- Cellulose sulfate: An efficient heterogeneous catalyst for the ring-opening of epoxides with alcohols and anilines
-
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)
-
- Rational design 2-hydroxypropylphosphonium salts as cancer cell mitochondria-targeted vectors: Synthesis, structure, and biological properties
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It has been shown for a wide range of epoxy compounds that their interaction with triphenylphosphonium triflate occurs with a high chemoselectivity and leads to the formation of (2-hydroxypropyl)triphenylphosphonium triflates 3 substituted in the 3-position with an alkoxy, alkylcarboxyl group, or halogen, which were isolated in a high yield. Using the methodology for the disclosure of epichlorohydrin with alcohols in the presence of boron trifluoride ether-ate, followed by the substitution of iodine for chlorine and treatment with triphenylphosphine, 2-hydroxypropyltriphenylphosphonium iodides 4 were also obtained. The molecular and supramolec-ular structure of the obtained phosphonium salts was established, and their high antitumor activity was revealed in relation to duodenal adenocarcinoma. The formation of liposomal systems based on phosphonium salt 3 and L-α-phosphatidylcholine (PC) was employed for improving the bioavailabil-ity and reducing the toxicity. They were produced by the thin film rehydration method and exhibited cytotoxic properties. This rational design of phosphonium salts 3 and 4 has promising potential of new vectors for targeted delivery into mitochondria of tumor cells.
- Amerhanova, Syumbelya K.,Dimukhametov, Mudaris N.,Gubaidullin, Aidar T.,Islamov, Daut R.,Litvinov, Igor A.,Lyubina, Anna P.,Mironov, Vladimir F.,Nemtarev, Andrey V.,Pashirova, Tatiana N.,Titov, Eugenii A.,Tsepaeva, Olga V.,Voloshina, Alexandra D.
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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
-
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
-
-
- Selective synthesis of epichlorohydrin: Via liquid-phase allyl chloride epoxidation over a modified Ti-MWW zeolite in a continuous slurry bed reactor
-
The epoxidation of allyl chloride (ALC) to epichlorohydrin (ECH) with H2O2 using a piperidine (PI)-modified Ti-MWW catalyst (Ti-MWW-PI) in a continuous slurry reactor was investigated to develop an efficient reaction system for the corresponding industrial process. The reaction parameters, including solvent, reaction temperature, t-butanol/ALC mass ratio, ALC/H2O2 molar ratio, weight hourly space velocity of H2O2, and the addition amount of ammonia, were studied in detail to pursue high H2O2 conversion and ECH selectivity. A long catalytic lifetime of 244 h was achieved at high H2O2 conversion (>97.0%) and ECH selectivity (>99.8%) under optimized reaction conditions. The crystallinity was well maintained for the deactivated Ti-MWW-PI catalyst, which was regenerated by a combination of calcination and piperidine treatment. This journal is
- Ding, Luoyi,Yin, Jinpeng,Tong, Wen,Peng, Rusi,Jiang, Jingang,Xu, Hao,Wu, Peng
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p. 331 - 342
(2021/01/11)
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- Readily Scalable Methodology for the Synthesis of Nonsymmetric Glyceryl Diethers by a Tandem Acid-/Base-Catalyzed Process
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A useful optimized synthetic methodology has been designed for the synthesis of nonsymmetric glyceryl diethers from epichlorohydrin. A tandem process combining a cheap, heterogeneous, and fully recoverable acid catalyst and alkaline hydroxide is used for the synthesis of a variety of glycerol-derived ethers bearing different alkyl substituents in 1 and 3 positions. Different heterogeneous acid catalysts have been tested for the reaction of epichlorohydrin with several alcohols, the best results being obtained with readily available recoverable and inexpensive montmorillonite-K10 and Nafion NR50. For the second reaction step, potassium hydroxide is used. In all the cases, good yields of the desired glyceryl diethers are obtained in smooth reaction conditions, always with total conversion of epichlorohydrin and without the need of intermediate purification. Scale-up of the tandem process has been carried out with good results.
- Leal-Duaso, Alejandro,Gracia-Barberán, Sara,Mayoral, José A.,Garciá, José I.,Pires, Elisabet
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p. 154 - 162
(2020/02/04)
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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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- Epoxide ring opening with alcohols using heterogeneous Lewis acid catalysts: Regioselectivity and mechanism
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Lewis acidic catalytic materials are investigated for the regioselective ring opening of epoxides with alcohols. For ring opening epichlorohydrin with methanol, the catalytic activity shows a strong dependence on the type of support and Lewis acidic species used. While Sn-SBA-15 is catalytically active, significantly higher catalytic activity can be achieved with hydrothermally synthesized zeolites of which Sn-Beta is 6 and 7 times more active than Zr-Beta or Hf-Beta, respectively. Sn-Beta is determined to be more active and more regioselective for epoxide ring opening of epichlorohydrin with methanol than Al-Beta. For Sn-Beta, the activation energy for the reaction between epichlorohydrin and methanol is determined to be 53 ± 7 kJ mol?1. For epichlorohydrin, the activation energy barrier and experimentally observed regioselectivity are found using DFT to be consistent with a concerted reaction mechanism involving activation of the epoxide on an alcohol adsorbed on the catalytic site and nucleophilic attack by a second alcohol. The epoxide is shown to impact the regioselectivity and the mechanism since isobutylene oxide is selectively ring opened by methanol to form the terminal alcohol. DFT calculations indicate the mechanism for isobutylene ring opening involves epoxide activation and ring opening on an alcohol adsorbed onto the catalytic site. Finally, catalyst reuse testing indicates that Sn-Beta can be used for multiple reactions with no decrease in activity and limited to no leaching of the tin site, demonstrating Sn-Beta is a promising catalytic material for epoxide ring opening reactions with alcohols.
- Deshpande, Nitish,Parulkar, Aamena,Joshi, Rutuja,Diep, Brian,Kulkarni, Ambarish,Brunelli, Nicholas A.
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- Scalable and super-stable exfoliation of graphitic carbon nitride in biomass-derived γ-valerolactone: Enhanced catalytic activity for the alcoholysis and cycloaddition of epoxides with CO2
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Biomass-derived γ-valerolactone (GVL) could exfoliate bulk g-C3N4 to form a super-stable dispersion of few-layer g-C3N4 nanosheets with a high concentration of up to 0.8 mg mL-1 due to the polarity and the appropriate surface energy of GVL. The exfoliation process can be easily extended to a 200 ml scale and should be extended further. The formed g-C3N4 nanosheets showed enhanced activity for the alcoholysis of epoxides and the cycloaddition of epoxides with CO2 owing to their higher specific surface areas and more exposed active centers than the bulk g-C3N4. This affords a green, facile and scalable method to form few-layer g-C3N4 nanosheets and further expand the application of g-C3N4 materials to the field of non-photocatalysis.
- Xue, Zhimin,Liu, Feijie,Jiang, Jingyun,Wang, Jinfang,Mu, Tiancheng
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p. 5041 - 5045
(2017/11/09)
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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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- 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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- 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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- 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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- 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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- Nucleophilic reactivity of ethers against terminal epoxides in the presence of BF3: A mechanistic study
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In the presence of BF3, a series of symmetrical and unsymmetrical ethers reacted with epichlorohydrin and 2-[(benzyloxy)methyl] oxirane, two terminal epoxides, to afford 1-alkoxy-3-chloropropan-2-ol and 1-alkoxy-3-(benzyloxy)propan-2-ol. The cleavage of unsymmetrical ethers occurred via an SN2 or SN1 mechanism. Secondary epoxides did not give similar ring-opening products. Copyright
- Kose, Aytekin,Altundas, Ramazan,Secen, Hasan,Kara, Yunus
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p. 1325 - 1330
(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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- Graphene oxide as an acid catalyst for the room temperature ring opening of epoxides
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The minute amount of hydrogen sulfate groups introduced into the graphene oxide (GO) obtained by Hummers oxidation of graphite renders this material as a highly efficient, recyclable acid catalyst for the ring opening of epoxides with methanol and other primary alcohols as nucleophile and solvent.
- Dhakshinamoorthy, Amarajothi,Alvaro, Mercedes,Concepcion, Patricia,Fornes, Vicente,Garcia, Hermenegildo
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supporting information; experimental part
p. 5443 - 5445
(2012/07/28)
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- Mild organic ammonium tribromide-mediated regioselective ring opening of epoxides with alcohols, water, acetic anhydride, and amines under solvent-free reaction conditions
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Organic ammonium tribromide (OATB), N-methylpyrrolidine-2-one hydrotribromide (MPHT) was found to be an efficient catalyst for the regioselective ring opening of epoxides with various nucleophiles under solvent free conditions. This procedure occurs under neutral and mild reaction conditions with out adding any additive and afforded high yields of products.
- Singhal, Sweety,Jain, Suman L.,Sain, Bir
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experimental part
p. 1829 - 1837
(2011/06/19)
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- AZIDE COMPOSITIONS AND METHODS OF MAKING AND USING THEREOF
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Azide compositions selected from i) UOCR2CR2N3 wherein U is D, or a urethane (—CO—NR2) and R is independently H, D, or an organic group; ii) R′2NCR2CR2N3 or A-R′3NCR2CR2N3 wherein R′ is an organic group and A is an anion; or iii) G(N3)m wherein m is an integer from 2 to about 10 and G is a m-valent organic group wherein at least two of the azido groups are connected via aliphatic carbon atoms wherein G may contain organic groups, and uses thereof are described. Specifically, the azide compositions selected from the group consisting of: N3CH2CH2OCH2CHOHCH2N3, CH3OCH2CHOHCH2N3, CH3OCH2CH(OCONHC4H9)CH2N3, N3CH2CH2O[CH2CH(CH2N3)O]6H, CH3CH2C[CH2(OCH2CH(CH2N3))2OCOCH3]3N3CH2CH2OCONH(CH2)6NHCOOCH2CH2N3, (CH3)3CNHCOOCH2CH2N3, n-C4H9NDCOOCH2CH2N3, C6H5N—HCOOCH2CH2N3, C4F9OCFCF3NDCOOCH2CH2N3, DOCH2CH2N3, and [(CH3)3NCH2CH2N3]+I are described.
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Page/Page column 6
(2011/10/10)
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- PROCESS FOR PRODUCING AN OXIRANE
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A multiple liquid phase composition and process for preparing an oxirane product, such as epichlorohydrin, including a reaction mixture of: (a) at least one olefin, wherein the olefin is selected from one of (i) an aliphatic olefin or substituted aliphatic olefin, with the proviso that the aliphatic olefin is not propylene, (ii) a cycloaliphatic olefin, (iii) an aromatic olefin, (iv) a cycloaromatic olefin, and (v) mixtures thereof; (b) at least one peroxide compound, (c) at least one catalyst, and (d) and a solvent mixture; wherein the solvent mixture comprises at least (i) at least one alcohol or a combination of alcohols, and (ii) at least one non-reactive co-solvent; wherein the solvents are mixed at a predetermined concentration; wherein the non-reactive co- solvent has a different boiling point than the oxirane product; and wherein the oxirane product partitions into a high affinity solvent during the reaction. The process of the present invention advantageously produces a waste stream with no significant amount of sodium chloride (NaCl). In one embodiment, the present invention includes a process for preparing epichlorohydrin from allyl chloride and hydrogen peroxide including reacting (a) an allyl chloride with (b) hydrogen peroxide, in the presence of (c) a titanium silicalite-1 (TS-1) catalyst and (d) in the presence of a predetermined amount of a mixed solvent system; wherein the mixed solvent system includes at least (i) methanol and (ii) at least one non-reactive co-solvent.
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Page/Page column 27; 31; 33
(2011/02/24)
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- Alumina-supported molybdenum (VI) oxide: An efficient and recyclable heterogeneous catalyst for regioselective ring opening of epoxides with thiols, acetic anhydride, and alcohols under solvent-free conditions
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An efficient and simple protocol for regioselective ring opening of epoxides with thiols, acetic anhydride, and alcohols using 16wt% MoO3 supported on alumina as a recyclable catalyst is described. Copyright
- Singhal, Sweety,Jain, Suman L.,Sain, Bir
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p. 620 - 621
(2008/12/21)
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- Mild and efficient ring opening of epoxides catalyzed by potassium dodecatungstocobaltate(III)
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Efficient ring opening of epoxides under mild conditions is reported. Potassium dodecatungstocobaltate(III) trihydrate was used as an efficient catalyst for the alcoholysis and acetolysis of epoxides. Conversion of epoxides to thiiranes was also performed efficiently in the presence of this catalyst. Springer-Verlag 2005.
- Tangestaninejad, Shahram,Moghadam, Majid,Mirkhani, Valiollah,Yadollahi, Bahram,Mirmohammadi, S. Mohammad R.
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p. 235 - 242
(2007/10/03)
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- Synthesis of 1-alkoxy-3-N-succinimido-2-propanols
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Procedures for preparing 1-alkoxy-3-chloro-2-propanols, with their subsequent transformation to 1-alkoxy-N-succinimido-2-propanols, were developed.
- Gasanov,Allakhverdiev
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p. 2026 - 2028
(2007/10/03)
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- Rapid and efficient ring opening of epoxides catalyzed by a new electron deficient tin(IV) porphyrin
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The new electron deficient tin(IV) tetraphenylporphyrinato trifluoromethanesulfonate, [SnIV(tpp)(OTf)2], was used as an efficient catalyst for the alcoholysis, hydrolysis and acetolysis of epoxides. Conversion of epoxides to thiiranes and acetonides were also performed efficiently in the presence of this catalyst.
- Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Shaibani, Reza
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p. 6105 - 6111
(2007/10/03)
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- Silica sulfuric acid; an efficient and reusable catalyst for regioselective ring opening of epoxides by alcohols and water
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The nucleophilic ring opening reactions of epoxides by aliphatic alcohols and water are achieved efficiently in the presence of catalytic amounts of silica sulfuric acid with high degree of regioselectivity. The catalyst is reusable and can be applied several times without any decrease in the yield of reactions.
- Salehi, Peyman,Dabiri, Minoo,Zolfigol, Mohammad Ali,Fard, Mohammad Ali Bodaghi
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p. 1113 - 1121
(2007/10/03)
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- Efficient regio- and stereoselective ring opening of epoxides with alcohols, acetic acid and water catalyzed by ammonium decatungstocerate(IV)
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Epoxides can be cleaved in a regio- and stereoselective manner under neutral conditions with alcohols and acetic acid in the presence of catalytic amounts of decatungstocerate(IV) ion, ([CeW10O36] 8-), affording the corresponding β-alkoxy and β-acetoxy alcohols in high yields. In water, ring opening of epoxides occurs with this catalyst to produce the corresponding diols in good yields.
- Mirkhani, Valiollah,Tangestaninejad, Shahram,Yadollahi, Bahram,Alipanah, Ladan
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p. 8213 - 8218
(2007/10/03)
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- Iron perchlorate on silica gel as multi-purpose reagent for catalysis of closure and rupture of carbon-oxygen bond in epoxides, alcohols, and esters
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Aliphatic alcohols and water in the presence of catalytic amounts of Fe3+ ion introduced as iron(III) perchlorate on silica gel carrier perform efficient regiospecific opening of an epoxy ring. Carbon acids esterification with various type alcohols was carried out using the system Fe(ClO4)3-silica gel in dichloromethane under conditions excluding solvolysis. Acetylation and formylation of alcohols was performed by efficient transesterification with ethyl acetate and ethyl formate.
- Salechi,Khodaei,Ghareghani,Motlagh
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p. 794 - 796
(2007/10/03)
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- Reactions of epoxides and episulfides with electrophilic halogens
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A novel method is described for the conversion of epoxides into β-bromoformates using Ph3PBr2, Ph3P/N-bromosuccinimdes (NBS) and or Ph3P/2,4,4,6-tetrabromo-2,5-cyclohexadiene-1-one (TABCO) in DMF. Epoxides in the presence of Ph3P/I2 were converted into olefins immediately in excellent yields. The application of NBS, NCS, and TABCO as compounds carrying electrophilic halogens for the highly selective alcoholysis of epoxides and dimerization or alcoholysis dimerization of episulfides are also described.
- Iranpoor, Nasser,Firouzabadi, Habib,Chitsazi, Maryam,Ali Jafari, Abbas
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p. 7037 - 7042
(2007/10/03)
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- Iron(III) trifluoroacetate as an efficient catalyst for solvolytic and nonsolvolytic nucleophilic ring opening of epoxides
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Iron(III) trifluoroacetate was used as an efficient and nonhygroscopic catalyst for the alcoholysis, hydrolysis, and acetolysis of epoxides. The addition of chloride, bromide, iodide, and nitrate ions to epoxides to produce the corresponding 2-halo and 2-nitratoalkanols and also the conversion of epoxides to acetonides and thiiranes were also performed efficiently in the presence of this catalyst.
- Iranpoor, Nasser,Adibi, Hadi
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p. 675 - 680
(2007/10/03)
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- Bismuth(III) chloride (BiCl3); an efficient catalyst for mild, regio- and stereoselective cleavage of epoxides with alcohols, acetic acid and water
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Epoxides can be cleaved in a regio- and stereoselective manner with alcohols, acetic acid and water in the presence of catalytic amounts of bismuth(III) chloride, affording the corresponding β-alkoxy and β-acetoxy alcohols and diols in high yields.
- Mohammadpoor-Baltork,Tangestaninejad,Aliyan,Mirkhani
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p. 2365 - 2374
(2007/10/03)
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- Ferric perchlorate: An efficient reagent for regio- and stereoselective alcoholysis and hydrolysis of epoxides
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Regio- and stereoselective ring opening reaction of epoxides is achieved efficiently by aliphatic alcohols and water in the presence of catalytic amounts of ferric perchlorate.
- Salehi, Peyman,Seddighi, Behnam,Irandoost, Mohsen,Kargar Behbahani, Farahnaz
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p. 2967 - 2973
(2007/10/03)
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- The kinetics of chloromethyloxirane reaction with alcohols and their adducts in the presence of stannic chloride
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Rate constants of the reaction of chloromethyloxirane (epichlorohydrin) with methyl, n-propyl, isopropyl, n-, sec-, tert-butyl, n-hexyl, n-octyl, and n-decyl alcohols in the presence of stannic chloride were studied at 30, 40, and 50°C. Reaction is not first order in respect to epichlorohydrine and is particularly fast at the beginning and its rate constants are proportional to the concentration of the catalyst. The rate constants increase in the homologous series of C1-C10 alcohols. The reaction rates of 2-chloromethyloxirane with 1-chloromethyl-2-alkoxyethanols are ca. 2.5-times larger than that with corresponding alcohols.
- Chlebicki,Pozniak
-
-
- TiCl3(OTf) and TiO(TFA)2 efficient catalysts for ring opening of epoxides with alcohols, acetic acid and water
-
TiCl3 (OTf) and TiO(TFA)2 can efficiently catalyze nucleophilic ring opening of epoxides in primary, secondary and tertiary alcohols, acetic acid and water to give the corresponding β-alkoxy alcohols, β-acetoxy alcohols and vicinal diols with high stereo- and regioselectivity in excellent yields. The reaction of optically active styrene oxide in MeOH with two titanium reagents was found to be highly stereospecific and afforded the corresponding S-(+)-2-methoxy-2-phenyl ethanol in 89-95% ee.
- Iranpoor, Nasser,Zeynizadeh, Behzad
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p. 1017 - 1024
(2007/10/03)
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- Highly efficient, regio- and stereoselective ring opening of epoxides and thiiranes with Ce(OTf)4
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Ceric triflate, Ce(OTf)4 is used as an efficient catalyst for ring opening of epoxides in the presence of alcohols, water, and acetic acid. The reactions proceed with high regio and stereoselectivity and in excellent yields. The reaction of R(+) styrene oxide with methanol occurs with excellent optical purity. Ring opening of thiiranes in alcohols, water and acetic acid followed by dimerisation to the corresponding disulfides occur efficiently in the presence of this reagent. A mild method for the preparation of dithianes from thiiranes and Ce(OTf)4 is also described.
- Iranpoor,Shekarriz,Shiriny
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p. 347 - 366
(2007/10/03)
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- Iodine and iodine supported on polyvinylpyrrolidone as catalysts and reagents for alcoholysis, hydrolysis, and acetolysis of epoxides and thiiranes
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Iodine and iodine supported on polyvinylpyrrolidone (betadine) have been used as catalysts for ring opening of epoxides and as reagent for ring-opening dimerization of thiiranes in alcohols, water, and acetic acid. The reactions occur with high regio-, chemo-, and stereoselectivity. The reaction of R-(+)-styrene oxide with I2 supported on PVP in methanol was found to be very stereospecific and the product was isolated in 93% ee.
- Iranpoor, Nasser,Tamami, Bahman,Niknam, Khodabakhsh
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p. 1913 - 1919
(2007/10/03)
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- On the mechanism of alcoholysis of allylic and benzylic alcohols and of epoxides in the presence of ceric ammonium nitrate
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The methanolysis of allylic alcohols, benzylic tertiary alcohols and epoxides in the presence of a catalytic amount of ceric ammonium nitrate (CAN) is shown to be catalysed by protons generated from the oxidation of methanol. This reaction is also catalysed by Lewis acids.
- Chapuzet, Jean-Marc,Beauchemin, Sophie,Daoust, Benoit,Lessard, Jean
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p. 4175 - 4180
(2007/10/03)
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- FeCl3·6H2O supported on SiO2 catalysed ring opening of epoxides with alcohols, acetic acid, water, chloride, bromide and nitrate ions
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FeCl3·6H2O absorbed on chromatographic silica gel can act as an efficient catalyst for alcoholysis, hydrolysis and acetolysis of epoxides. Methanolysis of (R)-styrene oxide proceeds with high stereospecificity and in excellent yield. This catalyst can also convert epoxides to their corresponding β-halohydrins and β-nitrato alcohols in the presence of chloride, bromide and nitrate ions respectively.
- Iranpoor, Nasser,Tarrian, Tahere,Movahedi, Zarangiz
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p. 1473 - 1476
(2007/10/03)
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- Fe3+-montmorillonite: An efficient heterogeneous catalyst for highly regioselective alcoholysis of epoxides
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Fe3+- exchanged montmorillonite (Fe3+ -mont) has shown to be a very efficient catalyst for regio and stereoselective alcoholysis of epoxides in primary, secondary and tertiary alcohols as solvents and nucleophiles. Copyright
- Choudary, Boyapati M.,Sudha, Yepuri
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p. 2989 - 2992
(2007/10/03)
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- Electrogenerated Acid as an Efficient Catalyst for Alcoholyses and Hydrolyses of Epoxides
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The electrochemical transformation of different epoxides to their corresponding β-alkoxy alcohols and diols was achieved by using an electrogenerated acid-catalyst.A competitive ring-opening reaction of activated epoxides in the presence of deactivated epoxides was also successfully carried out in both alcohols and water.
- Safavi, Afsaneh,Iranpoor, Nasser,Fotuhi, Lida
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p. 2591 - 2594
(2007/10/03)
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- Tris[Trinitrato Ce(IV)]paraperiodate, an efficient heterogeneous catalyst for alcoholysis, acetolysis and hydrolysis of epoxides
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Tristrinitrato [Ce(IV)]paraperiodate (TTCPP) catalyses ring opening of epoxides in alcohols and water stereo- and regioselectively and under heterogeneous conditions to produce the corresponding β-alkoxy alcohols and 1,2 diols respectively in good to high yields. In acetic acid, ring opening and dimerization of epoxides occurs with this catalyst to produce the corresponding succinic acid derivatives in high yields.
- Iranpoor,Zardaloo
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p. 1959 - 1969
(2007/10/02)
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- Highly efficient, regio- and stereoselective alcoholysis of epoxides catalyzed with iron(III) chloride
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An efficient, catalytic, simple and mild method for the conversion of epoxides into their corresponding β-alkoxy alcohols was performed in primary, secondary and tertiary alcohols and in the presence of catalytic amounts of ferric chloride. The β-alkoxy alcohols were obtained with high stereo- and regioselectivity and in good to excellent yields.
- Iranpoor,Salehi
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p. 1152 - 1154
(2007/10/02)
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- 2,3-Dichloro-5,6-dicyano-p-benzoquinone, an efficient, mild, neutral and highly regioselective catalyst for alcoholysis of epoxides
-
Ring-opening reactions of epoxides with catalytic amounts of 2,3- Dichloro-5,6-Dicyano-p-Benzoquinone (DDQ) are performed with high regioselectivity under neutral conditions, in primary, secondary and tertiary alcohols as solvents and nucleophiles. The corresponding β- alkoxy alcohols were obtained in excellent yields.
- Iranpoor,Mohammadpour Baltork
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p. 735 - 738
(2007/10/02)
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- Mild, Efficient and Selective Opening of Epoxides with Alcohols Catalyzed by Ceric(IV) Ammonium Nitrate
-
Commercially available Ceric(IV) Ammonium Nitrate (CAN) catalyzes nucleophilic ring opening of epoxides in primary, secondary and tertiary alcohols under mild conditions.The corresponding β-alkoxy-alcohols were obtained with high regio and stereoselectivity in high yields.
- Iranpoor, N.,Baltork, I. Mohammadpour
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p. 2789 - 2797
(2007/10/02)
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- Organotin Phosphate Condensates as a Catalyst of Selective Ring-Opening of Oxiranes by Alcohols
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The highly regioselective alcoholysis of oxiranes is catalyzed by organotin phosphate condensates, providing a variety of β-alkoxy alcohols in good yields.The selectivity of the nucleophilic attack is dependent on the structures of epoxides.The gem-dialkyloxiranes are cleaved on the tertiary carbon, while β,γ-epoxy alcohols and their derivatives gave C-3 attack products.The anti stereoisomers are solely produced in the latter case.Thus the catalysis is both acidic and coordinative.Of practical importance is the recycled use of the catalyst without any appreciable decrease in the activity and the selectivities.
- Otera, Junzo,Niibo, Yoshihisa,Tatsumi, Naofumi,Nozaki, Hitosi
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p. 275 - 278
(2007/10/02)
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- HIGHLY REGIOSELECTIVE RING OPENING OF EPOXIDES WITH ALCOHOLS CATALYZED BY ORGANOTIN PHOSPHATE CONDENSATES
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Organotin phosphate condensates proved to catalyze the ring opening reaction of epoxides with alcohols in a highly regioselective manner.
- Otera, Junzo,Yoshinaga, Yukari,Hirakawa, Kazuhisa,Nakata, Tetsuya
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p. 3219 - 3222
(2007/10/02)
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- REACTIONS OF 1-CHLORO-2,3-EPOXYPROPANE WITH ALCOHOLS IN THE PRESENCE OF STANNIC CHLORIDE I. KINETICS OF THE REACTION OF 1-CHLORO-2,3-EPOXYPROPANE WITH METHANOL
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During investigation of the kinetics of the addition of 1-chloro-2,3-epoxypropane to methanol in the presence of stannic chloride it was shown that the initial catalytic complex SnCl4.2ROH is converted into the complex (SnCl3OR.ROH)2.The process gives rise to a decrease in the activity of the catalyst during the process.A reaction mechanism is proposed.
- Drugov, M. V.,Barantsevich, E. N.,Drach, V. A.
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p. 1046 - 1051
(2007/10/02)
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- REACTIONS OF 1-CHLORO-2,3-EPOXYPROPANE WITH ALCOHOLS IN THE PRESENCE OF STANNIC CHLORIDE. II. DISTRIBUTION OF THE ADDITION PRODUCTS AND THE RELATIVE ACTIVITY OF THE ALCOHOLS
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In the distribution of the products from the reaction of 1-chloro-2,3-epoxypropane with alcohols in the presence of stannic chloride the determining factor is their capacity for complex formation with stannic chloride.This is confirmed by a correlation between the independently determined relative reaction constants and the constants for exchange of the alcohols and the complexes with stannic chloride.
- Drugov, M. V.,Barantsevich, E. N.,Smirnov P. A.
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p. 1052 - 1056
(2007/10/02)
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- Crown Cation Complex Effects. 20. Syntheses and Cation Binding Properties of Carbon-Pivot Lariat Ethers
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In an effort devise synthetic cation binders that will mimic the behavior of naturally occuring ionophores such as valinomycin, we have prepared approximately 30 macrocyclic (crown) polyethers bearing flexible side chains attached to the macro ring at carbon.In many of these "carbon-pivot" compounds, the side chain contains one or more neutral donor groups that, if in a suitable geometrical arrangement, may provide additional solvation to the macro-ring-bound cation.Although such donors often enhanced the cation binding ability, overall, the increases in stability constants were modest.The physical resemblance and concept of "roping and tying" the cation suggest the name "lariat ethers".Syntheses of these molecules and binding by them of Na+ and K+ cations are reported and conclusions drawn about the structural requirements and cation binding efficacy of these materials.
- Dishong, Dennis M.,Diamond, Craig J.,Cinoman, Michael I.,Gokel, Geoge W.
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p. 586 - 593
(2007/10/02)
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- Enhancement of Cation Binding in Lariat Ethers Bearing a Methyl Group at the Quaternary, Pivot Carbon Atom
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A number of carbon-pivot lariat ethers have been prepared and compared, with their counterparts having a methyl group bonded to the side-arm-bearing or pivot carbon.All of the compounds examined are 15-crown-5 derivatives, and in this series, the methyl lariats invariably show a higher affinity for sodium than do the nonmethylated species.The results are less consistent in the case of potassium cation which is larger than the 15-crown-5 compound's cation binding hole.The enhanced stability constant observed for sodium with the methyl lariats is attributed to reduced s ide-arm mobility or conformational changes in either the side arm or macroring.
- Nakatsuji, Yohji,Nakamura, Tetsuya,Okahara, Mitsuo,Dishong, Dennis M.,Gokel, George W.
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p. 1237 - 1242
(2007/10/02)
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- ALCOOLYSE DE L'EPICHLORHYDRINE DU GLYCEROL SUR CATALYSEUR SOLIDE. SYNTHESE COMMODE D'ETHERS DU CHLORO-3 PROPANE DIOL-1,2.
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Monoethers of 3-chloro-1,2 propanediol were easily obtained in good yields from epichlorohydrin and alcohols under catalysis of actived montmorillonite K 10.
- Thuy, Vu Moc,Petit, Huguette,Maitte, Pierre
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p. 261 - 262
(2007/10/02)
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