- Selective Placement of Bromide and Pinacolboronate Groups about a Tellurophene: New Building Blocks for Optoelectronic Applications
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Selective protodeboronation of preformed phosphorescent di- and tetrapinacolboronate (BPin)-substituted tellurophenes controllably affords new tellurophene products that show photoluminescence or, in the case of tellurophenes lacking BPin groups at the 2,5-positions, nonemissive behavior; for comparison the protodeboronation of select thiophene and selenophenes is also reported. The resulting BPin-appended tellurophenes are promising candidates for postfunctionalization via Suzuki-Miyaura cross-coupling and can be effectively converted into their respective brominated tellurophene counterparts via treatment with excess CuBr2. It is expected from prior studies that these brominated tellurophenes will be suitable building blocks (and monomers) for the preparation of conjugated oligomers and polymers featuring narrower optical band gaps in relation to their lighter chalcogen analogues; in this regard preliminary Stille coupling chemistry is reported.
- Torres Delgado, William,Shahin, Fatemeh,Ferguson, Michael J.,McDonald, Robert,He, Gang,Rivard, Eric
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Read Online
- Palladium-catalyzed borylation of aryl bromides and chlorides using phosphatrioxa-adamantane ligands
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Catalysts based on the combination of Pd(OAc)2 and the electron-deficient phosphatrioxa-adamantane ligands are described for borylation of aryl bromides and chlorides. Catalytic evaluation of a small library of phosphatrioxa-adamantane ligands provided some insights on the preferred ligand steric profile for borylation reactions. The corresponding aryl boronate esters were accessed under mild conditions (25–70 °C) and isolated in high yields (up to 96%).
- Lamola, Jairus L.,Moshapo, Paseka T.,Holzapfel, Cedric W.,Christopher Maumela, Munaka
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supporting information
(2021/12/13)
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- Cross-Coupling through Ag(I)/Ag(III) Redox Manifold
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In ample variety of transformations, the presence of silver as an additive or co-catalyst is believed to be innocuous for the efficiency of the operating metal catalyst. Even though Ag additives are required often as coupling partners, oxidants or halide scavengers, its role as a catalytically competent species is widely neglected in cross-coupling reactions. Most likely, this is due to the erroneously assumed incapacity of Ag to undergo 2e? redox steps. Definite proof is herein provided for the required elementary steps to accomplish the oxidative trifluoromethylation of arenes through AgI/AgIII redox catalysis (i. e. CEL coupling), namely: i) easy AgI/AgIII 2e? oxidation mediated by air; ii) bpy/phen ligation to AgIII; iii) boron-to-AgIII aryl transfer; and iv) ulterior reductive elimination of benzotrifluorides from an [aryl-AgIII-CF3] fragment. More precisely, an ultimate entry and full characterization of organosilver(III) compounds [K]+[AgIII(CF3)4]? (K-1), [(bpy)AgIII(CF3)3] (2) and [(phen)AgIII(CF3)3] (3), is described. The utility of 3 in cross-coupling has been showcased unambiguously, and a large variety of arylboron compounds was trifluoromethylated via [AgIII(aryl)(CF3)3]? intermediates. This work breaks with old stereotypes and misconceptions regarding the inability of Ag to undergo cross-coupling by itself.
- Demonti, Luca,Mézailles, Nicolas,Nebra, Noel,Saffon-Merceron, Nathalie
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supporting information
p. 15396 - 15405
(2021/10/12)
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- Remarkably Efficient Iridium Catalysts for Directed C(sp2)-H and C(sp3)-H Borylation of Diverse Classes of Substrates
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Here we describe the discovery of a new class of C-H borylation catalysts and their use for regioselective C-H borylation of aromatic, heteroaromatic, and aliphatic systems. The new catalysts have Ir-C(thienyl) or Ir-C(furyl) anionic ligands instead of the diamine-type neutral chelating ligands used in the standard C-H borylation conditions. It is reported that the employment of these newly discovered catalysts show excellent reactivity and ortho-selectivity for diverse classes of aromatic substrates with high isolated yields. Moreover, the catalysts proved to be efficient for a wide number of aliphatic substrates for selective C(sp3)-H bond borylations. Heterocyclic molecules are selectively borylated using the inherently elevated reactivity of the C-H bonds. A number of late-stage C-H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)-H and C(sp3)-H borylations enabling the method more general. Preliminary mechanistic studies suggest that the active catalytic intermediate is the Ir(bis)boryl complex, and the attached ligand acts as bidentate ligand. Collectively, this study underlines the discovery of new class of C-H borylation catalysts that should find wide application in the context of C-H functionalization chemistry.
- Chattopadhyay, Buddhadeb,Hassan, Mirja Md Mahamudul,Hoque, Md Emdadul
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supporting information
p. 5022 - 5037
(2021/05/04)
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- Benzoic Acid-Promoted C2-H Borylation of Indoles with Pinacolborane
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A benzoic acid-promoted C2-H borylation of indoles with pinacolborane to afford C2-borylated indoles is developed. Preliminary mechanistic studies indicate BH3-related borane species formed via the decomposition of pinacolborane to be the probable catalyst. This transformation provides a prompt route toward the synthesis of diverse C2-functionalized indoles.
- Zou, Youliang,Zhang, Binfeng,Wang, Li,Zhang, Hua
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supporting information
p. 2821 - 2825
(2021/04/13)
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- Improvement in the Palladium-Catalyzed Miyaura Borylation Reaction by Optimization of the Base: Scope and Mechanistic Study
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Aryl boronic acids and esters are important building blocks in API synthesis. The palladium-catalyzed Suzuki-Miyaura borylation is the most common method for their preparation. This paper describes an improvement of the current reaction conditions. By using lipophilic bases such as potassium 2-ethyl hexanoate, the borylation reaction could be achieved at 35 °C in less than 2 h with very low palladium loading (0.5 mol %). A preliminary mechanistic study shows a hitherto unrecognized inhibitory effect by the carboxylate anion on the catalytic cycle, whereas 2-ethyl hexanoate minimizes this inhibitory effect. This improved methodology enables borylation of a wide range of substrates under mild conditions.
- Barroso, Santiago,Joksch, Markus,Puylaert, Pim,Tin, Sergey,Bell, Stephen J.,Donnellan, Luke,Duguid, Stewart,Muir, Colin,Zhao, Peichao,Farina, Vittorio,Tran, Duc N.,De Vries, Johannes G.
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supporting information
p. 103 - 109
(2020/12/22)
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- Transformations of Aryl Ketones via Ligand-Promoted C?C Bond Activation
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The coupling of aromatic electrophiles (aryl halides, aryl ethers, aryl acids, aryl nitriles etc.) with nucleophiles is a core methodology for the synthesis of aryl compounds. Transformations of aryl ketones in an analogous manner via carbon–carbon bond activation could greatly expand the toolbox for the synthesis of aryl compounds due to the abundance of aryl ketones. An exploratory study of this approach is typically based on carbon–carbon cleavage triggered by ring-strain release and chelation assistance, and the products are also limited to a specific structural motif. Here we report a ligand-promoted β-carbon elimination strategy to activate the carbon–carbon bonds, which results in a range of transformations of aryl ketones, leading to useful aryl borates, and also to biaryls, aryl nitriles, and aryl alkenes. The use of a pyridine-oxazoline ligand is crucial for this catalytic transformation. A gram-scale borylation reaction of an aryl ketone via a simple one-pot operation is reported. The potential utility of this strategy is also demonstrated by the late-stage diversification of drug molecules probenecid, adapalene, and desoxyestrone, the fragrance tonalid as well as the natural product apocynin.
- Dai, Hui-Xiong,Li, Hanyuan,Li, Ling-Jun,Liu, Qi-Sheng,Ma, Biao,Wang, Mei-Ling,Wang, Xing,Wang, Zhen-Yu,Xu, Hui
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supporting information
p. 14388 - 14393
(2020/07/06)
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- Iron-catalysed C(sp2)-H borylation enabled by carboxylate activation
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Arene C(sp2)-H bond borylation reactions provide rapid and efficient routes to synthetically versatile boronic esters. While iridium catalysts are well established for this reaction, the discovery and development of methods using Earth-abundant alternatives is limited to just a few examples. Applying an in situ catalyst activation method using air-stable and easily handed reagents, the iron-catalysed C(sp2)-H borylation reactions of furans and thiophenes under blue light irradiation have been developed. Key reaction intermediates have been prepared and characterised, and suggest two mechanistic pathways are in action involving both C-H metallation and the formation of an iron boryl species.
- Britton, Luke,Docherty, Jamie H.,Dominey, Andrew P.,Thomas, Stephen P.
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- Copper-Photocatalyzed Borylation of Organic Halides under Batch and Continuous-Flow Conditions
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The copper-photocatalyzed borylation of aryl, heteroaryl, vinyl and alkyl halides (I and Br) was reported. The reaction proceeded using a new heteroleptic Cu complex under irradiation with blue LEDs, giving the corresponding boronic-acid esters in good to excellent yields. The reaction was extended to continuous-flow conditions to allow an easy scale-up. The mechanism of the reaction was studied and a mechanism based on a reductive quenching (CuI/CuI*/Cu0) was suggested.
- Nitelet, Antoine,Thevenet, Damien,Schiavi, Bruno,Hardouin, Christophe,Fournier, Jean,Tamion, Rodolphe,Pannecoucke, Xavier,Jubault, Philippe,Poisson, Thomas
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supporting information
p. 3262 - 3266
(2019/02/13)
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- Rhodium catalyzed C-C bond cleavage/coupling of 2-(azetidin-3-ylidene)acetates and analogs
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The C-C bond cleavage/coupling of 2-(azetidin-3-ylidene)acetates with aryl boronic acids catalyzed by a rhodium complex was studied with a "conjugate addition/β-C cleavage/protonation" strategy.
- Yang, Xuan,Kong, Wei-Yu,Gao, Jia-Ni,Cheng, Li,Li, Nan-Nan,Li, Meng,Li, Hui-Ting,Fan, Jun,Gao, Jin-Ming,Ouyang, Qin,Xie, Jian-Bo
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supporting information
p. 12707 - 12710
(2019/10/28)
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- Catalytic C?H Borylation Using Iron Complexes Bearing 4,5,6,7-Tetrahydroisoindol-2-ide-Based PNP-Type Pincer Ligand
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Catalytic C?H borylation has been reported using newly designed iron complexes bearing a 4,5,6,7-tetrahydroisoindol-2-ide-based PNP pincer ligand. The reaction tolerated various five-membered heteroarenes, such as pyrrole derivatives, as well as six-membered aromatic compounds, such as toluene. Successful examples of the iron-catalyzed sp3 C?H borylation of anisole derivatives were also presented.
- Kato, Takeru,Kuriyama, Shogo,Nakajima, Kazunari,Nishibayashi, Yoshiaki
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supporting information
p. 2097 - 2101
(2019/05/28)
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- Cleavage of C(aryl)?CH3 Bonds in the Absence of Directing Groups under Transition Metal Free Conditions
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Organic chemists now can construct carbon–carbon σ-bonds selectively and sequentially, whereas methods for the selective cleavage of carbon–carbon σ-bonds, especially for unreactive hydrocarbons, remain limited. Activation by ring strain, directing groups, or in the presence of a carbonyl or a cyano group is usually required. In this work, by using a sequential strategy site-selective cleavage and borylation of C(aryl)?CH3 bonds has been developed under directing group free and transition metal free conditions. Methyl groups of various arenes are selectively cleaved and replaced by boryl groups. Mechanistic analysis suggests that it proceeds by a sequential intermolecular oxidation and coupling of a transient aryl radical, generated by radical decarboxylation, involving a pyridine-stabilized persistent boryl radical.
- Dai, Peng-Fei,Ning, Xiao-Shan,Wang, Hua,Cui, Xian-Chao,Liu, Jie,Qu, Jian-Ping,Kang, Yan-Biao
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supporting information
p. 5392 - 5395
(2019/03/29)
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- Photoinduced Miyaura Borylation by a Rare-Earth-Metal Photoreductant: The Hexachlorocerate(III) Anion
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The first photoinduced carbon(sp2)–heteroatom bond forming reaction by a rare-earth-metal photoreductant, a Miyaura borylation, has been achieved. This simple, scalable, and novel borylation method that makes use of the hexachlorocerate(III) anion ([CeIIICl6]3?, derived from CeCl3) has a broad substrate scope and functional-group tolerance and can be conducted at room temperature. Combined with Suzuki–Miyaura cross-coupling, the method is applicable to the synthesis of various biaryl products, including through the use of aryl chloride substrates.
- Qiao, Yusen,Yang, Qiaomu,Schelter, Eric J.
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supporting information
p. 10999 - 11003
(2018/07/31)
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- Controllable Rh(III)-Catalyzed C-H Arylation and Dealcoholization: Access to Biphenyl-2-carbonitriles and Biphenyl-2-carbimidates
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A controllable Rh(III)-catalyzed C-H arylation and dealcoholization of benzimidates with arylboronic esters was developed, delivering various biphenyl-2-carbonitriles and biphenyl-2-carbimidates by simply tuning the reaction conditions. This approach features high efficiency, good functional group tolerance, and easy operation. It also provides an alternative pathway to thoroughly exploit the directing group in transition-metal-catalyzed C-H activations.
- Jiang, Bo,Wu, Songxiao,Zeng, Jing,Yang, Xiaobo
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supporting information
p. 6573 - 6577
(2018/10/09)
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- Metal-Free Radical Borylation of Alkyl and Aryl Iodides
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A metal-free radical borylation of alkyl and aryl iodides with bis(catecholato)diboron (B2cat2) as the boron source under mild conditions is introduced. The borylation reaction is operationally easy to conduct and shows high functional group tolerance and broad substrate scope. Radical clock experiments and density functional theory calculations provide insights into the mechanism and rate constants for C-radical borylation with B2cat2 are disclosed.
- Cheng, Ying,Mück-Lichtenfeld, Christian,Studer, Armido
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supporting information
p. 16832 - 16836
(2018/11/23)
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- Efficient Synthesis of Aryl Boronates via Cobalt-Catalyzed Borylation of Aryl Chlorides and Bromides
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An efficient catalytic system based on a Co(II)-NHC precursor has been developed for the cross coupling of bis(pinacolato)diboron with aryl halides including aryl chlorides, affording the aryl boronates in good to excellent yields. A wide range of functional groups are tolerated under mild reaction conditions. The reaction shows excellent chemoselectivity for bromide over chloride. Preliminary mechanistic investigations show that the catalytic cycle may rely on a cobalt(I)-(III) redox couple.
- Verma, Piyush Kumar,Mandal, Souvik,Geetharani
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p. 4049 - 4054
(2018/05/22)
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- Palladium-Catalyzed Decarbonylative Borylation of Carboxylic Acids: Tuning Reaction Selectivity by Computation
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Decarbonylative borylation of carboxylic acids is reported. Carbon electrophiles are generated directly after reagent-enabled decarbonylation of the in situ accessible sterically-hindered acyl derivative of a carboxylic acid under catalyst controlled conditions. The scope and the potential impact of this method are demonstrated in the selective borylation of a variety of aromatics (>50 examples). This strategy was used in the late-stage derivatization of pharmaceuticals and natural products. Computations reveal the mechanistic details of the unprecedented C?O bond activation of carboxylic acids. By circumventing the challenging decarboxylation, this strategy provides a general synthetic platform to access arylpalladium species for a wide array of bond formations from abundant carboxylic acids. The study shows a powerful combination of experiment and computation to predict decarbonylation selectivity.
- Liu, Chengwei,Ji, Chong-Lei,Hong, Xin,Szostak, Michal
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supporting information
p. 16721 - 16726
(2018/11/30)
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- Preparation method of aryl borate ester and allyl borate ester
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The invention discloses a preparation method of aryl borate ester and allyl borate ester. The method comprises the following step: under the catalytic action of pyridine or a derivative thereof, carrying out 1) or 2) to obtain substituted boric acid ester shown as a formula I-1 or a formula I-2: 1) a reaction of a halide, bi-boric acid ester and alkoxide; 2) a reaction of a halide and a bi-boric acid ester-alkoxide complex. The method is an efficient preparation method of the aryl borate ester and the allyl borate ester. In the preparation method provided by the invention, the inexpensive pyridine or the derivative thereof is taken as a catalyst instead of a transition metal catalyst, the reaction conditions are mild, the reaction yield is high, residues of trace transition metal in a boronation product are avoided, and the cost of an aryl and allyl borate ester synthesis reaction is lowered.
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Paragraph 0073-0074; 0078
(2017/07/12)
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- Pyridine-catalyzed radical borylation of aryl halides
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A pyridine-catalyzed transition-metal-free borylation reaction of haloarenes has been developed based on the selective cross-coupling of an aryl radical and a pyridine-stabilized boryl radical. Arylboronates were produced from haloarenes under mild conditions. This borylation reaction features a broad substrate scope, operational simplicity, and gram-scale synthetic ability.
- Zhang, Li,Jiao, Lei
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supporting information
p. 607 - 610
(2017/05/15)
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- Radical Metal-Free Borylation of Aryl Iodides
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A simple metal-free borylation of aryl iodides mediated by a fluoride sp 2 -sp 3 diboron adduct is described. The reaction conditions are compatible with various functional groups. Electronic effects of substituents do not affect the borylation while steric hindrance does. The reaction proceeds via a radical mechanism in which pyridine serves to stabilize the boryl radicals, generated in situ.
- Pinet, Sandra,Liautard, Virginie,Debiais, Mégane,Pucheault, Mathieu
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p. 4759 - 4768
(2017/10/03)
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- Base-Free Palladium-Catalyzed Borylation of Aryl Chlorides with Diborons
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The base-free palladium-catalyzed borylation of aryl chlorides with diborons was achieved. The base-free conditions offered acceptable functional group compatibility. Based on experimental and computational studies, it was shown that smooth boryl transfer from the diborons to the arylpalladium chloride was promoted by strong interaction between the Lewis acidic boron and the chlorine atom on palladium.
- Yamamoto, Yutaro,Matsubara, Hiroshi,Yorimitsu, Hideki,Osuka, Atsuhiro
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p. 2317 - 2320
(2016/07/28)
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- Miyaura Borylation and One-Pot Two-Step Homocoupling of Aryl Chlorides and Bromides under Solvent-Free Conditions
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Solvent-free protocols for Miyaura borylation and the one-pot, two-step homocoupling of aryl halides are reported for the first time. Bis(dibenzylideneacetone)palladium(0) [Pd(dba)2] is an optimal source of palladium for Miyaura borylation, while for one-pot two-step homocoupling palladium(II) acetate [Pd(OAc)2] gives highest yields. Aryl bromides are coupled most efficiently using the DPEphos ligand. Chlorides are coupled using XPhos. The developed protocols are robust, versatile and easily reproducible on a large scale.
- Dzhevakov, Pavel B.,Topchiy, Maxim A.,Zharkova, Daria A.,Morozov, Oleg S.,Asachenko, Andrey F.,Nechaev, Mikhail S.
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p. 977 - 983
(2016/04/05)
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- METHOD FOR PREPARING AMINOARYLBORANE COMPOUNDS OR DERIVATIVES THEREOF
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The present invention provides a process for the preparation of aminoarylborane compounds and derivatives thereof comprising a step of arylation by reacting an aryl chloride with an aminoborane compound in the presence of a catalytic system.
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Page/Page column 87; 88
(2015/06/18)
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- Amine-borane complexes: Air- and moisture-stable partners for palladium-catalyzed borylation of aryl bromides and chlorides
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A method for using amine-borane complexes directly in palladium catalyzed borylation has been developed. The reaction proceeds through the sequential formation of a boronium species followed by deprotonation leading to the aminoborane. This reagent is then directly used in the borylation process leading, after work-up, to various boronic acid derivatives. The reaction was applied to (hetero)aryl triflates, iodides, bromides and chlorides.
- Guerrand, Hélène D. S.,Vaultier, Michel,Pinet, Sandra,Pucheault, Mathieu
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supporting information
p. 1167 - 1174
(2015/04/22)
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- Method for preparing aminoarylborane compounds or derivatives thereof
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The present invention provides a process for the preparation of aminoarylborane compounds and derivatives thereof comprising a step of arylation by reacting an aryl chloride with an aminoborane compound in the presence of a catalytic system. Typically, th
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Paragraph 0269
(2015/06/17)
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- Gorlos-Phos for palladium-catalyzed borylation of aryl chlorides
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Using a readily available form of the mono-phosphine ligand, Gorlos-Phos·HBF4, Pd-catalyzed borylation of aryl chlorides afforded aryl boronates in high yields. A variety of functional groups are well compatible with this palladium catalyzed borylation reaction. This journal is the Partner Organisations 2014.
- Li, Pengbin,Fu, Chunling,Ma, Shengming
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p. 3604 - 3610
(2014/06/09)
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- Borylation of unactivated aryl chlorides under mild conditions by using diisopropylaminoborane as a borylating reagent
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The synthesis of arylboronic ester derivatives from aryl chlorides by using aryl(amino)boranes is described. Palladium-catalyzed coupling between aryl chlorides and diisopropylaminoborane leads to the formation of a C-B bond under mild conditions. A wide range of functional groups are tolerated, making this method particularly useful for the borylation of functionalized aromatics. Salts make the difference: The synthesis of arylboronic ester derivatives from aryl chlorides by using aryl(amino)boranes is described. Palladium-catalyzed coupling between aryl chlorides and diisopropylaminoborane leads to the formation of a C-B bond under mild conditions. A wide range of substituents, including electron-withdrawing groups, are tolerated (see scheme).
- Guerrand, Helene D. S.,Marciasini, Ludovic D.,Jousseaume, Melissa,Vaultier, Michel,Pucheault, Mathieu
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supporting information
p. 5573 - 5579
(2014/05/20)
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- Investigation of a lithium-halogen exchange flow process for the preparation of boronates by using a cryo-flow reactor
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Conducting low-temperature organometallic reactions under continuous flow conditions offers the potential to more accurately control exotherms and thus provide more reproducible and scalable processes. Herein, progress towards this goal with regards to the lithium-halogen exchange/borylation reaction is reported. In addition to improving the scope of substrates available on a research scale, methods to improve reaction profiles and expedite purification of the products are also described. On moving to a continuous system, thermocouple measurements have been used to track exotherms and provide a level of safety for continuous processing of organometallic reagents. The use of an in-line continuous liquid-liquid separation device to circumvent labour intensive downstream off-line processing is also reported. A cool setup: A small footprint, modular setup based around a cryo-flow reactor is reported for the preparation of gram quantities of boronic esters. With minimum alteration, including the addition of a data logger with thermocouples and a liquid-liquid separator, the same equipment can be used to scale the process, inclusive of an in-line extraction. Copyright
- Newby, James A.,Huck, Lena,Blaylock, D. Wayne,Witt, Paul M.,Ley, Steven V.,Browne, Duncan L.
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p. 263 - 271
(2014/01/17)
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- Convenient synthesis of arylboronates through a synergistic Pd/Cu-catalyzed miyaura borylation reaction under atmospheric conditions
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A highly efficient and practical borylation reaction of aryl iodides with bis(pinacolato)diboron has been established. By using Pd(OAc)2, CuI, and PPh3 as a ligand at room temperature under air in the presence of Cs2CO3, the protocol proved to be general. Various functionalized arylboronates were obtained in moderate to excellent yields. In addition, a possible reaction mechanism was proposed. An efficient borylation reaction of aryl iodides with bis(pinacolato)diboron is developed by using Pd(OAc)2 and CuI. This catalytic system has high catalytic efficiency at room temperature in air and functional-group tolerance for a wide range of substrates. Copyright
- Ratniyom, Jadsada,Dechnarong, Nattanee,Yotphan, Sirilata,Kiatisevi, Supavadee
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supporting information
p. 1381 - 1385
(2014/03/21)
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- Convenient Synthesis of Arylboronates through a Synergistic Pd/Cu-Catalyzed Miyaura Borylation Reaction under Atmospheric Conditions
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A highly efficient and practical borylation reaction of aryl iodides with bis(pinacolato)diboron has been established. By using Pd(OAc)2, CuI, and PPh3 as a ligand at room temperature under air in the presence of Cs2CO3, the protocol proved to be general. Various functionalized arylboronates were obtained in moderate to excellent yields. In addition, a possible reaction mechanism was proposed.
- Ratniyom, Jadsada,Dechnarong, Nattanee,Yotphan, Sirilata,Kiatisevi, Supavadee
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supporting information
p. 1381 - 1385
(2015/10/05)
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- Suzuki-miyaura cross-coupling under solvent-free conditions
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A solvent-free reaction protocol for Suzuki-Miyaura cross-couplings was developed. (Hetero)aryl bromides and chlorides are coupled with pinacol arylboronates in high yields. The reaction is catalyzed by conventional bis(triphenylphosphine)palladium(II) chloride [(PPh3) 2PdCl2] and/or palladium(II) acetate/SPhos [Pd(OAc) 2/SPhos] under air. Copyright
- Asachenko, Andrey F.,Sorochkina, Kristina R.,Dzhevakov, Pavel B.,Topchiy, Maxim A.,Nechaev, Mikhail S.
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supporting information
p. 3553 - 3557
(2014/01/06)
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- Nickel-catalyzed borylation of halides and pseudohalides with tetrahydroxydiboron [B2(OH)4]
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Arylboronic acids are gaining increased importance as reagents and target structures in a variety of useful applications. Recently, the palladium-catalyzed synthesis of arylboronic acids employing the atom-economical tetrahydroxydiboron (BBA) reagent has been reported. The high cost associated with palladium, combined with several limitations of both palladium- and copper-catalyzed processes, prompted us to develop an alternative method. Thus, the nickel-catalyzed borylation of aryl and heteroaryl halides and pseudohalides using tetrahydroxydiboron (BBA) has been formulated. The reaction proved to be widely functional group tolerant and applicable to a number of heterocyclic systems. To the best of our knowledge, the examples presented here represent the only effective Ni-catalyzed Miyaura borylations conducted at room temperature.
- Molander, Gary A.,Cavalcanti, Livia N.,Garcia-Garcia, Carolina
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p. 6427 - 6439
(2013/07/26)
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- Design, generation, and synthetic application of borylzincate: Borylation of aryl halides and borylzincation of benzynes/terminal alkyne
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Borylzincate was generated in situ from dialkylzinc, diboron, and metal alkoxide. Model DFT calculations showed that although the formation of borylzincate is kinetically favorable, it is thermodynamically unfavorable. Therefore, we designed a successive reaction sequence that would provide a compensating energy gain. This enabled Zn-catalyzed borylation of aryl halides and borylzincation of benzynes and terminal alkyne from diborons without the need for any cocatalyst.
- Nagashima, Yuki,Takita, Ryo,Yoshida, Kengo,Hirano, Keiichi,Uchiyama, Masanobu
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supporting information
p. 18730 - 18733
(2014/01/06)
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- Rapid synthesis of bis(hetero)aryls by one-pot Masuda borylation-Suzuki coupling sequence and its application to concise total syntheses of meridianins A and G
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3-(Hetero)aryl substituted indoles, 7-azaindoles, and pyrroles can be obtained in a very concise fashion via a one-pot Masuda borylation-Suzuki coupling sequence. The concise total syntheses of the marine natural products meridianins A (5) and G (4i) nice
- Merkul, Eugen,Schaefer, Elisabeth,Mueller, Thomas J. J.
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supporting information; experimental part
p. 3139 - 3141
(2011/06/28)
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- Gold(iii)-catalyzed halogenation of aromatic boronates with N -halosuccinimides
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Aromatic boronates bearing halogen substituents in the aromatic ring can be synthesized by AuCl3-catalyzed halogenations with N-halosuccinimides.
- Qiu, Di,Mo, Fanyang,Zheng, Zhitong,Zhang, Yan,Wang, Jianbo
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supporting information; experimental part
p. 5474 - 5477
(2011/02/22)
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- Cyclopalladated ferrocenylimine as efficient catalyst for the syntheses of arylboronate esters
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The cyclopalladated ferrocenylimine I and its phosphine adducts IIa-f were prepared and evaluated in the borylation of aryl halides. The tricyclohexylphosphine adduct IIb exhibited highly catalytic activity for the coupling of aryl and heteroaryl bromides containing various functional groups with low catalyst loading (2 mol%). Aryl and heteroaryl chlorides were smoothly converted into the corresponding boronates in the presence of the monophosphinobiaryl ligand (XPhos) adduct IIf. It was proposed that palladacycle was only a reservoir of the catalytically active species from the investigation on the reaction mechanism.
- Wang, Lianhui,Li, Jingya,Cui, Xiuling,Wu, Yusheng,Zhu, Zhiwu,Wu, Yangjie
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experimental part
p. 2002 - 2010
(2010/10/19)
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- An improved system for the palladium-catalyzed borylation of aryl halides with pinacol borane
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(Chemical Equation Presented) borylation of aryl halides with an inexpensive and atom-economical boron source, pinacol borane, has been developed. This system allows for the conversion of aryl and heteroaryl iodides, bromides, and several chlorides, containing a variety of functional groups, to the corresponding pinacol boronate esters. In addition to the increase in substrate scope, this is the first general method where relatively low quantities of catalyst and short reaction times can be employed.
- Billingsley, Kelvin L.,Buchwald, Stephen L.
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p. 5589 - 5591
(2008/12/20)
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- Palladium-catalyzed borylation of aryl chlorides: Scope, applications, and computational studies
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(Chemical Equation Presented) From chloride to boronate: Catalysts comprising palladium and biaryl monophosphine ligands provide highly active systems for the borylation of aryl and heteroaryl chlorides (see scheme). Symmetrical and unsymmetrical biaryl products can also be prepared directly from two aryl chlorides without isolation of the intermediate boronate esters. Computational studies provide insight into the roles of the biaryl phosphine ligand and the KOAc base in the catalytic cycle.
- Billingsley, Kelvin L.,Barder, Timothy E.,Buchwald, Stephen L.
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p. 5359 - 5363
(2008/03/18)
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- A novel transmetallation of arylzinc species into arylboronates from aryl halides in a barbier procedure
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A variety of functionalized arylboronates are obtained in moderate to excellent yield by a one-step chemical procedure from the corresponding halides and a haloboronic ester via an intermediate arylzinc species. The Royal Society of Chemistry.
- Claudel, Stephanie,Gosmini, Corinne,Paris, Jean Marc,Perichon, Jacques
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p. 3667 - 3669
(2008/03/14)
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- One-pot preparation of unsymmetrical biaryls via Suzuki cross-coupling reaction of aryl halide using phase-transfer catalyst in a biphasic solvent system
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A one-pot synthetic method of unsymmetrical biaryls was developed via the Suzuki cross-coupling reaction of aryl halide using a phase-transfer catalyst in a biphasic solvent system. Copyright Taylor & Francis Group, LLC.
- Miura, Masanori,Koike, Takanori,Ishihara, Tsukasa,Sakamoto, Shuichi,Okada, Minoru,Ohta, Mitsuaki,Tsukamoto, Shin-Ichi
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p. 667 - 674
(2007/10/03)
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- Hydroboronation process
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The invention relates to processes for the synthesis of aryl or alkene borates which comprises reacting: (i) an olefinic compound having a halogen or halogen-like substituent in a vinylic substitution position, or (ii) an aromatic ring having a halogen or halogen-like substituent in a ring substitution position, with a disubstituted monohydroborane in the presence of a Group 8-11 metal catalyst. The invention also relates to the use of these borates in coupling reactions. The invention further relates to certain disubstituted monohydroboranes and aryl or alkene borates.
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Page column 59
(2010/02/05)
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- Pinacolyl boronic esters as components in the Petasis reaction
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The multicomponent reaction of boronic esters with imine or iminium species (generated in situ by reaction of amines with glyoxylic acid) has received little attention in the literature despite the current interest in the corresponding reactions of boronic acids (Petasis reaction). Moreover, the use of boronic esters in this reaction is particularly attractive since chiral esters could act as auxiliaries in a novel enantioselective process. We set out to establish whether boronic esters were general substrates in the Petasis reaction. Pinacolyl boronic esters were selected for study as a model substrate for more complex homochiral boronic esters because of their ease of synthesis and chemical stability. We found that pinacolyl boronic esters do not react with imines derived from primary amines and glyoxylic acid under standard conditions. By contrast, imines derived from secondary amines and glyoxylic acid react readily with vinylboronic esters but less readily with heteroaryl- or arylboronic esters.
- Koolmeister, Tobias,S?dergren, Mikael,Scobie, Martin
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p. 5965 - 5968
(2007/10/03)
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- New boronic-acid- and boronate-substitued aromatic compounds as precursors of fluoride-responsive conjugated polymer films
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New electropolymerizable aromatic compounds (i.e. pyrrole, thiophene, aniline) bearing boronic acid and ester substituents have been synthesized and their electrochemical behavior has been investigated. Functionalized polythiophene and polypyrrole films could be anodically generated in acetonitrile, whereas the polyaniline derivative was electroformed in an acidic aqueous solution. The electrochemical responses of some of these materials were changed when fluoride ions were added to the electrolytic solutions. The strongest modifications, caused by binding of fluoride by the immobilized boron, were observed for the polypyrrole derivative in hydroorganic media.
- Nicolas, Mael,Fabre, Bruno,Marchand, Gilles,Simonet, Jacques
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p. 1703 - 1710
(2007/10/03)
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