- A novel photochemical DNA-cleaving agent, brominated dibenzoylmethanes
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Novel photochemical DNa-cleaving molecules possessing a dibenzoyldibromomethane chromophore have been prepared. The efficiency and the sequence selectivity for the DNA photocleavage have been described.
- Saito, Isao,Sakurai, Tomonori,Kurimoto, Tomoyuki,Takayama, Masami
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Read Online
- Preparation method of compound containing bipyrazole ring and intermediate thereof
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The invention discloses a preparation method of a compound containing a bipyrazole ring and an intermediate of the compound. The preparation method of a bipyrazole ring-containing compound as shown ina formula I comprises the following steps: (1) adding alkali into a mixture of a bipyrazole ring compound as shown in a formula I-1 and a solvent for replacement reaction to obtain a mixed system; and (2) adding an organic phosphorus compound shown as a formula I-2 into the mixed system in the step (1), and carrying out a phosphonation reaction shown in the specification, so as to obtain the bipyrazole ring-containing compound shown as the formula I, wherein R1 and R2 are independently a C1-C6 alkyl group, a C3-C8 cycloalkyl group and a phenyl group, R3 is a C1-C6 alkyl group, and X is halogen. The prepared compound containing a bipyrazole ring can be used as a ligand, and is suitable for the application range of amide in C-N coupling and the C-C coupling reaction of arylboronic acid andaryl chloride.
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Paragraph 0195-0197; 0199-0202; 0215-0218
(2020/05/14)
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- Pyrazolyl bistriazolyl phosphine compound and application of pyrazolyl bistriazolyl phosphine compound
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The invention discloses a pyrazolyl bistriazolyl phosphine compound and application thereof. The invention discloses a compound shown as a formula I. In the formula I, R1 is hydrogen, C1-C6 alkyl or phenyl; R2 and R3 are phenyl; R4 and R5 are independently a C1-C6 alkyl group, a C3-C8 cycloalkyl group, or a phenyl group. The pyrazolyl bistriazolyl phosphine compound disclosed by the invention is stable in property, excellent in catalytic effect and high in selectivity, and can be applied to catalytic coupling of amine, boric acid compounds and halides.
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Paragraph 0194-0196
(2020/07/24)
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- Preparation method of pyrazole bistriazolylphosphine compound
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The invention discloses a preparation method of a pyrazole bistriazolylphosphine compound. The invention discloses a preparation method of a compound as shown in a formula I. The preparation method comprises the following step: under the action of an alkali, carrying out a phosphonation reaction process as shown in the specification on a compound as shown in a formula II and a compound as shown ina formula III in a solvent in the presence of protective gas to obtain the compound as shown in the formula I, wherein R1 is hydrogen, a C1-C6 alkyl group or a phenyl group, R2 and R3 are phenyl, R4and R5 are independently a C1-C6 alkyl group, a C3-C8 cycloalkyl group or a phenyl group and x is halogen. The pyrazolyl bistriazolylphosphine compound obtained by the preparation method disclosed bythe invention is stable in property, excellent in catalytic effect and high in selectivity, and can be applied to catalytic coupling of amine, boric acid compounds and halides.
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Paragraph 0192-0194
(2020/05/30)
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- Compound containing bipyrazole ring, intermediate thereof and application thereof
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The invention discloses a compound containing a bipyrazole ring, and an intermediate and application thereof. The invention provides the compound containing a bipyrazole ring, as shown in a formula Iwhich is described in the specification. The compound can be used as a ligand, is high in selectivity, and is suitable for the application range of amide in C-N coupling and the C-C coupling reactionof arylboronic acid and aryl chloride, especially coupling with aryl chloride.
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Paragraph 0195; 0199-0202; 0215-218
(2020/05/14)
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- A Highly Efficient Method for the Bromination of Alkenes, Alkynes and Ketones Using Dimethyl Sulfoxide and Oxalyl Bromide
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The pairing of DMSO and oxalyl bromide is reported as a highly efficient brominating reagent for various alkenes, alkynes and ketones. This bromination approach demonstrates remarkable advantages, such as mild conditions, low cost, short reaction times, provides excellent yields in most cases and represents a very attractive alternative for the preparation of dibromides and α-bromoketones.
- Ding, Rui,Li, Jiaqi,Jiao, Wenyi,Han, Mengru,Liu, Yongguo,Tian, Hongyu,Sun, Baoguo
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p. 4325 - 4335
(2018/11/21)
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- Solvent-Controlled α-Monobromination, α,α-Dibromination or Imidation of 1,3-Diketones with N-Bromosuccinimide
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In this work, we present a solvent-controlled regioselective method for α-monobromination, dibromination or imidation of 1,3-diketones with N-bromosuccinimide under simple reaction conditions. The employment of solvents plays a key role on the reaction selectivity providing α-monobrominated, dibrominated and imidated products. Visible light irradiation accelerates the dibromination reaction of 1,3-diketones. In particular, one important solvent was found to be highly effective for the imidation of 1,3-diketones under base-free condition.
- Zou, Liang-Hua,Li, Yan-Chun,Li, Ping-Gui,Zhou, Jing,Wu, Zhimeng
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supporting information
p. 5639 - 5643
(2018/10/05)
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- Highly Regio- and Stereodivergent Access to 1,2-Amino Alcohols or 1,4-Fluoro Alcohols by NHC-Catalyzed Ring Opening of Epoxy enals
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Described is an unprecedented NHC-catalyzed (NHC=N-heterocyclic carbene), stereoselective ring opening of epoxy and cyclopropyl enals to deliver valuable compounds bearing multiple stereocenters. A straightforward three-step procedure involving two catalytic enantioselective transformations has been developed and leads to a regio- and stereodivergent synthesis of either 1,2-amino alcohols/diamines or 1,4-fluoro alcohols with excellent diastereo- and enantiopurity.
- Poh, Si Bei,Ong, Jun-Yang,Lu, Shenci,Zhao, Yu
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supporting information
p. 1645 - 1649
(2018/02/06)
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- One-pot synthesis of α-bromo- and α-azidoketones from olefins by catalytic oxidation with in situ-generated modified IBX as the key reaction
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Simple one-pot protocols for the syntheses of α-bromoketones and α-azidoketones starting from olefins have been developed by employing catalytic oxidation of the intermediary bromohydrins with in situ-generated modified IBX as the key reaction. The improved procedure involves initial formation of bromohydrin by the reaction of olefin with NBS in acetonitrile-water mixture (1:1) at rt followed by oxidation with in situ-generated 3,4,5,6-tetramethyl-2-iodoxybenzoic acid (TetMe-IBX), produced in catalytic amounts from 3,4,5,6-tetramethyl-2-iodobenzoic and Oxone. α-Bromoketones are further converted in the same pot to the corresponding α-azidoketones using NaN3/NaHCO3. The one-pot conversions are versatile for a variety of olefins that include cyclic as well as acyclic aliphatic olefins and electron-rich and electron-deficient styrenes. Chemoselective bromohydroxylation of electron-rich double bond and subsequent oxidation to the α-bromoketone is demonstrated for a substrate that contains both electron-rich and deficient double bonds.
- Chandra, Ajeet,Parida, Keshaba Nanda,Moorthy, Jarugu Narasimha
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supporting information
p. 5827 - 5832
(2017/09/09)
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- A quick, mild and efficient bromination using a CFBSA/KBr system
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Bromination is a fundamental transformation in organic chemistry and brominated compounds as building blocks are of paramount importance in organic synthesis. In our study, we have developed an efficient method of bromination by using a CFBSA/KBr system at room temperature in a short reaction time. Notably, this approach has been proven to be applicable to a range of substrates including 1,3-diketones and β-keto esters, phenols, aromatic amines and heteroarenes with good to excellent yields.
- Jiang, Pan-Pan,Yang, Xian-Jin
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p. 90031 - 90034
(2016/10/09)
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- Preparation method for 2-halogenated-1,3-dicarbonyl derivative
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The invention discloses a preparation method for a 2-halogenated-1,3-dicarbonyl derivative. The preparation method is suitable for wide 1,3-dicarbonyl derivatives. The raw materials are easy to obtain, and multiple varieties are achieved. The product obtained through the method is diversified in type, and can be directly used and used for other further reactions. According to the method, reaction conditions are gentle, the reaction operation and after-treatment process is simple, reaction time is short, the yield is high, pollution is low, and the preparation method is suitable for industrial production.
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Paragraph 0035
(2017/02/28)
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- 1,3-Dibromo-5,5-dimethylhydantoin (DBH) mediated one-pot syntheses of α-bromo/amino ketones from alkenes in water
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α-Bromo ketones are versatile intermediates of high practical utility. Traditional approaches to these compounds are restricted to a relatively hazardous/complex reagent combination, a long reaction time, the use of non-environmentally friendly solvents, or a limited substrate scope. Herein, we describe the development of a new methodology for the preparation of α-bromo ketones from alkenes using 1,3-dibromo-5,5-dimethylhydantoin (DBH) as a bromine source and an oxidant simultaneously. This easy to carry out two-step one-pot protocol proceeds in water and provides high yield of a great variety of α-bromo ketones. Addition of an amine to the intermediate α-bromo ketone further enables the preparation of α-amino ketones in a one-pot sequence.
- Xu, Senhan,Wu, Ping,Zhang, Wei
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p. 11389 - 11395
(2016/12/18)
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- Vanadium (V) oxide mediated bromolactonization of alkenoic acids
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A full account of our recently communicated method for the V2O5 mediated bromolactonization of alkenoic acids is presented. Here we describe the extensive evaluation of the metal oxide catalyst, terminal oxidant, halide source, solvent system, and reaction temperature that resulted in optimal conditions employing 0.05 equiv V2O5, 3 equiv urea-hydrogen peroxide complex (UHP), and 3 equiv of NH4Br in an acetone:H2O (6:1) solvent system at room temperature. Additionally, we have expanded the substrate scope of the reaction with the aim of evaluating the functional group tolerance of the transformation. Further, we present preliminary data of a related halogenation of β-diketones with our optimal conditions. Finally, we probed the role of urea in the transformation.
- Campbell, McKenzie L.,Rackley, Samuel A.,Giambalvo, Lauren N.,Whitehead, Daniel C.
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p. 3895 - 3902
(2015/06/02)
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- Hexamethonium bis(tribromide) (HMBTB) a recyclable and high bromine containing reagent
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A recyclable and high bromine containing di-(tribromide) reagent, hexamethonium bis(tribromide) (HMBTB) has been synthesized and utilized for the bromination of various organic substrates. The spent reagent hexamethonium bromide (HMB) can be effectively recycled by regenerating and reusing it without significant loss of activity. The crystalline and stable bis(tribromide) is an effective storehouse of very high percentage of active bromine requiring just half an equivalent of it for complete bromination. Both the Br3- moieties in HMBTB are nearly linear with Br-Br-Br angle of 179.55°.
- Paul, Bappi,Bhuyan, Bishal,Purkayastha, Debraj D.,Dhar, Siddhartha S.,Patel, Bhisma K.
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p. 5646 - 5650
(2015/09/21)
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- Novel Metal- and Mineral-Acid-Free Synthesis of Organic Ammonium Tribromides and Application of Ethylenephenanthrolium Bistribromide for Bromination of Active Methylene Group of 1,3-Diketones and β-Ketoesters
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A novel procedure for the preparation of organic ammonium tribromides (OATBs) is described from their corresponding bromides. Quaternary ammonium bromides (QABs) and a N,N′-heterocyclic dibromide are efficiently oxidized to their corresponding monotribromides and bistribromide by m-chloroperbenzoic acid (MCPBA) in the presence of 2 and 4 equiv of KBr, respectively. The reactions are carried out in an aqueous medium without the use of any mineral acid or metal catalyst/promoters. A variety of tribromides are synthesized in very good yields including a hitherto unknown reagent, 1,10-(ethane-1, 2-diyl)phenanthrolinediium bistribromide (EPDBT). EPDBT is investigated as brominating agent and found to be highly effective for selective bromination of active methylene groups of a variety of 1,3-diketones and β-ketoesters. GRAPHICAL ABSTRACT.
- Dey, Rupa Rani,Paul, Bappi,Dhar, Siddhartha Sankar
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supporting information
p. 724 - 736
(2015/10/29)
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- Magnetic-nanoparticle-supported 2,2′-bis[3-(triethoxysilyl)propyl] imidazolium-substituted diethyl ether bis(tribromide): A convenient recyclable reagent for bromination
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A new magnetic-nanoparticle-supported bromination reagent was synthesized by anchoring a 2,2′-bis[3-(triethoxysilyl)propyl]imidazolium-substituted diethyl ether bis(tribromide) onto the surface of γ-Fe2O 3 nanoparticles and subsequently treating this new ionic liquid with bromine. The nanoparticle reagent was obtained with good loading levels and has been successfully used for the efficient bromination of a wide range of alkenes, alkynes, ketones, and aromatic substrates. More importantly, the reagent could be easily recovered by an external magnet and reused six times without significant loss of activity. A new maghemite nanoparticle bromination reagent has been prepared. The nanoparticle reagent was obtained with good loading levels and has been successfully used for the efficient bromination of a wide range of alkenes, alkynes, ketones, and aromatic substrates. Copyright
- Wu, Liqiang,Yin, Zhikui
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p. 6156 - 6163
(2014/01/06)
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- Single and multiple additions of dibenzoylmethane onto buckminsterfullerene
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A novel dibenzoylmethane-fullerene e,e,e-tris adduct was synthesized by the application of a variation of the Bingel-Hirsch conditions and characterized among others by X-ray crystallography. In addition, the corresponding hexakis adduct was detected by MALDI-TOF-MS analysis. Its existence was supported by density-functional-theory (DFT) computations. Furthermore a new synthesis of bis(benzoyl)methanofullerene was established, and its molecular structure was elucidated by X-ray crystallography. DFT computations reproduced the experimentally determined conformation and predict a low energy barrier for the rotation of the two benzoyl moieties. We report the synthesis and crystal structure of tris-e,e,e-[bis(benzoyl)methano]fullerene. Furthermore, a new synthetic route to the corresponding mono adduct was developed, and its molecular structure was determined. The corresponding hexakis adduct was predicted by DFT calculations and identified by MALDI-TOF-MS as well as by 1H NMR spectroscopy. Copyright
- Giovannitti, Alexander,Seifermann, Stefan M.,Bihlmeier, Angela,Muller, Thierry,Topic, Filip,Rissanen, Kari,Nieger, Martin,Klopper, Wim,Braese, Stefan
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supporting information
p. 7907 - 7913
(2014/01/06)
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- Solvent-free bromination reactions with sodium bromide and oxone promoted by mechanical milling
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New solvent-free brominations of 1,3-dicarbonyl compounds, phenols, various alkenes including chalcones, azachalcones, 4-phenylbut-3-en-2-one, methyl cinnamate, styrene and 1,3-cyclohexadiene were efficiently achieved by employing sodium bromide and oxone under mechanical milling conditions. The brominated products were obtained in good to excellent yields.
- Wang, Guan-Wu,Gao, Jie
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experimental part
p. 1125 - 1131
(2012/06/04)
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- Oxidative bromination of ketones using ammonium bromide and oxone
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A highly efficient, environmentally safe and economic method for selective α-monobromination of aralkyl, cyclic, acyclic, 1,3-diketones and β-keto esters and α,α-dibromination of 1,3-diketones and β-keto esters without catalyst is reported using ammonium bromide as a bromine source and oxone as an oxidant. The reaction proceeds at ambient temperature and yields range from moderate to excellent. Bromination of unsymmetrical ketones takes place at the less substituted α-position predominantly. Aromatisation of tetralones is also carried out with this reagent system.
- MacHarla, Arun Kumar,Chozhiyath Nappunni, Rohitha,Marri, Mahender Reddy,Peraka, Swamy,Nama, Narender
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supporting information; experimental part
p. 191 - 195
(2012/01/17)
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- Brominated methanes as photoresponsive molecular storage of elemental Br2
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The photochemical generation of elemental Br2 from brominated methanes is reported. Br2 was generated by the vaporization of carbon oxides and HBr through oxidative photodecomposition of brominated methanes under a 20 W low-pressure mercury lamp, wherein the amount and situations of Br2 generation were photochemically controllable. Liquid CH 2Br2 can be used not only as an organic solvent but also for the photoresponsive molecular storage of Br2, which is of great technical benefit in a variety of organic syntheses and in materials science. By taking advantage of the in situ generation of Br2 from the organic solvent itself, many organobromine compounds were synthesized in high practical yields with or without the addition of a catalyst. Herein, Br2 that was generated by the photodecomposition of CH2Br2 retained its reactivity in solution to undergo essentially the same reactions as those that were carried out with solutions of Br2 dissolved in CH 2Br2 that were prepared without photoirradiation. Furthermore, HBr, which was generated during the course of the photodecomposition of CH2Br2, was also available for the substitution of the OH group for the Br group and for the preparation of the HBr salts of amines. Furthermore, the photochemical generation of Br2 from CH2Br2 was available for the area-selective photochemical bleaching of natural colored plants, such as red rose petals, wherein Br2 that was generated photochemically from CH 2Br2 was painted onto the petal to cause radical oxidations of the chromophoric anthocyanin molecules. The generation of Br 2 from brominated methanes occurred upon photoirradiation under O2. The solutions that contained elemental Br2 were useful for the synthesis of organobromine compounds and the macroscopic photochemical bleaching of colored plants. Copyright
- Kawakami, Kazumitsu,Tsuda, Akihiko
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p. 2240 - 2252
(2012/11/06)
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- Selective monobromination of 1,3-diones with N-bromosaccharin/Mg(ClO 4)2 system in solution and under solvent-free conditions
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N-Bromosaccharin/Mg(ClO4)2 is an effective and regioselective system for α-monobromination of 1,3-dicarbonyl compounds. A wide variety of β-keto esters and 1,3-diketones in reaction with this system afforded a regioselectively α-mono
- Alinezhad, Heshmatollah,Tajbakhsh, Mahmood,Tehrani, Shahram Shahriari
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experimental part
p. 1543 - 1546
(2011/12/04)
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- Liquid crystal polymorphism of boron difluoride β-diketonates
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Boron difluoride 2-alkyl-β-diketonates possessing liquid crystal polymorphism and luminescence properties were first obtained. Influence of the ligand structure on the liquid crystal properties of the boron difluoride complexes was demonstrated. Pleiades Publishing, Ltd., 2010.
- Turanova,Garifzyanova,Turanov
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experimental part
p. 2317 - 2322
(2011/04/14)
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- A general and efficient catalyst for palladium-catalyzed C-O coupling reactions of aryl halides with primary alcohols
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An efficient procedure for palladium-catalyzed coupling reactions of (hetero)aryl bromides and chlorides with primary aliphatic alcohols has been developed. Key to the success is the synthesis and exploitation of the novel bulky di-1-adamantyl-substituted bipyrazolylphosphine ligand L6. Reaction of aryl halides including activated, nonactivated, and (hetero)aryl bromides as well as aryl chlorides with primary alcohols gave the corresponding alkyl aryl ethers in high yield. Noteworthy, functionalizations of primary alcohols in the presence of secondary and tertiary alcohols proceed with excellent regioselectivity.
- Gowrisankar, Saravanan,Sergeev, Alexey G.,Anbarasan, Pazhamalai,Spannenberg, Anke,Neumann, Helfried,Beller, Matthias
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supporting information; experimental part
p. 11592 - 11598
(2010/10/02)
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- Molybdenum(VI) dichloride
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A novel and efficient method for the one-pot transformation of β-hydroxycarbonyl compounds to a-brominated 1,3-dicarbonyl compounds is achieved with MoO2Cl2 in the presence of N-bromosuccinimide. All the reactions were carried out un
- Jeyakumar, Kandasamy,Chand, Dillip Kumar
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experimental part
p. 306 - 310
(2009/06/24)
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- Ethylenebis(N-methylimidazolium) ditribromide (EBMIDTB): An efficient reagent for the monobromination of 1,3-diketones and β-ketoesters
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Ethylenebis(N-methylimidazolium) ditribromide, a stable crystalline solid, is easily prepared by reaction of the corresponding dibromide salt with bromine in n-hexane. 1,3-Diketones and β-ketoesters can be brominated chemoselectively to the corresponding α-monobrominated products by using this reagent at 0-5°C. Under the same reaction conditions, diethyl malonate, ethyl cyanoacetate, and malonitrile were monobrominated at moderate yield.
- Hosseinzadeh, Rahman,Tajbakhsh, Mahmood,Mohadjerani, Maryam,Lasemi, Zahra
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experimental part
p. 57 - 60
(2010/03/30)
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- Thioglycoluril as a novel organocatalyst: Rapid and efficient α-monobromination of 1,3-dicarbonyl compounds
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Thioglycoluril as a novel hydrogen-bonding organocatalyst, combined with NBS, in MeOH provided rapid and efficient α-monobromination of 1,3-dicarbonyl compounds in excellent yields at room temperature. A bifunctional catalytic mechanism was proposed from
- Cao, Liping,Ding, Jiaoyang,Yin, Guodong,Gao, Meng,Li, Yitao,Wu, Anxin
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scheme or table
p. 1445 - 1448
(2009/10/10)
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- Facile one-pot synthesis of α-bromoketones from olefins using bromide/bromate couple as a nonhazardous brominating agent
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A new method for the preparation of α-bromoketones from olefins using bromide/bromate couple as a nonhazardous brominating agent has been developed. Several α-bromoketones were successfully prepared from a variety of olefins by this method. This procedure is an alternative to conventional molecular bromine.
- Patil, Rajendra D.,Joshi, Girdhar,Adimurthy, Subbarayappa,Ranu, Brindaban C.
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experimental part
p. 2529 - 2532
(2009/09/06)
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- Streamlined synthesis of the bippyphos family of ligands and cross-coupling applications
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We describe the efficient preparation of Bippyphos, 1. The key precursor to Bippyphos, 5, was prepared via a one-pot bromination of diketone 2 followed by alkylation with pyrazole and condensation with phenylhydrazine. Lithiation of 5 and trapping with ditert-butylchlorophosphine afforded Bippyphos, 1. Using this approach we have prepared several derivatives of Bippyphos to probe the structure and activity relationships of this family of phosphine ligands. We also demonstrate the utility of these ligands in Pdcatalyzed amination reactions and other cross-coupling reactions.
- Withbroe, Gregory J.,Singer, Robert A.,Sieser, Janice E.
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p. 480 - 489
(2013/01/03)
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- Ionic liquid promoted selective debromination of α-bromoketones under microwave irradiation
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The debromination of α-bromoketones with an easily accessible ionic liquid, 1-methyl-3-pentylimidazolium tetrafluoroborate, [pmIm]BF4 under microwave irradiation has been investigated. By controlling the reaction time gem-α-dibromoketones are selectively debrominated to either monobromo or debromoketones. The α-monobromo- and α-monoiodoketones are dehalogenated while the corresponding chloroketones remain inert. The activated vic-bromoacetates are converted to the corresponding (E)-alkenes by the same procedure. These reactions do not require any organic solvent, any metal or any conventional reducing agent. The ionic liquid works here as catalyst as well as reaction medium and is recycled without any appreciable loss of its catalytic efficiency.
- Ranu, Brindaban C.,Chattopadhyay, Kalicharan,Jana, Ranjan
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p. 155 - 159
(2007/10/03)
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- Chemoselective bromination of active methylene and methyne compounds by potassium bromide, hydrochloric acid and hydrogen peroxide
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Active methylene and methyne compounds can be chemoselectively brominated in high yields using potassium bromide, hydrochloric acid, and hydrogen peroxide at room temperature. Georg Thieme Verlag Stuttgart.
- Kirihara, Masayuki,Ogawa, Shiho,Noguchi, Takuya,Okubo, Kumiko,Monma, Yoshinari,Shimizu, Ikuko,Shimosaki, Ryuji,Hatano, Akihiko,Hirai, Yoshiro
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p. 2287 - 2289
(2007/10/03)
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- A mild and regioselective method for α-bromination of β-keto esters and 1,3-diketones using bromodimethylsulfonium bromide (BDMS)
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Bromodimethylsulfonium bromide has been found to be an effective and regioselective reagent for α-monobromination of β-keto esters and 1,3-diketones. A wide variety of β-keto esters and 1,3-diketones undergo chemoselective α-monobromination with excellent yields at 0-5 °C or room temperature. The notable advantages of this protocol are no need of chromatographic separation, use of less hazardous reagent than molecular bromine, and no added base, Lewis acid, or other catalyst.
- Khan, Abu T.,Ali, Md. Ashif,Goswami, Papori,Choudhury, Lokman H.
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p. 8961 - 8963
(2007/10/03)
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- A mild and environmentally acceptable synthetic protocol for chemoselective α-bromination of β-keto esters and 1,3-diketones
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A wide variety of unsubstituted β-keto esters can be brominated chemoselectively to the corresponding α-monobromo-β-keto esters by using a combination of vanadium pentoxide, hydrogen peroxide and ammonium bromide in a biphasic system, dichloromethane-wate
- Khan, Abu T.,Goswami, Papori,Choudhury, Lokman H.
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p. 2751 - 2754
(2007/10/03)
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- Development of nonproprietary phosphine ligands for the Pd-catalyzed amination reaction
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A new family of pyrazole and bi-pyrazole phosphine ligands are reported that perform efficiently in the Pd-catalyzed amination reaction. Of the ligands screened, ligand 1 emerged as the most compatible for couplings involving both primary and secondary am
- Singer, Robert A.,Doré, Micha?l,Sieser, Janice E.,Berliner, Martin A.
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p. 3727 - 3731
(2007/10/03)
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- A green approach for efficient α-halogenation of β-dicarbonyl compounds and cyclic ketones using N-halosuccinimides in ionic liquids
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Room temperature ionic liquids (ILs) are used as a green recyclable reaction media for the α-monohalogenation of 1,3-diketones, β-keto-esters and cyclic ketones with N-halosuccinimides in excellent yields in the absence of a catalyst. The recovered ionic liquid was reused five to six times with consistent activity.
- Meshram,Reddy,Vishnu,Sadashiv,Yadav
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p. 991 - 995
(2007/10/03)
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- Directed regioselectivity of bromination of ketones with NBS: solvent-free conditions versus water
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The reaction conditions employed directed the site of functionalisation of ketones with NBS: under solvent-free conditions α-bromination was the exclusive process, while in water, ring functionalisation occurred in the case of methoxy substituted aromatic ketones.
- Pravst, Igor,Zupan, Marko,Stavber, Stojan
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p. 4707 - 4710
(2007/10/03)
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- THERAPEUTIC AGENT FOR CANCER
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A medicament for the prevention and/or treatment of cancers and the like which comprises as an active ingredient a substance selected from the group consisting of a compound represented by the following general formula (I) and a pharmacologically acceptable salt thereof, and a hydrate thereof and a solvate thereof: wherein A represents hydrogen atom or acetyl group, E represents a 2,5-di-substituted or a 3,5-di-substituted phenyl group, or a monocyclic or a fused polycyclic heteroaryl group which may be substituted, provided that the compound wherein said heteroaryl group is 1? a fused polycyclic heteroaryl group wherein the ring which binds directly to ―CONH― group in the formula (I) is a benzene ring, 2? unsubstituted thiazol-2-yl group, or 3? unsubstituted benzothiazol-2-yl group is excluded, ring Z represents an arene which may have one or more substituents in addition to the group represented by formula ―O―A wherein A has the same meaning as that defined above and the group represented by formula ―CONH―E wherein E has the same meaning as that defined above, or a heteroarene which may have one or more substituents in addition to the group represented by formula ―O―A wherein A has the same meaning as that defined above and the group represented by formula ― CONH―E wherein E has the same meaning as that defined above.
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Page/Page column 114
(2010/02/11)
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- NF-KB ACTIVATION INHIBITORS
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A medicament having inhibitory activity against NF-κB activation which comprises as an active ingredient a substance selected from the group consisting of a compound represented by the following general formula (I) and a pharmacologically acceptable salt thereof, and a hydrate thereof and a solvate thereof: wherein A represents hydrogen atom or acetyl group, E represents a 2,5-di-substituted or a 3,5-di-substituted phenyl group, or a monocyclic or a fused polycyclic heteroaryl group which may be substituted, provided that the compound wherein said heteroaryl group is 1○ a fused polycyclic heteroaryl group wherein the ring which binds directly to ―CONH― group in the formula (I) is a benzene ring, 2○ unsubstituted thiazol-2-yl group, or 3○ unsubstituted benzothiazol-2-yl group is excluded, ring Z represents an arene which may have one or more substituents in addition to the group represented by formula ―O―A wherein A has the same meaning as that defined above and the group represented by formula -CONH-E wherein E has the same meaning as that defined above, or a heteroarene which may have one or more substituents in addition to the group represented by formula ―O―A wherein A has the same meaning as that defined above and the group represented by formula ― CONH―E wherein E has the same meaning as that defined above.
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- REMEDIES FOR NEURODEGENERATIVE DISEASES
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A medicament for preventive and/or therapeutic treatment of neurodegenerative diseases such as Alzheimer's disease or the like which comprises as an active ingredient a substance selected from the group consisting of a compound represented by the following general formula (I) and a pharmacologically acceptable salt thereof, and a hydrate thereof and a solvate thereof: wherein A represents hydrogen atom or acetyl group, E represents a 2,5-di-substituted or a 3,5-di-substituted phenyl group, or a monocyclic or a fused polycyclic heteroaryl group which may be substituted, provided that the compound wherein said heteroaryl group is 1○ a fused polycyclic heteroaryl group wherein the ring which binds directly to -CONH- group in the formula (I) is a benzene ring, 2○ unsubstituted thiazol-2-yl group, or 3○ unsubstituted benzothiazol-2-yl group is excluded, ring Z represents an arene which may have one or more substituents in addition to the group represented by formula -O-A wherein A has the same meaning as that defined above and the group represented by formula -CONH-E wherein E has the same meaning as that defined above, or a heteroarene which may have one or more substituents in addition to the group represented by formula -O-A wherein A has the same meaning as that defined above and the group represented by formula -CONH-E wherein E has the same meaning as that defined above.
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- INHIBITORS AGAINST THE ACTIVATION OF AP-1 AND NFAT
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A medicament inhibiting the activation of AP-1 which comprises as an active ingredient a substance selected from the group consisting of a compound represented by the following general formula (I) and a pharmacologically acceptable salt thereof, and a hydrate thereof and a solvate thereof: wherein X represents a connecting group whose number of atoms in the main chain is 2 to 5 (said connecting group may be substituted), A represents hydrogen atom or acetyl group, E represents an aryl group which may be substituted or a hetero aryl group which may be substituted, ring Z represents an arene which may have one or more substituents in addition to the group represented by formula -O-A wherein A has the same meaning as that defined above and the group represented by formula -X-E wherein each of X and E has the same meaning as that defined above, or a heteroarene which may have one or more substituents in addition to the group represented by formula -O-A wherein A has the same meaning as that defined above and the group represented by formula -X-E wherein each of X and E has the same meaning as that defined above.
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- INHIBITORS AGAINST THE PRODUCTION AND RELEASE OF INFLAMMATORY CYTOKINES
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A medicament having inhibitory activity against NF- κ B activation, which comprises a compound represented by the following general formula (I) or a pharmacologically acceptable salt as an active ingredient: wherein X represents a connecting group, A represents hydrogen atom or acetyl group, E represents an aryl group or a heteroaryl group, and ring X represents an arene or a heteroarene.
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- Alkylation of α-Halo Diketones via Enol Phosphate Intermediate
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β-Substituted α,β-unsaturated carbonyl compounds were obtained in moderate to high yields by a 1,4-addition of organocuprates to enol phosphate intermediates formed in situ from triethyl phosphite and 2-bromo-1,3-dicarbonyl compounds.
- Onishi, Jim Yoshitaka,Takuwa, Tomofumi,Mukaiyama, Teruaki
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p. 994 - 995
(2007/10/03)
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- Synthesis and study of the anodic behavior of 1,3,4,6-tetraaryl-2λ4δ2-thieno[3,4-c] thiophenes
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Two heterocyclic compounds based on the thieno[3,4-c]thiophene structure with four aryl substituents were prepared and their behavior in electrooxidation studied. These tetraarylthieno[3,4-c]thiophenes were synthesized in three steps starting from 1,3-dibenzoylmethane in the case of 1,3,4,6-tetraphenyl-2λ4δ2-thieno[3,4-c] thiophene 1a and from 1,3-bis(4′-methoxyphenyl)propane-1,3-dione in the case of 1,3,4,6-tetrakis(4′-methoxyphenyl)-2λ4δ 2-thieno[3,4-c]thiophene 1b, a new compound. Both cyclic and hydrodynamic voltamperometric analyses indicate two reversible one-electron oxidation stages for compound 1b, while for compound 1a only the first stage is reversible. The preparative electrooxidation of the two compounds results in the opening of one thiophene ring giving rise to γ-keto-thioketones.
- Douadi, Tahar,Cariou, Michel
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p. 509 - 520
(2007/10/03)
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- A Convenient Halogenation Procedure for the Preparation of α-Halocarbonyl Compounds
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Except for substituted acetophenones (p-Y-C6H4COCH3, Y=H, Br, CH3O), simple ketones, α-ketoesters and 1,3-diketones reacted smoothly with a preformed homogeneous mixture of hydrochloric acid and potassium permanganate in acetonitrile to give moderate to good yields of the corresponding α-chlorocarbonyl compounds.Mixtures of α-chloro- and α,α-dichlorocarbonyl compounds were obtained for substituted acetophenones.Brominations proceeded similarly with higher yields when the hydrochloric acid was replaced with hydrobromic acid. - Key words: α-chlorocarbonyl compounds; α-bromocarbonyl compounds; potassium permanganate; chlorination; bromination.
- Cheng, Sheng-Fan,Lin, Ching-Shan,Liu, Lilian Kao
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p. 309 - 312
(2007/10/03)
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- α-Substituted β-diketones: Effect of the α substituent on the complexation and selectivity for lanthanides
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Some β-diketones having a substituent at the α position have been prepared and their keto-enol tautomerism, acid dissociation reaction and complexation with lanthanides have been studied. The tautomerism was examined by 1H NMR spectroscopy, rev
- Le, Quyen T. H.,Umetani, Shigeo,Suzuki, Mitsuko,Matsui, Masakazu
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p. 643 - 647
(2007/10/03)
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- A new convenient bromination with KBrO3/KBr/Dowex
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Bromination of various 1,3-dicarbonyl compounds was achieved by using the mixture of potassium bromate and potassium bromide in the presence of Dowex 50X2-200 ion-exchange resin. Reactions were carried out under mild conditions and gave good yields of the
- Kosmrlj, Janez,Kocevar, Marijan,Polanc, Slovenko
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p. 3583 - 3592
(2007/10/03)
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- Imidazo[2,1-b]thiazole derivatives XII. Synthesis and immunoactivity in vitro on human T lymphocyte of several 3-aroylmethyl and 2-aroyl-3-methyl(aryl)-5,6-dihydroimidazo[2,1-b]thiazoles
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To estimate the influence of aryl group position on the immunostimulant properties of imidazo[2,1-b]thiazole derivatives, several compounds were obtained and tested, versus tetramisole hydrochloride, on the mobilisation of CD2 receptor by human T lymphocyte. The synthesis use the action of monobrominated β-diketones on the 2-mercaptoimidazoline. So, 1-aryl-4-bromobutane-1,3-diones lead to 3-aroylmethyl-5,6-dihydroimidazo[2,1-b]thiazoles 4. Same, 1-aryl-2-bromobutane-1,3-diones and 1,3-diaryl-2-bromopentane-1,3-diones give respectively 3-aroyl-2-methyl-5,6-dihydroimidazo[2,1-b]thiazoles 5 and 3-aroyl-2-aryl-5,6-dihydroimidazo[2,1-b]thiazoles 6. Better yields are obtained when the reaction presents two steps. The first one, realized in acetone at room temperature, leads to an intermediate S-substituted 4,5-dihydroimidazole which, in second step, is cyclized in imidazo[2,1-b]thiazole compound via an unisolated carbinolamine. This one explains the univocal formation of 5 derivatives and the feasible blending in case of 6. The immunoactivity of several imidazothiazoles 4, 5 and 6 is lower that them of 6-aryl substituted compounds and particularly that the levamisole which is the reference product in this series.
- Robert,Hassanine,Harraga,Seilles
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p. 261 - 271
(2007/10/02)
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- The Conversion of α-Bromo-β-Dicarbonyls to Vicinal Tricarbonyls Using Dimethyldioxirane and Base
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Vicinal tricarbonyls are prepared from α-bromo-β-dicarbonyl precursors by base promoted oxygen transfer from dimethyldioxirane.The α-bromo-β-dicarbonyls were prepared by the reaction of CuBr2 and benzene (Koser's reagent) with a β-dicarbonyl system.
- Coats, Steven J.,Wasserman, Harry H.
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p. 7735 - 7738
(2007/10/02)
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- Substituent Dependence of the Selectivity in Alkene Bromination through Bromocarbenium Ions
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Substituent effects on the rates of bromination of alkenes GαRαC=CRβR'β, where G is a conjugatively electron-donating group, are consistent with a carbenium ion like transition state, whereas by the same criteria the transition state for nonconjugated alkenes is bromonium type.The reactivities of compounds with the same substituent G are analyzed in terms of the sensitivity to structural and solvent effects.The lowest sensitivity is attributed to the earliest transition state.The dependence of the reaction constant on G leads to a general equation including cross terms: log k = -7.7Σ(?p+)α - 13.7Σ(?m+)β - 7.0(?p+)Gα(?p+)Rα - 5.8Σ(?p+)αΣ(?m+)β + 1.64.The carbenium ion character, common to both bromination and hydration, results in highly dissymmetric α- and β-substituent effects.However, these two reactions respond differently to β-substituents: a β methyl increases the bromination rate but decreases the hydration rate.Similarities and differences in the transition state models are discussed; the kinetic data suggest that the transition state is earlier in bromination than in hydration.
- Bienvenue-Goetz, Elizabeth,Dubois, Jaques-Emile
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p. 5388 - 5392
(2007/10/02)
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- Stable Enols of α-dibenzoylmethanes
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The enols 13a-m of α-(aryloxy)- and α-(alkyloxy)dibenzoylmethanes 4a-m are obtained by decomposition of the copper chelates 11a-m with sulfuric acid.The copper compounds are synthesized either by ester condensation of the acetophenones 6h-m with phenyl benzoate (7) or by nucleophilic substitution of α-bromodibenzoylmethane (9) with the phenols 10a-g.The enolates 8, primarily formed in the presence of sodium hydride or triethylamine, respectively, are directly converted into the chelates 11 with copper(II) acetate.The enols 13 are characterized by isomerization to the β-diketones 4 as well as by bromination to 12.
- Regitz, Manfred,Schaefer, Ansgar
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p. 1172 - 1185
(2007/10/02)
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