- 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
-
supporting information
p. 1834 - 1846
(2021/05/10)
-
- Sulfone Group as a Versatile and Removable Directing Group for Asymmetric Transfer Hydrogenation of Ketones
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The sulfone functional group has a strong capacity to direct the asymmetric transfer hydrogenation (ATH) of ketones in the presence of [(arene)Ru(TsDPEN)H] complexes by adopting a position distal to the η6-arene ring. This preference provides a
- Clarkson, Guy J.,Vyas, Vijyesh K.,Wills, Martin
-
supporting information
p. 14265 - 14269
(2020/07/04)
-
- A urea-containing metal-organic framework as a multifunctional heterogeneous hydrogen bond-donating catalyst
-
A urea-containing metal-organic framework (MOF) was synthesized from a V-shaped dicarboxylate ligand and Cu(II) ions. As the undesirable self-aggregation of the urea moiety has been prohibited in the framework, this MOF can act as a heterogeneous hydrogen
- Zhu, Chengfeng,Tang, Haitong,Yang, Keke,Wu, Xiang,Luo, Yunfei,Wang, Jin,Li, Yougui
-
-
- Dodecatungstocobaltate heteropolyanion encapsulation into MIL-101(Cr) metal–organic framework scaffold provides a highly efficient heterogeneous catalyst for methanolysis of epoxides
-
A heterogeneous catalyst was synthesized by encapsulation of a Keggin-type heteropolytungstate, potassium dodecatungstocobaltate trihydrate, K5[CoW12O40]·(Co-POM), into chromium(III) terephthalate (MIL-101). Encapsulation was achieved via a ‘build bottle around ship’ strategy in aqueous media, following a hydrothermal method. The structure of the resulting crystalline solid was characterized using X-ray diffraction, correlated with Fourier transform infrared and UV–visible spectroscopy. The metal content was analysed using optical emission spectroscopy. Transmission electron microscopy was used to measure particle size and N2 adsorption in a Brunauer–Emmett–Teller instrument to characterize the specific surface area. The catalytic activity was investigated using methanolysis of epoxides under mild conditions as a test reaction. The turnover frequency of the heterogeneous Co-POM@MIL-101 catalyst was more than 20 times higher than that of the homogeneous Co-POM catalyst. The Co-POM@MIL-101 catalyst was reused several times with negligible leaching of Co-POM and with no considerable loss of its initial efficiency. The simplicity of preparation, extraordinary stability and high reactivity make Co-POM@MIL-101 an exceptional catalytic matrix that is easily separable from reaction media.
- Marandi, Afsaneh,Tangestaninejad, Shahram,Moghadam, Majid,Mirkhani, Valiollah,Mechler, Adam,Mohammadpoor-Baltork, Iraj,Zadehahmadi, Farnaz
-
-
- Ru(III) complex anchored onto amino-functionalized MIL-101(Cr) framework via post-synthetic modification: an efficient heterogeneous catalyst for ring opening of epoxides
-
In this work, the metallo Schiff base-functionalized metal–organic framework was prepared by post-synthetic method and used as an electron-deficient catalyst for the alcoholysis of epoxides. In this manner, the aminated MIL-101 was modified with 2-pyridine carboxaldehyde and then the prepared Schiff base reacted with RuCl3. This new catalyst, MIL-101–NH2–PC–Ru, was characterized by Fourier transform infrared, UV–Vis spectroscopic techniques, X-ray diffraction, BET, inductively coupled plasma atomic emission spectroscopy and field-emission scanning electron microscopy. In the presence of this heterogeneous catalyst, ring opening of epoxides was performed under mild condition to show the significant ability and successful applications of Lewis acid containing catalysts in corporation with metal–organic frameworks. The reusability of the catalyst was also investigated. No noticeable decrease in the catalytic activity was found after four consecutive times.
- Jafari, Aneseh Khalatbari,Kardanpour, Reihaneh,Tangestaninejad, Shahram,Mirkhani, Valiollah,Moghadam, Majid,Mohammadpoor-Baltork, Iraj,Zadehahmadi, Farnaz
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p. 997 - 1006
(2018/05/23)
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- Asymmetric Transfer Hydrogenation of 1,3-Alkoxy/Aryloxy Propanones Using Tethered Arene/Ru(II)/TsDPEN Complexes
-
A series of propanones containing combinations of aryloxy and alkoxy substituents at the 1- and 3-positions were reduced to the alcohols via asymmetric transfer hydrogenation using a tethered Ru(II)/TsDPEN catalyst. The enantioselectivities of the reductions reveal a complex pattern of electronic and steric effects which, when used in a matched combination, can lead to the formation of products of up to 68% ee (84:16 er) from this highly challenging class of substrate.
- Forshaw, Sam,Matthews, Alexander J.,Brown, Thomas J.,Diorazio, Louis J.,Williams, Luke,Wills, Martin
-
supporting information
p. 2789 - 2792
(2017/06/07)
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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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- 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
-
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
-
supporting information
p. 5041 - 5045
(2017/11/09)
-
- Aniline-terephthalaldehyde resin p-toluenesulfonate (ATRT) as a highly efficient and reusable catalyst for alcoholysis, hydrolysis, and acetolysis of epoxides
-
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
-
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
-
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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- 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)
-
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
-
p. 1076 - 1088
(2016/02/09)
-
- Graphite oxide: A simple and efficient solid acid catalyst for the ring-opening of epoxides by alcohols
-
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)
-
- Ring opening of epoxides with alcohols using Fe(Cp)2BF 4 as catalyst
-
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
-
supporting information
p. 3979 - 3983
(2014/07/08)
-
- Efficient and regioselective ring-opening of epoxides with alcohols and sodium azide by using catalytic amounts of gacl3/polyvinylpyrrolidone
-
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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- Enantioselective ring-opening reaction of epoxides with MeOH catalyzed by homochiral metal-organic framework
-
Two new copper metal-organic frameworks containing 2,2′-dihydroxy-1, 1′-binaphthalene-5,5′-dicarboxylic acid (5,5′-H 2BDA) and 2,2′-dihydroxy-1,1′-binaphthalene-4,4′- dicarboxylic acid (4,4′-H2BDA) have been prepared. X-ray structure determination of [Cu2(5,5′-BDA)2(H 2O)2]·MeOH·2H2O (MOF-1) and [Cu2(4,4′-BDA)2(H2O)2] ·4H2O (MOF-2) revealed similar 2D sheet structures, containing square-grid coordination networks, but differences in the stacking motif. The desolvated MOF-1 and -2 were used as Lewis acid catalysts in the asymmetric ring-opening reaction of epoxides with MeOH.
- Tanaka, Koichi,Otani, Ken-Ichi,Murase, Takanori,Nishihote, Shyota,Urbanczyk-Lipkowska, Zofia
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experimental part
p. 709 - 714
(2012/08/08)
-
- Allyltin tribromide: A versatile reagent involved in the ring-opening of epoxides
-
This paper presents a versatile reagent for epoxide cleavage. The allyltin tribromide could act as a novel and easily prepared allylation reagent and halide atom donor to convert epoxides to the corresponding homoallyl alcohols and halohydrins in high yields with excellent regioselectivities under mild reaction conditions, respectively. It could also act as a Lewis acid to catalyze the ring opening reactions of epoxides with alcohols.
- Chen, Guohong,Wang, Xin,Jin, Xiaoqian,Liu, Lingyan,Chang, Weixing,Li, Jing
-
experimental part
p. 1294 - 1301
(2010/11/05)
-
- Erbium(III) triflate is a highly efficient catalyst for the synthesis of β-alkoxy alcohols, 1,2-diols and β-hydroxy sulfides by ring opening of epoxides
-
Chemo- and stereoselectivity in the ring-opening reaction of epoxides with erbium(III) triflate are described. Epoxides can be cleaved under neutral conditions with alcohols and thiols in the presence of catalytic amounts of Lewis acid, affording the corresponding β-alkoxy alcohols and β-hydroxy sulfides in high yields. In water, epoxide ring opening occurs to produce the corresponding diols in good yields.
- Dalpozzo, Renato,Nardi, Monica,Oliverio, Manuela,Paonessa, Rosina,Procopio, Antonio
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experimental part
p. 3433 - 3438
(2010/02/28)
-
- Epoxide ring-opening and Meinwald rearrangement reactions of epoxides catalyzed by mesoporous aluminosilicates
-
Mesoporous aluminosilicates efficiently catalyze the ring-opening of epoxides to produce β-alkoxyalcohols in high yields under extremely mild reaction conditions. These materials also catalyze the corresponding Meinwald rearrangement in non-nucleophilic solvents to give aldehydes which can be trapped in situ to provide the corresponding acetals in an efficient tandem process. The Royal Society of Chemistry 2009.
- Robinson, Mathew W. C.,Davies, A. Matthew,Buckle, Richard,Mabbett, Ian,Taylor, Stuart H.,Graham, Andrew E.
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experimental part
p. 2559 - 2564
(2009/10/30)
-
- Mild and efficient ring opening of epoxides catalyzed by potassium dodecatungstocobaltate(III)
-
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)
-
- ANDROGEN MODULATORS
-
The present invention is directed to a class of 4-cyano-phenoxy derivatives of formula I and to their use as androgen receptor modulators. Other aspects of the invention are directed to the use of these compounds to decrease excess sebum secretions and to
- -
-
Page/Page column 42-43
(2008/06/13)
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- Carbon tetrabromide: An efficient catalyst for regioselective ring opening of epoxides with alcohols and water
-
Epoxides undergo rapid ring opening with a range of alcohols in the presence of catalytic amount of carbon tetrabromide under mild and convenient conditions to afford the corresponding β-alkoxy alcohols and 1,2-diols in high yields with high regioselectivity. Georg Thieme Verlag Stuttgart.
- Yadav,Reddy,Harikishan,Madan,Narsaiah
-
p. 2897 - 2900
(2007/10/03)
-
- Rapid and efficient ring opening of epoxides catalyzed by a new electron deficient tin(IV) porphyrin
-
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)
-
- Silica sulfuric acid; an efficient and reusable catalyst for regioselective ring opening of epoxides by alcohols and water
-
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)
-
- Magnesium hydrogensulfate: A cheap and efficient catalyst for the conversion of epoxides into β-alkoxy alcohols, vicinal-diols, and thiiranes
-
The nucleophilic ring opening reactions of epoxides by aliphatic alcohols and water are achieved efficiently in the presence of catalytic amounts of magnesium hydrogensulfate, Mg(HSO4)2, with high degree of regioselectivity. The reactions are chemoselective and many of the other functional groups such as ethereal carbon oxygen bonds as well as carbon-carbon double bond remain intact under the reaction conditions. Epoxides also react with thiourea or ammonium thiocyanate in the presence of Mg(HSO 4)2 to afford the corresponding thiiranes in good to excellent yields.
- Salehi, Peyman,Khodaei, Mohammad Mahdi,Zolfigol, Mohammad Ali,Keyvan, Afsaneh
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p. 3041 - 3048
(2007/10/03)
-
- Efficient regio- and stereoselective ring opening of epoxides with alcohols, acetic acid and water catalyzed by ammonium decatungstocerate(IV)
-
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)
-
- Iron perchlorate on silica gel as multi-purpose reagent for catalysis of closure and rupture of carbon-oxygen bond in epoxides, alcohols, and esters
-
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)
-
- Aminopropyl silica gel supported iodine as catalyst in nucleophilic ring opening of epoxides and episulfides
-
Silica gel functionalized by aminopropyl group was prepared. Iodine was then supported on this inorganic polymer and used as a stable and efficient heterogeneous catalyst for nucleophilic ring opening reactions of epoxides and episulfides in different nucleophilic solvents such as alcohols, water and acetic acid.
- Tamami,Iranpoor,Mahdavi
-
p. 1251 - 1258
(2007/10/03)
-
- Ferric perchlorate: An efficient reagent for regio- and stereoselective alcoholysis and hydrolysis of epoxides
-
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
-
p. 2967 - 2973
(2007/10/03)
-
- Iron(III) trifluoroacetate as an efficient catalyst for solvolytic and nonsolvolytic nucleophilic ring opening of epoxides
-
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
-
p. 675 - 680
(2007/10/03)
-
- 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
-
p. 1017 - 1024
(2007/10/03)
-
- Highly efficient, regio- and stereoselective ring opening of epoxides and thiiranes with Ce(OTf)4
-
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
-
p. 347 - 366
(2007/10/03)
-
- Iodine and iodine supported on polyvinylpyrrolidone as catalysts and reagents for alcoholysis, hydrolysis, and acetolysis of epoxides and thiiranes
-
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
-
p. 1913 - 1919
(2007/10/03)
-
- Fe3+-montmorillonite: An efficient heterogeneous catalyst for highly regioselective alcoholysis of epoxides
-
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)
-
- Electrogenerated Acid as an Efficient Catalyst for Alcoholyses and Hydrolyses of Epoxides
-
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
-
p. 2591 - 2594
(2007/10/03)
-
- Highly efficient, regio- and stereoselective alcoholysis of epoxides catalyzed with iron(III) chloride
-
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
-
p. 1152 - 1154
(2007/10/02)
-
- Enzymatic resolution of butanoic esters of 1-phenyl, 1-phenylmethyl, 1-[2-phenylethyl] and 1-[2-phenoxyethyl] ethers of 3-methoxy-1,2-propanediol
-
The enzymatic hydrolysis of butanoic esters of 1-phenyl-, 1-phenylmethyl-, 1-[2-phenylethyl] and 1-[2-phenoxyethyl] ethers of 3-methoxy-1,2-propanediol has been studied by using lipases. Highest enantioselectivity E was obtained with amano PS lipase for the phenyl ether E ~ 55, and with lipase B from Candida antarctica for the other derivatives, E ~ 20, >100 and >55 respectively. The absolute configurations of the products were verified from comparison with reference compounds synthesised from (S)-epichlorohydrin or (S)-glycidol.
- Waagen,Hollingsaeter,Partali,Thorstad,Anthonsen
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p. 2265 - 2274
(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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- Photochemical Reactions of Arylglycidyl Ethers
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The absorption, fluorescence and phosphorescence spectra, respectively, of arylglycidyl ether 1 correspond to those of other alkyl aryl ethers.Also the photolysis product distribution (λ = 254 nm) is in agreement with a normal ether photolysis.Furthermore, photoinduced epoxy ring opening takes place giving homopolyaddition oligomers and in methanolic solution also CH3OH addition products.These reactions can be explained using the model of bichromophoric molecules with the ArO-chromophore as a donor and the epoxy ring as acceptor.The calculations based on this model ar e in agreement with the experimental data.In the aromatic nucleus halogene substituted 1 were dehalogenated with high quantum yields (0.25 in the case of bromo substituted compound 1g).The quantum yields of the ArO-C-bond scission are about 0.08 independently of the aromatic ring substituents.As indicated by sensitization and quenching experiments, respectively, with aromatic hydrocarbons the photo reactions proceed via S1 state.It was found that phenol quenches the photodegradation of 1 very efficiently.Excited methyl phenyl glycerol ether 5a reacts with phenyl glycidylether 1a in its ground state producing oligomers.
- Timpe, H.-J.,Garcia, C.,Fedtke, M.
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p. 616 - 626
(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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