- Size selectivity of a copper metal-organic framework and origin of catalytic activity in epoxide alcoholysis
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{(Cu(bpy)(H2O)2(BF4)2(bpy)} (Cu-MOF; MOF = metal-organic framework; bpy = 4,4'-bipyridine), with a 3D-interpenetrated structure and saturated Cu coordination sites in the framework, possesses unexpectedly high a
- Jiang, Dongmei,Urakawa, Atsushi,Yulikov, Maxim,Mallat, Tamas,Jeschke, Gunnar,Baiker, Alfons
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- Lanthanide-polyphosphonate coordination polymers combining catalytic and photoluminescence properties
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A rapid, mild and high-yield microwave synthesis of 1D isotypical [Ln(H4bmt)(H5bmt)(H2O)2] ·3H2O coordination polymers is presented. The La 3+-based material is highly active as a heterogen
- Vilela, Sergio M. F.,Firmino, Ana D. G.,Mendes, Ricardo F.,Fernandes, Jose A.,Ananias, Duarte,Valente, Anabela A.,Ott, Holger,Carlos, Luis D.,Rocha, Joao,Tome, Joao P. C.,Almeida Paz, Filipe A.
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- Cr-MIL-101 encapsulated Keggin phosphotungstic acid as active nanomaterial for catalysing the alcoholysis of styrene oxide
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Mesoporous chromium-based terephthalate metal-organic framework (MIL-101) encapsulated Keggin phosphotungstic acid (HPW) [MIL-101(HPW)] was demonstrated to be an active heterogeneous catalyst for selective catalysis of the ring opening reaction of styrene
- Wee, Lik H.,Bonino, Francesca,Lamberti, Carlo,Bordiga, Silvia,Martens, Johan A.
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- Multifunctionality and cytotoxicity of a layered coordination polymer
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This work reports the synthesis and multifunctionality of 2D layered coordination polymers formulated as [Ln2(H3nmp)2]·xH2O (1, where Ln = Sm3+, Eu3+, Tb3+, Dy3+, Hos
- Almeida Paz, Filipe A.,Ananias, Duarte,Borges, Fernanda,Fernandes, Carlos,Gomes, Ana C.,Mendes, Ricardo F.,Remia?, Fernando,Silva, Patrícia,Valente, Anabela A.
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- Sulfur and iron co-doped titanoniobate nanosheets: A novel efficient solid acid catalyst for alcoholysis of styrene epoxide at room temperature
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Sulfur and iron co-doped titanoniobate nanosheets were prepared and evaluated in alcoholysis of styrene epoxide. The resultant co-doped catalyst exhibited excellent catalytic performance (yield of 99% with methanol as the nucleophile in only 1 h at room temperature) and may act as a promising candidate in many acid-catalyzed reactions.
- Zhang, Lihong,Hu, Chenhui,Zhang, Junfeng,Cheng, Liyuan,Zhai, Zheng,Chen, Jing,Ding, Weiping,Hou, Wenhua
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- Thermal transformation of a layered multifunctional network into a metal-organic framework based on a polymeric organic linker
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The preparation of layered [La(H3nmp)] as microcrystalline powders from optimized microwave-assisted synthesis or dynamic hydrothermal synthesis (i.e., with constant rotation of the autoclaves) from the reaction of nitrilotris(methylenephosphonic acid) (H6nmp) with LaCl 3?7H2O is reported. Thermogravimetry in conjunction with thermodiffractometry showed that the material undergoes a microcrystal-to-microcrystal phase transformation above 300 °C, being transformed into either a three-dimensional or a two-dimensional network (two models are proposed based on dislocation of molecular units) formulated as [La(L)] (where L3- = [-(PO3CH2) 2(NH)(CH2PO2)O1/2-]n 3n-). The two crystal structures were solved from ab initio methods based on powder X-ray diffraction data in conjunction with structural information derived from 13C and 31P solid-state NMR, electron microscopy (SEM and EDS mapping), FT-IR spectroscopy, thermodiffractometry, and photoluminescence studies. It is shown that upon heating the coordinated H3nmp3- anionic organic ligand undergoes a polymerization (condensation) reaction to form in situ a novel and unprecedented one-dimensional polymeric organic ligand. The lanthanum oxide layers act, thus, simultaneously as insulating and templating two-dimensional scaffolds. A rationalization of the various steps involved in these transformations is provided for the two models. Photoluminescent materials, isotypical with both the as-prepared ([(La0.95Eu0.05) (H3nmp)] and [(La0.95Tb0.05)(H 3nmp)]) and the calcined ([(La0.95Eu0.05)(L)]) compounds and containing stoichiometric amounts of optically active lanthanide centers, have been prepared and their photoluminescent properties studied in detail. The lifetimes of Eu3+ vary between 2.04 ± 0.01 and 2.31 ± 0.01 ms (considering both ambient and low-temperature studies). [La(H3nmp)] is shown to be an effective heterogeneous catalyst in the ring opening of styrene oxide with methanol or ethanol, producing 2-methoxy-2-phenylethanol or 2-ethoxy-2-phenylethanol, respectively, in quantitative yields in the temperature range 40-70 °C. The material exhibits excellent regioselectivity to the β-alkoxy alcohol products even in the presence of water. Catalyst recycling and leaching tests performed for [La(H3nmp)] confirm the heterogeneous nature of the catalytic reaction. Catalytic activity may be attributed to structural defect sites. This assumption is somewhat supported by the much higher catalytic activity of [La(L)] in comparison to [La(H3nmp)].
- Silva, Patricia,Vieira, Fabiana,Gomes, Ana C.,Ananias, Duarte,Fernandes, Jose A.,Bruno, Sofia M.,Soares, Rosario,Valente, Anabela A.,Rocha, Joao,Paz, Filipe A. Almeida
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- Sulfated Carbon Quantum Dots as Efficient Visible-Light Switchable Acid Catalysts for Room-Temperature Ring-Opening Reactions
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Acid catalytic processes play a classic and important role in modern organic synthesis. How well the acid can be controlled often plays the key role in the controllable synthesis of the products with high conversion yield and selectivity. The preparation of a novel, photo-switchable solid-acid catalyst based on carbon quantum dots is described. The carbon quantum dots are decorated with small amounts of hydrogensulfate groups and thus exhibit a photogenerated acidity that produces a highly efficient acid catalysis of the ring opening of epoxides with methanol and other primary alcohols. This reversible, light-switchable acidity is shown to be due to photoexcitation and charge separation in the carbon quantum dots, which create an electron withdrawing effect from the acidic groups. The catalyst is easily separated by filtration, and we demonstrate multiple cycles of its recovery and reuse.
- Li, Haitao,Sun, Chenghua,Ali, Muataz,Zhou, Fengling,Zhang, Xinyi,MacFarlane, Douglas R.
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- Multi-functional metal-organic frameworks assembled from a tripodal organic linker
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The reaction between (benzene-1,3,5-triyltris(methylene))triphosphonic acid (H6bmt) and lanthanide chlorides, under typical hydrothermal conditions (180 °C for 3 days) or using microwave heating (5 minutes above 150 °C), led to the isolation of
- Vilela, Sergio M. F.,Ananias, Duarte,Gomes, Ana C.,Valente, Anabela A.,Carlos, Luis D.,Cavaleiro, Jose A. S.,Rocha, Joao,Tome, Joao P. C.,Almeida Paz, Filipe A.
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- Microporous Nanotubes and Nanospheres with Iron-Catechol Sites: Efficient Lewis Acid Catalyst and Support for Ag Nanoparticles in CO2 Fixation Reaction
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FeIII-containing hyper-crosslinked microporous nanotubes (FeNTs) and nanospheres (FeNSs) are synthesized through the reaction of catechol and dimethoxymethane in the presence of FeCl3 or CF3SO3H. Both FeNTs and FeNSs demonstrate excellent catalytic activity in Lewis acid catalysis (hydrolysis and regioselective methanolysis of styrene oxide) and tandem catalysis involving a sequential oxidation-cyclization process, which selectively converts benzyl alcohol to 2-phenyl benzimidazole. Apart from Lewis acidity, the FeNTs and FeNSs also showed CO2 uptake capacities of 2.6 and 2.2 mmol g?1, respectively, at a pressure of 1 atm and temperature of 273 K. Furthermore, Ag nanoparticles are immobilized successfully on the surfaces of FeNTs and FeNSs by the liquid-phase impregnation method to prepare Ag@FeNT and Ag@FeNS nanocomposites, which show high catalytic activity for the selective fixation of CO2 to phenylacetylene to yield phenylpropiolic acid at 60 °C and 1 atm CO2 pressure. Hence, FeIII-catechol-containing hyper-crosslinked nanotubes and nanospheres have huge potential not only as Lewis acid catalysts, but also as excellent supports for immobilizing Ag nanoparticles in the design of a robust catalyst for the carboxylation of terminal alkynes, which has wide scope in catalysis and environmental research.
- Modak, Arindam,Bhanja, Piyali,Bhaumik, Asim
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- A copper-phosphonate network as a high-performance heterogeneous catalyst for the CO2 cycloaddition reactions and alcoholysis of epoxides
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A novel 3D copper-phosphonate network, with the general formula Cu7(H1L)2(TPT)3(H2O)6, namely compound 1, has been synthesized using a rigid tetrahedral linker tetraphenylsilane tetrakis-4-
- Ai, Jing,Min, Xue,Gao, Chao-Ying,Tian, Hong-Rui,Dang, Song,Sun, Zhong-Ming
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- A series of sulfonic acid functionalized mixed-linker DUT-4 analogues: Synthesis, gas sorption properties and catalytic performance
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In this work, we present the successful synthesis of a series of sulfonic acid functionalized mixed-linker metal-organic frameworks (MOFs) having the DUT-4 topology by using different ratios of 2,6-naphthalenedicarboxylic acid (H2-NDC) and 4,8-
- Wang, Guang-Bo,Leus, Karen,Hendrickx, Kevin,Wieme, Jelle,Depauw, Hannes,Liu, Ying-Ya,Van Speybroeck, Veronique,Van Der Voort, Pascal
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- Photoluminescent metal-organic frameworks - Rapid preparation, catalytic activity, and framework relationships
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An optimized microwave-assisted synthesis has been used to prepare an isotypical series of 3D Ln3+ metal-organic frameworks (MOFs) based on residues of 2,5-pyridinedicarboxylic (pydc), namely, [Ln2(pydc) 3(H2O)
- Silva, Patricia,Ananias, Duarte,Bruno, Sofia M.,Valente, Anabela A.,Carlos, Luis D.,Rocha, Joao,Almeida Paz, Filipe A.
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- A new series of CuII coordination polymers derived from bis-pyridyl-bis-urea ligands and various dicarboxylates and their role in methanolysis of epoxide ring-opening catalysis
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A crystal engineering approach has been adopted in synthesizing six new mixed ligand based CuII coordination polymers (CPs) derived from two bis-pyridyl-bis-urea ligands, namely, N,N′-bis-(3-pyridyl)ethylene-bis- urea (L1) and N,N′-bis-(3-pyridyl)propylene-bis-urea (L2), and various dicarboxylates. The single crystal structures of the coordination polymers displayed diverse supramolecular architectures such as a one-dimensional (1D) chain, 1D-looped chain, and two-dimensional grid. Although none of them displayed an open-framework structure, which is believed to be conducive for heterogeneous catalysis, almost all of them showed moderate to excellent epoxide ring-opening catalysis. Powder X-ray diffraction indicated structural changes/degradation of the CPs, which might be generating substrate accessible CuII species that presumably acted as the catalyst.
- Banerjee, Subhabrata,Kumar, Dhurjati Prasad,Bandyopadhay, Sabyasachi,Adarsh,Dastidar, Parthasarathi
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- Controllable construction of metal-organic polyhedra in confined cavities via in situ site-induced assembly
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Poor dispersity and low stability are two predominant shortcomings hindering the applications of metal-organic polyhedra (MOPs). The confinement of MOPs in nanoscale cavities of mesoporous matrices is efficient in overcoming both shortcomings, while the i
- Kang, Ying-Hu,Yan, Ni,Gao, Zhen-Yu,Tan, Peng,Jiang, Yao,Liu, Xiao-Qin,Sun, Lin-Bing
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- Naphthalene Derivative Sensitized Photosolvolysis of Oxiranes via Electron-Transfer Mechanisms
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Sensitized photosolvolysis of cyclohexene and styrene oxide by the singlet excited states of naphthalene derivatives occurs through the oxide anion radical intermediate by electron transfer.
- Chow, Yuan L.,Marciniak, Bronislaw,Mishra, Pratiba
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- Enhancement of catalytic activity by homo-dispersing S2O82–-Fe2O3 nanoparticles on SBA-15 through ultrasonic adsorption
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Mesoporous superacids S2O82–-Fe2O3/SBA-15 (SFS) with active nanoparticles are prepared by ultrasonic adsorption method. This method is adopted to ensure a homo-dispersed nanoparticle active phase, large specific surface area and many acidic sites. Compared with bulk S2O82–-Fe2O3, Br?nsted acid catalysts and other reported catalysts, SFS with an Fe2O3 loading of 30% (SFS-30) exhibits an outstanding activity in the probe reaction of alcoholysis of styrene oxide by methanol with 100% yield. Moreover, SFS-30 also shows a more excellent catalytic performance than bulk S2O82–-Fe2O3 towards the alcoholysis of other ROHs (R = C2H5-C4H9). Lewis and Br?nsted acid sites on the SFS-30 surfaces are confirmed by pyridine adsorbed infrared spectra. The highly efficient catalytic activity of SFS-30 may be attributed to the synergistic effect from the nano-effect of S2O82–-Fe2O3 nanoparticles and the mesostructure of SBA-15. Finally, SFS-30 shows a good catalytic reusability, providing an 84.1% yield after seven catalytic cycles.
- Chu, Qingyan,Chen, Jing,Hou, Wenhua,Yu, Haoxuan,Wang, Ping,Liu, Rui,Song, Guangliang,Zhu, Hongjun,Zhao, Pingping
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- Enhanced catalytic activity of a hierarchical porous metal-organic framework CuBTC
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A previously reported mixed ligand strategy was used to synthesize a classic metal-organic framework CuBTC, which exhibited a hierarchical porous structure including micropores and around 3.9 nm. Thanks to the facile mass transfer and denser open metal si
- Hu, Zhigang,Peng, Yongwu,Tan, Kai Min,Zhao, Dan
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- Particular Handedness Excess through Symmetry-Breaking Crystallization of a 3D Cobalt Phosphonate
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A 3D chiral cobalt phosphonate has been obtained from achiral precursors in the absence of chiral inducers. Remarkably, the bulk sample is largely enantio-enriched with particular handedness through symmetry-breaking crystallization in spite of multiple r
- Gao, Chao-Ying,Wang, Fei,Tian, Hong-Rui,Li, Lei-Jiao,Zhang, Jian,Sun, Zhong-Ming
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- Iodine-Initiated Dioxygenation of Aryl Alkenes Using tert-Butylhydroperoxides and Water: A Route to Vicinal Diols and Bisperoxides
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An environment-friendly and efficient dioxygenation of aryl alkenes for the construction of vicinal diols has been developed in water with iodine as the catalyst and tert-butylhydroperoxides (TBHPs) as the oxidant. The protocol was efficient, sustainable, and operationally simple. Detailed mechanistic studies indicated that one of the hydroxyl groups is derived from water and the other one is derived from TBHP. Additionally, the bisperoxides could be obtained in good yields with iodine as the catalyst, Na2CO3 as the additive, and propylene carbonate as the solvent, instead.
- Gao, Xiaofang,Lin, Jiani,Zhang, Li,Lou, Xinyao,Guo, Guanghui,Peng, Na,Xu, Huan,Liu, Yi
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p. 15469 - 15480
(2021/11/16)
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- MBA-cross-linked poly(N-vinyl-2-pyrrolidone)/ferric chloride macromolecular coordination complex as a novel and recyclable Lewis acid catalyst: Synthesis, characterization, and performance toward for regioselective ring-opening alcoholysis of epoxides
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A novel macromolecular-metal coordination complex, MBA-cross-linked PNVP/FeCl3 material was fabricated by immobilization of water intolerant ferric chloride onto the porous cross-linked poly(N-vinyl-2-pyrrolidone) carrier beads as a macromolecular ligand or carrier which was prepared by suspension free-radical copolymerization of N-vinyl-2-pyrrolidone (NVP) and N,N′-methylene bis-acrylamide (MBA) as a crosslinking agent in water. The obtained PNVP/FeCl3 was characterized by UV/vis and FT-IR spectroscopies, TGA, FE-SEM, EDX, and ICP techniques. This heterogenized version of ferric chloride is a convenient and safe alternative to highly water intolerant ferric chloride. The catalytic performance of (PNVP/FeCl3) as an efficient and recyclable polymeric Lewis acid catalyst was appropriately probed in the regio-and stereoselective nucleophilic ring opening of various epoxides with various alcohols in excellent yields with TOF up to 182.48 h?1 without generating any waste. The activity data indicate that this heterogeneous catalyst is very active and could be easily recovered, and reused at least six times without appreciable loss of activity indicating its stability under experimental conditions.
- Rahmatpour, Ali,Zamani, Maryam
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- Visible-Light-Mediated Divergent Silylfunctionalization of Alkenes
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1,2-Silylfunctionalization of alkenes is an efficient way to construct highly functionalized silicon-containing compounds. However, examples of 1,2-silylfunctionalization of alkenes using readily available hydrosilanes are limited. Herein, we present a visible-light-mediated divergent 1,2-silylfunctionalization of alkenes using hydrosilane under ambient conditions. A series of β-Alkoxy, β-Alkylthio, β-hydroxy, and β-indolyl silanes was obtained in good to excellent yields. Moreover, vinylsilanes were successfully prepared in the absence of an additional nucleophile.
- Zheng, Ming,Hou, Jing,Hua, Li-Li,Tang, Wan-Ying,Zhan, Le-Wu,Li, Bin-Dong
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p. 5128 - 5132
(2021/07/20)
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- Cross-linked poly(N-vinylpyrrolidone)-titanium tetrachloride complex: A novel stable solid TiCl4 equivalent as a recyclable polymeric Lewis acid catalyst for regioselective ring-opening alcoholysis of epoxides
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Cross-linked poly(N-vinylpyrrolidone) resin beads were prepared as macromolecular ligand precursors by suspension copolymerization of N-vinyl-2-pyrrolidone and N,N′-methylenebisacrylamide (MBA) as a crosslinking agent in water. Subsequently, the resulting polymer carrier precursor was readily combined with titanium tetrachloride to form a stable polymeric coordination complex (PNVP/TiCl4), and this novel stable TiCl4 equivalent evaluated as a heterogeneous and reusable solid Lewis acid catalyst for the regio-and stereoselective nucleophilic ring opening of various epoxides with various alcohols to prepare β-alkoxy alcohols in excellent yields without generating any waste. The MBA-cross-linked PNVP and resultant catalyst were characterized by Fourier transform infrared spectroscopy (FT–IR), field-emission scanning electron microscope (FE–SEM), energy dispersive X-ray (EDX), inductively coupled plasma (ICP), and thermogravimetric analysis (TGA) techniques. Moreover, the catalyst is very stable, easily separated, and reused at least five times without significant loss of activity. In terms of scope, yields, the amount of catalyst used, and reaction time, the PNVP-TiCl4 complex catalyst is an improvement over previously reported heterogeneous catalysts for ring opening of epoxides methods. Further, the experimental outcome revealed that using the copolymer beads as carriers with a high percentage of crosslinking and the high mesh size leads had an adverse effect on the reaction rate.
- Rahmatpour, Ali,Sajjadinezhad, Seyed Mehrzad
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- Cellulose sulfate: An efficient heterogeneous catalyst for the ring-opening of epoxides with alcohols and anilines
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Cellulose sulfate was synthesized by esterification of α-cellulose with concentrated sulfuric acid at ?10°C in ethanol. Cellulose is mainly sulfated on 3-, 6- and 3, 6-positions of the cellulose. It acts as a heterogeneous catalyst for the ring-opening of epoxides with alcohols or anilines and the Friedel-Crafts reaction between N-benzylindole and crotonaldehyde at room temperature. Methanolysis of cyclic epoxides, styrene oxide, terminal aliphatic epoxides, and glycidyl ethers were carried out using the catalyst (0.4–6.8 mg/mmol of epoxide) and afforded the corresponding products in 53–97% isolated yields after 10 min–24 h. Cellulose sulfate was successfully recycled and reused up to 3 catalytic cycles for the ring-opening of styrene oxide with methanol.
- Chaudhary, Pooja,Deepa,Meena, Dhan Raj,Aalam, Mohd Jubair,Yadav, Geeta Devi,Singh, Surendra
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supporting information
p. 1834 - 1846
(2021/05/10)
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- Polyoxometalate-modified reduced graphene oxide foam as a monolith reactor for efficient flow catalysis of epoxide ring-opening reactions
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Continuous flow catalysis has been attracting significant interest due to its remarkable advantages over traditional batch reactions. In this work, a facile and broad-spectrum hydrothermal approach has been developed to construct polyoxometalate-modified reduced graphene oxide (POM@rGO) foam, which worked as a monolith reactor for efficient continuous flow catalysis of epoxide ring-opening reactions. The porous structures of rGO foam allow the high dispersion of the POM catalyst onto the substrate through electrostatic interactions. Specifically, a phosphotungstic acid (H3PW12O40, denoted as PW12)-modified rGO (PW12@rGO) monolith reactor exhibits remarkable catalytic activity and durability towards epoxide ring-opening reactions with alcohols, achieving 99% conversion and 92% selectivity for the methanolysis product in 10 min under ambient conditions without stirring. Notably, while coupling with a micro-injection pump, such PW12@rGO foam can work as an efficient continuous flow reactor towards methanolysis of styrene oxide for 38 h with 99% conversion and over 90% selectivity, reaching a turnover number (TON) as high as 28?044.
- Jing, Xiaoting,Li, Zhen,Geng, Weijie,Lv, Hongjin,Chi, Yingnan,Hu, Changwen
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p. 8480 - 8488
(2021/04/12)
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- A Stable Zn-Based Metal–Organic Framework as an Efficient Catalyst for Carbon Dioxide Cycloaddition and Alcoholysis at Mild Conditions
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Abstract: Developing highly efficient heterogeneous catalysts for cycloaddition of CO2 and epoxides to produce cyclic carbonates is promising but challenging. In this work, a novel three-dimensional metal organic framework (MOF) with cylinder pore systems and unsaturated Zn sites has been demonstrated as potent candidate in CO2 fixation at mild and solvent-free conditions. The Zn(atz)(bdc)0.5, where atz = aminotriazole and H2bdc = terephthalic, exhibits microporous nature that can regulate the catalytic interaction of active centers and substrates. The structure stability has been systematically investigated and proven to be sufficient for practical application. Furthermore, the cooperative effects of porosity, CO2 binding affinity, activation centers, and synergism with co-catalyst have been deeply investigated. Moreover, high propylene epoxide conversion (97%) and selectivity (> 99%) have been achieved at mild conditions (60?°C and 1?MPa) with excellent cycle stability. Owing to the well-defined pore system, an obvious substrates selectivity has been clearly observed. A possible catalytic mechanism has been proposed and verified by DFT calculations. Furthermore, the prepared Zn-MOF can also be used as an efficient heterogeneous catalyst for the reaction of epoxides with alcohols to produce β-alkoxy alcohol. Graphic Abstract: [Figure not available: see fulltext.].
- Luo, Zhiqiang,Wang, Jun,He, Yanqing,Ao, Qiong,Deng, Qiang,Zeng, Zheling,Wang, Hongming,Deng, Shuguang
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p. 1408 - 1417
(2019/12/09)
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- The charge-assisted hydrogen-bonded organic framework (CAHOF) self-assembled from the conjugated acid of tetrakis(4-aminophenyl)methane and 2,6-naphthalenedisulfonate as a new class of recyclable Br?nsted acid catalysts
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The acid–base neutralization reaction of commercially available disodium 2,6-naphthalenedisulfonate (NDS, 2 equivalents) and the tetrahydrochloride salt of tetrakis(4-aminophenyl)methane (TAPM, 1 equivalent) in water gave a novel three-dimensional charge-assisted hydrogen-bonded framework (CAHOF, F-1). The framework F-1 was characterized by X-ray diffraction, TGA, elemental analysis, and 1H NMR spectroscopy. The framework was supported by hydrogen bonds between the sulfonate anions and the ammonium cations of NDS and protonated TAPM moieties, respectively. The CAHOF material functioned as a new type of catalytically active Br?nsted acid in a series of reactions, including the ring opening of epoxides by water and alcohols. A Diels–Alder reaction between cyclopentadiene and methyl vinyl ketone was also catalyzed by F-1 in heptane. Depending on the polarity of the solvent mixture, the CAHOF F-1 could function as a purely heterogeneous catalyst or partly dissociate, providing some dissolved F-1 as the real catalyst. In all cases, the catalyst could easily be recovered and recycled.
- Belokon, Yuri N.,Dmitrienko, Artem O.,Gak, Alexander S.,Gerasimov, Igor S.,Kuznetsova, Svetlana A.,Larionov, Vladimir A.,Li, Han,Medvedev, Michael G.,Nelyubina, Yulia V.,North, Michael,Saghyan, Ashot S.,Smol'yakov, Alexander F.,Zhereb, Vladimir P.
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supporting information
p. 1124 - 1134
(2020/07/10)
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- Fiber-supported Fe(iii) complex catalyst in spinning basket reactor for cleaner ring-opening of epoxides with alcohols
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Herein, a newly designed fiber-supported iron catalyst was successfully synthesized by rooting diamine ligands into the surface layer of commercially available polyacrylonitrile fiber and then utilizing the diamine groups to immobilize Fe(iii) ions for heterogeneous catalytic ring-opening reactions. The resulting materials were characterized and observed in detail by elemental analysis, mechanical properties, FTIR spectroscopy and morphology during both the preparation and the utilization processes. Moreover, the fiber catalyst was used in the spinning basket reactor-mediated ring-opening of various epoxides by a series of alcohols under mild reaction conditions, giving good to quantitative yields of the corresponding β-alkoxy alcohols. In addition, the fiber catalyst in the impellers of the agitation system was shown to be reusable multiple times without leaching of the Fe(iii) ions, and when stored on the shelf remained equally active for at least three months. Furthermore, the catalytic system was convenient and effective for scaling-up experiments and thereby has prospects in industrial applications.
- Shi, Xian-Lei,Sun, Benyu,Hu, Qianqian,Chen, Yongju,Duan, Peigao
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p. 3573 - 3582
(2019/07/09)
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- A Linear Trinuclear Oxidodiperoxido-molybdenum(VI) Complex with Single Triazole Bridges: Catalytic Activity in Epoxidation, Alcoholysis, and Acetalization Reactions
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The complex (Htrz)2[Mo3O6(O2)4(trz)2]?H2O (1), isolated from the reaction of MoO3 with H2O2 in the presence of 1,2,4-triazole (trz), displays singular structural features such as double bridges comprising one oxido and one triazole ligand, and peripheral oxidodiperoxido-molybdenum(VI) units. A comparative study was performed regarding the catalytic activity and stability of complex 1 and the hybrid material [MoO3(trz)0.5] (2) for the epoxidation of cis-cyclooctene (Cy8), the alcoholysis of epoxides, and the acetalization of benzaldehyde (PhCHO). Methanol or ethanol were used as solvents and reagents for the latter two reactions. For the substrates Cy8, styrene oxide, and PhCHO, the corresponding epoxide, β-alkoxy alcohol, and dialkyl acetal were obtained with 100 % selectivity at very high conversions. In general, 1 performed better than 2 for the different catalytic reactions. Under certain oxidant/co-solvent conditions used for Cy8 epoxidation, 1 was converted to 2 during the reaction.
- Antunes, Margarida M.,Amarante, Tatiana R.,Valente, Anabela A.,Almeida Paz, Filipe A.,Gon?alves, Isabel S.,Pillinger, Martyn
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p. 2782 - 2791
(2018/07/24)
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- Synthesis and structure of an air-stable bis(pentamethylcyclopentadienyl) zirconium pentafluorbezenesulfonate and its application in catalytic epoxide ring-opening reactions
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An air-stable mononuclear complex of bis(pentamethylcyclopentadienyl) zirconium pentafluorbezenesulfonate was successfully synthesized by treating C6F5SO3Ag with [(CH3)5Cp]2ZrCl2, which showed the cationic uninuclear structure of [{(CH3)5Cp}2Zr(CH3CN)2(H2O)][OSO2C6F5]2·CH3CN (1) confirmed by the X-ray analysis. Complex 1 was also characterized by other techniques and found to have the good nature of air-stability, water tolerance, thermally-stability and strong Lewis-acidity. Moreover, the complex showed high catalytic activity and recyclability in catalytic epoxide ring-opening reactions by amines or alcohols. This catalytic system affords a simple and efficient approach for synthesis of β-amino alcohols or β-alkoxy alcohols.
- Li, Ningbo,Wang, Lingxiao,Wang, Haojiang,Qiao, Jie,Zhao, Wenjie,Xu, Xinhua,Liang, Zhiwu
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p. 1033 - 1039
(2018/02/06)
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- Acid-catalyzed epoxide alcoholysis in the presence of indenyl molybdenum carbonyl complexes
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The indenyl molybdenum carbonyl complexes [IndMo(CO)2(L)n]BF4 (L = NCMe with n = 3 (1), 2,2′-bipyridine (2) or 1,4,7-trimethyltriazacyclononane (3) with n = 1) promote epoxide alcoholysis under moderate reaction conditions. Complexes 1 and 2 showed the best performance for the alcoholysis of styrene oxide with different alcohol nucleophiles (acting as both reactant and solvent), leading to the corresponding 2-alkoxy-2-phenylethanol with 100% yield at 10 min and 35 °C. These catalytic results are far superior to those found for previously studied molybdenum carbonyl complexes. An efficient procedure for catalyst recovery and reuse without decrease in reaction rate is described.
- Bruno, Sofia M.,Gon?alves, Isabel S.,Pillinger, Martyn,Rom?o, Carlos C.,Valente, Anabela A.
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- Ionic Pathways in the Photochemistry of Cyclic Sulfite Esters
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The photochemistry of cyclic carbonate esters proceeds by the photochemical extrusion of carbon dioxide to give 1, 3-diradicals which produce oxiranes as well as other radical derived species. The corresponding cyclic sulfite esters, upon irradiation, give intermediates that are trapped by alcohols yet generate no oxiranes. These results are consistent with ionic intermediates.
- White, Rick C.,Arney Jr, Benny E.,Perry, Jacob,Thompson, Nathan,Pithan, Phil M.,von Gradowski, Sebastian,Ihmels, Heiko
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p. 1656 - 1659
(2017/03/27)
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- Specific microwave effect on Sn- and Ti-MFI zeolite synthesis
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A specific microwave effect on the Sn- and Ti-MFI zeolite synthesis is exactly demonstrated by separating it from thermal effects through using Pyrex and SiC reaction vessels. Different from the reported conventional thermal effect on the organic reactions, this finding is of great significance to further investigate the microwave effect.
- Sun, Zhen,Li, Ting,Li, Gang,Zhang, Yahong,Tang, Yi
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p. 35252 - 35256
(2017/07/25)
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- Robust Multifunctional Yttrium-Based Metal-Organic Frameworks with Breathing Effect
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Phosphonate- and yttrium-based metal-organic frameworks (MOFs), formulated as [Y(H5btp)]·5.5H2O (1), [Y(H5btp)]·2.5H2O (2), (H3O)[Y2(H5btp)(H4btp)]·H2O (3), and [Y(H5btp)]·H2O·0.5(MeOH) (4), were prepared using a “green” microwave-assisted synthesis methodology which promoted the self-assembly of the tetraphosphonic organic linker [1,1′-biphenyl]-3,3′,5,5′-tetrayltetrakis(phosphonic acid) (H8btp) with Y3+ cations. This new family of functional materials, isolated in bulk quantities, exhibits a remarkable breathing effect. Structural flexibility was thoroughly studied by means of X-ray crystallography, thermogravimetry, variable-temperature X-ray diffraction, and dehydration and rehydration processes, ultimately evidencing a remarkable reversible single-crystal to single-crystal (SC-SC) transformation solely through the loss and gain of crystallization solvent molecules. Topologically, frameworks remained unaltered throughout this interconversion mechanism, with all compounds being binodal 6,6-connected network with a Scha?fli symbol of {413.62}{48.66.8}. Results show that this is one of the most stable and thermally robust families of tetraphosphonate-based MOFs synthesized reported to date. Porous materials 2 and 3 were further studied to ascertain their performance as heterogeneous catalysts and proton conductors, respectively, with outstanding results being registered for both materials. Compound 2 showed a 94% conversion of benzaldehyde into (dimethoxymethyl)benzene after just 1 h of reaction, among the best results registered to date for MOF materials. On the other hand, the protonic conductivity of compound 3 at 98% of relative humidity (2.58 × 10-2 S cm-1) was among the highest registered among MOFs, with the great advantage of the material to be prepared using a simpler and sustainable synthesis methodology, as well as exhibiting a good stability at ambient conditions (temperature and humidity) over time when compared to others.
- Firmino, Ana D. G.,Mendes, Ricardo F.,Antunes, Margarida M.,Barbosa, Paula C.,Vilela, Sérgio M. F.,Valente, Anabela A.,Figueiredo, Filipe M. L.,Tomé, Jo?o P. C.,Paz, Filipe A. Almeida
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supporting information
p. 1193 - 1208
(2017/02/15)
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- Introduction of an effective and economical heterogeneous ruthenium catalyst for regioselective ring-opening of epoxides and the friedel-crafts alkylation reaction of indoles and pyrroles
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Background: Metal organic frameworks square measure crystalline materials with fascinating chemical and physical attributes that include metal ions or clusters and multidentate organic particles. MOFs acquire the expected traits to be employed in classical applications similar to heterogeneous catalysis and storage and separation of gases and different Compounds. Post-synthetic modification (PSM) is an associate replacement method to prepare functionalized MOFs. Methods: The IRMOF-3-PI-RuCl3 was prepared by refluxing a combination of IRMOF-3-PI, [H(DMSO)2][RuCl4(DMSO)2] and ethanol. The amount of ruthenium metal in catalyst was found to be 2.35 w% based on ICP analysis. To perform the ring opening reaction, a solution of styrene oxide, indole, pyrole or alcohol nucleophile, in methanol, IRMOF-3-PI-RuCl3 was added. After completion of the reaction, the catalyst was precipitated. Results: A MOF-supported metal catalyst (IRMOF-3-PI-RuCl3) was designed and synthesized by postsynthetic method. The BET surface area of the final catalyst was slightly reduced as determined by N2 sorption experiments. The results showed that the provided catalyst has a high potential for the ring opening of epoxides with alcohols, indoles and pyrroles under gentle conditions. Conclusion: In summary, a simple, rapid, economical and an effective route for the alcoholysis of epoxides and therefore the Friedel-Crafts alkylation of indoles and pyrroles via an basically regioselective ring opening of epoxides with aliphatic and aromatic amines using IRMOF-3-PI-RuCl3 with cage type poriferous structure as heterogeneous catalysts, has been established. This methodology is very regioselective in numerous instances that give the products with high yield for e.g. in aromatic and aliphatic amines. Ease of separation and straightforward workup are among other advantages of this catalyst.
- Tabatabaeian, Khalil,Zanjanchi, Mohammad Ali,Mahmoodi, Nosrat O.,Eftekhari, Tooraj
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p. 207 - 217
(2017/06/21)
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- Donor–Acceptor Complex Enables Alkoxyl Radical Generation for Metal-Free C(sp3)–C(sp3) Cleavage and Allylation/Alkenylation
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The alkoxyl radical is an essential and prevalent reactive intermediate for chemical and biological studies. Here we report the first donor–acceptor complex-enabled alkoxyl radical generation under metal-free reaction conditions induced by visible light. Hantzsch ester forms the key donor–acceptor complex with N-alkoxyl derivatives, which is elucidated by a series of spectrometry and mechanistic experiments. Selective C(sp3)-C(sp3) bond cleavage and allylation/alkenylation is demonstrated for the first time using this photocatalyst-free approach with linear primary, secondary, and tertiary alkoxyl radicals.
- Zhang, Jing,Li, Yang,Xu, Ruoyu,Chen, Yiyun
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supporting information
p. 12619 - 12623
(2017/09/11)
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- Zirconium triflate grafted on SBA-15 as a highly efficient solid acid catalyst for ring opening of epoxides by amines and alcohols
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Metal (Al, Ti, Zr) triflate grafted mesoporous SBA-15 (AlTf/S, TiTf/S, ZrTf/S) samples were synthesized as inexpensive solid acid materials by a simple one-pot-two-step synthesis methodology. These materials were characterized by X-ray diffraction, N2-sorption, thermogravimetric analysis, Fourier transform infrared spectroscopy (FT-IR), in-situ pyridine FT-IR spectroscopy, and elemental analysis. ZrTf/S was found to be a highly efficient and reusable solid acid catalyst for ring opening of epoxides with amines and alcohols and produced β-amino alcohols and β-alkoxy alcohols respectively under ambient reaction conditions. The ZrTf/S catalyst showed the highest activity, which was attributed to its high acidity compared with that of the Ti and Al containing samples.
- Tayade, Kamlesh N.,Wang, Lianyue,Shang, Sensen,Dai, Wen,Mishra, Manish,Gao, Shuang
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p. 758 - 766
(2017/04/24)
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- Influence of Terephthalic Acid Substituents on the Catalytic Activity of MIL-101(Cr) in Three Lewis Acid Catalyzed Reactions
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Six isostructural MIL-101(Cr)-X (X: H, NO2, SO3H, Cl, CH3, and NH2) materials have been prepared directly by the reaction of CrIII salts and the corresponding terephthalic acid or by postsynthetic treatments of preformed MIL-101(Cr) following reported procedures. The materials were characterized by using XRD (crystallinity and coincident diffraction pattern), isothermal N2 adsorption (specific surface areas range from 2740 m2 g?1 for MIL-101(Cr)-H to 1250 m2 g?1 for MIL-101(Cr)-Cl), thermogravimetry (thermal stability up to 400 °C), and IR spectroscopy (detection of the corresponding substituents), and the results were all in agreement with the reported data for these materials. The MIL-101(Cr) materials were tested as heterogeneous catalysts for epoxide ring opening by methanol, benzaldehyde acetalization by methanol, and Prins coupling, observing a clear influence of the substituent that in general follows a linear relationship with the Hammett σmeta constant of the substituent: the catalytic activity increases as the electron-withdrawing ability of the substituents increases. An up to three orders of magnitude enhancement in the presence of the NO2 substituent was found for some of these reactions. The present study illustrates the versatility that metal–organic frameworks offer as heterogeneous catalysts that allow the design of actives sites with adequate properties tuned for each reaction.
- Santiago-Portillo, Andrea,Navalón, Sergio,Concepción, Patricia,álvaro, Mercedes,García, Hermenegildo
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p. 2506 - 2511
(2017/07/12)
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- An Fe3O4 nanoparticle-supported Mn (II)-azo Schiff complex acts as a heterogeneous catalyst in alcoholysis of epoxides
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In this paper, an azo-containing Schiff base complex of manganese [Mn2+-azo ligand@APTES-SiO2@Fe3O4] immobilized on chemically modified Fe3O4 nanoparticles has been used as a magnetically retrievable catalyst for the alcoholysis of different epoxides to their corresponding alkoxy alcohols with methanol, ethanol and n-propanol. The newly magnetic nanoparticles (MNPs) were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and vibrating sample magnetometry (VSM).
- Olia, Fahimeh Karami,Sayyahi, Soheil,Taheri, Narges
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p. 370 - 376
(2017/03/15)
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- Highly Enantioselective Iron-Catalyzed cis-Dihydroxylation of Alkenes with Hydrogen Peroxide Oxidant via an FeIII-OOH Reactive Intermediate
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The development of environmentally benign catalysts for highly enantioselective asymmetric cis-dihydroxylation (AD) of alkenes with broad substrate scope remains a challenge. By employing [FeII(L)(OTf)2] (L=N,N′-dimethyl-N,N′-bis(2-methyl-8-quinolyl)-cyclohexane-1,2-diamine) as a catalyst, cis-diols in up to 99.8 % ee with 85 % isolated yield have been achieved in AD of alkenes with H2O2as an oxidant and alkenes in a limiting amount. This “[FeII(L)(OTf)2]+H2O2” method is applicable to both (E)-alkenes and terminal alkenes (24 examples >80 % ee, up to 1 g scale). Mechanistic studies, including18O-labeling, UV/Vis, EPR, ESI-MS analyses, and DFT calculations lend evidence for the involvement of chiral FeIII-OOH active species in enantioselective formation of the two C?O bonds.
- Zang, Chao,Liu, Yungen,Xu, Zhen-Jiang,Tse, Chun-Wai,Guan, Xiangguo,Wei, Jinhu,Huang, Jie-Sheng,Che, Chi-Ming
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supporting information
p. 10253 - 10257
(2016/08/24)
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- Aniline-terephthalaldehyde resin p-toluenesulfonate (ATRT) as a highly efficient and reusable catalyst for alcoholysis, hydrolysis, and acetolysis of epoxides
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Alcoholysis, hydrolysis, and acetolysis of epoxides were carried out in the presence of a catalytic amount of aniline-terephthalaldehyde resin p-toluenesulfonate (ATRT) to give the corresponding β-substituted alcohols in good yields. Alcoholysis and hydrolysis of epoxides catalyzed by ATRT proceeded faster than those by pyridinium p-toluenesulfonate (PPTS).
- Tanemura, Kiyoshi,Suzuki, Tsuneo
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supporting information
p. 1781 - 1789
(2016/11/17)
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- A highly efficient protocol for regioselective ring-opening of epoxides with alcohols, water, acetic acid, and acetic anhydride catalyzed by SbF3
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SbF3as an efficient catalyst has been used for regioselective alcoholysis, acetolysis and hydrolysis of epoxides to the corresponding β-alkoxy, β-acetoxy alcohols, and 1,2-diols in high to excellent yields. This study also represents a convenient synthesis of vic-diacetates from ring-opening of epoxides with acetic anhydride.
- Zeynizadeh, Behzad,Gilanizadeh, Masumeh,Aminzadeh, Farkhondeh Mohammad
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p. 1051 - 1056
(2016/07/06)
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- Influence of functionalization of terephthalate linker on the catalytic activity of UiO-66 for epoxide ring opening
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A series of five isostructural zirconium terephthalate UiO-66 metal organic frameworks bearing different functional groups on the terephthalate linker (UiO-66-X; X = H, NH2, NO2, Br, Cl,) have been successfully prepared and characterized. UiO-66-X materials were evaluated as heterogeneous catalysts for the epoxide ring opening of styrene oxide by methanol, observing an increase in the initial reaction rate from UiO-66-H to UiO-66-Br, over one order of magnitude. The reactivity order, however, does not follow a linear relationship between the Hammett constant value of the substituent and the initial reaction rate. UiO-66-Br exhibits a wide scope, its activity depending on the structure of epoxide and nucleophile. The absence of Zr leaching to the solution together with the preservation of the UiO-66-X crystallinity confirms the stability of the framework under the reaction conditions. Nevertheless, UiO-66 undergoes a progressive deactivation upon reuse that was attributed to a strong adsorption of the reaction product.
- Blandez, Juan F.,Santiago-Portillo, Andrea,Navalón, Sergio,Giménez-Marqués, Mónica,álvaro, Mercedes,Horcajada, Patricia,García, Hermenegildo
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p. 332 - 339
(2016/12/09)
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- Enhancement of CO2 Adsorption and Catalytic Properties by Fe-Doping of [Ga2(OH)2(L)] (H4L = Biphenyl-3,3′,5,5′-tetracarboxylic Acid), MFM-300(Ga2)
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Metal-organic frameworks (MOFs) are usually synthesized using a single type of metal ion, and MOFs containing mixtures of different metal ions are of great interest and represent a methodology to enhance and tune materials properties. We report the synthesis of [Ga2(OH)2(L)] (H4L = biphenyl-3,3′,5,5′-tetracarboxylic acid), designated as MFM-300(Ga2), (MFM = Manchester Framework Material replacing NOTT designation), by solvothermal reaction of Ga(NO3)3 and H4L in a mixture of DMF, THF, and water containing HCl for 3 days. MFM-300(Ga2) crystallizes in the tetragonal space group I4122, a = b = 15.0174(7) ? and c = 11.9111(11) ? and is isostructural with the Al(III) analogue MFM-300(Al2) with pores decorated with -OH groups bridging Ga(III) centers. The isostructural Fe-doped material [Ga1.87Fe0.13(OH)2(L)], MFM-300(Ga1.87Fe0.13), can be prepared under similar conditions to MFM-300(Ga2) via reaction of a homogeneous mixture of Fe(NO3)3 and Ga(NO3)3 with biphenyl-3,3′,5,5′-tetracarboxylic acid. An Fe(III)-based material [Fe3O1.5(OH)(HL)(L)0.5(H2O)3.5], MFM-310(Fe), was synthesized with Fe(NO3)3 and the same ligand via hydrothermal methods. [MFM-310(Fe)] crystallizes in the orthorhombic space group Pmn21 with a = 10.560(4) ?, b = 19.451(8) ?, and c = 11.773(5) ? and incorporates μ3-oxo-centered trinuclear iron cluster nodes connected by ligands to give a 3D nonporous framework that has a different structure to the MFM-300 series. Thus, Fe-doping can be used to monitor the effects of the heteroatom center within a parent Ga(III) framework without the requirement of synthesizing the isostructural Fe(III) analogue [Fe2(OH)2(L)], MFM-300(Fe2), which we have thus far been unable to prepare. Fe-doping of MFM-300(Ga2) affords positive effects on gas adsorption capacities, particularly for CO2 adsorption, whereby MFM-300(Ga1.87Fe0.13) shows a 49% enhancement of CO2 adsorption capacity in comparison to the homometallic parent material. We thus report herein the highest CO2 uptake (2.86 mmol g-1 at 273 K at 1 bar) for a Ga-based MOF. The single-crystal X-ray structures of MFM-300(Ga2)-solv, MFM-300(Ga2), MFM-300(Ga2)·2.35CO2, MFM-300(Ga1.87Fe0.13)-solv, MFM-300(Ga1.87Fe0.13), and MFM-300(Ga1.87Fe0.13)·2.0CO2 have been determined. Most notably, in situ single-crystal diffraction studies of gas-loaded materials have revealed that Fe-doping has a significant impact on the molecular details for CO2 binding in the pore, with the bridging M-OH hydroxyl groups being preferred binding sites for CO2 within these framework materials. In situ synchrotron IR spectroscopic measurements on CO2 binding with respect to the -OH groups in the pore are consistent with the above structural analyses. In addition, we found that, compared to MFM-300(Ga2), Fe-doped MFM-300(Ga1.87Fe0.13) shows improved catalytic properties for the ring-opening reaction of styrene oxide, but similar activity for the room-temperature acetylation of benzaldehyde by methanol. The role of Fe-doping in these systems is discussed as a mechanism for enhancing porosity and the structural integrity of the parent material.
- Krap, Cristina P.,Newby, Ruth,Dhakshinamoorthy, Amarajothi,García, Hermenegildo,Cebula, Izabela,Easun, Timothy L.,Savage, Mathew,Eyley, Jennifer E.,Gao, Shan,Blake, Alexander J.,Lewis, William,Beton, Peter H.,Warren, Mark R.,Allan, David R.,Frogley, Mark D.,Tang, Chiu C.,Cinque, Gianfelice,Yang, Sihai,Schr?der, Martin
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p. 1076 - 1088
(2016/02/09)
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- A Lamellar Coordination Polymer with Remarkable Catalytic Activity
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A positively charged lamellar coordination polymer based on a flexible triphosphonic acid linker is reported. [Gd(H4nmp)(H2O)2]Cl?2 H2O (1) [H6nmp=nitrilotris(methylenephosphonic acid)] was obtained by a one-pot approach by using water as a green solvent and by forcing the inclusion of additional acid sites by employing HCl in the synthesis. Compound 1 acts as a versatile heterogeneous acid catalyst with outstanding activity in organic reactions such as alcoholysis of styrene oxide, acetalization of benzaldehyde and cyclohexanaldehyde and ketalization of cyclohexanone. For all reaction systems, very high conversions were reached (92–97 %) in only 15–30 min under mild conditions (35 °C, atmospheric pressure). The coordination polymer exhibits a protonic conductivity of 1.23×10?5S cm?1at 98 % relative humidity and 40 °C.
- Mendes, Ricardo F.,Antunes, Margarida M.,Silva, Patrícia,Barbosa, Paula,Figueiredo, Filipe,Linden, Anthony,Rocha, Jo?o,Valente, Anabela A.,Almeida Paz, Filipe A.
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p. 13136 - 13146
(2016/09/09)
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- Synthesis, structure and multifunctional catalytic properties of a Cu(i)-coordination polymer with outer-hanging CuBr2
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A 1D Cu(i)-coordination polymer [(CuL1)(CuBr2), 1] carrying external copper bromide moieties was synthesized. The outer-hanging [CuBr2]- moiety is attached to the 1D Cu(i)-CP backbone via a Cu?Cu bonding interaction, which makes it look like a coordination polymer supported CuBr2 species. 1 exhibits excellent multifunctional catalytic activity for phenol acetylation, A3-coupling (aldehyde-alkyne-amine) and styrene oxide methanolysis reactions. Its heterogeneous catalytic nature was confirmed by solution leaching experiment and it can be reused without significant loss of its catalytic activity and selectivity for the above reactions.
- Zhu, Neng-Xiu,Zhao, Chao-Wei,Yang, Jing,Wang, Xue-Ru,Ma, Jian-Ping,Dong, Yu-Bin
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p. 108645 - 108653
(2016/11/30)
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- An epoxide ring-opening reaction by using sol–gel-synthesized palladium supported on a strontium hydroxyl fluoride catalyst
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Palladium supported on a strontium hydroxyl fluoride catalyst was synthesized by a one-pot fluorolytic sol–gel method. The prepared catalyst was characterized by various physicochemical techniques. The sol–gel method has led to the formation of a high surface area (57?m2g?1), mesoporous (pore diameter?=?13.0?nm) catalyst with uniform dispersion of Pd nanoparticles of size ~7?nm on the surface of strontium hydroxyl fluoride. The catalyst was used for epoxide alcoholysis, and 100% conversion was obtained with 96% selectivity for β-alkoxy alcohols under mild conditions. The catalyst could be recycled for up to three catalytic cycles without any appreciable decrease in conversion and selectivity, indicating the stability of the catalyst under the reaction conditions. Further, the mechanism of alcoholysis was proposed on the basis of the physicochemical characteristics of the catalyst and on the basis of the products formed during the catalytic reaction.
- Acham, Vaibhav R.,Dongare, Mohan K.,Kemnitz, Erhard,Umbarkar, Shubhangi B.
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p. 1237 - 1246
(2016/10/13)
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- Temperature-dependent immobilization of a tungsten peroxo complex that catalyzes the hydroxymethoxylation of olefins
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Abstract A tungsten peroxo complex stabilized by the bidentate picolinato ligand has been synthesized and then immobilized successfully on imidazole-functionalized silica. The immobilized tungsten-based catalyst was employed as an efficient catalyst for the one-pot synthesis of β-alkoxy alcohols from olefins and methanol with H2O2. Regarding the catalyst evaluation and the results of characterization by the various methods, it was demonstrated that the immobilization of tungsten peroxo complex was highly temperature-dependent. The tungsten peroxo complex can dissociate and diffuse into the liquid phase at reaction temperature, resulting in a homogeneous reaction. Nevertheless, the catalytically active species was anchored on the imidazole-functionalized silica by hydrogen bonding as the temperature was lowered to 0°C after the reaction, which thus offered a highly effective approach for recycling the catalyst for consecutive cycles. In addition, various olefins can be converted to the corresponding β-alkoxy alcohols with good conversion and selectivity under relative mild conditions by H2O2. Running hot and cold: A tungsten peroxo complex (see picture) can dissociate and diffuse into the liquid phase at the reaction temperature, resulting in a homogeneous reaction. After reaction, the catalytically active species was anchored on the functionalized silica by hydrogen-bonding as the temperature was lowered to 0°C. This offers an effective approach for catalyst recovery and recycling.
- Chen, Jizhong,Hua, Li,Chen, Chen,Guo, Li,Zhang, Ran,Chen, Angjun,Xiu, Yuhe,Liu, Xuerui,Hou, Zhenshan
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p. 1029 - 1037
(2015/06/08)
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- Mild regiospecific alcoholysis and aminolysis of epoxides catalyzed by zirconium(IV) oxynitrate
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A regiospecific method for the ring-opening reaction of epoxides by the primary, secondary, tertiary alcohols, and aryl, aliphatic amines has been developed using non-toxic metal nitrate salt as a catalyst. The best results were obtained using zirconium(IV) oxynitrate among the various screened metal nitrate salts. The reported protocol works efficiently for styrene epoxide and aliphatic as well.
- Shinde, Sandip S.,Said, Madhukar S.,Surwase, Trupti B.,Kumar, Pradeep
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supporting information
p. 5916 - 5919
(2015/11/02)
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- Urea-containing metal-organic frameworks as heterogeneous organocatalysts
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Two novel pillared metal-organic frameworks (MOFs) containing a urea-functional group are introduced. Herein, the urea functional group was incorporated into the MOF backbone by preparing a urea-ditopic ligand. These frameworks (TMU-18 and TMU-19) were fabricated using the synthesized urea-containing ligand, 4,4′-bipyridine (bipy) and 1,2-bis(4-pyridyl)ethane (bpe), and using zinc nitrate as the metal source. Subsequently, TMU-18 and TMU-19 were characterized by X-ray diffraction, IR spectroscopy, elemental analysis, scanning electron microscopy (SEM) and thermogravimetric analysis. Furthermore, their potential efficiency as organocatalysts was evaluated in the regioselective methanolysis of epoxides.
- Tehrani, Alireza Azhdari,Abedi, Sedigheh,Morsali, Ali,Wang, Jun,Junk, Peter C.
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p. 20408 - 20415
(2015/10/19)
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- Sustainable synthesis of a catalytic active one-dimensional lanthanide-organic coordination polymer
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Rationalization of the synthetic conditions allowed the predictable fast sustainable preparation of [La2(H3nmp)2(H2O)4]·4.5H2O having a 1D coordination polymer. The material exhibits a remarkable chemical stability, can be converted into other layered compounds, and is an excellent catalyst surpassing other related materials.
- Mendes, Ricardo F.,Silva, Patrícia,Antunes, Margarida M.,Valente, Anabela A.,Almeida Paz, Filipe A.
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supporting information
p. 10807 - 10810
(2015/06/30)
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- Ring opening of epoxides with alcohols using Fe(Cp)2BF 4 as catalyst
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Fe(Cp)2BF4 is an efficient catalyst for the alcoholysis of aromatic, aliphatic, and cyclic epoxides giving excellent yields of the corresponding β-alkoxy alcohols under ambient conditions. The methanolysis of styrene oxide using Fe(Cp)2BF4 as a catalyst (5 mol %) gave excellent yield of 2-methoxy-2-phenylethanol with complete regio-selectivity. The ring opening of cyclic epoxides gave 77-97% yields of trans-β-methoxy alcohols, in 0.5-6 h. The use of 1,2-epoxyhexane and 1,2-epoxydodecane as substrates gave both regioisomers in excellent yields. The first order rate of reaction with respect to catalyst was observed for the kinetics of ring opening of 1,2-epoxyhexane with methanol.
- Yadav, Geeta Devi,Singh, Surendra
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supporting information
p. 3979 - 3983
(2014/07/08)
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- Graphite oxide: A simple and efficient solid acid catalyst for the ring-opening of epoxides by alcohols
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A simple, efficient, and general procedure for the ring-opening of epoxides with various alcohols to give the corresponding β-alkoxy alcohols using graphite oxide (GO) as the catalyst, under very mild reaction conditions is described. The method proceeds in good to excellent yields and in short reaction times at room temperature under metal-free conditions.
- Mirza-Aghayan, Maryam,Alizadeh, Mahdi,Molaee Tavana, Mahdieh,Boukherroub, Rabah
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p. 6694 - 6697
(2014/12/11)
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- MIL-101-SO3H: A highly efficient Bronsted acid catalyst for heterogeneous alcoholysis of epoxides under ambient conditions
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For the first time, a ~100% sulfonic acid functionalized metal-organic framework (MOF), MIL-101-SO3H, with giant pores has been prepared by a hydrothermal process followed by a facile postsynthetic HCl treatment strategy. The replete readily accessible Lewis acidic and especially Bronsted acidic sites distributed throughout the framework as well as high stability endow the resultant MOF exceptionally high efficiency and recyclability, which surpass all other MOF-based catalysts, for the ring opening of epoxides with alcohols (especially, methanol) as nucleophiles under ambient conditions.
- Zhou, Yu-Xiao,Chen, Yu-Zhen,Hu, Yingli,Huang, Gang,Yu, Shu-Hong,Jiang, Hai-Long
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p. 14976 - 14980
(2015/01/09)
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- Highly efficient nanocrystalline zirconosilicate catalysts for the aminolysis, alcoholysis, and hydroamination reactions
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Nanocrystalline zirconosilicates and titanosilicates with MFI framework structure were hydrothermally synthesized by the addition of organosilanes in the synthesis composition of conventional zirconosilicate and titanosilicate materials. Materials were characterized by a complementary combination of X-ray diffraction, nitrogen sorption, scanning/transmission electron microscopy (S/TEM), ammonia temperature-programmed desorption (TPD), Fourier transform infrared (FT-IR) spectroscopy, and ultraviolet-visible (UV-vis) spectroscopic investigations. Nanocrystalline zeolite catalysts of the present study are reusable. They exhibit significantly higher catalytic activities in aminolysis and alcoholysis compared with the hitherto known catalysts. A range of β-amino alcohols/β-alkoxy alcohols with high regioselectivity were synthesized using zirconosilicates. Application of these materials was also extended in the synthesis of aminoesters by the hydroamination reaction of methyl acrylates and amines. Structure activity relationship was explained based on acidity measurements, reactivity of amines/alcohols, and adsorption of reactants on catalysts.
- Kore, Rajkumar,Srivastava, Rajendra,Satpati, Biswarup
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p. 2891 - 2904
(2014/01/06)
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- Efficient and regioselective ring-opening of epoxides with alcohols and sodium azide by using catalytic amounts of gacl3/polyvinylpyrrolidone
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A new polymeric catalyst was prepared by supporting GaCl3 on cross-linked polyvinylpyrrolidone (GaCl3/ PVP). This catalyst was employed for efficient and regioselective ring-opening reaction of epoxides by various alcohols under solvent-free conditions at room temperature. In our procedure, this heterogeneous catalyst was used at neutral and mild reaction conditions to afford high yields of β-alkoxy alcohols. Also, regioselective conversion of epoxides to β-azidohydrines was accomplished by sodium azide in MeOH in the presence of GaCl3/PVP at room temperature. GaCl3/PVP is a non-hygroscopic and recoverable catalyst and is easily separated from reaction mixture by a simple filtration and re-used repeatedly. Also, this catalyst has good handling and can be stored for long time without any reducing of its reactivity.
- Pourali, Ali Reza,Ghayeni, Samaneh,Afghahi, Fatemeh
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p. 1741 - 1744
(2013/07/26)
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