- Influence of Hydrogen Bond Donating Sites in UiO-66 Metal-Organic Framework for Highly Regioselective Methanolysis of Epoxides
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A Zr(IV)-based UiO-66 metal-organic framework (MOF) (named 1) was synthesized by employing 1-(aminomethyl)naphthalene-2-ol appended terephthalate linker and Zr(IV) salt via solvothermal method and subsequently characterized. Furthermore, the potential efficiency of activated (named 1′) form of as-synthesized MOF was investigated as an organocatalyst for the ring-opening of epoxide by methanol. The catalytic performance of 1 and 1′ was studied in the methanolysis of styrene oxide as a model substrate and the activity of 1′ was also examined with various alcohols. Under the optimized reaction conditions, the catalytic performance of 1′ reached 96 % conversion of styrene oxide to its corresponding product with 98 % regioselectivity. The reusability and stability of the catalyst were proved by recycling up to four runs in the methanolysis of styrene oxide. The Lewis acidity originating from metal nodes and hydrogen bond donating (HBD) sites in the linker is distributed homogeneously throughout the framework, thus playing crucial role in the activation of epoxide with easy accessibility.
- Anbu, Nagaraj,Biswas, Shyam,Das, Aniruddha,Dhakshinamoorthy, Amarajothi,Sk, Mostakim
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- A new Br?nsted acid MIL-101(Cr) catalyst by tandem post-functionalization; synthesis and its catalytic application
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A new heterogeneous Br?nsted solid acid catalyst was prepared by tandem post-functionalization of MIL-101(Cr) and utilized for acetic acid esterification and alcoholysis of epoxides under solvent-free conditions. First, MIL-101(Cr) was functionalized with pyrazine to achieve MIL-101(Cr)-Pyz. Afterwards, the nucleophilic reaction of MIL-101(Cr)-Pyz with 1,3-propane sultone and next acidification with diluted sulfuric acid gave MIL-101(Cr)-Pyz-RSO3H Br?nsted solid acid catalyst. Various characterization methods such as Fourier transformation infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), elemental analysis (CHNS), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy-dispersiveX-ray(EDX) spectroscopy, thermal analysis (TGA/DTA), acid–base titration, and N2 adsorption/desorption analysis were employed to fully characterize the prepared catalyst. The catalyst showed high activity compared to unmodified MIL-101(Cr) in both catalytic acetic acid esterification and alcoholysis of epoxides. It can also be readily isolated from the reaction mixture and reused three times without major decrease in its activity.
- Mortazavi, Saeideh-Sadat,Abbasi, Alireza,Masteri-Farahani, Majid
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- Lead-Free Cs3Bi2Br9 Perovskite as Photocatalyst for Ring-Opening Reactions of Epoxides
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Herein, an innovative approach was developed by using stable, lead-free halide perovskite for solar-driven organic synthesis. The ring-opening reaction of epoxides was chosen as a model system for the synthesis of value-added β-alkoxy alcohols, which require energy-intensive process conditions and corrosive, strong acids for conventional synthesis. The developed concept included the in situ preparation of Cs3Bi2Br9 and its simultaneous application as photocatalyst for epoxide alcoholysis under visible-light irradiation in air at 293 K, with exceptional high activity and selectivity ≥86 % for β-alkoxy alcohols and thia-compounds. The Cs3Bi2Br9 photocatalyst exhibited good stability and recyclability. In contrast, the lead-based perovskite showed a conversion rate of only 1 %. The origin of the unexpected catalytic behavior was attributed to the combination of the photocatalytic process and the presence of suitable Lewis-acidic centers on the surface of the bismuth halide perovskite photocatalyst.
- Dai, Yitao,Tüysüz, Harun
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p. 2587 - 2592
(2019/06/08)
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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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- 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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p. 955 - 963
(2018/05/23)
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- Catalytic alcoholysis of epoxides using metal-free cucurbituril-based solids
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Metal-free cucurbit[7]uril (CB7) solid-state assemblies promote acid-catalysed alcoholysis of aliphatic and aromatic epoxides under mild conditions to give β-alkoxy alcohols, which are important intermediates for the synthesis of a vast range of compounds such as bioactive pharmaceuticals. The catalytic process is heterogeneous and the catalyst can be reused in consecutive runs without any reactivation treatment. The acid species responsible for the catalytic activity of CB7 may be entrapped hydronium ions.
- Bruno, Sofia M.,Gomes, Ana C.,Oliveira, Tania S. M.,Antunes, Margarida M.,Lopes, André D.,Valente, Anabela A.,Gon?alves, Isabel S.,Pillinger, Martyn
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supporting information
p. 3873 - 3877
(2016/05/24)
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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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- 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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- 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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- 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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supporting information
p. 7507 - 7509
(2013/08/23)
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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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- 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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- Mesoporous carbon as an efficient catalyst for alcoholysis and aminolysis of epoxides
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The ring opening reaction of epoxides by alcohols and amines using mesoporous activated carbon as efficient and environmentally friendly heterogeneous catalyst is reported. Carbon xerogels were synthesized by polymerization of resorcinol and formaldehyde. The surface of the activated carbon was oxidized in liquid phase with HNO3 and then functionalized with H2SO4. Chemical and textural characterization by elemental analysis, pHPZC, TPD, BET and XPS indicates that oxidation in liquid phase is effective in the introduction of strong acid groups in the carbon surface. The functionalization with H2SO4 led to more acid functional groups, as expected. The activated carbons were tested in alcoholysis and aminolysis of epoxides, having been obtained excellent results of conversion and selectivity, both over 95%.
- Matos, Inês,Neves, Paulo Duarte,Castanheiro, José Eduardo,Perez-Mayoral, Elena,Martin-Aranda, Rosa,Duran-Valle, Carlos,Vital, Joaquim,Botelho Do Rego, Ana M.,Fonseca, Isabel M.
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experimental part
p. 24 - 30
(2012/10/08)
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- Metal-organic frameworks as efficient heterogeneous catalysts for the regioselective ring opening of epoxides
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An iron-based metal-organic framework, [Fe(BTC)] (BTC: 1,3, 5benzenetricarboxylate) is an efficient catalyst in the ring opening of styrene oxide with alcohols and aniline under mild reaction conditions. Out of the various alcohols tested for ring opening of styrene oxide, methanol was found to be the most reactive in terms of percentage conversion and reactivity. The rate of the ring-opening reaction of styrene oxide decreases as the size of the alcohol is increased, suggesting the location of active sites in micropores. [Fe(BTC)] was a truly heterogeneous catalyst and could be reused without loss of activity. The analogous compound [Cu3(BTC)2] was also found to be effective, although with somewhat lower activity than [Fe(BTC)]. The present heterogeneous protocol is compared with a homogeneous catalyst to give an insight into the reaction mechanism.
- Dhakshinamoorthy, Amarajothi,Alvaro, Mercedes,Garcia, Hermenegildo
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experimental part
p. 8530 - 8536
(2010/09/15)
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- Activation and reactivity of epoxides on solid acid catalysts
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The aminolysis of epoxides over novel solid catalysts (Broensted-acidic SBA-15 functionalized with propylsulfonic acid and Lewis-acidic Ti-MCM-41) is reported. The acidic properties of these catalysts were determined by FTIR spectroscopy and temperature-programmed desorption of pyridine and NH3, respectively. The mesoporous solid acids of the present study are reusable and exhibit significantly higher catalytic activities than known catalysts for opening of the oxirane ring with nitrogen (aromatic and aliphatic amines)-containing and oxygen (alcohols)-containing nucleophiles. A range of β-amino alcohols with high regioselectivity and stereoselectivity were synthesized. Adsorption studies as well as the sigmoid shape of the conversion-versus-time plots show that the epoxide and amine compete for adsorption on the acidic sites ({single bond}SO3H or Ti4+) on the catalyst surface. Epoxide adsorption and activation on acid sites are the more critical processes. Catalytic activity decreases with increasing basicity of the amines and/or the alcohol, as well as the dielectric constant of the solvent.
- Saikia,Satyarthi,Srinivas,Ratnasamy
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p. 148 - 160
(2008/09/18)
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- Aluminium triflate: A remarkable Lewis acid catalyst for the ring opening of epoxides by alcohols
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Al(OTf)3 was found to be an extremely effective catalyst (at ppm levels) for ring opening reactions of epoxides using a range of alcohols. The Royal Society of Chemistry 2005.
- Bradley,Williams,Lawton, Michelle
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p. 3269 - 3272
(2007/10/03)
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- Ytterbium trifluoromethanesulfonate Yb(OTf)3: An efficient, reusable catalyst for highly selective formation of β-alkoxy alcohols via ring-opening of 1,2-epoxides with alcohols
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Ytterbium(III)triflate-catalysed ring-opening reactions of epoxides derived from styrene, cyclohexene, norbornene and stilbene, in the presence of alcohols (C1-C4 1°, 2° and 3° aliphatic alcohols, cyclohexyl alcohol, allyl and propargyl alcohol) resulted in the formation of β-alkoxy alcohols in good to excellent yield with high regio-, and, where applicable, stereoselectivity. Reaction of stilbene oxide with methanol in the presence of the diethyl ester of L-(+)-tartaric acid afforded the threo form of 1,2-diphenyl-2-methoxy ethanol with high diastereoselectivity (de 94%). Mechanistic implications of the results are discussed.
- Likhar,Kumar,Bandyopadhyay
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p. 836 - 838
(2007/10/03)
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- ALKOXYLATION OF SUBSTITUTED OXIRANES BY ALKOXYTITANIUN TOSYLATES
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Under mild conditions alkoxytitanium tosylates convert substituted oxiranes into the monoethers of 1,2-glycols with high regioselectivity.
- Sosnovskii, G. M.,Astapovich, I. V.,Nemogai, T. N.
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- The Use of Proton-exchanged X-Type Zeolite in Catalysing Ring-opening Reactions of 2-Substituted Epoxides with Nucleophiles and its Effect on Regioselectivity
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The use of proton-exchanged X-type zeolite in catalysing ring-opening reactions of 2-alkyl substituted epoxides with nucleophiles gives a high regioselectivity and functional-selective catalysis giving allylic products from allylic nucleophiles.Mechanistic aspects are discussed.
- Takeuchi, Hiroshi,Kitajima, Kunio,Yamamoto, Yasuhiro,Mizuno, Kiyokazu
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p. 199 - 203
(2007/10/02)
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