalyst has also been studied. Oxidation of alkenes, cycloalkenes and terpenes gave corresponding epoxy derivatives. The developed catalyst can be facilely recovered and reused six times without significant decrease in its activity and selectivity.
- Islam, Sk Manirul,Ghosh, Kajari,Molla, Rostam Ali,Roy, Anupam Singha,Salam, Noor,Iqubal, Md Asif
-
-
Read Online
- Co2 +-exchanged SAPO-5 and SAPO-34 as efficient heterogeneous catalysts for aerobic epoxidation of alkenes
-
Co-SAPO-5 and Co-SAPO-34 were prepared by a simple ion-exchange route and firstly applied in the aerobic epoxidation of alkenes. Both catalysts exhibited high activities in the epoxidation of alkenes with air to achieve 92.0-91.9 mol% conversion with the epoxide selectivity of 89.5-90.5% for styrene, 71.6-80.0 mol% conversion with 94.8-95.0% selectivity for α-pinene, and 95.3-96.8 mol% conversion with 75.2-73.6% selectivity for α-methyl styrene. Recycling studies and control experiments showed the recyclability and stability of Co-SAPO-5 and Co-SAPO-34 as heterogeneous catalysts.
- Tang,Lu,Zhou,Tian,Niu,Zhang,Chen,Xia
-
-
Read Online
- Epoxidation of olefins by molecular oxygen using perfluorocarbons as reaction media
-
Epoxidation of olefins by dioxygen in combination with aldehyde as reducing agent can be carried out at room temperature, in the absence of metal catalysts, using perfluorocarbons as inert reaction media. These non-toxic, non ozone-depleting fluids are good alternatives to the chlorinated solvents normally used.
- Pozzi, Gianluca,Montanari, Fernando,Rispens, Minze T.
-
-
Read Online
- Chemoenzymatic epoxidation of alkenes by dimethyl carbonate and hydrogen peroxide
-
(matrix presented) Monoperoxy carbonic acid methyl ester can be generated under neutral conditions by lipase-catalyzed perhydrolysis of dimethyl carbonate with hydrogen peroxide. It can be used in situ for the selective and efficient epoxidation of olefins; the unstable coproduct carbonic acid monomethylester decomposes to carbon dioxide and methanol. Thus, an "acid-free" Prileshajev epoxidation is realized, which is especially useful for the epoxidation of acid-sensitive substrates such as β-pinene.
- Rusch Gen Klaas, Mark,Warwel, Siegfried
-
-
Read Online
- Hierarchical PS/PANI nanostructure supported Cu(ii) complexes: Facile synthesis and study of catalytic applications in aerobic oxidation
-
Hierarchical heterogeneous copper catalysts were prepared by immobilization of a homogeneous copper(ii) complex on the surface of polystyrene/polyaniline (PS/PANI) microspheres with oriented PANI nanofibers. EDX element maps and XPS spectra indicated that Cu2+ ions strongly coordinated with PANI imine. PS/PANI@Cu(OSO2CF3)2 exhibited excellent catalytic activity for selective aerobic oxidation of alcohols and highly efficient aerobic epoxidation of alkenes under mild conditions. The supported copper(ii) catalyst maintained high levels of conversion and selectivity in these reactions after six cycles and showed good stability. This journal is
- Yu, Jie,Luan, Yi,Qi, Yue,Hou, Junying,Dong, Wenjun,Yang, Mu,Wang, Ge
-
-
Read Online
- Single bilayered organic nanotubes: Anchors for production of a reusable catalyst with nickel ions
-
Organic nanotubes self-assembled from lipid compounds facilitate the synthesis of a new nano-catalyst with nickel ions. The nickel ions were fixed on the surface of the organic nanotubes through coordination. The nanotubes catalyzed oxidation of a wide range of organic compounds with hydrogen peroxide without organic solvent, and are reusable in at least five cycles without loss of activity.
- Chattopadhyay, Tanmay,Kogiso, Masaki,Aoyagi, Masaru,Yui, Hiroharu,Asakawa, Masumi,Shimizu, Toshimi
-
-
Read Online
- Synthesis, characterization, and application of a new nanohybrid Schiff base polyoxometalate in epoxidation of olefins in the presence of tert-butyl hydroperoxide
-
The new molybdenyl acetylacetonate Schiff base complex with mono-lacunary polyoxometalate (1) was synthesized in the reaction of [PMo11O39]7-, molybdenum acetylacetonate (MoO2(acac)2), and ethylenediamine. The catalyst was characterized by elemental analysis and various routine techniques like FT-IR, XRD, FESEM, EDX, UV–Vis, and TGA. The catalytic activities of this nanocatalyst were examined for epoxidation of linear, cyclic and phenyl-substituted olefins using tert-butyl hydroperoxide (tert-BuOOH) as oxidant.
- Hosseinyzade, Samira S.,Zonoz, Farrokhzad M.,Bahramian, Bahram
-
-
Read Online
- Catalytic epoxidation of alkenes with 30% H2O2 over Mn2+-exchanged zeolites
-
The Mn2+-exchanged zeolites Mn-Y, Mn-beta, Mn-A and Mn-ZSM-5 were prepared and used as heterogeneous catalysts for the liquid phase epoxidation of alkenes with aqueous hydrogen peroxide (30% H2O2) at 273-298 K in the NaHCO3 buffer system. The structures of catalysts were characterized by powder X-ray diffraction (XRD), UV-vis, ICP, BET and IR techniques. Mn-beta and Mn-Y exhibited the best recyclable activity for the epoxidation of styrene to achieve styrene conversions higher than 96.0 and 98.5 mol%, respectively. Mn-beta showed higher activity for cyclohexene and norbornene but lower activity for α-methylstyrene, cinnamyl chloride, indene, cyclooctene and α-pinene than Mn-Y, which could be correlated with the difference of their pore sizes. However, these catalysts did not show any activity for the epoxidation of 1-octene with H2O2, possibly due to low electron density of double bonds of linear terminal alkenes.
- Qi,Lu,Zhou,Xia,Tang,Fang,Pang,Dong
-
-
Read Online
- Dry gel conversion method for the synthesis of organic-inorganic hybrid MOR zeolites with modifiable catalytic activities
-
Dry gel conversion (DGC) technique is first applied in the synthesis of organic-inorganic hybrid aluminosilicate zeolites. By using the DGC method, methylene-bridged organic-inorganic hybrid zeolites with an MOR topology are synthesized without organic additive, which are structurally characterized by powder XRD, FTIR, solid-state 29Si, 13C, 27Al MAS NMR, SEM, elemental analysis, XRF, XPS, and N2 adsorption techniques. This work first reports that thus-synthesized methylene-bridged hybrid zeolites can be successfully bestowed with excellent catalytic activities through different modification treatments. Co2+-exchanged hybrid zeolites are applied in the epoxidation of alkenes with air to achieve good conversions and selectivities. Especially, methylene-bridged hybrid zeolites can be sulfonated with fuming sulfuric acid to form acidic MOR-SO3H catalyst, which exhibits highly catalytic activity for the acid-catalyzed condensation reaction of cyclohexanone and glycol. This method will be one potential route for the fabrication of organic-inorganic hybrid zeolite or related molecular sieve catalysts.
- Zhou, Dan,Lu, Xinhuan,Xu, Jun,Yu, Anan,Li, Jiyang,Deng, Feng,Xia, Qinghua
-
-
Read Online
- Products and mechanism of the gas-phase reaction of NO3 radicals with α-pinene
-
The gas-phase reaction of NO3 radicals with a-pinene has been studied under flow conditions in the pressure range 20 2 + NO RO NO2, the following product yields were obtained at p = 200 mbar and [O2] > 1017 molecule cm-3, pinonaldehyde 75 ±6%, a-pinene oxide 15 ±3%, organic nitrates (total) 14 ±3%, a-campholene aldehyde 3 ±1%. In the absence of NO, nitroperoxy-group-containing substances were observed, arising from the reaction RO2 + NO2 -RO2NO2. A reaction mechanism is proposed and a tropospheric application of the results is discussed.
- Berndt, Torsten,Boege, Olaf
-
-
Read Online
- Development of the catalytic reactiVIty of an oxo-peroxo Mo(VI) Schiff base complex supported on supermagnetic nanoparticles as a reusable green nanocatalyst for selective epoxidation of olefins
-
A novel ancillary branch coated oxo-peroxo Mo(vi)tetradentate Schiff base complex on superparamagnetic nanoparticles was prepared and characterized by IR spectroscopy, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), diffuse reflectance spectra (DRS) and atomic absorption spectroscopy (AAS). The catalyst was used for the selective epoxidation of cyclooctene, cyclohexene, styrene, indene, α-pinene, 1-hepten, 1-octene, 1-dodecen and trans-stilben using tert-butyl hydroperoxide as an oxidant in 1,2-dichloroethane. This catalyst is efficient for the oxidation of cyclooctene, with a moderate 100% selectivity for epoxidation with 97% conversion in 30 min. We were able to separate the supermagnetic nanocatalyst by using an external magnetic field, and to use the catalyst at least five successive times without significant decrease in conversion. The proposed supermagnetic nanocatalyst has advantages in catalytic activity, selectivity, catalytic reaction time and reusability by easy separation.
- Bezaatpour, Abolfazl,Khatami, Sahar,Amiri, Mandana
-
-
Read Online
- Ultrasound and ionic liquid: An efficient combination to tune the mechanism of alkenes epoxidation
-
In this proof of concept study, the advantageous properties of both H 2O2/NaHCO3/imidazole/Mn(TPP)OAc oxidation system and MOPyrroNTf2 ionic liquid have been combined under ultrasonic irradiation to give an exceptionally favorable environment for Mn(TPP)OAc catalyzed olefin oxidations. The results reveal the crucial role played by the ultrasonic irradiations that influence drastically the oxidation process. In MOPyrroNTf2 and under ultrasonic irradiation, the mechanism probably involves an oxo-manganyl intermediate at the expense of the classical bicarbonate-activated peroxide route.
- Chatel, Gregory,Goux-Henry, Catherine,Kardos, Nathalie,Suptil, Joel,Andrioletti, Bruno,Draye, Micheline
-
-
Read Online
- Fast-synthesis and catalytic property of heterogeneous Co-MOF catalysts for the epoxidation of α-pinene with air
-
In the past decades, many methods have been developed for synthesizing MOFs, including solvothermal synthesis, mechanical synthesis, electrochemical synthesis, and microwave synthesis. Based on the existing research, a method is proposed for synthesizing Co-MOF by rapidly rotating hydrothermal crystallization, which largely shortens the crystallization time of Co-MOF. When the rotation speed was 150 rpm, only 2 h of crystallization time was needed to synthesize Co-MOF-150-2 with high crystallinity and stability. The optimal Co-MOF-150-2 manifested remarkable activity and selectivity for the epoxidation of α-pinene under mild conditions. The catalytic conversion of α-pinene reached the highest over the Co-MOF-150-2 catalyst, in which the conversion of α-pinene was 99.5% and the yield of 2,3-epoxypinane was 95.7%. The Co-MOF materials synthesized by the rotary method also had excellent stability and highly catalytic activity in recycling experiments. This journal is
- Zhang, Haifu,He, Jie,Lu, Xinhuan,Yang, Lu,Wang, Chenlong,Yue, Fanfan,Zhou, Dan,Xia, Qinghua
-
-
Read Online
- Nanohybrid Complexes with Molybdenyl Acetylacetonate, Schiff Base and Lacunary Keggin-Type Polyoxometalates: Synthesis and Catalytic Epoxidation of Olefins in the Presence of tert-Butyl Hydroperoxide
-
Abstract: Two new nanohybrid compounds as heterogenous catalyst were prepared by reaction of Lacunary Keggin-type polyoxometalate compounds ([SiW11O39]8? and [PW11O39]7?), molybdenyl acetylacetonate [MoO2(acac)2] and ethylenediamine (en), (1 and 2 respectively) species and characterized by elemental analysis and various routine techniques. The catalytic activities of these nanocatalysts examined for the epoxidation of linear, cyclic and phenyl-substituted olefins using tert-Butyl hydroperoxide (tert-BuOOH) as oxidants. The synergistic effect between molybdenyl acetylacetonate complex and lacunary Keggin-type polyoxometalate plays an important role in the promotion of catalytic activity. The catalysts were recovered and reused at least six times without obvious losing of activity and the yields for catalyst recovery are all above 91%. Graphical Abstract: [Figure not available: see fulltext.].
- Hosseinyzade, Samira S.,Zonoz, Farrokhzad M.,Bahramian, Bahram
-
-
Read Online
- Aerobic oxidation of Α-pinene catalyzed by homogeneous and MOF-based Mn catalysts
-
Manganese catalysts were investigated for the liquid-phase aerobic oxidation of α‐pinene. First, the influence of reaction parameters such as time, solvent, temperature, oxidant flow rate and catalyst concentration on conversion, yield and selectivity were evaluated using Mn(III) acetate as homogeneous catalyst. Mn(III) acetate afforded pinene oxide as the main product along with small amounts of verbenol and verbenone. The optimized reaction conditions were likewise applied to a novel mixed-linker metal-organic framework (MOF) based on MIL-53-NH2(Al), which was successfully synthesized and modified in a two-step post-synthetic reaction using maleic anhydride and Mn(III) acetate. The performance of the Mn-containing MOF catalyst was directly compared to its homogeneous counterpart Mn(III) acetate, showing very similar activity in a mixture of diethyl carbonate/dimethylformamide (DEC/DMF) as solvent. In both cases, a conversion of 31% and the formation of 17% pinene oxide (55% selectivity) were observed after 6 h. The heterogeneous MOF catalyst was easily removed from the reaction mixture by filtration and reused for at least five catalytic cycles without significant loss of activity. A hot filtration test showed that the catalysis mainly proceeded heterogeneously, although minor contributions of homogeneous species could not be completely excluded.
- Raupp, Yasmin S.,Yildiz, Ceylan,Kleist, Wolfgang,Meier, Michael A.R.
-
-
Read Online
- Organocatalyzed epoxidation of alkenes in continuous flow using a multi-jet oscillating disk reactor
-
The times are changing: A batch process, the Minisci epoxidation, is transformed into a continuous-flow protocol for the selective aerobic radical epoxidation of alkenes. The use of a novel reactor type allows to considerably shorten reactor residence times. Experimental results suggest that two different reaction mechanisms exist for the oxidation: one for the batch conditions and a different one for flow synthesis protocol. Copyright
- Spaccini, Raffaele,Liguori, Lucia,Punta, Carlo,Bj?rsvik, Hans-René
-
-
Read Online
- Synthesis and catalytic properties of titanium containing extra-large pore zeolite CIT-5
-
Titanium containing extra-large pore zeolite CIT-5 (IZA code: CFI) was successfully prepared by direct synthesis using Cab-O-Sil M5 and titanium(IV) butoxide in the presence of LiOH. N-Methylsparteinium hydroxide was used as a structure directing agent. The product crystallized into thin plate crystals with an approximate size of 20 × 5 × 0.2 μm. The lowest achieved Si/Ti ratio was 23. The necessary duration of hydrothermal synthesis increased with increasing concentration of Ti in the reaction mixture from 11 days (Si/Ti = 63 in product) to 17 days (Si/Ti = 36) at 155 C. Prepared Ti-CFI samples exhibit BET surface areas in the range of 308-346 m2/g and micropore volumes of 0.094-0.097 cm3/g. CFI possesses extra-large pores (14-ring, 7.2 × 7.5 A?) accessible for bulky molecules, therefore, Ti-CFI is a useful catalyst for epoxidation of double bonds in bulky molecules used in perfumery and pharmacy. The Ti-CFI samples proved to be catalytically active in epoxidation of 1-octene, cyclooctene, α-pinene, and norbornene with hydrogen peroxide as oxidation agent.
- P?ech, Jan,Kub?, Martin,?ejka, Ji?í
-
-
Read Online
- Biomimetic conversion of α-pinene with H2O2 to sobrerol over V2O5: Dihydroxylation by a peroxo vanadium peracid vectoring gentle synergistic oxidation
-
In this communication, we report the gentle preparation of sobrerol from dihydroxylation of α-pinene synergistically catalyzed by V2O5-H2O2 under benign conditions. It was proposed that a “peroxo vanadium acid”, VVO(OH)(OOH), was formed by HOO? insertion and proton transfer between V2O5 and H2O2. Theoretical DFT calculations that using the dimer?vanadium peracid as a model of the catalytically active species revealed that peroxo vanadium acid exhibited bifunctional catalytic capabilities resembling epoxidation of α-pinene by peracetic acid and then open-ring hydration with an acetic media.
- He, Huiting,Huang, Geng,Kirk, Steven Robert,Li, Hui,Liu, Jian,Liu, Qiang,Liu, Xianxiang,Mao, Liqiu,Su, Shengpei,Xu, Qiong,Yin, Dulin
-
-
Read Online
- Synthesis, characterization, crystal structure determination and catalytic activity in epoxidation reaction of two new oxidovanadium(IV) Schiff base complexes
-
The five coordinated vanadium(IV) Schiff base complexes of VOL1 (1) and VOL2 (2), HL1?=?2-{(E)-[2-bromoethyl)imino]methyl}-2- naphthol, HL2?=?2-{(E)-[2-chloroethyl)imino]methyl}-2- naphthol, have been synthesized and they were characterized by using single-crystal X-ray crystallography, elemental analysis (CHN) and FT-IR spectroscopy. Crystal structure determination of these complexes shows that the Schiff base ligands (L1 and L2) act as bidentate ligands with two phenolato oxygen atoms and two imine nitrogen atoms in the trans geometry. The coordination geometry around the vanadium(IV) is distorted square pyramidal in which vanadium(IV) is coordinated by two nitrogen and two oxygen atoms of two independent ligands in the basal plane and by one oxygen atom in the apical position. The catalytic activity of the Schiff base complexes of 1 and 2 in the epoxidation of alkenes were investigated using different reaction parameters such as solvent effect, oxidant, alkene/oxidant ratio and the catalyst amount. The results showed that in the presence of TBHP as oxidant in 1: 4 and 1:3 ratio of the cyclooctene/oxidant ratio, high epoxide yield was obtained for 1 (76%) and 2 (80%) with TON(= mole of substrate/mole of catalyst) of 27 and 28.5, respectively, in epoxidation of cyclooctene.
- Tahmasebi, Vida,Grivani, Gholamhossein,Bruno, Giuseppe
-
-
Read Online
- Immobilization of [MoO2(acac)2] on surface of hydroxyapatite nanoparticles: A heterogeneous and reusable catalyst for olefin epoxidation reactions
-
A new heterogeneous catalyst was prepared by grafting [MoO2(acac)2] on the hydroxyapatite (HAP) nanoparticle surfaces. The resulting catalyst, [MoO2(acac)]@HAP, was characterized by the powder X-ray diffraction, FT-IR spectroscopy, inductively coupled plasma/atomic emission spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray analysis, thermogravimetery analysis, and transmission electron microscopy techniques. The results obtained confirmed that the catalyst could be successfully used for the efficient epoxidation of olefins with tert-butyl hydrogen peroxide in 1,2-dichloroethane as the solvent. This heterogeneous catalyst could be reused for several times without a significant loss in its catalytic activity and with no significant reduction in the reaction yield. This novel material showed a great catalytic performance, and the reactions carried out using this catalyst showed a good-to-excellent yield, high purity of the desired products, and a short reaction time.
- Ghanbari Resketi, Farzane,Salehi, Samie,Bahramian, Bahram,Mirzaee, Mahdi
-
-
Read Online
- A convenient 3-step synthesis of (R)-7-hydroxycarvone from (S)-α-pinene
-
A convenient 3-step synthesis of (R)-7-hydroxycarvone (2) has been developed starting from (S)-α-pinene (7), using photooxygenation, oxidation, and fragmentation reactions. An improved synthesis of epoxy alcohol 6 and an unusual Ti(OiPr)4 catalyzed hydroxy epoxide to keto alcohol rearrangement are also described.
- Lakshmi, Rajamma,Bateman, T. David,McIntosh, Matthias C.
-
-
Read Online
- Cobalt imine–pyridine–carbonyl complex functionalized metal–organic frameworks as catalysts for alkene epoxidation
-
Aerobic epoxidation of alkene is a green and economical route to produce epoxides. For such reaction, transition metal complexes exhibit favorable catalytic activity. In this work, NH2-MIL-101, a stable metal–organic framework (MOF) material with large surface area and high pore volume, was functionalized with pyridine-2,6-dicarbaldehyde and Co(NO3)2, to realize the immobilization of Co(II) via imine–pyridine–carbonyl (N,N,O) tridentate ligands bonding to MOF skeleton. The modified materials were applied as heterogeneous catalysts for the aerobic epoxidation of cyclohexene at ambient temperature, and multiple factors were studied to explore their influences on catalytic effects. Under the optimal reaction conditions, satisfactory substrate conversion and epoxide selectivity were reached. In addition, this catalytic system is suitable for a variety of alkene substrates. Furthermore, recycle experiments and infrared spectroscopy characterization illustrated that the coordination surroundings of Co are altering smoothly during the reaction process, thus having?an impact on the performance of catalyst.
- Qin, Yutian,Wang, Bowei,Li, Jiayi,Wu, Xingchun,Chen, Ligong
-
-
Read Online
- A recyclable cobalt(iii)-ammonia complex catalyst for catalytic epoxidation of olefins with air as the oxidant
-
[Co(NH3)6]Cl3and other ammonia complexes with different external anions or metal ions were synthesized to catalyze the epoxidation of α-pinene. The synthesized complexes were characterized using XRD, SEM, TGA, FTIR and UV spectra. With air as the oxidant, [Co(NH3)6]Cl3exhibited excellent catalytic activity for the epoxidation of α-pinene among the prepared complexes. The conversion of α-pinene reached 97.4%, with 98.3% selectivity of epoxide when using a small amount of cumene hydroperoxide (CHP) as the initiator. The results revealed that a single Co(iii) system can also catalyze the epoxidation process in the absence of Co(ii), even showing better catalytic performance than single Co(ii). Recycling experiments showed that there was no significant drop in activity after 10 cycles, demonstrating that it is a stable and efficient heterogeneous catalyst for the epoxidation of α-pinene. The excellent recycling performance may be attributed to the stability of the coordination complex itself.
- Wang, Chenlong,Zhan, Hongju,Lu, Xinhuan,Jing, Run,Zhang, Haifu,Yang, Lu,Li, Xixi,Yue, Fanfan,Zhou, Dan,Xia, Qinghua
-
supporting information
p. 2147 - 2156
(2021/02/06)
-
- Anchoring of a terpyridine-based Mo(VI) complex on manganese ferrite as a recoverable catalyst for epoxidation of olefins under solvent-free conditions
-
A magnetically separable heterogeneous nanocatalyst was obtained by anchoring a terpyridine-based Mo(VI) complex on modified MnFe2O4 nanoparticles and characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD) and diffuse reflectance spectroscopies (DRS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), vibrating sample magnetometry (VSM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) analysis. The catalytic activity of the supported molybdenum based catalyst was evaluated in the selective epoxidation of various olefins (cyclooctene, limonene, 1-dodecane, 1-heptene, styrene, 1-indene, α-pinene, cyclohexene) with tert-butyl hydroperoxide (TBHP) as an oxidant under solvent-free conditions. This nanocatalyst was easily separated by using an external magnetic field and reused consecutively at least five times with no significant loss in selectivity and catalytic activity. The short reaction time, simple preparation, high conversion, good physicochemical stability and magnetic recycling of the catalysts are beneficial.
- Fadaei Sarabi, Mahsa,Bezaatpour, Abolfazl,Mahmoudi, Ali
-
p. 1597 - 1612
(2021/03/29)
-
- Sustainable catalytic epoxidation of biorenewable terpene feedstocks using H2O2as an oxidant in flow microreactors
-
Solvent-free continuous flow epoxidation of the alkene bonds of a range of biorenewable terpene substrates have been carried out using a recyclable tungsten-based polyoxometalate phase transfer catalyst and aqueous H2O2 as a benign oxidant. These sustainable flow epoxidation reactions are carried out in commercial microreactors containing static mixing channels that enable common monoterpenes (e.g. untreated crude sulfate turpentine, limonene, etc.) to be safely epoxidized in short reaction times and in good yields. These flow procedures are applicable for the flow epoxidation of trisubstituted and disubstituted alkenes for the safe production of multigram quantities of a wide range of epoxides. This journal is
- Bull, Steven D.,Cunningham, William B.,Plucinski, Pawel,Tibbetts, Joshua D.,Vezzoli, Massimiliano
-
supporting information
p. 5449 - 5455
(2021/08/16)
-
- Easy Epoxidation of Monoterpenes from Common Starting Materials
-
Epoxidation of monoterpenes, α-pinene, β-pinene, limonene, α-terpinene, and (R)-carvone was carried out by the in situ production of a peroxyacid rather than direct addition of such an expensive and difficult to handle chemical. Previous reports showed use of metal catalysts with high yields, while methodologies without catalysts at high temperature showed yields lower than 30%. The authors report a methodology that produces peroxyacetic acid in situ yielding up to 75% pure epoxide at room temperature avoiding the use of catalysts. The products were analyzed by gas chromatography mass spectrometry (GC-MS), and structures were characterized by 1H and 13C nuclear magnetic resonance (NMR).
- Benitez, Ricardo B.,Bermudez, John H.,Franco, Jaime M.,Rojas, Giovanni
-
p. 1086 - 1092
(2020/10/14)
-
- Sustainable catalytic protocols for the solvent free epoxidation and: Anti -dihydroxylation of the alkene bonds of biorenewable terpene feedstocks using H2O2 as oxidant
-
A tungsten-based polyoxometalate catalyst employing aqueous H2O2 as a benign oxidant has been used for the solvent free catalytic epoxidation of the trisubstituted alkene bonds of a wide range of biorenewable terpene substrates. This epoxidation protocol has been scaled up to produce limonene oxide, 3-carene oxide and α-pinene oxide on a multigram scale, with the catalyst being recycled three times to produce 3-carene oxide. Epoxidation of the less reactive disubstituted alkene bonds of terpene substrates could be achieved by carrying out catalytic epoxidation reactions at 50 °C. Methods have been developed that enable direct epoxidation of untreated crude sulfate turpentine to afford 3-carene oxide, α-pinene oxide and β-pinene oxide. Treatment of crude epoxide products (no work-up) with a heterogeneous acid catalyst (Amberlyst-15) results in clean epoxide hydrolysis to afford their corresponding terpene-anti-diols in good yields.
- Cunningham, William B.,Tibbetts, Joshua D.,Hutchby, Marc,Maltby, Katarzyna A.,Davidson, Matthew G.,Hintermair, Ulrich,Plucinski, Pawel,Bull, Steven D.
-
supporting information
p. 513 - 524
(2020/02/13)
-
- Selective Allylic Oxidation of Terpenic Olefins Using Co-Ag Supported on SiO2 as a Novel, Efficient, and Recyclable Catalyst
-
Co-Ag supported on the SiO2 catalyst was synthesized by the sol-gel method and characterized using XRD, FT-IR, TG-DTG, BET, CV, and SEM/EDX analysis. The catalytic performance of the resulting catalyst was examined by the oxidation of mono and sesquiterpenic olefins using hydrogen peroxide and tert-butyl peroxide as oxidant agents. Various parameters such as catalyst amount, temperature, and solvents have been studied. The Co-Ag supported on the SiO2 catalyst showed a high activity, selectivity, and recyclability for the selected oxidation reaction.
- Aberkouks, Abderrazak,Mekkaoui, Ayoub Abdelkader,Ait Ali, Mustapha,El Firdoussi, Larbi,El Houssame, Soufiane
-
-
- Modification of Cu2+ into Zr-based metal–organic framework (MOF) with carboxylic units as an efficient heterogeneous catalyst for aerobic epoxidation of olefins
-
A series of metal-organic framework (MOF) based catalysts for aerobic epoxidation were reported. A post-synthetic modification strategy using a solvothermal method enabled the incorporation of three different copper salts on a Zr-based MOF material UiO-66-(COOH)2; catalysts Cu@UiO-1, Cu@UiO-2 and Cu@UiO-3 were obtained. When analyzed by SEM and EDX, no impact of the post-synthetic modification on the core structure of the UiO-66-(COOH)2 framework was noticed. Studies showed Cu@UiO-1 to be the optimal catalyst for aerobic epoxidation thanks to its broad substrate scope, thermal stability, excellent recyclability. Observed catalytic properties are also better than those of previously reported copper catalysts.
- Zhao, Jian,Wang, Wenyu,Tang, Houliang,Ramella, Daniele,Luan, Yi
-
-
- High-yield synthesis and catalytic response of chainlike hybrid materials of the [(MoO3): M(2,2′-bipyridine)n] family
-
The one-dimensional organic-inorganic hybrid material [MoO3(2,2′-bipy)] (1) (2,2′-bipy = 2,2′-bipyridine) has been used as a starting material to prepare the bipy-deficient phases [Mo2O6(2,2′-bipy)] (2) and [Mo3O9(2,2′-bipy)2] (3) in excellent yields. The hybrid 2 was obtained by a solid-state thermal treatment of 1 (300 °C, 10 min) while 3 was obtained by a hydrothermal treatment of 1 (160 °C, 6 d). A study was performed to compare the catalytic properties of 1-3 in the epoxidation of cis-cyclooctene at 55 °C with tert-butylhydroperoxide (TBHP) or aqueous H2O2 as oxidant. In all cases Cy was converted to cyclooctene oxide (CyO) with 100% selectivity, and Cy conversions increased in the order 1 2O2 (cosolvent CH3CN). The catalytic reactions occurred in homogeneous phase with active species formed in situ from 1-3. All three hybrids react with aqueous H2O2 to give the catalytically active oxodiperoxo complex [MoO(O2)2(2,2′-bipy)]. The 2:1 hybrid 2 was further examined for the epoxidation of other cyclic and linear non-functionalised olefins with TBHP, namely cyclododecene, 1-octene and trans-2-octene, and the biomass-derived olefins dl-limonene, α-pinene and methyl oleate.
- Bruno, Sofia M.,Nogueira, Lucie S.,Gomes, Ana C.,Valente, Anabela A.,Gon?alves, Isabel S.,Pillinger, Martyn
-
p. 16483 - 16492
(2018/10/24)
-
- Production method for preparing 2,3-epoxypinane through epoxidizing alpha-pinene
-
The invention discloses a production method for preparing 2,3-epoxypinane through epoxidizing alpha-pinene. The production method of the 2,3-epoxypinane comprises the following steps: adding alpha-pinene, acetonitrile, acetone, urea, sodium bicarbonate and manganese sulfate into a reaction kettle according to a certain ratio, dropwise adding low concentration hydrogen peroxide at a certain temperature under a controlled dropwise adding speed while stirring, stirring and reacting above substances for a period of time, filtering out precipitates after the above reaction ends, carrying out extraction, and removing a solvent to obtain the 2,3-epoxypinane product. The synthesis production technology adopts the low concentration H2O (30%) as an oxygen source and adopts the acetonitrile, urea, acetone and sodium bicarbonate as a hydrogen peroxide stabilizer, so the safety risk and the production cost in traditional technologies are reduced, the yield and the purity of the product are high; and the method is simple to operate, is economic and practical, and is suitable for industrial production.
- -
-
Paragraph 0011
(2017/05/04)
-
- Activated vs. pyrolytic carbon as support matrix for chemical functionalization: Efficient heterogeneous non-heme Mn(II) catalysts for alkene oxidation with H2O2
-
Two types of heterogeneous catalytic materials, MnII-L3imid@Cox and MnII-L3imid@PCox, have been synthesized and compared by covalent grafting of a catalytically active [MnII-L3imid] complex on the surface of an oxidized activated carbon (Cox) and an oxidized pyrolytic carbon from recycled-tire char (PCox). Both hybrids are non-porous bearing graphitic layers intermixed with disordered sp2/sp3 carbon units. Raman spectra show that (ID/IG)activatedcarbon > (ID/IG)pyrolyticcarbon revealing that oxidized activated carbon(Cox) is less graphitized than oxidized pyrolytic carbon (PCox). The MnII-L3imid@Cox and MnII-L3imid@PCox catalysts were evaluated for alkene oxidation with H2O2 in the presence of CH3COONH4. Both showed high selectivity towards epoxides and comparing the achieved yields and TONs, they appear equivalent. However, MnII-L3imid@PCox catalyst is kinetically faster than the MnII-L3imid@Cox (accomplishing the catalytic runs in 1.5 h vs. 5 h). Thus, despite the similarity in TONs MnII-L3imid@PCox achieved extremely higher TOFs vs. MnII-L3imid@Cox. Intriguingly, in terms of recyclability, MnII-L3imid@Cox could be reused for a 2th run showing a ～20% loss of its catalytic activity, while MnII-L3imid@PCox practically no recyclable. This phenomenon is discussed in a mechanistic context; interlinking oxidative destruction of the Mn-complex with high TOFs for MnII-L3imid@PCox, while the low-TOFs of MnII-L3imid@Cox are preventive for the oxidative destruction of the Mn-complex.
- Simaioforidou,Papastergiou,Margellou,Petrakis,Louloudi
-
p. 516 - 525
(2016/12/16)
-
- Rhenium complex-catalyzed Meinwald rearrangement reactions of oxiranes
-
The Meinwald rearrangement reaction of oxiranes to the corresponding carbonyl compounds is efficiently catalyzed by the ReBr(CO)5 complex.
- Umeda, Rui,Muraki, Masahito,Nakamura, Yuudai,Tanaka, Tomoyuki,Kamiguchi, Kyohei,Nishiyama, Yutaka
-
supporting information
p. 2393 - 2395
(2017/05/29)
-
- Metallophthalocyanine intercalated layered double hydroxides as an efficient catalyst for the selective epoxidation of olefin with oxygen
-
Varied metallophthalocyanine intercalated layered double hydroxides (LDHs) as bifunctional hybrid catalysts for selective epoxidation have been prepared and characterized. Systematic characterizations suggested the successful intercalation of the metallophthalocyanines into the interlayer of ZnAl LDHs. The synthesized hybrid exhibited excellent catalytic activity in the selective epoxidation of various olefins through O2/isobutaldehyde system. The basicity of the hybrid benefits to the selectivity of epoxide, and the bifunctional roles of the catalyst in the reaction have been discussed and verified by a series of controlled experiments. On the basis of obtained results, a probable mechanism of the epoxidation by the hybrid has been proposed and detailedly investigated. Under the catalysis of metallophthalocyanines intercalated LDHs in the presence of O2/isobutaldehyde, the production of epoxide undergoes two reaction paths. And two types of intermediates, namely acylperoxy radical and peroxyacid, are formed in the reaction, and the former is predominant.
- Zhou, Weiyou,Zhou, Jiacheng,Chen, Yong,Cui, Aijun,Sun, Fu'an,He, Mingyang,Xu, Zhixiang,Chen, Qun
-
p. 191 - 200
(2017/06/09)
-
- Preparation method of carvone
-
The invention relates to a preparation method of carvone. The carvone is prepared by using easily-obtained alpha-pinene as a raw material and performing three-step reaction of epoxidation- isomerism-oxidization. The epoxidation- isomerism reaction can be carried out continuously; after finishing the epoxidation reaction, ligand, free radical initiator and transition metal additive are added to perform isomerism reaction and generate carvone; furthermore, the carvone is prepared through oxidization reaction. The method is simple in process, easy to obtain pinene raw material; the method avoids the shortcomings of low yield, poor selectivity, difficult separation, and massive hardly-disposed waste water of a traditional process, and is applicable to the industrial production.
- -
-
Paragraph 0060; 0061; 0065; 0068; 0071; 0074; 0077
(2017/08/31)
-
- Zeolite Y encaged Ru(III) and Fe(III) complexes for oxidation of styrene, cyclohexene, limonene, and α-pinene: An eye-catching impact of H2SO4 on product selectivity
-
A novel Ru(III) and Fe(III) complexes of ligands 1 and/or 2 {where 1 = 2,2'-((1E,1'E)-((azanediylbis(ethane-2,1-diyl))bis(azanylylidene))bis(methanylylidene))diphenol and 2 = 2,2'-((1E,1'E)-((azanediylbis(ethane-2,1-diyl))bis(azanylylidene))bis(methanylylidene)) bis(4-nitrophenol)} have been synthesized as ‘neat’ and zeolite Y encapsulated complexes. These catalysts are characterized by various analytical tools such as FTIR, UV–vis, elemental analysis, ICP-AES, molar conductivity, 1H- and 13C NMR, TGA, SEM, AAS, BET, magnetic susceptibility and powder XRD to endorse the complex formation, absence of peripheral redundant ligands and complexes, conservation of zeolite Y morphology and crystallinity, and the encapsulation of complexes without devastation in the zeolite Y framework. Out of these synthesized catalysts, 5Y is found to be a potent candidate for styrene (Conv. 76.1%, TOF: 2130 h?1), cyclohexene (Conv. 84.4%, TOF: 2351 h?1), limonene (Conv. 81.6%, TOF: 2273 h?1), and α-pinene (Conv. 72.6%, TOF: 2023 h?1) oxidation with high selectivity of respective allylic products excluding the styrene oxidation, which undergoes epoxidation only. The addition of H2SO4 in an identical reaction catalyzed by 5Y not only surge the conversion up to 100% in a short time span with high TOF but also increase the selectivity of respective epoxidation products. This switchover in the selectivities could be credited to the presence of H2SO4 that facilitates the heterolytic [sbnd]O[sbnd]O[sbnd] bond cleavage of metal hydroperoxide and stimulates the epoxidation over allylic oxidation. Furthermore, the results establish that the heterogeneous systems are effortlessly recovered and reused without ample drop in the activity and selectivity.
- Godhani, Dinesh R.,Nakum, Haresh D.,Parmar, Digvijaysinh K.,Mehta, Jignasu P.,Desai, Nisheeth C.
-
p. 223 - 237
(2016/12/09)
-
- Catalytic Activity of Crystallographically Characterized Organic–Inorganic Hybrid Containing 1,5-Di-amino-pentane Tetrachloro Manganate with Perovskite Type Structure
-
Abstract: Layered 2D organic–inorganic hybrid perovskite (OIHS) of the diammonium series, 1,5 di-aminepentane tetrachloro mangenate ([NH3–(CH2)5–NH3] MnCl4) was prepared by slow evaporation and reducing temperature method and characterized by single crystal X-ray diffraction analysis. Its structure consists of organic cation, [NH3(CH2)5NH3]+2 extended in a zigzag fashion and inorganic anion, [MnCl6]?2 where Mn2+ is coordinated by six Cl? ion in octahedral fashion. The organic and inorganic segments are alternately stacked along c-axis where inorganic layer is extended through corner-shared octahedra sandwiched by the di-aminopentane molecules. The layers (organic and inorganic) were connected to each other through N–HCl hydrogen bonds and van-der Waals interaction to build cation–anion–cation cohesion. The hybrid crystal had orthorhombic non-centrosymetric system having I212121 space group with unit cell parameters a = 7.1742(3) ?, b = 7.3817(3) ?, c = 23.9650(10) ?, V = 1269.13 ?3 and Z = 4. The hybrid exhibited excellent catalytic activity towards sulphide and alkene oxidation using aqueous H2O2 as an oxidant. Graphical Abstract: OIHS of the diammonium series [NH3–(CH2)5–NH3] MnCl4; 1,5 di-aminepentane tetrachloro mangenate were prepared by slow evaporation and temperature decrease method, characterized by single crystal X-ray diffraction. This complex exhibits excellent catalytic activity towards sulphide oxidation and alkene oxidation using aqueous H2O2 as an oxidant. [Figure not available: see fulltext.].
- Mondal, Paramita,Abdel-Aal, Seham Kamal,Das, Debasis,Islam, Sk Manirul
-
p. 2332 - 2339
(2017/08/22)
-
- Superparamagnetic Core–Shell Metal–Organic Framework Fe3O4/Cu3(btc)2 Microspheres and Their Catalytic Activity in the Aerobic Oxidation of Alcohols and Olefins
-
Core–shell structured Fe3O4/Cu3(btc)2 (btc = 1,3,5-benzenetricarboxylate) microspheres have been successfully synthesized by coating the metal–organic frameworks on poly(acrylic acid) (PAA) functionalized Fe3O4 microspheres by the layer-by-layer assembly method. The MOF composite exhibited excellent catalytic activity in the aerobic oxidation of alcohols and the epoxidation of olefins due to the porosity of MOFs and large amount of readily accessible Cu2+. Furthermore, the catalyst could be easily segregated from the catalytic system by using an external magnetic field due to its magnetic properties. The heterogeneous catalyst displayed good reusability and broad reagent scope in the aerobic oxidation of alcohols and epoxidation of olefins.
- Li, Jie,Gao, Hongyi,Tan, Li,Luan, Yi,Yang, Mu
-
p. 4906 - 4912
(2016/10/26)
-
- A heteropoly acid hyamines catalytic olefin epoxidation method
-
The invention provides a method utilizing quaternary ammonium heteropolyate to catalyze alkene epoxidation. Alkene and an oxidant carry out reactions in the presence of a quaternary ammonium heteropolyate catalyst, a reductive auxiliary agent, and an organic solvent for 2 to 10 hours at a temperature of 50 to 80 DEG C. After the reaction, the precipitated catalyst can be separated and recycled, and the reaction liquid is subjected to a steaming treatment so as to obtain the target epoxides. The method has the advantages of simple technology, mild conditions, green, and environment-friendliness, and has a vast industrial application prospect, and moreover, the catalyst is easy to separate, recycle and reutilize.
- -
-
Paragraph 0026; 0027; 0028; 0029
(2017/03/14)
-
- Optimization of the lipase mediated epoxidation of monoterpenes using the design of experiments—Taguchi method
-
This work deals with the optimization of the Candida antartica lipase B (CALB) mediated epoxidation of monoterpenes by using the design of experiments (DoE) working with the Taguchi Method. Epoxides are essential organic intermediates that find various industrial applications making the epoxidation one of the most investigated processes in chemical industry. As many as 8 parameters such as the reaction medium, carboxylic acid type, carboxylic acid concentration, temperature, monoterpene type, monoterpene concentration, hydrogen peroxide concentration and amount of lipase were optimized using as less as 18 runs in triplicates (54 runs). As a result, the hydrogen peroxide concentration used was found to be the most influential parameter of this process while the type of monoterpene was least influential. Scaling up of the reaction conditions according to the findings of the optimization achieved full conversion in less than 6?h. In addition, a purification process for the epoxides was developed leading to an isolated yield of ca. 72.3%, 88.8% and 62.5% for α-pinene, 3-carene and limonene, respectively.
- Ranganathan, Sumanth,Tebbe, Johannes,Wiemann, Lars O.,Sieber, Volker
-
p. 1479 - 1485
(2016/10/03)
-
- Co(ii) complexes loaded into metal-organic frameworks as efficient heterogeneous catalysts for aerobic epoxidation of olefins
-
A series of efficient cobalt(ii)-anchored Cr-MOF (Cr-MIL-101-NH2) catalysts, such as Co(ii)@Cr-MIL-101-Sal, Co(ii)@Cr-MIL-101-P2I and Co(ii)@Cr-MIL-101-P3I, have been successfully synthesized by one-pot modification of the terminal amino group with salicylaldehyde, pyridine-2-aldehyde or pyridine-3-aldehyde and anchoring of Co(ii) ions into the mesoporous Cr-MOF supports. The Co(ii)@Cr-MIL-101-P2I catalyst exhibited high catalytic performance for epoxidation of olefins with air as an oxidant due to the nitrogen atom in the pyridine ring as a strong electron-withdrawing substituent, high dispersion of Co(ii) species and high surface area for sufficient contact between the substrate and active sites. The strong coordination interaction between the Co(ii) ions and chelating groups in the Co(ii)@Cr-MIL-101-P2I catalyst guaranteed the excellent recycling performance. Furthermore, the synthesized Co(ii)@Cr-MIL-101-P2I catalyst realized its general applicability towards various olefins, such as cyclic olefins, tri-substituted olefins, aliphatic olefins and aromatic olefins.
- Wang, Jingjing,Yang, Mu,Dong, Wenjun,Jin, Zhaokui,Tang, Jia,Fan, Shuang,Lu, Yunfeng,Wang, Ge
-
p. 161 - 168
(2015/12/31)
-
- Mn-Schiff base modified MCM-41, SBA-15 and CMK-3 NMs as single-site heterogeneous catalysts: Alkene epoxidation with H2O2 incorporation
-
The development of new functional catalytic materials prepared via appropriate chemical modification of mesoporous silica SBA-15, MCM-41 or carbon nanomaterials CMK-3, are presented. Their synthesis has been carried out via two synthetic approaches: (a) a two steps procedure which includes grafting of the Schiff base ligand 1,3-bis[3-aza-3-(1-methyl-3-oxobut-1-enyl)-prop-3-en-1-yl]-2-(4-hydroxy-phenyl)-1,3-imidazolidine (L) onto the suppors and subsequent metalation of the so-formed hybrid material, and (b) an one step procedure which allows covalent grafting of the entire [MnII-Schiff base] catalyst onto the carbonaceous support. The resulting single-site heterogeneous catalysts were characterized and evaluated for alkene epoxidation with H2O2 in the presence of CH3COONH4 as additive. They are efficient and selective towards formation of epoxides. The highest TONs have been achieved by L@MCM-41-MnII and MnII-L@CMK-3. Moreover, MnII-L@CMK-3 is operative for a second use and kinetically very fast, demonstrating remarkably high TOFs 65-634 h-1 that is correlated to its practically zero porosity. Based on the present data, the textural features of the obtained catalysts are discussed in correlation with their catalytic performance.
- Mavrogiorgou,Baikousi,Costas,Mouzourakis,Deligiannakis,Karakassides,Louloudi
-
-
- Indium(III) Chloride Promoted Highly Efficient Tandem Rearrangement-α-Addition Strategy towards the Synthesis of α-Hydroxyamides
-
A new tandem process is reported that provides access to α-hydroxyamides from epoxides for the first time. Herein, we explore InCl3-mediated tandem rearrangement of epoxides to aldehydes and α-addition of TosMIC to in situ derived aldehydes. An unprecedented C-C bond-forming reaction is disclosed that features mild conditions, high yields, and shorter reaction times.
- Lingaswamy, Kadari,Mohan, Dumpala,Krishna, Palakodety Radha,Prapurna, Y. Lakshmi
-
supporting information
p. 1693 - 1698
(2016/07/06)
-
- Facile access to α-acyloxyamides via epoxide rearrangement/three-component domino reaction catalyzed by indium(III) chloride
-
A simple and efficient Passerini reaction of epoxides involving highly regioselective rearrangement of epoxide to aldehyde/three-component Passerini reaction catalyzed by indium(III) chloride is described. In the present protocol, epoxides served as wonderful substrates to furnish a library of α-acyloxyamides under mild reaction conditions in shorter reaction times and in good yields.
- Lingaswamy, Kadari,Krishna, Palakodety Radha,Prapurna, Y. Lakshmi
-
supporting information
p. 1275 - 1282
(2016/08/16)
-
- Enhanced aqueous oxidation activity and durability of simple manganese(III) salen complex axially anchored to maghemite nanoparticles
-
Simple Mn-salen complex was anchored coordinatively to γ-Fe2O3 nanoparticles through amine functionality which provide a new magnetically recoverable nanocatalyst with high oxidation activity and stability. Catalyst characterization was performed using FT-IR, UV-Vis, XRD, EDS, TGA and ICP-AES. TEM image revealed a quasi-spherical structure with size smaller than 20 nm for nanocatalyst. A thermal stability up to around 300 °C was verified for prepared nanocatalyst based on thermogravimetric analysis. Finally, the catalytic performance of magnetically recoverable Mn-catalyst was exploited in the green oxidation of different types of functional groups including olefins, alcohols, saturated hydrocarbons and sulfur containing compounds with n-Bu4NHSO5 (TBAOX) in water under heterogeneous conditions. The salen catalyst proved to be reusable for at least eight times and the oxidant's by-product (n-Bu4NHSO4) could also be recycled.
- Rezaeifard, Abdolreza,Jafarpour, Maasoumeh,Farrokhi, Alireza,Parvin, Sousan,Feizpour, Fahimeh
-
p. 64640 - 64650
(2016/07/21)
-
- Use of α-pinene preparation of 2,3- epoxy pinane method
-
The invention provides a method employing a-pinene to prepare 2,3-epoxy pinane; the method comprises the following steps: 1, preparing reaction solution; 2, droping peroxyacetic acid with concentration at 18% under stirring condition to the reaction solution for reaction, and the temperature of the reaction liquid is controlled to be under 20 DEG C; 3, carrying out pumping filtration to reaction products of the step 2 so as to obtain filter liquid and filter cake; 4, adding 200mL water to clean the filter cake, collecting filter liquid standing and layering the filter liquid, and isolating a water layer from an organic layer; 5, using saturation sodium chloride solution and saturation sodium hyposulfite solution to clean the organic layer for once in order, using the saturation sodium chloride solution to clean the organic layer to a middle layer, using waterless sodium sulfate to dry, and evaporating solvent in normal temperature to obtain the product. The method improves yield of the 2,3-epoxy pinane, reduces production cost, and simultaneously removes the danger of employing high density peroxyacetic acid to cause explosion.
- -
-
Paragraph 0024-0026
(2017/03/08)
-
- Biologically Inspired and Magnetically Recoverable Copper Porphyrinic Catalysts: A Greener Approach for Oxidation of Hydrocarbons with Molecular Oxygen
-
An efficient synthetic method for magnetically recoverable hybrid copper porphyrinic nanomaterials is reported. These functionalized magnetic materials prove to be efficient bioinspired oxidation catalysts of olefins and thiols, using molecular oxygen as oxidant, in total absence of reductants and solvents, with the highest TON (turnover number) yet achieved for this reaction (≈200 000). A comparative study between homogeneous and heterogeneous oxidation of cyclohexene is discussed, revealing the heterogeneous system to be the most promising concerning stability and reusability of the catalysts. The full characterization of the magnetic hybrid porphyrinic nanomaterials, by transmission electron microscopy, flame atomic absorption spectrometry, thermogravimetry, N2 sorption, and infrared spectroscopy, is also described.
- Henriques, César A.,Fernandes, Auguste,Rossi, Liane M.,Ribeiro, M. Filipa,Calvete, Mário J. F.,Pereira, Mariette M.
-
p. 3359 - 3368
(2016/06/06)
-
- Cis-Dioxomolybdenum(VI) complexes with unsymmetric linear tetradentate ligands: Syntheses, structures and bromoperoxidase activities
-
Reactions of [MoO2(acetylacetonate)2], 2-((2-(2-hydroxyethylamino)ethylamino)methyl)-4-R-phenols (H2Ln, n = 1-5 for R = H, Me, OMe, Cl and Br, respectively) and KOH in 1:1:2 mole ratio in methanol afford a series of complexes having the general formula cis-[MoO2(Ln)] (1, 2, 3, 4, 5) in 81-86% yields. The complexes have been characterized using elemental analysis, spectroscopy (infrared, UV-visible, and 1H NMR, 13C NMR and 13C-DEPT NMR) and electrochemical measurements. The molecular structures of 1, 2, 3, 4 have been determined using single-crystal X-ray crystallography. In each of 1, 2, 3, 4, the ONNO-donor 6,5,5-membered fused chelate rings forming (Ln)2- and the two mutually cis oxo groups assemble a distorted octahedral N2O4 coordination sphere around the metal centre. In the crystal lattice, each of 1, 2, 3, 4 forms a one-dimensional infinite chain structure via intermolecular N-H...O hydrogen bonding interactions. In cyclic voltammograms, the diamagnetic complexes display an irreversible metal-centred reduction in the potential range -0.73 to -0.88 V (vs Ag/AgCl). The physicochemical data are consistent with a very similar gross molecular structure for all of 1, 2, 3, 4, 5. All the complexes exhibit decent bromoperoxidase activities and are also able to effectively catalyse benzoin and methyl(phenyl)sulfide oxidation reactions.
- Kurapati, Sathish Kumar,Pal, Samudranil
-
p. 116 - 124
(2016/02/18)
-
- Nanoscaled copper metal-organic framework (MOF) based on carboxylate ligands as an efficient heterogeneous catalyst for aerobic epoxidation of olefins and oxidation of benzylic and allylic alcohols
-
Aerobic epoxidation of olefins at a mild reaction temperature has been carried out by using nanomorphology of [Cu3(BTC)2 ] (BTC = 1,3,5-benzenetricarboxylate) as a high-performance catalyst through a simple synthetic strategy. An aromatic carboxylate ligand was employed to furnish a heterogeneous copper catalyst and also serves as the ligand for enhanced catalytic activities in the catalytic reaction. The utilization of a copper metal-organic framework catalyst was further extended to the aerobic oxidation of aromatic alcohols. The shape and size selectivity of the catalyst in olefin epoxidation and alcohol oxidation was investigated. Furthermore, the as-synthesized copper catalyst can be easily recovered and reused several times without leaching of active species or significant loss of activity.
- Qi, Yue,Luan, Yi,Yu, Jie,Peng, Xiong,Wang, Ge
-
p. 1589 - 1597
(2015/01/30)
-
- Schiff base-functionalized boehmite nanoparticle-supported molybdenum and vanadium complexes: Efficient catalysts for the epoxidation of alkenes
-
Boehmite nanoparticles were prepared using aluminium 2-butoxide. They were covalently functionalized with 3-(trimethoxysilyl)propylamine, after which all the terminal amine groups were changed to Schiff base by refluxing with salicylaldehyde in order to support vanadium oxosulfate and molybdenum hexacarbonyl complexes. These catalysts were applied in the epoxidation of olefins with tert-BuOOH in CCl4. The catalytic procedures for both catalysts were optimized for various parameters such as solvent, oxidant, temperature and time.
- Mirzaee, Mahdi,Bahramian, Bahram,Amoli, Adonis
-
p. 593 - 600
(2015/09/01)
-
- Synthesis, characterization, magnetic and catalytic properties of a ladder-shaped MnII coordination polymer
-
[Mn(LH)(H2O)]n {1, where LH2- is the dianion of N-(4-carboxybenzyl)iminodiacetic acid} has been synthesized and its crystal structure has been determined. The crystal of 1 is built from 1D polymeric ladder-shaped chains that extend to a 3D supramolecular architecture through H-bonds. The compound was characterized with spectroscopic and physicochemical techniques. Variable-temperature magnetic data suggest that there are weak antiferromagnetic interactions. Compound 1 has been evaluated as a heterogeneous oxidation catalyst. It catalyzes alkene epoxidation selectively in relatively high yields.
- Lymperopoulou, Smaragda,Papastergiou, Maria,Louloudi, Maria,Raptopoulou, Catherine P.,Psycharis, Vassilis,Milios, Constantinos J.,Plakatouras, John C.
-
p. 3638 - 3644
(2015/05/05)
-
- Spectroscopic, calorimetric, and catalytic evidences of hydrophobicity on Ti-MCM-41 silylated materials for olefin epoxidations
-
Hydrophobic Ti-MCM-41 samples prepared by post-synthesis silylation treatment demonstrate to be highly active and selective catalysts in olefins epoxidation by using organic hydroperoxides as oxidizing agents in liquid phase reaction systems. Epoxide yields show important enhancements with increased silylation degrees of the Ti-mesoporous samples. Catalytic studies are combined and correlated with spectroscopic techniques (e.g. XRD, XANES, UV-Visible, 29Si MAS-NMR) and calorimetric measurements to better understand the changes in the surface chemistry of Ti-MCM-41 samples due to the post-synthesis silylation treatment and to ascertain the role of these trimethylsilyl groups incorporated in olefin epoxidation. In such manner, the effect of the organic moieties on solids, and both water and glycol molecules contents on the catalytic activity and selectivity are analyzed in detail. Results show that the hydrophobicity level of the samples is responsible for the decrease in water adsorption and, consequently, the negligible formation of the non-desired glycol during the catalytic process. Thus, catalyst deactivation by glycol poisoning of Ti active sites is greatly diminished, this increasing catalyst stability and leading to practically quantitative production of the corresponding epoxide. The extended use of these hydrophobic Ti-MCM-41 catalysts together with organic hydroperoxides for the highly efficient and selective epoxidation of natural terpenes is also exemplified.
- Silvestre-Alberó, Joaquín,Domine, Marcelo E.,Jordá, José L.,Navarro, María T.,Rey, Fernando,Rodríguez-Reinoso, Francisco,Corma, Avelino
-
-
- An ionic liquid immobilized copper complex for catalytic epoxidation
-
This article brings into focus an in situ strategy of immobilization of a copper complex onto an ionic liquid support. A practical method of olefin and terpene epoxidation by immobilizing a copper complex and 1-ethyl-3-methylimidazolium hexafluorophosphate and using H2O2 as the terminal oxidant is developed. The advantageous properties of this catalytic system redefine an exceptionally clean environment for catalytic epoxidations.
- Dileep,Rudresha
-
p. 65870 - 65873
(2015/08/18)
-
- Selectively catalytic epoxidation of α-pinene with dry air over the composite catalysts of Co-MOR(L) with Schiff-base ligands
-
Twelve bi-/tridentate Schiff-base ligands (L1-L12) have been designed, synthesized and coordinated with ion-exchanged Co-MOR (Mordenite) forming a series of Co-MOR(L) composite catalysts, for which various analyzes and characterizations are conducted. Selectively catalytic epoxidation of α-pinene with dry air over Co-MOR(L) catalysts has been carried out, where uses TBHP in small amounts as the initiator. Among these Co-MOR(L) catalysts, Co-MOR(L8) exhibits the best activity for the titled reaction to obtain 85.8 mol% conversion and 90.8% selectivity of epoxide. Some factors such as the structure of ligands, the oxidants, the solvents, the catalyst amount, the reaction temperature and time play important roles in controlling the epoxidation. The recyclable stability of the Co-MOR(L8) catalyst is confirmed. The studies on the electrochemical behaviors of Co species in Co-MOR(L8) reveal the importance of reversible change between Co oxidation states for the epoxidation.
- Lu,Lei,Wei,Ma,Zhang,Hu,Zhou,Xia
-
-
- Infrared Matrix Isolation and Theoretical Studies of Reactions of Ozone with Bicyclic Alkenes: α-Pinene, Norbornene, and Norbornadiene
-
The reactions of ozone with three bicyclic alkenes, α-pinene, norbornene, and norbornadiene, were studied by low-temperature (14 K), argon matrix isolation infrared spectroscopy including 18O isotope-labeling studies. Theoretical calculations of some of the proposed reaction intermediates and products were carried out using the Gaussian 09 suite of programs, applying density functional theory (DFT), the B3LYP functional, and the 6-311G++(d,2p) basis set. In the α-pinene/ozone system, the thermal reaction between α-pinene and ozone was too slow to observe under the twin-jet or merged-jet deposition conditions of these experiments. However, red light (λ ≥ 600 nm) irradiation of the argon matrixes containing α-pinene and ozone caused new infrared peaks to appear that could be readily assigned to reaction products of α-pinene with O(3P) resulting from ozone photolysis: α-pinene oxide (with an epoxide ring) and two isomeric ketones. Norbornene and norbornadiene were both found to react with ozone in the gas phase during twin-jet or merged-jet deposition of these mixtures with argon. New peaks observed in the infrared spectra were assigned to the primary ozonides, Criegee intermediates, and secondary ozonides of norbornene and norbornadiene, indicating that the bulk of these reactions proceeded via the "classic" Criegee mechanism for ozonolysis of alkenes. Calculated infrared frequencies and molecular energies support these conclusions. Ultraviolet irradiation of these mixtures resulted in complete decomposition of the early intermediates and the formation of acids, aldehydes, alcohols, carbon dioxide, and carbon monoxide. In any case, no evidence for "unusual" chemistry, prompted by the bicyclic nature of the reactants, was observed. (Figure Presented).
- Kugel, Roger W.,Ault, Bruce S.
-
p. 312 - 322
(2015/04/22)
-
- Biomass toward fine chemical products: Oxidation of α-pinene over sieves nanostructured modified with vanadium
-
Vanadium-containing molecular sieves (V-M(x)) were synthetized and applied as heterogeneous catalysts for the liquid phase oxidation of α-pinene with hydrogen peroxide at 70°C. It has been found that the vanadium content in V-M(x) materials affected the conversion of α-pinene and product distribution. The turnover numbers increased strongly with the decreasing of V content probably caused by a high V dispersion. The major products were verbenone, trans-sobrerol and campholenic aldehyde. The acid-base properties of V-M(x) affected the distribution of products formed via the isomerization of α-pinene oxide over Lewis acid sites to campholenic aldehyde while Br?nsted acid sites brought about the formation of 1,2 pinanediol and trans-sobrerol by hydrolysis and by the opening of oxirane ring. The increase in V content in V-M(x) led to the increase in campholenic aldehyde, 1,2 pinanediol, trans- sobrerol and over oxidation products. Moreover, the effect of several solvents on the reaction oxidation was studied. The results showed that the highest α-pinene conversions are obtained in the following order: acetonitrile > ethanol > isoamyl alcohol > methyl ethyl ketone. Thus, using aprotic solvents, the catalytic activity was increased and the formation of alkyl glycol ethers as by-product was not observed.
- Cánepa, Analía L.,Chanquía, Corina M.,Vaschetti, Virginia M.,Eimer, Griselda A.,Casuscelli, Sandra G.
-
-
- Synthesis, Characterization, Magnetic and Catalytic Properties of a Ladder-Shaped MnII Coordination Polymer
-
[Mn(LH)(H2O)]n {1, where LH2- is the dianion of N-(4-carboxybenzyl)iminodiacetic acid} has been synthesized and its crystal structure has been determined. The crystal of 1 is built from 1D polymeric ladder-shaped chains that extend to a 3D supramolecular architecture through H-bonds. The compound was characterized with spectroscopic and physicochemical techniques. Variable-temperature magnetic data suggest that there are weak antiferromagnetic interactions. Compound 1 has been evaluated as a heterogeneous oxidation catalyst. It catalyzes alkene epoxidation selectively in relatively high yields.
- Lymperopoulou, Smaragda,Papastergiou, Maria,Louloudi, Maria,Raptopoulou, Catherine P.,Psycharis, Vassilis,Milios, Constantinos J.,Plakatouras, John C.
-
p. 3638 - 3644
(2015/04/27)
-
- Co2+-exchanged MOR and 5A zeolites as efficient solid catalysts for the epoxidation of styrene with air
-
Selective oxidation of alkenes with air to corresponding epoxides was performed over simple ion-exchanged Co-MOR and Co-5A. Among all transition metal ions-exchanged M-zeolites, both Co-MOR and Co-5A exhibited the highest activity at 363 K. Notably, for the epoxidation of styrene, α-pinene, α-methyl styrene and cyclooctene, Co-MOR obtained higher conversions than Co-5A, in agreement with the difference of pore sizes of both zeolitic materials. Recycling and control tests showed high durability of Co-MOR as a heterogeneous catalyst in our catalytic system.
- Zhou,Tang,Lu,Wei,Li,Xia
-
p. 124 - 128
(2014/01/06)
-
- Eco-friendly solvents and amphiphilic catalytic polyoxometalate nanoparticles: A winning combination for olefin epoxidation
-
Eighteen eco-friendly solvents were examined to carry out the epoxidation of olefins with the amphiphilic catalytic dodecyltrimethylammonium polyoxometalate nanoparticles [C12]3[PW12O 40] in comparison with [H]3[PW12O40] and [Na]3[PW12O40]. Surprisingly, the screening of solvents with cyclooctene has revealed that the [C 12]3[PW12O40] catalyst is much more active with initial turn-over frequencies, TOF0, increasing up to a factor of 10. Moreover, the reaction occurs at competitive rates in four relevant solvents, i.e. cyclopentyl methyl ether, 2-methyl tetrahydrofuran, methyl acetate and glycerol triacetate, for which TOF0 values are higher than 260 h-1. The recyclability of the systems is demonstrated and the scope of substrates has been successfully extended to cyclohexene, 1-octene, limonene, 3-carene, α-pinene, β-pinene and neryl acetate with good epoxide selectivity. The catalytic performances in the "green" solvent are assigned to the formation of stable [C 12]3[PW12O40] nanoparticle dispersions which have been characterized by transmission electron microscopy and dynamic and multiple light scattering experiments. Finally, the Kamlet-Taft parameters were measured in order to correlate the physicochemical properties of the solvents and the catalytic activity.
- Mouret, Adrien,Leclercq, Loic,Muehlbauer, Andrea,Nardello-Rataj, Veronique
-
p. 269 - 278
(2014/01/06)
-
