- Control of chain ends of polyesters in polycondensation of AA and BB monomers by use of solid-phase reagent
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For selective synthesis of linear polyester having a functional group at one end, polycondensation between 1,4-butanediol (1a) and sebacoyl chloride (2a) and between 1,12-dodecanediol (1b) and isophthaloyl chloride (2b) was conducted in the presence of ox
- Sugiura, Toshihiko,Yajima, Daisuke,Shoji, Kento,Ohta, Yoshihiro,Yokozawa, Tsutomu
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Read Online
- Nickel-Catalyzed Reductive Cross-Coupling of Aryl Bromides with Vinyl Acetate in Dimethyl Isosorbide as a Sustainable Solvent
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A nickel-catalyzed reductive cross-coupling has been achieved using (hetero)aryl bromides and vinyl acetate as the coupling partners. This mild, applicable method provides a reliable access to a variety of vinyl arenes, heteroarenes, and benzoheterocycles, which should expand the chemical space of precursors to fine chemicals and polymers. Importantly, a sustainable solvent, dimethyl isosorbide, is used, making this protocol more attractive from the point of view of green chemistry.
- Su, Mincong,Huang, Xia,Lei, Chuanhu,Jin, Jian
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supporting information
p. 354 - 358
(2022/01/15)
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- Copper-Catalyzed Trifluoromethylthio-arylsulfonylation of Styrene Derivatives via the Insertion of Sulfur Dioxide
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A copper-catalyzed four-component trifluoromethylthio-arylsulfonylation between styrene derivatives, AgSCF3, aryldiazonium tetrafluoroborates, and ex situ generated sulfur dioxide (from SOgen) is presented. This reaction features mild reaction conditions, good functional group tolerance, a broad substrate scope, good yields, and excellent diastereoselectivity. Preliminary mechanistic studies revealed that a radical process might be involved in this transformation.
- Chen, Gang,Xu, Jie,Xiong, Baojian,Song, Hongzhuo,Zhang, Xuemei,Ma, Xuelei,Lian, Zhong
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supporting information
p. 1207 - 1212
(2022/02/09)
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- Nickel-Catalyzed Ligand-Free Hiyama Coupling of Aryl Bromides and Vinyltrimethoxysilane
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We herein disclose the first Ni-catalyzed Hiyama coupling of aryl halides with vinylsilanes. This protocol uses cheap, nontoxic, and stable vinyltrimethoxysilane as the vinyl donor, proceeds under mild and ligand-free conditions, furnishing a diverse variety of styrene derivatives in high yields with excellent functional group compatibility.
- Wei, Shichao,Mao, Yongjun,Shi, Shi-Liang
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supporting information
p. 1670 - 1674
(2021/02/26)
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- Polymer, and mixture or formulation, and organic electronic device containing same, and monomer thereof
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Disclosed are a polymer, and a mixture or a formulation and an organic electronic device containing same, and applications thereof, and further a monomer of which the polymer is made; the polymer comprises on its side chain a repeating structure unit E, characterizing in that its S1(E)?T1(E))≤0.35 eV or even less, which may allow the said polymer having thermally activated delayed fluorescence (TADF) property. Thus a TADF polymer suitable for printing processes is provided, thereby reducing OLED manufacturing costs.
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Page/Page column 61
(2020/11/23)
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- Process method for preparing [1-(4-vinylphenyl)-1, 2, 2-triphenyl] ethylene
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The invention discloses a process method for preparing [1-(4-vinylphenyl)-1, 2, 2-triphenyl] ethylene, comprising the following steps of: 1, styrene used as a raw material reacts with a benzoic acid compound under the action of a catalyst to obtain 4-vinylbenzophenone; and 2, 4-vinyl benzophenone as a raw material reacts with benzophenone under the action of a catalyst so as to obtain [1-(4-vinylphenyl)-1, 2, 2-triphenyl] ethylene. The process method is reasonable in route design, cheap in raw material price and friendly to operators.
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Paragraph 0039-0047
(2020/08/29)
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- Copper-Catalyzed Defluorinative Hydroarylation of Alkenes with Polyfluoroarenes
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A catalytic defluorinative hydroarylation of alkenes with polyfluoroarenes in the presence of dppbz-ligated Cu catalyst and silanes was developed. This method provides a straightforward and alternative avenue to synthetic important polyfluorinated arenes with readily available and bench-stable alkenes as latent nucleophiles, and therefore avoids conventional reliance on stoichiometric quantities of organometallic reagents. This reaction proceeds under very mild conditions and exhibits good functional group compatibility and high level of regioselectivity. The synthetic potential of this method was further demonstrated by a gram-scale synthesis, and an array of experimental studies were also carried out to elaborate the probable mechanism.
- Fu, Bin,Li, Xiaohong,Xiong, Tao,Yuan, Xiuping,Zhang, Qian,Zhang, Qiao
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supporting information
p. 23056 - 23060
(2020/10/19)
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- Diboron-Assisted Copper-Catalyzed Z-Selective Semihydrogenation of Alkynes Using Ethanol as a Hydrogen Donor
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We herein describe a B2Pin2-assisted copper-catalyzed semihydrogenation of alkynes. A variety of alkenes were obtained in good to excellent yields with Z-selectivity under mild reaction conditions. Mechanistic studies indicated that a transfer hydrogenation process was involved and ethanol acted as both a solvent and a hydrogen donor in this reaction. The present protocol enabled convenient synthesis of deuterium-substituted Z-alkenes such as Z-Combretastain A4-d2 in a high deuteration ratio by using readily available ethanol-d1 as the deuterium source.
- Bao, Hanyang,Zhou, Bingwei,Jin, Hongwei,Liu, Yunkui
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p. 3579 - 3589
(2019/03/11)
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- Pd-Catalyzed Vinylation of Aryl Halides with Inexpensive Organosilicon Reagents Under Mild Conditions
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Pd-catalyzed Hiyama vinylation reaction of non-activated aryl chlorides and bromides under mild conditions was developed. The use of efficient vinyl donors and electron-rich sterically hindered phosphine ligands was critical for the success of the reaction. The products of this transformation can be used for Am/Cm separation, an important challenge in nuclear fuel reprocessing. The substituent effect on Am/Cm separating selectivity was also achieved, which could contribute to the development of new chromatographic materials for the separation of Am and Cm.
- Yang, Chu-Ting,Han, Jun,Liu, Jun,Li, Yi,Zhang, Fan,Yu, Hai-Zhu,Hu, Sheng,Wang, Xiaolin
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supporting information
p. 10324 - 10328
(2018/07/31)
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- PERMANENTLY GRAFTED GLACIOPHOBIC NANOMATERIALS AND METHODS OF MAKING
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The present disclosure provides for substrates for glaciophobic polymer-nanoparticle composites, glaciophobic polymer-nanoparticle composites, methods of making glaciophobic polymer-nanoparticle composites, methods of making films on substrates, and the like.
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Page/Page column 13
(2017/09/02)
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- Rhodium-Catalyzed Hydrocarboxylation of Olefins with Carbon Dioxide
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The catalytic hydrocarboxylation of styrenes derivatives and α,β-unsaturated carbonyl compounds with CO2(101.3 kPa) in the presence of an air-stable rhodium catalyst was explored. The combination of [RhCl(cod)]2(cod = cyclooctadiene) as a catalyst and diethylzinc as a hydride source allowed for effective hydrocarboxylation and provided the corresponding α-aryl carboxylic acids in moderate to excellent yields. In this catalytic process with carbon dioxide, intervention of the RhI–H species, which could be generated from the RhIcatalyst and diethylzinc, was clarified. Significantly, the catalytic asymmetric hydrocarboxylation of α,β-unsaturated esters with carbon dioxide was also performed by employing a cationic rhodium complex possessing (S)-(–)-4,4′-bi-1,3-benzodioxole-5,5′-diylbis(diphenylphosphine) [(S)-SEGPHOS] as a chiral diphosphine ligand. A plausible model for asymmetric induction was proposed by determination of the absolute configuration of the product.
- Kawashima, Shingo,Aikawa, Kohsuke,Mikami, Koichi
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p. 3166 - 3170
(2016/07/19)
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- Permanently grafted icephobic nanocomposites with high abrasion resistance
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In this work, a series of copolymer/silica nanocomposites are investigated that exhibit excellent anti-icing behavior and can be covalently grafted to any substrate containing C-H bonds with high durability. The copolymers of interest consist of pendant benzophenone, hexafluorobutyl, and a variety of other comonomers that, under mild UV irradiation, can be covalently grafted on a variety of substrates and generate a densely cross-linked network of polymer and well-dispersed nanoparticles. The robustness of thin films was compared in a series of terpolymers with different acrylic comonomer content. Thin films prepared with tert-butyl ester side groups had less backbone chain scission and, therefore, a greater extent of cross-linking than films prepared with n-butyl ester side groups. The iso-butyl acrylate comonomer promotes photoreaction efficiency in terms of kinetic rate and network robustness, leading to films that can sustain high shear forces and abrasion. The anti-icing capability of the composite was investigated using the impact of supercooled water on different substrates. The composite maintains its icephobicity after modified Taber testing with multiple abrasion cycles using a 300 g load, which demonstrates excellent mechanical resistance. In addition, this study has led to rational design rules for copolymers that maximize permanent attachment of different surface functionalities in terms of both grafting density and reaction kinetics.
- Gao, Jing,Martin, Andrew,Yatvin, Jeremy,White, Evan,Locklin, Jason
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p. 11719 - 11728
(2016/08/04)
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- Palladium-catalyzed Suzuki-Miyaura coupling of amides by carbon-nitrogen cleavage: General strategy for amide N-C bond activation
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The first palladium-catalyzed Suzuki-Miyaura cross-coupling of amides with boronic acids for the synthesis of ketones by sterically-controlled N-C bond activation is reported. The transformation is characterized by operational simplicity using bench-stable, commercial reagents and catalysts, and a broad substrate scope, including substrates with electron-donating and withdrawing groups on both coupling partners, steric-hindrance, heterocycles, halides, esters and ketones. The scope and limitations are presented in the synthesis of >60 functionalized ketones. Mechanistic studies provide insight into the catalytic cycle of the cross-coupling, including the first experimental evidence for Pd insertion into the amide N-C bond. The synthetic utility is showcased by a gram-scale cross-coupling and cross-coupling at room temperature. Most importantly, this process provides a blueprint for the development of a plethora of metal catalyzed reactions of typically inert amide bonds via acyl-metal intermediates. A unified strategy for amide bond activation to enable metal insertion into N-C amide bond is outlined (Scheme 1).
- Meng, Guangrong,Szostak, Michal
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supporting information
p. 5690 - 5707
(2016/07/06)
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- In Situ Generation of Formaldehyde and Triphenylphosphine from (Hydroxymethyl)triphenylphosphonium and Its Application in Wittig Olefination
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The reaction of (hydroxymethyl)triphenylphosphonium with benzylic or allylic halide under basic conditions at room temperature affords terminal alkenes in 61-89% yields. In this reaction, both formaldehyde and triphenylphosphine are in situ generated from (hydroxymethyl)triphenylphosphonium and further undergo Wittig olefination with benzylic or allylic halide.
- Huang, Wenhua,Xu, Jie
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supporting information
p. 1777 - 1782
(2015/08/06)
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- AIBN-catalyzed oxidative cleavage of gem -disubstituted alkenes with O 2 as an oxidant
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A 2,2-azobis(isobutyronitrile) (AIBN) catalyzed oxidative cleavage of gem-disubstituted alkenes with molecular oxygen as the oxidant has been described. Carbonyl compounds were obtained as the desired products in high yield under mild conditions. Based on previous documents and current experimental results, a relatively reasonable mechanism is proposed.
- Wang, Guang-Zu,Li, Xing-Long,Dai, Jian-Jun,Xu, Hua-Jian
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p. 7220 - 7225
(2014/08/18)
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- Palladium-Catalyzed Synthesis of Biaryl Ketones via tert -Butyl Isocyanide Insertion
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A simple and efficient palladium-catalyzed carbonylative Suzuki coupling via tert-butyl isocyanide insertion has been developed, which demonstrates the utility of isocyanides in intermolecular C-C bond construction. This methodology provides a novel pathway for the synthesis of diaryl ketones in moderate to good yields. The approach is tolerant to a wide range of substrates and applicable to library synthesis. A possible reaction mechanism was proposed based on the experimental results. Georg Thieme Verlag Stuttgart. New York.
- Chen, Zhong,Duan, Huaqing,Jiang, Xiao,Wang, Jinmei,Zhu, Yongming,Yang, Shilin
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supporting information
p. 1425 - 1430
(2014/06/23)
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- NHC-catalyzed hydroacylation of styrenes
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New hydroacylation catalysts: Highly electron-rich N-heterocyclic carbenes (NHCs) facilitate the intermolecular hydroacylation of unstrained olefins. This unprecedented organocatalytic coupling joins simple and abundant aldehydes and styrenes to yield valuable ketone products. EWG=electron-withdrawing group, EDG=electron-donating group. Copyright
- Schedler, Michael,Wang, Duo-Sheng,Glorius, Frank
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supporting information
p. 2585 - 2589
(2013/04/10)
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- The synthesis and properties of vinyl substituted naphthopyrans and their styrene copolymers
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A comprehensive series of mono-, di- and tri-bromo-3H-naphtho[2,1-b]pyrans was synthesised by the traditional union of a 2-naphthol with an alkynol. The bromine atom(s) in these naphthopyrans was readily replaced by a vinyl group using a Suzuki coupling reaction with vinyl boronic anhydride pyridine complex. The efficiency of the Suzuki vinylation reaction decreases with the increasing number of bromine atoms to be substituted. The vinylnaphthopyrans served as styrene analogues and readily underwent a thermally initiated free radical addition co-polymerisation with styrene to efficiently afford low molecular weight poly(styrene-co-naphthopyrans). The photochromic response of the bromonaphthopyrans and vinylnaphthopyrans followed the established colour-structure relationships for photochromic naphthopyrans. The photochromic response of toluene solutions of the poly(styrene-co-naphthopyrans) was characterised by a hypsochromic shift of the λmax relative to that recorded for the vinylnaphthopyran monomers. Increased half-lives were noted for the copolymers derived from the bis- and tris-vinylnaphthopyrans where some degree of crosslinking was expected. A further hypsochromic shift in λmax resulted for the thin films of the poly(styrene-co- naphthopyrans). Of particular note was the behaviour of the 3-(2-vinylphenyl)-3- phenylnaphthopyran which gave the typical yellow colour of the photomerocyanine coupled with the predictable large half-life. However, all photochromism of this naphthopyran was lost upon polymerisation suggesting that an alternative pathway supervenes in the expected polymerisation sequence.
- Blackwell, Catherine J.,Gabbutt, Christopher D.,Guthrie, James T.,Heron, B. Mark
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experimental part
p. 408 - 420
(2012/08/28)
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- General reaction conditions for the palladium-catalyzed vinylation of aryl chlorides with potassium alkenyltrifluoroborates
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(Chemical Equation Presented) Activated and deactivated aryl and heteroaryl chlorides are efficiently cross-coupled with potassium vinyl- and alkenyltrifluoroborates using 4-hydroxyacetophenone oxime derived palladacycle as precatalyst in 1 to 3 mol % Pd loading, Binap as ligand, and Cs 2CO3 as base in DMF at 120°C. The reactions can also be performed using Pd(OAc)2 as Pd(0) source, although with lower efficiency. Bidentate ligands such as Binap and dppp can be used, the former being the best choice. Only in the case of deactivated aryl chlorides should the reaction temperature be increased to 160°C to achieve good yields. The corresponding cross-coupled compounds, such as styrenes, stilbenes, and alkenylarenes, are obtained in good yields and with high regio- and diastereoselectivity. 2009 American Chemical Society.
- Alacid, Emilio,Najera, Carmen
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supporting information; experimental part
p. 8191 - 8195
(2010/03/04)
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- Nickel-catalyzed vinylation of aryl chlorides and bromides with vinyl ZnBr · MgBrCl
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The Ni-catalyzed cross-coupling of aryl halides and vinylzinc bromide for the synthesis of styrene derivatives was investigated. Of the catalysts surveyed, the combination of Ni(acac)2 and Xantphos was found to be the most effective for this cr
- Yamamoto, Tetsuya,Yamakawa, Tetsu
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supporting information; experimental part
p. 3603 - 3605
(2009/09/06)
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- Vinylation of aromatic halides using inexpensive organosilicon reagents. Illustration of design of experiment protocols
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The preparation of styrenes by palladium-catalyzed cross-coupling of aromatic iodides and bromides with divinyltetramethyldisiloxane (DVDS) in the presence of inexpensive silanolate activators has been developed. To facilitate the discovery of optimal reaction conditions, Design of Experiment (DoE) protocols were used. By the guided selection of reagents, stoichiometries, temperatures, and solvents, the vinylation reaction was rapidly optimized with three stages consisting of ca. 175 experiments (of a possible 1440 combinations). A variety of aromatic iodides undergo cross-coupling at room temperature in the presence of potassium trimethylsilanoate using Pd(dba) 2 in DMF in good yields. Triphenylphosphine oxide is needed to extend catalyst lifetime. Application of these conditions to aryl bromides was accomplished by the development of two complementary protocols. First, the direct implementation of the successful reaction conditions using aryl iodides at elevated temperature in THF provided the corresponding styrenes in good to excellent yields. Alternatively, the use of potassium triethylsilanolate and a bulky "Buchwald-type" ligand allows for the vinylation reactions to occur at or just above room temperature. A wide range of bromides underwent coupling in good yields for each of the protocols described.
- Denmark, Scott E.,Butler, Christopher R.
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p. 3690 - 3704
(2008/10/09)
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- Aqueous sodium hydroxide promoted cross-coupling reactions of alkenyltrialkoxysilanes under ligand-free conditions
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(Chemical Equation Presented) Fluoride-free cross-coupling reactions of alkenyltrialkoxysilanes with aryl iodides, bromides, and chlorides are performed on water using sodium hydroxide as activator at 120 °C under normal or microwave heating. This process occurs in the presence of Pd(OAc)2 or 4-hydroxyacetophenone oxime-derived palladacycle 1 as precatalysts under ligand-free conditions with low Pd loadings (0.01-1 mol %) and using tetra-n-butylammonium bromide as additive. Different commercially available vinylalkoxylsilanes can be cross-coupled under these reaction conditions to the corresponding styrenes, the best substrates being vinyltrimethoxy- or vinyltriethoxysilane. Alkenyltriethoxysilanes, prepared by Wilkinson-catalyzed hydrosilylation of alkynes with triethoxysilane, are stereospecifically arylated with aryl and vinyl halides under microwave irradiation in moderate to high β/α regioselectivity affording unsymmetrical stilbenes, alkenylbenzenes, and conjugate dienes, respectively. This simple procedure allows the palladium recycling from the aqueous phase during three runs by extractive separation of the products, which contain very low levels of Pd (21-27.5 ppm for an aryl iodide and up to 76 ppm for a bromide).
- Alacid, Emilio,Najera, Carmen
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p. 2315 - 2322
(2008/09/19)
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- Nickel-catalyzed reductive carboxylation of styrenes using CO2
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A nickel-catalyzed reductive carboxylation of styrenes using CO2 has been developed. The reaction proceeds under mild conditions using diethylzinc as the reductant. Preliminary data suggests the mechanism involves two discrete nickel-mediated catalytic cycles, the first involving a catalyzed hydrozincation of the alkene followed by a second, slower nickel-catalyzed carboxylation of the in situ formed organozinc reagent. Importantly, the catalyst system is very robust and will fixate CO2 in good yield even if exposed to only an equimolar amount introduced into the headspace above the reaction. Copyright
- Williams, Catherine M.,Johnson, Jeffrey B.,Rovis, Tomislav
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supporting information; experimental part
p. 14936 - 14937
(2009/03/12)
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- Synthesis of ketones from acyl chlorides and triorganoindium reagents by Pd-catalyzed cross-coupling
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Triorganoindium reagents prepared from indium tribromide and 3 equiv of organolithium reagents react with acyl chlorides in palladium-catalyzed cross-coupling for preparation of new ketones. Copyright Taylor & Francis Group, LLC.
- Croix,Balland-Longeau,Duchene,Thibonnet, Jerome
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p. 3261 - 3270
(2007/10/03)
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- The first fluoride-free Hiyama reaction of vinylsiloxanes promoted by sodium hydroxide in water
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The first cross-coupling reaction between vinylalkoxysilanes and aryl bromides or chlorides promoted by aqueous sodium hydroxide under fluoride-free conditions to provide styrenes is reported. The reaction is catalyzed by palladium(II) acetate or a 4-hydroxyacetophenone oxime-derived palladacycle either under thermal or microwave heating at 120°C with low catalyst loading (0.01-1 mol% of palladium) in the presence of tetra-n-butylammonium bromide (TBAB) as additive in air. In the case of styryltriethoxysilane, the coupling with aryl or vinyl bromides takes place stereospecifically to give the corresponding stilbenes or dienes, respectively. These mild and simple reaction conditions prevent undesirable polymerization of the products.
- Alacid, Emilio,Najera, Carmen
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p. 2085 - 2091
(2007/10/03)
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- Suzuki-Miyaura cross-coupling reactions of potassium vinyltrifluoroborate with aryl and heteroaryl electrophiles
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We have previously reported that the palladium-catalyzed cross-coupling reaction of potassium vinyltrifluoroborate with aryl electrophiles proceeds with good yields. Herein, we describe recent progress in optimizing the reaction, as well as outlining the scope and limitations of the reaction. The cross-coupling reaction can generally be effected using 2 mol % of PdCl2 and 6 mol % of PPh3 as a catalyst system in THF/H2O with Cs 2CO3 as a base. Moderate to good yields are obtained in the presence of a variety of functional groups.
- Molander, Gary A.,Brown, Adam R.
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p. 9681 - 9686
(2007/10/03)
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- Improved synthesis of (4-ethenylphenyl)diphenyl methanol and its application in the preparation of trityl functionalized polystyrene resin containing tetrahydrofuran derived cross-linker
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An improved and straightforward synthesis of (4-ethenylphenyl)diphenyl methanol is described. This monomer was used in the preparation of trityl functionalized polystyrene containing a flexible tetrahydrofuran cross-linker, giving rise to a suitable support for solid-phase organic synthesis. (C) 2000 Elsevier Science Ltd.
- Manzotti,Reger,Janda
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p. 8417 - 8420
(2007/10/03)
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- Synthetic attempts towards polymer-bound 'push-pull' acetylenes
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In view of possible applications of 'push-pull' acetylenes 1 and 'push- pull' olefins 2 as potential non-linear optics materials, synthetic attempts towards polymers of type 4 and 6 (Scheme 2) have been undertaken. Two so far unknown 'push-pull' acetylene
- Wilhelm, Patrick,Neuenschwander, Markus
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p. 338 - 346
(2007/10/03)
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- Cross-coupling reaction of organostannanes with aryl halides catalyzed by nickeltriphenylphosphine or nickel-lithium halide complex
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A nickel(0) complex used in combination with lithium bromide was found to enhance the rate of the cross-coupling reaction of aryl halides with organostannanes, whereas a Ni(0) catalyst combined with Ph3P was applicable to a wide variety of aryl halides including aryl chlorides.
- Shirakawa, Eiji,Yamasaki, Kenji,Hiyama, Tamejiro
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p. 1544 - 1549
(2007/10/03)
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- AROMATIC KETONES EITH TERMINAL VINYL GROUPS
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The Friedel-Crafts acylation of a hydrocarbon by an acylating agent containing bromoalkyl substituents gave a series of new ketones.Their subsequent dehydrobromination with potassium tert-butoxide gave high yields of aromatic ketones containing terminal vinyl groups.
- Uvarova, L. R.,Burykina, L. K.,Zubareva, M. M.,Polyanskii, I. D.
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p. 1346 - 1349
(2007/10/02)
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