- Clay (Montmorillonite K10) catalysis of the Michael addition of α,β-unsaturated carbonyl compounds to indoles: The beneficial role of alcohols
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The Michael addition of methylvinylketone to indole can be performed under smooth conditions by running the reaction in the presence of an acidic clay catalyst (K10 Montmorillonite) and an aliphatic alcohol such as ethanol or 2-propanol. Presence of an alcohol along with a polar solvent (nitromethane) in the reaction medium considerably improves the reaction.
- Poupaert, Jacques H.,Bukuru, Jacques,Gozzo, Andrea
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Read Online
- Practical Chemoselective Acylation: Organocatalytic Chemodivergent Esterification and Amidation of Amino Alcohols with N-Carbonylimidazoles
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Chemoselective transformations are a cornerstone of efficient organic synthesis; however, achieving this goal for even simple transformations, such as acylation reactions, is often a challenge. We report that N-carbonylimidazoles enable catalytic chemodivergent aniline or alcohol acylation in the presence of pyridinium ions or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), respectively. Both acylation reactions display high and broad chemoselectivity for the target group. Unprecedented levels of chemoselectivity were observed in the DBU-catalyzed esterification: A single esterification product was obtained from a molecule containing primary aniline, alcohol, phenol, secondary amide, and N?H indole groups. These acylation reactions are highly practical as they involve only readily available, inexpensive, and relatively safe reagents; can be performed on a multigram scale; and can be used on carboxylic acids directly by in situ formation of the acylimidazole electrophile.
- Nelson, Hope,Richard, William,Brown, Hailee,Medlin, Abigail,Light, Christina,Heller, Stephen T.
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supporting information
p. 22818 - 22825
(2021/09/13)
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- Metal–Organic Layers Hierarchically Integrate Three Synergistic Active Sites for Tandem Catalysis
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We report the design of a bifunctional metal–organic layer (MOL), Hf12-Ru-Co, composed of [Ru(DBB)(bpy)2]2+ [DBB-Ru, DBB=4,4′-di(4-benzoato)-2,2′-bipyridine; bpy=2,2′-bipyridine] connecting ligand as a photosensitizer and Co(dmgH)2(PPA)Cl (PPA-Co, dmgH=dimethylglyoxime; PPA=4-pyridinepropionic acid) on the Hf12 secondary building unit (SBU) as a hydrogen-transfer catalyst. Hf12-Ru-Co efficiently catalyzed acceptorless dehydrogenation of indolines and tetrahydroquinolines to afford indoles and quinolones. We extended this strategy to prepare Hf12-Ru-Co-OTf MOL with a [Ru(DBB)(bpy)2]2+ photosensitizer and Hf12 SBU capped with triflate as strong Lewis acids and PPA-Co as a hydrogen transfer catalyst. With three synergistic active sites, Hf12-Ru-Co-OTf competently catalyzed dehydrogenative tandem transformations of indolines with alkenes or aldehydes to afford 3-alkylindoles and bisindolylmethanes with turnover numbers of up to 500 and 460, respectively, illustrating the potential use of MOLs in constructing novel multifunctional heterogeneous catalysts.
- Quan, Yangjian,Lan, Guangxu,Shi, Wenjie,Xu, Ziwan,Fan, Yingjie,You, Eric,Jiang, Xiaomin,Wang, Cheng,Lin, Wenbin
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p. 3115 - 3120
(2020/12/09)
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- Boron-Catalyzed Dehydrative Friedel-Crafts Alkylation of Arenes Using β-Hydroxyl Ketone as MVK Precursor
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Boron-catalyzed environmentally benign dehydrative Friedel-Crafts alkylation of indole/pyrrole and aniline derivatives with β-hydroxyl ketones has been developed for the first time. This method provides an efficient and green replacement of toxic and unst
- San, Htet Htet,Huang, Jie,Lei Aye, Seinn,Tang, Xiang-Ying
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supporting information
p. 2386 - 2391
(2021/01/04)
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- Synthesis of CF3-Containing Spirocyclic Indolines via a Red-Light-Mediated Trifluoromethylation/Dearomatization Cascade
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A red-light-mediated nPr-DMQA+-catalyzed cascade intramolecular trifluoromethylation and dearomatization of indole derivatives with Umemoto's reagent has been developed. This protocol provides a facile and efficient approach for the construction of functionalized and potentially biologically important CF3-containing 3,3-spirocyclic indolines with moderate to high yields and excellent diastereoselectivities under mild conditions. The success of multiple gram-scale (1 and 10 g) experiments further highlights the robustness and practicality of this protocol and the merit of the employment of red light. Mechanistic studies support the formation of a crucial CF3 radical species and a dearomatized benzyl carbocation intermediate.
- Gianetti, Thomas L.,Mei, Liangyong,Moutet, Jules,Stull, Savannah M.
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supporting information
p. 10640 - 10653
(2021/07/31)
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- Alkylation of Indoles with α,β-Unsaturated Ketones using Alumina in Hexanes
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We evaluated the influence of solvent on the alumina-promoted C3-alkylation of indoles with α,β-unsaturated ketones. We found that lipophilic solvents were generally superior to hydrophilic ones with hexanes offering the 3-alkyl indole products in high yields. Thus, we demonstrate an inexpensive and procedurally simple new process that pairs acidic alumina with hexanes to achieve this important Michael alkylation. The substrate scope includes twenty-four examples with reaction yields ranging from 61 to 96%. (Figure presented.).
- Zhang, Xiong,Jones-Mensah, Ebenezer,Deobald, Jackson,Magolan, Jakob
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supporting information
p. 5548 - 5551
(2019/11/19)
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- Ruthenium-Catalyzed Selective C?C Coupling of Allylic Alcohols with Free Indoles: Influence of the Metal Catalyst
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Versatile reactive activities of allyl alcohols with free indoles in C?H functionalization reactions were investigated. Direct alkylation or cascade cyclization reactions could be selectively controlled based on the catalyst system: Ru(PPh3)3Cl2 provided C3-substituted β-ketone indoles whereas [Ru(p-cymene)Cl2]2 yielded cyclized indoles.
- Xia, Ying-Qi,Li, Chao,Liu, Man,Dong, Lin
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supporting information
p. 5474 - 5478
(2018/03/29)
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- Regioselective Cyclization of (Indol-3-yl)pentyn-3-ols as an Approach to (Tetrahydro)carbazoles
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An acid-catalyzed, highly regioselective cycloisomerization as well as dehydro-cyclization of (indol-3-yl)pentyn-3-ols has been reported for the selective synthesis of tetrahydrocarbazoles and carbazoles. This process is mild and found to be very general in terms of structural diversity of substrates. Utilizing the strategy, an efficient synthetic approach for the functionalized frameworks of carbazomycins A-D has also been developed.
- Tharra, Prabhakararao,Baire, Beeraiah
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supporting information
p. 1118 - 1121
(2018/02/23)
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- Ruthenium-Catalyzed Cascade Annulation of Indole with Propargyl Alcohols
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Cascade transformations forming multiple bonds and one-pot procedures provide rapid access to natural-product-like scaffolds from simple precursors. These atom-economic processes are valuable tools in organic synthesis and drug discovery. Herein, we report on ruthenium-catalyzed cascade annulations of indole with readily available propargyl alcohols. These provide rapid access to diverse carbazoles, cyclohepta[b]indoles, and further fused polycycles with high selectivity. A bifunctional ruthenium complex featuring a redox-coupled cyclopentadienone ligand acts as a common catalyst for the different cascade processes.
- Kaufmann, Julia,J?ckel, Elisabeth,Haak, Edgar
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supporting information
p. 5908 - 5911
(2018/04/20)
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- Supported iron catalysts for Michael addition reactions
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Heterogeneous catalysts have been widely used for chemical transformations and offer easy product separation in addition to their high activity. Iron is an earth-abundant metal, but it has not been studied thoroughly as heterogeneous catalysts for organic
- Ye, Rong,Faucher, Franco F.,Somorjai, Gabor A.
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- TiCl2(OTf)-SiO2: A solid stable lewis acid catalyst for Michael addition of α-Aminophosphonates, Amines, Indoles and Pyrrole
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TiCl2(OTf)-SiO2 is simply prepared by immobilization of TiCl3(OTf) on silica gel surface and introduced as a non-hygroscopic Lewis acid catalyst for C-N and C-C bond formation via Michael addition reaction. A variety of structurally diverse nitrogen nucleophiles including α-aminophosphonates, aliphatic and aromatic amines and imidazole were evaluated as Michael donors. Friedel–Crafts alkylation of indoles and pyrrole was also investigated through Michael addition reaction in the presence of TiCl2(OTf)-SiO2 as a catalyst. The reactions were conducted at room temperature or 60 °C under solvent-free conditions and the desired Michael adducts were obtained in high to excellent yields.
- Firouzabadi, Habib,Iranpoor, Naser,Farahi, Soghra
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p. 317 - 323
(2018/02/06)
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- A rapid and highly efficient Michael addition of methoxybenzenes and indoles to α,β-unsaturated ketones using BF3·OEt2 as a catalyst
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An efficient and general protocol is described for the Michael addition of α,β-unsaturated ketones with electron-rich arenes/indoles to give alkylated arenes/indoles under mild reaction condition at room temperature. Shorter reaction time, convenient and
- Swetha,Raghavender Reddy,Madhu Babu,Meshram
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supporting information
p. 4427 - 4431
(2017/10/30)
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- Development and Application of a Recyclable High-Load Magnetic Co/C Hybrid ROMP-Derived Benzenesulfonyl Chloride Reagent and Utility of Corresponding Analogues
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The development and application of high-load, recyclable magnetic Co/C hybrid ROMP-derived benzenesulfonyl chloride and analogues is reported. The regeneration and utility of these reagents in the methylation/alkylation of various carboxylic acids is demonstrated via efficient retrieval of the magnetic reagent with a neodymium magnet. Additional reactions employing the analogue sulfonic acid and in situ generated magnetic benzenesulfonyl azide are also reported.
- Faisal, Saqib,Zang, Qin,Maity, Pradip K.,Brandhofer, Agnes,Kearney, Patrick C.,Reiser, Oliver,Grass, Robert N.,Stoianova, Diana,Hanson, Paul R.
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supporting information
p. 2274 - 2277
(2017/05/12)
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- Copper(II) bromide-catalyzed conjugate addition of furans to α,β-unsaturated carbonyl compounds
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[Figure not available: see fulltext.] A simple method for the synthesis of 2-(3-oxoalkyl)furan derivatives based on conjugate addition of 2-substituted furans to various α,β-unsaturated carbonyl compounds in the presence of copper(II) bromide as catalyst was developed.
- Fadeev, Alexander A.,Uchuskin, Maxim G.,Trushkov, Igor V.,Makarov, Anton S.
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p. 1286 - 1293
(2018/01/27)
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- The Friedel-Crafts Reaction of Indoles with Michael Acceptors Catalyzed by Magnesium and Calcium Salts
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Friedel-Crafts alylation of indole and its derivatives with a variety of electron-deficient alkenes catalyzed by Mg and Ca salts has been studied. The dependence of the results on the nature of the starting olefins, substituents on indole, and Michael acc
- Feofanov, Mikhail N.,Anokhin, Maxim V.,Averin, Alexei D.,Beletskaya, Irina P.
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p. 5045 - 5058
(2017/10/06)
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- Triethylbenzylammonium chloride as a useful and efficient catalyst for the alkylation of indole/substituted indoles in water: A comparative study between conventional and microwave irradiation
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A green and facile method for the alkylation of indole/substituted indole in water using a phase Transfer catalyst (Triethylbenzylammonium Chloride, TEBA) to synthesise bis-indolyl methanes (BIMs) and Michael addition of indole to α,β-unsaturated carbonyl compounds is reported. The substitution of indoles occurred exclusively at the 3-position and products of N-alkylation has not been observed. However, for 3-substituted indoles, reactions were found to occur at the 2-position. A comparative study between conventional heating and microwave irradiation has also been reported. A comparative study between conventional heating and microwave irradiation for the alkylation of indole/substituted indole in water using a phase transfer catalyst (Triethylbenzylammonium Chloride, TEBA) to synthesise bis-indolyl methanes (BIMs) and Michael addition of indole to α, β-unsaturated carbonyl compounds is reported.
- Tumtina, Shokip,Kathing, Chingrishon,Phucho, Ivulho Tovishe,Nongrum, Ridaphun,Myrboh, Bekington,Nongkhlaw, Rishanlang
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p. 321 - 327
(2015/05/20)
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- Sulfonic acid-functionalized magnetic nanoparticles as a recyclable and eco-friendly catalyst for atom economical Michael addition reactions and bis indolyl methane synthesis
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A modified sulfonic acid functionalized magnetic nanoparticle composite (Fe3O4@γFe2O3-SO3H) is prepared by the use of ultrasonic irradiation. By this modification, the size of the nano-particles was r
- Mahmoudi, Hajar,Jafari, Abbas Ali,Saeedi, Soroosh,Firouzabadi, Habib
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p. 3023 - 3030
(2015/02/05)
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- Strong Lewis acids of air-stable binuclear triphenylantimony(V) complexes and their catalytic application in C-C bond-forming reactions
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Two air-stable novel Lewis acids of triphenylantimony(V) pentafluorbezenesulfonates (2) and perfluorooctanesulfonates (3) were successfully synthesized and characterized. X-ray studies and thermo-gravimetric analysis found that these complexes showed high anti-hydrolyzability and thermal stability. The high catalytic activity and excellent recyclability of these complexes were achieved in the Michael addition reaction and the allylation reaction. On account of their stability, storability, as well as catalytic efficiency, these complexes should find a broad range of utility in organic synthesis.
- Li, Ningbo,Qiu, Renhua,Zhang, Xiaohong,Chen, Yun,Yin, Shuang-Feng,Xu, Xinhua
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p. 4275 - 4281
(2015/06/08)
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- Palladium(II) in electrophilic activation of aldehydes and enones: Efficient C-3 functionalization of indoles
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The regioselective C-3 alkylation of indoles with aldehydes and enones as electrophiles is catalyzed by a d8 late transition metal complex PdCl2(MeCN)2 at room temperature in the presence of air/moisture and in the absence
- Mohapatra, Swapna Sarita,Mukhi, Priyabrata,Mohanty, Anuradha,Pal, Satyanarayan,Sahoo, Aditya Omprakash,Das, Debjit,Roy, Sujit
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supporting information
p. 5709 - 5713
(2015/09/29)
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- The combined use of cationic palladium(II) with a surfactant for the C-H functionalization of indoles and pyrroles in water
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The utility of electrophilic palladium(II) species was demonstrated for C-H bond functionalization of indoles and pyrroles in water. The system displayed attractive features that are reminiscent of both precious-metal catalysis and micellar catalysis.
- Kitanosono, Taku,Miyo, Masumi,Kobayashi, Shu
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p. 7739 - 7744
(2015/09/07)
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- Calix[6]arene sulfonic acids catalysed Michael reactions of indoles with α,β-unsaturated ketones in water assisted by microwave radiation
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Michael reactions of indoles with α,β-unsaturated ketones were carried out under microwave irradiation in water, affording the corresponding products in good to excellent yields. The calix[6]arene sulfonic acids bearing pendent aliphatic chains, as effici
- Xie, Yuanyuan,Mao, Linfeng,Li, Lehuan
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p. 476 - 479
(2013/09/12)
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- Synthesis and structures of air-stable binuclear hafnocene perfluorobutanesulfonate and perfluorobenzenesulfonate and their catalytic application in C-C bond-forming reactions
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The two air-stable m2-hydroxy-bridged binuclear hafnocene perfluorobutanesulfonate and perfluorobenzenesulfonate complexes were successfully synthesized. The high catalytic activity and recyclability of these complexes were exemplified for various carbon-carbon bond formation reactions. Compared with our previously reported hafnocene perfluorooctanesulfonate, these complexes show stronger Lewis acidity and better catalytic activity, and should find broad applications in organic synthesis.
- Li, Ningbo,Zhang, Xiaohong,Xu, Xinhua,Chen, Yun,Qiu, Renhua,Chen, Jinyang,Wang, Xie,Yin, Shuang-Feng
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supporting information
p. 2430 - 2440
(2013/10/01)
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- Al(OTf)3 catalysed Friedel-Crafts Michael type addition of indoles to α,β-unsaturated ketones with PEG-200 as recyclable solvent
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An Al(OTf)3 catalysed efficient Friedel-Crafts Michael type addition of indoles to α,β-unsaturated ketones using recyclable PEG-200 as an alternative reaction solvent is disclosed. The reaction under microwave irradiation is clean, leads to exc
- Gohain, Mukut,Jacobs,Marais, Charlene,Bezuidenhoudt, Barend C. B.
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p. 1594 - 1599
(2014/01/23)
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- Highly effective and regioselective Michael addition of indoles to α,β-unsaturated ketones promoted by pentafluorophenylammonium triflate
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A simple, inexpensive, environmentally friendly and efficient route for Michael addition of indoles to α,β-unsaturated ketones using pentafluorophenylammonium triflate (PFPAT) as a catalyst is described. Various indole derivatives were synthesized in good
- Khaksar, Samad,Vahdat, Seyed Mohammad,Rezaee, Fatemeh
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p. 144 - 147
(2013/04/24)
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- Catalytic enantioconvergent decarboxylative allylic alkylation of allyl indolenin-3-carboxylates
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A catalytic enantioconvergent process has been developed for the conversion of racemic allyl indolenin-3-carboxylates into enantiomerically enriched C3-quaternary indolenines. A Pd-catalyzed decarboxylative allylic alkylation reaction was employed for both stereoablation of the racemic allyl indolenin-3-carboxylates and enantioselective formation of the quaternary carbon center. The enantioconvergent conversion of racemic allyl indolenin-3- carboxylates into enantiomerically enriched C3-quaternary indolenines is reported. A Pd-catalyzed decarboxylative allylic alkylation reaction is employed for both stereoablation and enantioselective formation of the quaternary carbon center. Copyright
- Kaiser, Thomas M.,Yang, Jiong
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p. 3983 - 3987
(2013/07/19)
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- Ruthenium-catalyzed functionalization of pyrroles and indoles with propargyl alcohols
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Several ruthenium-catalyzed atom-economic transformations of propargyl alcohols with pyrroles or indoles leading to alkylated, propargylated, or annulated heteroaromatics are reported. The mechanistically distinct reactions are catalyzed by a single ruthenium(0) complex containing a redox-coupled dienone ligand. The mode of activation regarding the propargyl alcohols determines the reaction pathway and depends on the alcohols' substitution pattern. Secondary substrates form alkenyl complexes by a 1,2-hydrogen shift, whereas the transformation of tertiary substrates involves allenylidene intermediates. 1-Vinyl propargyl alcohols are converted by a cascade allylation/cyclization sequence. The environmentally benign processes are of broad scope and allow the selective synthesis of highly functionalized pyrroles and indoles generating water as the only waste product. Copyright
- Thies, Nora,Hrib, Cristian G.,Haak, Edgar
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supporting information; experimental part
p. 6302 - 6308
(2012/06/18)
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- Al-MCM-41 as a mild and ecofriendly catalyst for Michael addition of indole to α,β-unsaturated ketones
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Mesoporous Al-MCM-41 catalyzes the chemoselective Michael addition reaction between indoles and α,β-unsaturated ketones to afford β-indolylketones at room temperature with excellent yields. The higher catalytic activity is attributed to Lewis acidic Al and the large surface area. The catalyst is readily recovered and reused more than six times without loss in its catalytic activity. The substitution at the indole nucleus occurs exclusively at the 3-position and N-alkylation products are not observed.
- Subramanian, Thirumeni,Pitchumani, Kasi,Kumarraja, Mayilvasagam
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p. 115 - 121,7
(2020/07/30)
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- Poly(N,N'-dibromo-N-ethyl-benzene-1,3-disulfonamide), N,N,N',N'- tetrabromobenzene-1,3-disulfonamide as new reagents for conjugate addition of indole, pyrrole with a,b-unsaturated ketones
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Poly(N,N'-dibromo-N-ethyl-benzene-1,3-disulfonamide) [PBBS] and N,N,N',N'-tetrabromobenzene-1,3- disulfonamide[TBBDA] were used as efficient reagents for conjugate addition of indole and pyrrole with a,b-unsaturated ketones and also, double-conjugate 1,4-
- Ghorbani-Vaghei,Hajinazari,Engashte
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p. 655 - 660
(2013/02/23)
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- Recyclable graphite oxide catalyzed Friedel-Crafts addition of indoles to α,β-unsaturated ketones
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The Friedel-Crafts addition of indoles to α,β-unsaturated ketones, and nitro styrenes was studied with graphite oxide as catalyst. Various indole derivatives were synthesized in good to excellent yields. The preparation of graphite oxide catalyst from sim
- Vijay Kumar,Rama Rao
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supporting information; experimental part
p. 5188 - 5191
(2011/10/12)
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- Sulfamic acid as a cost-effective and recyclable solid acid catalyst for Friedel-Crafts alkylation of indole with α,β-unsaturated carbonyl compound and benzyl alcohol
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Sulfamic acid was proved to be a cost-effective and recyclable catalyst for Friedel-Crafts type reaction of indole with α,β-unsaturated carbonyl compound and benzyl alcohol. Various indoles, α,β-unsaturated carbonyl compounds and a benzyl alcohol were suc
- Yang, Jing,Zhang, Juan,Chen, Tian Tian,Sun, De Mei,Li, Ji,Wu, Xue Fen
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experimental part
p. 1391 - 1394
(2012/06/01)
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- Synthesis and application of modified silica sulfuric acid as a solid acid heterogeneous catalyst in Michael addition reactions
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Figure represented. Modified silica sulfuric acid (MSSA) as a new type of silica sulfuric acid was prepared and effectively used in the conjugate addition of indole, pyrrole, and thiols with Michael acceptors under mild conditions at room temperature. Als
- Zolfigol, Mohammad Ali,Veisi, Hojat,Mohanazadeh, Farajollah,Sedrpoushan, Alireza
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experimental part
p. 977 - 986
(2011/09/16)
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- Platinum-catalyzed multi-step reaction of propargyl alcohols with N-heteroaromatics
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N-Methyl indole reacts with but-2-yn-1-ol in the presence of PtCl 2 in MeOH giving indole derivatives having a substituted 3-oxobutyl group at the 3-position in good yield. Under the reaction conditions, various substituted indoles and substituted propargyl alcohols are successfully involved in the reaction giving the corresponding addition products in good to moderate yields. The catalytic reaction can be further extended to N-phenyl pyrrole. In the present multi-step reaction, PtCl2 likely plays dual roles: as the catalyst for the rearrangement of proparg-yl alcohols to the corresponding alken-yl ketones and as the catalyst for the addition of indoles to the alkenyl ke-tones. Experimental evidence is provided to support the proposed mechanism.
- Bhuvaneswari, Sivakolundu,Jeganmohan, Masilamani,Cheng, Chien-Hong
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experimental part
p. 141 - 146
(2010/04/23)
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- Task-specific ionic-liquid-catalyzed efficient synthesis of indole derivatives under solvent-free conditions
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A sulfonic-acid-functionalized ionic liquid is used as a Bronsted acid catalyst for the efficient synthesis of indole derivatives in good-to-high yields at room temperature under solvent-free conditions. The catalyst can be reused for ten consecutive runs without significant loss of activity.
- Das, Sudarshan,Rahman, Matiur,Kundu, Dhiman,Majee, Adinath,Hajra, Alakananda
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experimental part
p. 150 - 154
(2010/04/03)
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- Recyclable sulfonated amorphous carbon catalyzed friedel-crafts alkylation of indoles with α,β-unsaturated carbonyl compounds in water
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Green practice: A sulfonated amorphous carbon-based solid acid derived from d-glucose was synthesized. It was explored for its catalytic efficiency in Friedel-Crafts reactions of indoles with various a,b-unsaturated carbonyl compounds in H2O or H2O/THF at
- Ma, Jimei,Ng, Simon,Yong, Youjun,Luo, Xiao-Zhou,Wang, Xin,Liu, Xue-Wei
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supporting information; experimental part
p. 778 - 782
(2010/07/03)
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- AlCl3 as a powerful catalyst for the one-pot preparation of 1,1,3-triheteroaryl compounds
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A general and efficient procedure for the synthesis of 1,1,3-triheteroaryl compounds in good to excellent yield at room temperature is developed. The reaction proceeds via mixed Michael and Friedel-Crafts reactions of α,β-enals or α,β-enones and indoles, 2-methylfuran or 2-methylthiophene in the presence of a catalytic amount of AlCl3.
- Shiri, Morteza,Zolfigol, Mohammad Ali,Ayazi-Nasrabadi, Roya
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experimental part
p. 264 - 268
(2010/03/24)
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- Supported cobalt complex-catalysed conjugate addition of indoles, amines and thiols to α,β-unsaturated compounds
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A highly active and reusable supported Co(ii) complex on SBA-15 shows an excellent activity and selectivity to target products in aza- and thia-Michael conjugate additions of indoles, amines and thiols to α,β-unsaturated compounds under solventless mild reaction conditions. The Co-catalyst was also highly reusable and comparably more active than related catalysts in the reaction.
- Rajabi, Fatemeh,Razavi, Sepideh,Luque, Rafael
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experimental part
p. 786 - 789
(2010/09/05)
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- Iron salt-catalyzed cascade type one-pot double alkylation of indole with vinyl ketones
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Indole was reacted with vinyl ketones in the presence of 5-8 mol % of iron (II) tetrafluoroborate or iron (III) perchlorate to give 2,3-dialkylated products; initial alkylation took place at 3-position on the indole ring and subsequent alkylation occurred at 2-position. It was found that the first alkylation proceeded very quickly, while the reaction rate of the second alkylation was very slow. Using this, cascade type synthesis of 2,3-dialkylated-indoles has been accomplished using iron (III)salt as catalyst.
- Kobayashi, Jun-ka,Matsui, Shin-ichiro,Ogiso, Koji,Hayase, Shuichi,Kawatsura, Motoi,Itoh, Toshiyuki
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experimental part
p. 3917 - 3922
(2010/07/05)
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- Copper(II) chloride catalyzed Friedel-Crafts-type conjugate addition of indoles to a,(3-unsaturated enones: Synthesis of 3-substituted indoles
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Several 3-substituted indoles have been synthesized in good to excellent yields by conjugate addition of indoles to a,|3-unsaturated enones such as chalcones, methyl vinyl ketone and cyclohexenone in the presence of catalytic amount of copper(II) chloride
- Kan war, Deepika,Rani, Rashmi,Agarwal, Jyoti,Peddinti, Rama Krishna
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experimental part
p. 1290 - 1299
(2010/12/20)
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- Enantioselective Fujiwara-Moritani indole and pyrrole annulations catalyzed by chiral palladium(II)-NicOx complexes
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The catalytic asymmetric Fujiwara-Moritani ring closures of several indole-and pyrrole-based cyclization precursors are reported. These unprecedented oxidative palladium(II)-catalyzed annulations allow for the formation of a stereogenic quaternary carbon atom, and decent levels of enantiocontrol are seen in 5-exo-trig cyclizations (54% ee for an indole and 76% ee for a pyrrole) while 6-exo-trig ring closures afford essentially racemic material. Novel oxazoline ligands with a nicotine platform (NicOx) are pivotal for good catalytic turnover as conventional PyOx ligands failed to produce acceptable chemical yields. The preparation of these NicOx ligands as well as the syntheses of the cyclization precursors are described in detail.
- Schiffner, Julia A.,Woeste, Thorsten H.,Oestreich, Martin
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supporting information; experimental part
p. 174 - 182
(2010/04/02)
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- Zirconium tetrakis(dodecylsulfate) as an efficient and recyclable lewis acid-surfactant-combined catalyzed C-C and C-N bond forming under mild and environmentally benign conditions
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A green catalytic method for C-C and C-N bond forming via Michael addition of aromatic amines and indoles to electron-deficient olefins using Zirconium tetrakis(dodecylsulfate) in water under mild conditions with high yields and selectivity has been developed. The reusability of the catalyst has been successfully examined without any noticeable loss of its catalytic activity.
- Jafarpour, Maasoumeh,Rezaeifard, Abdolreza,Aliabadi, Marzieh
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scheme or table
p. 94 - 99
(2010/04/23)
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- Efficient, one-pot transformation of indoles into functionalized oxindole and spirooxindole systems under Swern conditions
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The reaction of indole derivatives bearing a 3- or 4-hydroxyalkyl chain with dimethylsulfoxide and oxalyl chloride under Swern conditions led to a one-pot, three-component process involving three different synthetic transformations, namely oxidation of indole to oxindole, introduction of a chlorine substituent at the oxindole C-3 position and substitution of the hydroxyl group in the side chain by chlorine, in good to excellent overall yields. The same conditions, applied to a 2-methylindole, afforded a 2-formylindole derivative oxidized at its side chain. The reaction starting from one indole with a 2-hydroxyalkyl chain furnished 3-(2-hydroxyalkyl)oxindoles. Finally, application of the Swern conditions to derivatives of indole-3-propionic or -butyric acid afforded 3-spirooxindole lactones.
- López-Alvarado, Pilar,Steinhoff, Judith,Miranda, Sonia,Avenda?o, Carmen,Carlos Menéndez
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experimental part
p. 1660 - 1672
(2009/05/09)
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- Glycerol as an efficient promoting medium for organic reactions
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Whereas the beneficial effect of water on reaction rate is decreased with an increase of the reactant's hydrophobicity, we report here that the use of glycerol as solvent was able to considerably accelerate the reaction rate of an organic reaction even st
- Gu, Yanlong,Barrault, Joel,Jerome, Francois
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supporting information; experimental part
p. 2007 - 2012
(2009/08/14)
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- Synthesis of 3-substituted indoles promoted by pulverization-activation method catalyzed by Bi(NO3)3·5H2O
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(Chemical Equation Presented) A new, facile, efficient, "green" and chemoselective procedure for the synthesis of indole derivatives has been developed with pulverization-activation method catalyzed by Bi(NO 3)3·5H2O (PAMC- Bi(NO3) 3·5H2O) through grinding of indoles with aldehydes or Michael acceptors in the presence of catalytic amounts of Bi(NO 3)3·5H2O under solvent-free conditions.
- Khodaei, Mohammad M.,Mohammadpoor-Baltork, Iraj,Memarian, Hamid R.,Khosropour, Ahmad R.,Nikoofar, Kobra,Ghanbary, Parvin
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p. 377 - 381
(2008/09/20)
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- Yttrium triflate-catalyzed reactions of indoles with electron-deficient olefins
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The reaction condition for Michael addition of indoles to a series of electron-deficient olefins catalyzed by Y(OTf)3 has been carefully optimized at ambient temperature and the reaction affords the corresponding Michael adducts in good to exce
- Sun, Liangdong,Gao, Changshui,Zhou, Weiyi,Wei, Yuping
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p. 481 - 484
(2008/09/20)
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- Mild and efficient Michael addition of activated olefins to indoles using TBAB as a catalyst: Synthesis of 3-substituted indoles
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A mild and efficient method for the synthesis of 3-substituted indoles by treatment of activated olefins with indoles using TBAB as a catalyst afforded the corresponding products in excellent yields. The method is general for the preparation of a wide var
- Suresh Babu,Rama Subba Rao,Sunitha,Sivaram Babu,Madhusudana Rao
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p. 1784 - 1791
(2008/09/20)
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- Sustainable conjugate addition of indoles catalyzed by acidic ionic liquid immobilized on silica
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A new protocol for 1,4-conjugate addition of indoles to vinyl ketones has been developed, employing Lewis acidic ionic liquid immobilized on silica, ILIS-SO2Cl, as a catalyst, which exhibited an efficient, mild and recyclable nature. The reacti
- Hagiwara, Hisahiro,Sekifuji, Masayoshi,Hoshi, Takashi,Suzuki, Toshio,Quanxi, Bao,Qiao, Kun,Yokoyama, Chiaki
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p. 608 - 610
(2008/12/22)
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- Antimony(III) sulfate catalyzed condensation reaction of indoles with carbonyl compounds
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Antimony sulfate was found to be on effective catalyst for the condensation reaction of indoles with carbonyl compounds at room temperature. This catalyst is inexpensive, easily available and it was also found that this catalyst could be recovered quantitatively and reused without much loss of catalytic activity.
- Srinivasa, Aswathanarayana,Varma, Putta Prabhakar,Hulikal, Vijaykumar,Mahadevan, Kittappa M.
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p. 111 - 115
(2008/09/21)
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- Thermal rearrangement of indolyl oxime esters to pyridoindoles
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(Chemical Equation Presented) Acyl oximes derived from a variety of indolylalkanones underwent a ring closure sequence during FVP to afford 9H-pyrido[2,3-b]indoles. Unlike UV light promoted reactions of oxime esters, the mechanism is almost certainly not mediated by iminyl radicals but probably involves tautomerism, elimination of acetic acid, and a final electrocyclic ring closure.
- Portela-Cubillo, Fernando,Surgenor, Brian A.,Aitken, R. Alan,Walton, John C.
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p. 8124 - 8127
(2008/12/22)
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- BENZAZEPIN-2(1H)-ONE DERIVATIVES
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Compounds of formula (I) and pharmaceutically acceptable salts thereof are agonists at the beta-2 adrenoceptor. They are useful as feed additives for livestock animals.
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Page/Page column 47
(2008/06/13)
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- Microwave-assisted syntheses of N-heterocycles using alkenone-, alkynone- and aryl-carbonyl O-phenyl oximes: Formal synthesis of neocryptolepine
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(Chemical Equation Presented) This research aimed to provide a new and "clean" synthetic method that would enable both known and novel N-heterocycles to be prepared efficiently. O-Phenyl oximes were found to be excellent precursors for iminyl radicals with a variety of acceptor side chains. Dihyropyrroles were made in good yields from O-phenyl oximes containing pent-4-ene acceptors. The analogous process with a hex-5-enyl acceptor did not yield a dihydropyridine, probably because the 6-exo-trig ring closure of the iminyl radical was too slow to compete with H-atom abstraction. The iminyl radical from a precursor with a pent-4-yne type side chain underwent ring closure followed by rearrangement to afford a pyrrole derivative. Suitably substituted iminyl radicals ring closed readily onto aromatic acceptors, thus enabling several polycyclic systems to be accessed. Quinolines were made from 3-phenylpropanones via their O-phenyl oximes. Syntheses of phenanthridines starting from 2-formylbiphenyls were particularly efficient, and this approach enabled the natural product trisphaeridine to be made. Starting from 2-phenylnicotinaldehyde derivatives, ring closures of the derived iminyl radicals onto the phenyl rings yielded benzo[h][1,6]naphthyridines. Similarly, ring closure onto a phenyl ring from a benzothiophene-based iminyl yielded a benzo[b-]thieno[2,3-c]quinoline. By way of contrast, iminyl radical ring closure onto pyridine rings was not observed. However, iminyl radicals did cyclize onto indoles, enabling indolopyridines to be prepared. The latter route was exploited in a short formal synthesis of neocryptolepine starting from 2-((1H-indol-3-yl)methyl)cyclohexanone.
- Portela-Cubillo, Fernando,Scott, Jackie S.,Walton, John C.
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p. 5558 - 5565
(2008/12/20)
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- Catalyzed Reaction for Forming Indole-Based Compounds and Their Application in Anticancer Agents
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The present invention discloses a method for forming indole-based compounds, wherein the method comprises a reaction of α,β-unsaturated ketone or aldehyde with indole or its derivative in the presence of at least one kind of Lewis acid. The Lewis acid com
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Page/Page column 3-4
(2008/12/06)
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