- An efficient method for chlorination of alcohols using PPh3/Cl3CCONH2
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A new and convenient method for the chlorination of alcohols utilizing PPh3/Cl3CCONH2 is addressed. Various alcohols could smoothly be converted into their corresponding alkyl chlorides in high yield under mild conditions with short reaction times. A mechanism is disclosed with the evidence of inversion of configuration of the analogous alkyl chloride derived from R-(-)-2-octanol.
- Pluempanupat, Wanchai,Chavasiri, Warinthorn
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- Indium(III)-catalyzed reductive bromination and iodination of carboxylic acids to alkyl bromides and iodides: Scope, mechanism, and one-pot transformation to alkyl halides and amine derivatives
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Highly effective indium(III)-catalyzed reductive bromination or iodination of a variety of carboxylic acids with 1,1,3,3-tetramethyldisiloxane (TMDS) and a source of bromine or iodine is described. This functional group interconversion has high tolerance for several functional groups, such as halogens, a hydroxy group, a nitro group, an olefin part, and a sulfide moiety. This indium catalytic system is also applicable to the reductive iodination of aldehyded, acyl chlorides, and esters. Furthermore, this reducing system can be applied to the one-pot synthesis of alkyl halides and amine derivatives via the addition of nucleophiles. Insight into the reaction mechanism was gained via the time course of 1H and 13C NMR monitoring experiments and the corresponding stepwise reactions.
- Moriya, Toshimitsu,Yoneda, Shinichiro,Kawana, Keita,Ikeda, Reiko,Konakahara, Takeo,Sakai, Norio
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- Remarkable interaction effects of molecular packing on site- and stereoselectivity in photocycloaddition of 2-pyrones with maleimide in the solid state
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Solid-state photoirradiation of 1:1 complex crystals of 4-[ω-(2-furyl)alkyloxy]-6-methyl-2-pyrones 1b, 1c or 4-(ω-arylalkyloxy)-6-methyl-2-pyrones 1d-j with maleimide 2 gave [2+2]cycloadducts 3b-f, 3i, 3j with exclusive stereoselectivity. The high reaction selectivity was confirmed by X-ray structure analyses and MO method of the complex crystals, which were composed of two sets of a 1:1 complex between 1 and 2, arising from an CH-π interaction between 2 and the aromatic rings of 1, and/or π-π stacking between the aromatic rings in addition to four kinds of hydrogen bonding between the ground state 2-pyrone moieties and 2.
- Obata, Toru,Shimo, Tetsuro,Yasutake, Mikio,Shinmyozu, Teruo,Kawaminami, Masaru,Yoshida, Ryosuke,Somekawa, Kenichi
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- Synthesis, crystal structure, and fluorescence properties of a novel coordination polymer [Zn(L)(4,4'-bipyridine)(H2O)] n ·(H2O) 4
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In this work, a novel and rare coordination polymer, [Zn(L)(Bipy)(H 2O)] n ·(H2O) 4 (H 2L-sphe-nylpropylmalonate acid, Bipy-4,4'-bipyridine), has been synthesized and characterized by elemental analysis, FT-IR spectroscopy, and solid fluorimetry studies. In the crystal, the Zn2+ ion of the complex is hexa-coordinated in a slightly distorted octahedral configuration forming the unit structure, 2D structure, and 3D framework. The supramolecular architecture was constructed by a unit of (H2O) 4 discrete water cluster. Besides, the coordination polymer displays strong emission spectra due to the metal-to-ligand charge-transfer transition, having potential applications as fluorescent materials. Pleiades Publishing, Ltd., 2012.
- Gao,Wang,Lin,Liu,Sun,Zhu
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- Photochemical Decarboxylative C(sp3)-X Coupling Facilitated by Weak Interaction of N-Heterocyclic Carbene
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While N-hydroxyphthalimide (NHPI) ester has emerged as a powerful reagent as an alkyl radical source for a variety of C-C bond formations, the corresponding C(sp3)-N bond formation is still in its infancy. We demonstrate herein transition-metal-free decarboxylative C(sp3)-X bond formation enabled by the photochemical activity of the NHPI ester-NaI-NHC complex, giving primary C(sp3)-(N)phth, secondary C(sp3)-I, or tertiary C(sp3)-(meta C)phth coupling products. The primary C(sp3)-(N)phth coupling offers convenient access to primary amines.
- Chen, Kun-Quan,Wang, Zhi-Xiang,Chen, Xiang-Yu
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- Chemoselective Homologation-Deoxygenation Strategy Enabling the Direct Conversion of Carbonyls into (n+1)-Halomethyl-Alkanes
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The sequential installation of a carbenoid and a hydride into a carbonyl, furnishing halomethyl alkyl derivatives, is reported. Despite the employment of carbenoids as nucleophiles in reactions with carbon-centered electrophiles, sp3-type alkyl halides remain elusive materials for selective one-carbon homologations. Our tactic levers on using carbonyls as starting materials and enables uniformly high yields and chemocontrol. The tactic is flexible and is not limited to carbenoids. Also, diverse carbanion-like species can act as nucleophiles, thus making it of general applicability.
- Citarella, Andrea,Holzer, Wolfgang,Ielo, Laura,Langer, Thierry,Miele, Margherita,Pace, Vittorio,Urban, Ernst,Zehl, Martin
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supporting information
p. 7629 - 7634
(2020/10/12)
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- A General Approach to Deboronative Radical Chain Reactions with Pinacol Alkylboronic Esters
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The generation of carbon-centered radicals from air-sensitive organoboron compounds through nucleohomolytic substitution at boron is a general method to generate non-functionalized and functionalized radicals. Due to their reduced Lewis acidity, alkylboronic pinacol esters are not suitable substrates. We report their in situ conversion into alkylboronic catechol esters by boron-transesterification with a substoichiometric amount of catechol methyl borate combined with an array of radical chain processes. This simple one-pot radical-chain deboronative method enables the conversion of pinacol boronic esters into iodides, bromides, chlorides, and thioethers. The process is also suitable the formation of nitriles and allylated compounds through C?C bond formation using sulfonyl radical traps. The power of combining radical and classical boron chemistry is illustrated with a modular 5-membered ring formation using a combination of three-component coupling and protodeboronative cyclization.
- André-Joyaux, Emy,Kuzovlev, Andrey,Renaud, Philippe,Tappin, Nicholas D. C.
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p. 13859 - 13864
(2020/06/10)
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- Preparation method of 3-phenylpropylamine
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The embodiment of the invention discloses a preparation method of 3-phenylpropylamine. The method comprises the following steps: 2-(3-phenylpropyl)isoindoline-1,3-diketone is obtained through 1-chloro-3-phenylpropane under the action of a phthalimide salt compound and a base; then the 2-(3-phenylpropyl)isoindoline-1,3-diketone is subjected to hydrazinolysis through hydrazine hydrate; after alkalization, recrystallization is performed to obtain the 3- phenylpropylamine. According to the preparation method of the 3-phenylpropylamine disclosed by the embodiment of the invention, 3- phenylpropanol is used as a raw material, substitution reaction is performed to obtain the 1-chloro-3-phenylpropane, the 1-chloro-3-phenylpropane is reacted with the phthalimide salt to obtain the 2-(3-phenylpropyl)isoindoline-1,3-diketon, and then hydrazine hydrate hydrolysis is performed to obtain the 3-phenylpropylamine. The preparation method disclosed by the embodiment of the invention has the beneficial effects that the raw material required is cheap and easy to obtain, the reaction conditions are simple, the operation is simple and convenient, the toxicity and the pollution are small, the yield and the purity are high, and the method is suitable for industrial production.
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Page/Page column 4-6
(2019/10/08)
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- Ionic-Liquid-Supported 1,3-Dimethylimidazolidin-2-one: Application as a Reusable Halogenation Reagent
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We describe the synthesis of ionic-liquid-supported 1,3-dimethylimidazolidin-2-one, together with the halogenation of alcohols in a reaction system in which this reagent is combined with oxalyl chloride. A new method was established that does not require additives such as bases, and which permits the ready isolation and purification of the product. Good conversions were obtained, and good reusability of the reagent was observed.
- Koguchi, Shinichi,Shibuya, Yuga,Igarashi, Yusuke,Takemura, Haruka
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supporting information
p. 943 - 946
(2019/05/10)
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- Organocatalytic Chlorination of Alcohols by P(III)/P(V) Redox Cycling
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A catalytic system for the chlorination of alcohols under Appel conditions was developed. Benzotrichloride is used as a cheap and readily available chlorinating agent in combination with trioctylphosphane as the catalyst and phenylsilane as the terminal reductant. The reaction has several advantages over other variants of the Appel reaction, e.g., no additional solvent is required and the phosphane reagent is used only in catalytic amounts. In total, 27 different primary, secondary, and tertiary alkyl chlorides were synthesized in yields up to 95%. Under optimized conditions, it was also possible to convert epoxides and an oxetane to the dichlorinated products.
- Longwitz, Lars,Jopp, Stefan,Werner, Thomas
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p. 7863 - 7870
(2019/06/27)
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- NMP-mediated chlorination of aliphatic alcohols with aryl sulfonyl chloride for the synthesis of alkyl chlorides
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NMP-mediated chlorination of aliphatic alcohols has been developed for the synthesis of alkyl chlorides. This facile, efficient and practical approach used simple and readily available aryl sulfonyl chlorides as the chlorination reagent for the construction of C–Cl bond in good to excellent yields with mild conditions and broad substrate scope.
- Zheng, Dagui,Mao, Liu-Liang,Zhu, Xian-Hong,Zhou, An-Xi
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supporting information
p. 2793 - 2800
(2018/11/06)
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- Hypervalent Iodine-Based Activation of Triphenylphosphine for the Functionalization of Alcohols
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The use of hypervalent iodine reagents as a general tool for the activation of PPh 3 and its application to the functionalization of alcohols is reported. Combination of PPh 3 with PhICl 2 or TolIF 2 gives dihalophosphoranes that are characterized by 31 P NMR, however, with PhIOAc 2, PhI(OTFA) 2, or the cyclic chloro(benzoyloxy)iodane, no phosphoranes were observed. Reaction of these iodanes with PPh 3 in the presence of primary, secondary, or tertiary alcohols results in either halogenation or acyl-transfer products in moderate to high yield.
- Eljo, Jasmin,Carle, Myriam S.,Murphy, Graham K.
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supporting information
p. 2871 - 2875
(2017/10/06)
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- Stereospecific Electrophilic Fluorination of Alkylcarbastannatrane Reagents
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We report the use of isolable primary and secondary alkylcarbastannatrane nucleophiles in site-specific fluorination reactions. These reactions occur without the need for transition metal catalysis or in situ activation of the nucleophile. In the absence of the carbastannatrane backbone, alkyltin nucleophiles exhibit no activity towards fluorination. When enantioenriched alkylcarbastannatranes are employed, fluorination occurs predominately via a stereoinvertive mechanism to generate highly enantioenriched alkyl fluoride compounds. These conditions can also be extended to stereospecific chlorination, bromination, and iodination reactions.
- Ma, Xinghua,Diane, Mohamed,Ralph, Glenn,Chen, Christine,Biscoe, Mark R.
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supporting information
p. 12663 - 12667
(2017/09/11)
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- Manganese-Catalyzed Borylation of Unactivated Alkyl Chlorides
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The use of low-cost manganese(II) bromide (MnBr2) and tetramethylethylenediamine (TMEDA) catalyzes the cross coupling of (bis)pinacolatodiboron with a wide range of alkyl halides, demonstrating the first manganese-catalyzed coupling with alkyl electrophiles. This method allows access to primary, secondary, and tertiary boronic esters from the parent chlorides, which were previously inaccessible as coupling partners. The reaction proceeds in high yield with as little as 1000 ppm catalyst loading, while 5 mol % can provide high yields in as little as 30 min. Finally, radical-clock experiments revealed that at 0 °C direct borylation outcompetes alternative radical processes, thereby providing synthetically useful, temperature-controlled reaction outcomes.
- Atack, Thomas C.,Cook, Silas P.
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supporting information
p. 6139 - 6142
(2016/06/09)
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- Formononetin derivatives and preparation methods and medical application thereof
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The invention relates to the field of pharmaceutical chemistry, and relates to formononetin derivatives and preparation methods and medical application thereof, in particular to formononetin derivatives with the general formula as shown in (I), preparation methods thereof, pharmaceutical compositions containing the compounds and medical application of the derivatives and the pharmaceutical compositions, particularly, application of the derivatives and the pharmaceutical compositions serving as drugs for preventing or treating hyperlipidaemia or obesity or type-II diabetes. Please see the formula in the description.
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Paragraph 0189; 0190; 0191; 0198; 0199; 0200
(2017/04/29)
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- Trichloroisocynuric acid/DMF as efficient reagent for chlorodehydration of alcohols under conventional and ultrasonic conditions
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A new and efficient method for the chlorodehydration of alcohols utilizing TCCA/DMF is described. Various alcohols can be converted smoothly into their corresponding alkyl chlorides in high yields under mild conditions with short reaction times. Taylor & Francis Group, LLC.
- Venkana, Purugula,Kumar, Mukka Satish,Rajanna, Kamatala Chinna,Ali, Mir Moazzam
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- Mechanistic insights into Br?nsted acid-induced nucleophilic substitution of aliphatic imidazole carbamate with halide ions
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Herein we report interesting reactivity of imidazole carbamate towards nucleophilic substitution with halide ions under Br?nsted acidic conditions. Depending upon reaction conditions, halide ions could readily attack the carboxyl position and trigger decarboxylative alkyl halide formation. Alternatively, halide ions were also found to competitively undergo nucleophilic acyl substitution, which ultimately results in the generation of carbonate dimerization product.
- Saputra, Mirza A.,Forgey, Rashel L.,Henry, Jeffrey L.,Kartika, Rendy
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p. 1392 - 1396
(2015/03/04)
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- Rasta resin-triphenylphosphine oxides and their use as recyclable heterogeneous reagent precursors in halogenation reactions
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Heterogeneous polymer-supported triphenylphosphine oxides based on the rasta resin architecture have been synthesized, and applied as reagent precursors in a wide range of halogenation reactions. The rasta resin-triphenylphosphine oxides were reacted with either oxalyl chloride or oxalyl bromide to form the corresponding halophosphonium salts, and these in turn were reacted with alcohols, aldehydes, aziridines and epoxides to form halogenated products in high yields after simple purification. The polymersupported triphenylphosphine oxides formed as a byproduct during these reactions could be recovered and reused numerous times with no appreciable decrease in reactivity.
- Xia, Xuanshu,Toy, Patrick H.
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supporting information
p. 1397 - 1405
(2014/07/22)
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- Gallium-catalyzed reductive chlorination of carboxylic acids with copper(II) chloride
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Described herein is the direct chlorination of carboxylic acids using copper(II) chloride via a gallium(III)-catalyzed reduction in the presence of a hydrosiloxane. During this reductive chlorination, the counteranions of CuCl2 functioned as a chloride source.
- Sakai, Norio,Nakajima, Takumi,Yoneda, Shinichiro,Konakahara, Takeo,Ogiwara, Yohei
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p. 10619 - 10623
(2015/02/19)
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- Preparation of ionic liquid-based vilsmier reagent from novel multi-purpose dimethyl formamide-like ionic liquid and its application
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In continuation of research to explore the applied potential of DMF-like ionic liquid, the ionic liquid version of N,N-dimethyliminiumchloride (Vilsmier reagent) has been synthesized from DMF-like ionic liquid and tested effectively for its capacity to achieve more useful organic transformations. The results show that DMF-like ionic liquid is world's first task specific ionic liquid which has catalyzed numerous diverse type of reaction and is multipurpose in its application. Thus a new term for this DMF-like ionic liquid has been coined that is DMF-like "multipurpose" ionic liquid. Copyright
- Hullio, Ahmed Ali,Mastoi
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scheme or table
p. 1647 - 1657
(2012/09/21)
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- A facile and green protocol for nucleophilic substitution reactions of sulfonate esters by recyclable ionic liquids [bmim][X]
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Ionic liquids [bmim][X] (X = Cl, Br, I, OAc, SCN) are highly efficient reagents for nucleophilic substitution reactions of sulfonate esters derived from primary and secondary alcohols. The counter anions (X-) of the ionic liquids, [bmim][X], effectively replace the sufonates affording the corresponding substitution products such as alkyl halides, acetates, and thiocyanides in excellent yields. The newly developed protocol is very environmentally attractive because the reactions use stoichiometric amounts of ionic liquids as sole reagents in most cases and do not require additional solvents, any other activating reagents, non-conventional equipment, or special precautions. Moreover, these ionic liquids can be readily recycled without loss of reactivity, making the whole process greener.
- Liu, Yajun,Xu, Yongnan,Jung, Sun Ho,Chae, Junghyun
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p. 2692 - 2698,7
(2012/12/12)
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- A facile and green protocol for nucleophilic substitution reactions of sulfonate esters by recyclable ionic liquids [bmim][X]
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Ionic liquids [bmim][X] (X = Cl, Br, I, OAc, SCN) are highly efficient reagents for nucleophilic substitution reactions of sulfonate esters derived from primary and secondary alcohols. The counter anions (X-) of the ionic liquids, [bmim][X], effectively replace the sufonates affording the corresponding substitution products such as alkyl halides, acetates, and thiocyanides in excellent yields. The newly developed protocol is very environmentally attractive because the reactions use stoichiometric amounts of ionic liquids as sole reagents in most cases and do not require additional solvents, any other activating reagents, non-conventional equipment, or special precautions. Moreover, these ionic liquids can be readily recycled without loss of reactivity, making the whole process greener. Georg Thieme Verlag KG Stuttgart · New York.
- Liu, Yajun,Xu, Yongnan,Jung, Sun Ho,Chae, Junghyun
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p. 2692 - 2698
(2013/01/15)
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- Synthesis, characterization and cytotoxicity of a carboxylic ligand 2,2-bis(3-phenylpropyl) malonic acid and a corresponding Mn(ii) complex
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The organic ligand Hbpmc and the polymeric complex [Mn(bpmc) 2(4,4′-bipy)(H2O)2]n· 3H2O (4,4′-bipy = 4,4′-bipyridine, Hbpmc = 2,2-bis(3-phenylpropyl) malonic acid), which have both a lipophilic group (aromatic ring) and a hydrophilic group (non-coordination carboxyl), were synthesized and characterized by IR spectra, elemental analysis and X-ray single-crystal diffraction. The interaction of the complexes with HC-DNA was investigated by fluorescence spectroscopy. Gel electrophoresis assay demonstrates the ability to cleave the extracted HC-DNA. The value of IC 50 is to understand the effect of cytotoxic activity which is lower than cisplatin and higher than the ligand Hbpmc. The apoptotic tests show that the complexes apparently have an apoptotic effect on Hela cells.
- Zhu, Ming-Chang,Dai, Lei,Gao, En-Jun,Lin, Lin,Wang, Bo,Liu, Lei
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p. 13352 - 13358
(2013/01/15)
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- Chlorination of aliphatic primary alcohols via triphosgene-triethylamine activation
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Activation of primary aliphatic alcohols with triphosgene and triethylamine mixtures afforded either alkyl chloride or diethylcarbamate products, and the switch in selectivity appeared to be driven by sterics. The reaction conditions to achieve this highly useful transformation were unexceptionally mild and readily tolerated by a wide range of sensitive functionalities.
- Ayala, Caitlan E.,Villalpando, Andres,Nguyen, Alex L.,McCandless, Gregory T.,Kartika, Rendy
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supporting information; experimental part
p. 3676 - 3679
(2012/09/08)
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- N-(tert -butoxycarbonyl)- N -[(triethylenediammonium)sulfonyl]azanide: A convenient sulfamoylation reagent for alcohols
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A convenient and efficient procedure is described for the sulfamoylation of alcohols using N-(tert-butoxycarbonyl)-N-[(triethylenediammonium)sulfonyl] azanide (1). The ambient temperature stable reagent 1 reacts with phenols as well as primary and secondary alcohols to give high to modest yields. The relative reaction rate of substrates was determined (primary > phenol > secondary ? tertiary). The reagent's utility as a selective sulfamoylation reagent with polyols is also demonstrated.
- Armitage, Ian,Berne, Alexander M.,Elliott, Eric L.,Fu, Mingkun,Hicks, Frederick,McCubbin, Quentin,Zhu, Lei
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supporting information; experimental part
p. 2626 - 2629
(2012/07/28)
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- Catalytic phosphorus(V)-mediated nucleophilic substitution reactions: Development of a catalytic appel reaction
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Catalytic phosphorus(V)-mediated chlorination and bromination reactions of alcohols have been developed. The new reactions constitute a catalytic version of the classical Appel halogenation reaction. In these new reactions oxalyl chloride is used as a consumable stoichiometric reagent to generate the halophosphonium salts responsible for halogenation from catalytic phosphine oxides. Thus, phosphine oxides have been transformed from stoichiometric waste products into catalysts and a new concept for catalytic phosphorus-based activation and nucleophilic substitution of alcohols has been validated. The present study has focused on a full exploration of the scope and limitations of phosphine oxide catalyzed chlorination reactions as well as the development of the analogous bromination reactions. Further mechanistic studies, including density functional theory calculations on proposed intermediates of the catalytic cycle, are consistent with a catalytic cycle involving halo- and alkoxyphosphonium salts as intermediates.
- Denton, Ross M.,An, Jie,Adeniran, Beatrice,Blake, Alexander J.,Lewis, William,Poulton, Andrew M.
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experimental part
p. 6749 - 6767
(2011/10/02)
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- Pivaloyl chloride/DMF: a new reagent for conversion of alcohols to chlorides
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An efficient procedure for conversion of alcohols into the corresponding chlorides is described. Pivaloyl chloride/DMF complex is employed as a mild and inexpensive reagent. A possible reaction mechanism is proposed.
- Dubey, Abhishek,Upadhyay, Arun K.,Kumar, Pradeep
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experimental part
p. 744 - 746
(2010/04/05)
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- Phosphine oxide-catalysed chlorination reactions of alcohols under Appel conditions
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A phosphine oxide-catalysed chlorination reaction of primary and secondary alcohols has been developed. This process represents the first triphenylphosphine oxide-catalysed alcohol chlorination under Appel conditions. The Royal Society of Chemistry 2010.
- Denton, Ross M.,An, Jie,Adeniran, Beatrice
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supporting information; experimental part
p. 3025 - 3027
(2010/08/04)
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- Impact of the carbon chain length of novel palladium(ll) Complexes on interaction with DNA and cytotoxic activity
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A series of Pd(II) complexes with a benzenealkyl dicarboxlate chain, with the formulas [Pd(Ln)(bipy)].mH2O (bipy = 2,2'-bipyridine, complex 1: L1 = phenylmalonate, m = 2.5; complex 2: L2 = benzylmalonate, m = 1; complex 3: L3 = phenethylmatonate, m = 2; complex 4: L4 = phenylpropylmalonate, m = 5), have been prepared in an attempt to correlate factors about the carbon chain of the compounds with DNA binding and cytotoxic activity. The binding of complexes with fish sperm DNA (FS-DNA) was carried out by UV absorption and fluorescence spectra. A gel electrophoresis assay demonstrated the ability of the complexes to cleave the pBR322 plasmid DNA. The cytotoxic effects of these complexes were examined on four cancer cell lines, HeLa, Hep-G2, KB, and AGZY-83a. The four complexes exhibited cytotoxic specificity and a significant cancer cell inhibitory rate. An apparent dependence of DNAbinding properties and cytotoxicity on the carbon chain length was obtained: the longer the carbon chain length, the higher the efficiency of DNA-binding and the greater the cytotoxicity. 2010 American Chemical Society.
- Gao, Enjun,Zhu, Mingchang,Liu, Lei,Huang, Yun,Wang, Lei,Shi, Chuyue,Zhang, Wanzhong,Sun, Yaguang
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experimental part
p. 3261 - 3270
(2010/06/13)
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- Identification of dinitrotoluene selective peptides by phage display cloning
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Biomolecules specific to explosives can be exploited as chemical sensors. Peptides specific to immobilized dinitrotoluene (DNT) were identified using a phage display library. A derivative of DNT that contained an extended amine group, 4-(2,4-dinitrophenyl)butan-1-amine, was synthesized and immobilized using a self-assembled monolayer surface on gold. Filamentous M13 phages displaying random sequences of 12-mer peptides specific to the immobilized DNT- derivate were isolated from the M13 phage library by biopanning. A common peptide sequence was identified from the isolated phages and the synthesized peptides showed selective binding to DNT. When the peptide was immobilized on a quartz crystal microbalance (QCM) chip, it showed a binding signal to DNT, while toluene barely showed significant binding to the QCM chip. These results demonstrate that peptides screened by biopanning against immobilized DNT can be useful for quick and accurate detection of DNT.
- Jang, Hyeon-Jun,Na, Jung-Hyun,Jin, Bong-Suk,Lee, Won-Kyu,Lee, Woong-Hee,Jung, Hyun Jin,Kim, Seok-Chan,Lim, Si-Hyung,Yu, Yeon Gyu
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scheme or table
p. 3703 - 3706
(2011/10/01)
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- Facile, high regio- And chemoselective conversion of epoxides to β-chlorohydrins using chlorodiphenylphosphine under solvent-free conditions
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A new method is described for the mild and high regioselective conversion of epoxides to β-chlcrohydrins in high yields even in the presence of alcohols, carboxylic acids, oximes, amides, thiols and tetrahydropyranyl ethers using chlorodiphenylphosphine (ClPPh2) under solvent-free and neutral conditions at room temperature and in short reaction times. In addition, some other functional groups such as carbon-carbon double bonds, ester groups and also phenyl ring that are present in the epoxide molecules remain intact in this method.
- Aghapour, Ghasem,Afzali, Asieh,Salek, Fahimeh
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body text
p. 231 - 236
(2009/12/03)
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- Facile cleavage of ethers in ionic liquid
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Various alkyl ethers were efficiently cleaved by treating them with pyridinium halides in ionic liquid, and the desired products were obtained in excellent yields.
- Cheng, Lili,Aw, Carlin,Ong, Siew Siang,Lu, Yixin
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supporting information; experimental part
p. 2008 - 2010
(2009/08/14)
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- NUCLEOPHILE ASSISTING LEAVING GROUPS
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Sulfonate leaving groups include a cation chelating moiety, e.g. a polyether or crown ether. The chelating moiety stabilizes the sulfonate leaving group by forming a complex with a cation of a cation-nucleophile combination. The stabilized leaving group is more easily displaced under many conditions than are standard arylsulfonate leaving groups such as the toxyl group. The chelating moiety also favors certain cations depending on the identity of the moiety thereby enhancing the reaction rate with nucleophilic salts containing the preferred cation. Use of the inventive leaving groups results in improved yields, decreased reaction times and improved product purity.
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Page/Page column 14-15
(2010/11/08)
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- 4-Aminophenyldiphenylphosphinite (APDPP), a new heterogeneous and acid scavenger phosphinite - Conversion of alcohols, trimethylsilyl, and tetrahydropyranyl ethers to alkyl halides with halogens or N-halosuccinimides
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A new heterogeneous phosphinite, 4-aminophenyldiphenylphosphinite (APDPP), is prepared and used for the efficient conversion of alcohols, trimethylsilyl ethers, and tetrahydropyranyl ethers to their corresponding bromides, iodides, and chlorides in the presence of molecular halogens or N-halosuccinimides. The amino group in this phosphinite acts as an acid scavenger and removes the produced acid. A simple filtration easily removes the phosphinate by-product.
- Iranpoor, Nasser,Firouzabadi, Habib,Gholinejad, Mohammad
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p. 1006 - 1012
(2007/10/03)
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- Cobalt-catalyzed cross-coupling reactions of alkyl halides with aryl Grignard reagents and their application to sequential radical cyclization/cross-coupling reactions
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Reactions of alkyl halides with arylmagnesium bromides in the presence of cobalt(II)(diphosphine) complexes are discussed. Treatment of 1-bromooctane with phenylmagnesium bromide with the aid of a catalytic amount of CoCl 2(dppp) [DPPP=1,3-bis(diphenylphosphino)propane] yielded octylbenzene in good yield. The reaction mechanism would include single electron transfer from an electron-rich cobalt complex to alkyl halide to generate the corresponding alkyl radical. The mechanism was justified by CoCl 2(dppe)-catalyzed [DPPE=1,2-bis(diphenylphosphino)ethane] sequential radical cyclization/cross-coupling reactions of 6-halo-1-hexene derivatives that yielded benzyl-substituted cyclopentane skeletons.
- Ohmiya, Hirohisa,Wakabayashi, Katsuyu,Yorimitsu, Hideki,Oshima, Koichiro
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p. 2207 - 2213
(2007/10/03)
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- A novel stereoselective one-pot conversion of alcohols into alkyl halides mediated by N,N′-diisopropylcarbodiimide
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Alcohols can be converted in high yields to the corresponding alkyl halides in a one-pot procedure via the corresponding O-alkylisourea; very short reaction times are possible when microwave irradiation is used.
- Crosignani, Stefano,Nadal, Brice,Li, Zhengning,Linclau, Bruno
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p. 260 - 261
(2007/10/03)
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- A mild, phosphine-free method for the conversion of alcohols into halides (Cl, Br, I) via the corresponding O-alkyl isoureas
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A novel procedure for the conversion of primary and secondary alcohols into the corresponding alkyl chlorides, bromides and iodides is described. The transformation is high-yielding in the case of chlorides and bromides, tolerates a range of functional groups, and does not rely on the use of phosphines.
- Li, Zhengning,Crosignani, Stefano,Linclau, Bruno
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p. 8143 - 8147
(2007/10/03)
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- An efficient route to alkyl chlorides from alcohols using the complex TCT/DMF
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(formula presented) Efficient conversion of alcohols and β-amino alcohols to the corresponding chlorides (and bromides) can be carried out at room temperature in methylene chloride, using 2,4,6-trichloro[1,3,5]triazine and N,N-dimethyl formamide. This procedure can also be applied to optically active carbinols.
- De Luca, Lidia,Giacomelli, Giampaolo,Porcheddu, Andrea
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p. 553 - 555
(2007/10/03)
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- Conversion of alcohols into alkyl chlorides using trichloroisocyanuric acid with triphenylphosphine
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Trichloroisocyanuric acid with triphenylphosphine in anhydrous acetonitrile will convert alcohols into alkyl halides.
- Hiegel, Gene A.,Rubino, Mark
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p. 2691 - 2694
(2007/10/03)
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- Rapid defunctionalization of carbonyl group to methylene with polymethylhydrosiloxane-B(C6F5)3
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The polymethylhydrosiloxane-B(C6F5)3 combination is found to be a versatile carbonyl defunctionalization system under mild and rapid conditions. For the first time, B(C6F5)3 has been used as a nonconventional Lewis acid catalyst to activate PMHS. Aromatic and aliphatic carbonyl compounds were effectively reduced to give the corresponding alkanes in high yields.
- Chandrasekhar,Raji Reddy, Ch.,Nagendra Babu
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p. 9080 - 9082
(2007/10/03)
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- Direct reduction of alcohols: Highly chemoselective reducing system for secondary or tertiary alcohols using chlorodiphenylsilane with a catalytic amount of indium trichloride
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The direct reduction of alcohols using chlorodiphenylsilane as A hydride source in the presence of a catalytic amount of indium trichloride is described. Benzylic alcohols, secondary alcohols, and tertiary alcohols were effectively reduced to give the corresponding alkanes in high yields. A compound bearing both primary and secondary hydroxyl groups was reduced only at the secondary site to afford the primary alcohol after workup with Bu4NF. This system showed high chemoselectivity only for the hydroxyl group while not reducing other functional groups that are readily reduced by standard reducing systems. Thus alcohols bearing ester, chloro, bromo, or nitro groups, which are sensitive to LiAlH4 or Zn/H+, were selectively reduced only at the hydroxyl sites by the chlorodiphenylsilane/InCl3 system. NMR studies revealed the reaction course. The hydrodiphenyl-silyl ether is initially formed and then, with InCl3 acting as a Lewis acid, forms an oxonium complex, which accelerates the desiloxylation with donation of the hydrogen to the carbon.
- Yasuda,Onishi,Ueba,Miyai,Baba
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p. 7741 - 7744
(2007/10/03)
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- Interpretation of retention indices in gas chromatography for establishing structures of isomeric products of alkylarenes radical chlorination
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By an example of previously uncharacterized products obtained by alkylarenes radical chlorination was demonstrated that combination of various interpretation methods applied to the retention indices (RI) in the gas chromatography on the standard nonpolar phases (comparison of RI of products and initial compounds, characteristics of succession of the chromatographic elution of the structural isomers with the use of estimation of molecular dynamic parameters, application of the additive schemes to RI calculation, and using of structural analogy CH3?Cl for testing the results obtained) permitted unambiguous identification of the structure even without data of mass spectrometry.
- Zenkevich
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p. 270 - 280
(2007/10/03)
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- PHOTODECARBOXYLATIVE CHLORINATION OF CARBOXYLIC ACIDS VIA THEIR BENZOPHENONE OXIME ESTERS
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Decarboxylative chlorination of various aromatic and aliphatic carboxylic acids is performed successfully by the photolysis of their benzophenone oxime esters in carbon tetrachloride and corresponding chloro compounds are prepared in good yields.High selective generation of the certain radical and efficiency of the stable radical precursor, benzophenone oxime ester, afford much advantage for radical chemistry.
- Hasebe, Masato,Tsuchiya, Takashi
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p. 6287 - 6290
(2007/10/02)
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- MOLECULAR REARRANGEMENTS. IV. PHOTOLYSIS OF SOME ARYLALKYL HALIDES
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The photolysis of seven selected arylalkyl halides (1-7) using a low-pressure mercury lamp has been carried out in CCl4 as solvent.These halides include benzyl bromide, 1, 2-phenylethyl bromide, 2, 3-phenylpropyl bromide, 3, 4-phenylbutyl chloride, 4, 1-methyl-3-phenylpropyl chloride, 5, 1,1-dimethyl-3-phenylpropyl chloride, 6, and 1,1-dimethyl-4-phenylbutyl chloride, 7.Separation and analyses of the photolysates indicated that mainly dimerization products, arylalkanes, arylalkenes, indan, and tetralin derivatives, have been formed.Evidence is offered that the reaction takes place through homolytic C-H bond fission followed by dimerization, dehydrogenation, hydrogen (or halogen) abstraction, rearrangement or photocylization of the produced arylalkyl radical, whenever possible.Distribution of the reaction products was found to be mainly dependent on the starting arylalkyl halide.
- Abdel-Wahab, Aboel-Magd A.,Ismail, Mohamed T.,Mohamed, Omaima S.,Khalaf, Ali A.
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p. 591 - 594
(2007/10/02)
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- Preparation of Alkyl Chlorides, Acid Chlorides, and Amides Using Polymer-Supported Phosphines and Carbon Tetrachloride: Mechanism of These Reactions
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Alcohols and thiols were converted into alkyl chlorides, carboxylic acids were converted into acid chlorides, and mixtures of carboxylic acids and amines were converted into amides by reaction with carbon tetrachloride and 1percent cross-linked polystyrenes containing phosphine residues.Some of these conversions were also effected by using a linear polymer containing phosphine residues.The reactions proceed in high yield, and isolation of the products is facilitated by the ready removal of all the polymer-supported species.The mechanism of the reactions between triphenylphosphine, carbon tetrachloride, and alcohols is complex, but the polymer-supported reactions appear to follow analogous pathways to the low molecular weight reactions as judged by the yields of chloroform and the number of equivalents of phosphine consumed per mole of alkyl chloride produced.The mechanism requires polymer-supported groups reacting together.The slow step in the reactions appears to be the generation of the chlorinating species.The polymer-supported reactions are faster than those using triphenylphosphine or 4-(diphenylphosphinyl)isopropylbenzene.It is suggested that this is due to a microenvironmental effect.
- Harrison, Charles R.,Hodge, Philip,Hunt, Barry J.,Khoshdel, Ezzatollah,Richardson, Graham
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p. 3721 - 3728
(2007/10/02)
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- Structure of ω-Arylalkyl Radicals: A 13C CIDNP Investigation
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Thermolysis of a series of ω-arylalkanoyl m-chlorobenzoyl (and acetyl) peroxides at ca. 100 deg C in cyclohexanone and in hexachloroacetone was studied by using 13C chemically induced dynamic nuclear polarization.Analysis of the observed 13C polarizations indicate that all the three radicals (β-arylethyl, γ-arylpropyl and δ-arylbutyl) have open-chain structures with no evidence for aryl participation resulting in spirocycloalkylcyclohexadienyl radicals.
- Olah, George A.,Krishnamurthy, V. V.,Singh, Brij P.,Iyer, Pradeep S.
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p. 955 - 963
(2007/10/02)
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- PREPARATION OF ALKYL HALIDES VIA ORGANOTELLURIUMS
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The conversion of phenyltelluroalkanes to haloalkanes was studied in connection with the homologation of alkyl halides.Similar reactions of 1,1-bis(phenyltelluro)alkanes provided a new synthetic method of aldehydes.
- Chikamatsu, Kiyofumi,Otsubo, Tetsuo,Ogura, Fumio,Yamaguchi, Hachiro
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p. 1081 - 1084
(2007/10/02)
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