- 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
-
supporting information
p. 15396 - 15405
(2021/10/12)
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- Ligand-Enabled, Iridium-Catalyzed ortho-Borylation of Fluoroarenes
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A terpyridine derivative and an iridium complex catalyze the C-H borylation of a stoichiometric amount of a fluoroarene with high ortho-selectivity and tolerance of functional groups such as bromide, chloride, ester, ketone, amine, and in situ-borylated hydroxyl. Complex drug molecules such as haloperidol can be selectively borylated ortho to the F atom. The terpyridine ligand undergoes rollover cyclometalation to produce an N,N,C-coordinated iridium complex, which may either selectively borylate the fluoroarene by itself or undergo reductive elimination to produce a borylated ligand.
- Kuleshova, Olena,Asako, Sobi,Ilies, Laurean
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p. 5968 - 5973
(2021/05/31)
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- One-pot synthesis of Ag-Cu-Cu2O/C nanocomposites derived from a metal-organic framework as a photocatalyst for borylation of aryl halide
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Mixed metal-metal oxide/C (Ag-Cu-Cu2O/C) nanocomposites were synthesized by the heat treatment of a metal-organic framework under a N2 flow using the one-pot synthesis method. The as-prepared nanocomposites were characterized using a range of techniques,
- Annas, Dicky,Bae, Jong-Seong,Hira, Shamim Ahmed,Park, Kang Hyun,Park, Sungkyun,Song, Sehwan
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p. 32965 - 32972
(2021/12/07)
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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
-
supporting information
p. 14388 - 14393
(2020/07/06)
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- Visible Light-Induced Borylation of C-O, C-N, and C-X Bonds
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Boronic acids are centrally important functional motifs and synthetic precursors. Visible light-induced borylation may provide access to structurally diverse boronates, but a broadly efficient photocatalytic borylation method that can effect borylation of a wide range of substrates, including strong C-O bonds, remains elusive. Herein, we report a general, metal-free visible light-induced photocatalytic borylation platform that enables borylation of electron-rich derivatives of phenols and anilines, chloroarenes, as well as other haloarenes. The reaction exhibits excellent functional group tolerance, as demonstrated by the borylation of a range of structurally complex substrates. Remarkably, the reaction is catalyzed by phenothiazine, a simple organic photocatalyst with MW 200 that mediates the previously unachievable visible light-induced single electron reduction of phenol derivatives with reduction potentials as negative as approximately - 3 V versus SCE by a proton-coupled electron transfer mechanism. Mechanistic studies point to the crucial role of the photocatalyst-base interaction.
- Arman, Hadi D.,Dang, Hang. T.,Haug, Graham C.,He, Ru,Jin, Shengfei,Larionov, Oleg V.,Nguyen, Viet D.,Nguyen, Vu T.,Schanze, Kirk S.
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supporting information
(2020/02/04)
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- Hydride Transfer Enables the Nickel-Catalyzed ipso-Borylation and Silylation of Aldehydes
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Nickel-catalyzed ipso-borylations and silylations of aldehydes are described for the first time. The new functional-group interconversion protocol is characterized by its scalability, functional-group tolerance and wide substrate scope, including examples of late-stage functionalization of complex molecules. The key for the successful reaction outcome is the use of a ketone as a hydride acceptor that intercepts the nickel hydride to undergo a reductive pathway, thus allowing formation of the desired C?B and C?Si bonds.
- Srimontree, Watchara,Guo, Lin,Rueping, Magnus
-
supporting information
p. 423 - 427
(2019/12/27)
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- Direct C?H Borylation of Arenes Catalyzed by Saturated Hydride-Boryl-Iridium-POP Complexes: Kinetic Analysis of the Elemental Steps
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The saturated trihydride IrH3{κ3-P,O,P-[xant(PiPr2)2]} (1; xant(PiPr2)2=9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) activates the B?H bond of two molecules of pinacolborane (HBpin) to give H2, the hydride-boryl derivatives IrH2(Bpin){κ3-P,O,P-[xant(PiPr2)2]} (2) and IrH(Bpin)2{κ3-P,O,P-[xant(PiPr2)2]} (3) in a sequential manner. Complex 3 activates a C?H bond of two molecules of benzene to form PhBpin and regenerates 2 and 1, also in a sequential manner. Thus, complexes 1, 2, and 3 define two cycles for the catalytic direct C?H borylation of arenes with HBpin, which have dihydride 2 as a common intermediate. C?H bond activation of the arenes is the rate-determining step of both cycles, as the C?H oxidative addition to 3 is faster than to 2. The results from a kinetic study of the reactions of 1 and 2 with HBpin support a cooperative function of the hydride ligands in the B?H bond activation. The addition of the boron atom of the borane to a hydride facilitates the coordination of the B?H bond through the formation of κ1- and κ2-dihydrideborate intermediates.
- Esteruelas, Miguel A.,Martínez, Antonio,Oliván, Montserrat,O?ate, Enrique
-
supporting information
p. 12632 - 12644
(2020/09/09)
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- Redox-Neutral Borylation of Aryl Sulfonium Salts via C-S Activation Enabled by Light
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Reported here is a novel photoinduced strategy for the borylation of aryl sulfonium salts using bis(pinacolato)diboron as the boron source. This method exploits redox-neutral aryl sulfoniums to gain access to aryl radicals via C-S bond activation upon photoexcitation under transition-metal-free conditions. Therefore, it grants access to diverse arylboronate esters with good performance from easily available aryl sulfoniums accompanied by mild conditions, operational simplicity, and easy scalability.
- Huang, Chen,Feng, Jie,Ma, Rui,Fang, Shuaishuai,Lu, Tao,Tang, Weifang,Du, Ding,Gao, Jian
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p. 9688 - 9692
(2019/12/02)
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- Group 4 Post-Metallocenes Supported by [OCH2 N,C(σ-aryl)] Auxiliaries Bearing a Seven-Membered Metallacycle: Synthesis, Characterization, and Catalysts for Olefin Polymerization
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A series of pyridine-2-phenolate-6-(σ-aryl) [OCH2 N,C] group 4 bis(benzyl) precatalysts, featuring a flexible O,N-donor chelate, have been prepared and characterized by multinuclear NMR spectroscopy. These complexes adopt C1/su
- Liu, Cham-Chuen,Liu, Qian,Yiu, Shek-Man,Chan, Michael C. W.
-
supporting information
p. 2963 - 2971
(2019/08/22)
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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
-
supporting information
p. 6573 - 6577
(2018/10/09)
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- Additive- and Photocatalyst-Free Borylation of Arylazo Sulfones under Visible Light
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We developed a photocatalyst-free and additive-free, visible light induced borylation reaction using arylazo sulfones as starting material. This protocol shows some advantages such as mild conditions, simple equipment, and wide substrate scope, which gives a complementary protocol for the preparation of arylboronates.
- Xu, Yuliang,Yang, Xinying,Fang, Hao
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p. 12831 - 12837
(2018/10/20)
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- Discovery and evaluation of 3,5-disubstituted indole derivatives as Pim kinase inhibitors
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Pim kinases are promising therapeutic targets for the treatment of hematological cancers. A potent Pim kinase inhibitor 7f, derived from meridianin C, was further optimized by the replacement of 2-aminopyrimidine with substituted benzene. The optimization of the C-3 and C-5 positions of indole yielded compound 43 with improved cellular potency and high selectivity against a panel of 14 different kinases.
- More, Kunal N.,Hong, Victor S.,Lee, Ahyeon,Park, Jongsung,Kim, Shin,Lee, Jinho
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supporting information
p. 2513 - 2517
(2018/06/06)
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- METHODS OF MANUFACTURING OF BORON COMPOUND WITHOUT TRANSITION METALS
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The present invention refers to aryl boron compound number bath method relates to search, more particularly transition metal catalyst to a tank without the use of boron compounds number is given to the aryl organic halo [ceyn [ceyn] freight method are disclosed to boron. (by machine translation)
- -
-
Paragraph 0062; 0063; 0071; 0072; 0076
(2018/05/03)
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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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- C-H borylation by platinum catalysis
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Herein, we describe the platinum-catalyzed borylation of aromatic C-H bonds. N-Heterocyclic carbene-ligated platinum catalysts are found to be efficient catalysts for the borylation of aromatic C(sp2)-H bonds when bis(pinacolato)diboron is used as the boron source. The most remarkable feature of these Pt catalysts is their lack of sensitivity towards the degree of steric hindrance around the C-H bonds undergoing the borylation reaction. These Pt catalysts allow for the synthesis of sterically congested 2,6-disubstituted phenylboronic esters, which are otherwise difficult to synthesize using existing C-H borylation methods. Furthermore, platinum catalysis allows for the site-selective borylation of the C-H bonds ortho to fluorine substituents in fluoroarene systems. Preliminary mechanistic studies and work towards the synthetic application of this platinum catalyzed C-H borylation process are described.
- Furukawa, Takayuki,Tobisu, Mamoru,Chatani, Naoto
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p. 332 - 342
(2017/05/09)
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- Room Temperature Ni0/PCy3-Catalyzed Coupling Reactions of Aryl Arenesulfonates with Bis(pinacolato)diboron
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Room temperature Ni0/PCy3-catalyzed cross-coupling reactions of aryl arenesulfonates with bis(pinacolato)diboron are described. The Ni0/PCy3 catalysts, generated from Ni(COD)2 and PCy3, or air-stable 4-MeOC6H4NiII(PCy3)2OTs, were efficient catalyst systems for the Miyaura borylation reactions of a variety of aryl arenesulfonates with bis(pinacolato)diboron. The mild reaction condition, the easy availability of the catalysts and good yields make these reactions potentially useful in organic synthesis (Cy = cyclohexyl, COD = cyclooctadiene, OTs = tosyl).
- Dong, Jie,Guo, Hui,Hu, Qiao-Sheng
-
supporting information
p. 7087 - 7090
(2017/12/28)
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- Simple and Efficient Generation of Aryl Radicals from Aryl Triflates: Synthesis of Aryl Boronates and Aryl Iodides at Room Temperature
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Despite the wide use of aryl radicals in organic synthesis, current methods to prepare them from aryl halides, carboxylic acids, boronic acids, and diazonium salts suffer from limitations. Aryl triflates, easily obtained from phenols, are promising aryl radical progenitors but remain elusive in this regard. Inspired by the single electron transfer process for aryl halides to access aryl radicals, we developed a simple and efficient protocol to convert aryl triflates to aryl radicals. Our success lies in exploiting sodium iodide as the soft electron donor assisted by light. This strategy enables the scalable synthesis of two types of important organic molecules, i.e., aryl boronates and aryl iodides, in good to high yields, with broad functional group compatibility in a transition-metal-free manner at room temperature. This protocol is anticipated to find potential applications in other aryl-radical-involved reactions by using aryl triflates as aryl radical precursors.
- Liu, Wenbo,Yang, Xiaobo,Gao, Yang,Li, Chao-Jun
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supporting information
p. 8621 - 8627
(2017/07/06)
-
- Chemoselective coupling of 1,1-bis[(pinacolato)boryl]alkanes for the transition-metal-frec borylation of aryl and vinyl halides: A combined experimental and theoretical investigation
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A new transition-metal-frec borylation of aryl and vinyl halides using l,l-bis[(pinacolato)boryl]alkanes as boron sources is described. In this transformation one of the boron groups from 1,1-bis[(pinacolato)boryl]alkanes is selectively transferred to aryl and vinyl halides in the presence of sodium tert-butoxide as the only activator to form organoboronate esters. Under the developed borylation conditions, a broad range of organohalides are borylated with excellent chemo-selectivity and functional group compatibility, thus offering a rare example of a transition-metal-frec borylation protocol. Experimental and theoretical studies have becn performed to elucidate the reaction mechanism, revealing the unusual formation of Lewis acid/base adduct betwecn organohalides and α-borylcarbanion, generated in situ from the reaction of l,l-bis[(pinacolato)boryl]alkanes with an alkoxide base, to facilitate the borylation reactions.
- Lee, Yeosan,Baek, Seung-Yeol,Park, Jinyoung,Kim, Seoung-Tae,Tussupbayev, Samat,Kim, Jeongho,Baik, Mu-Hyun,Cho, Seung Hwan
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p. 975 - 984
(2017/05/16)
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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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- Iridium/N-heterocyclic carbene-catalyzed C-H borylation of arenes by diisopropylaminoborane
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Catalytic C-H borylation of arenes has been widely used in organic synthesis because it allows the introduction of a versatile boron functionality directly onto simple, unfunctionalized arenes. We report herein the use of diisopropylaminoborane as a boron source in C-H borylation of arenes. An iridium(I) complex with 1,3-dicyclohexylimidazol-2-ylidene is found to efficiently catalyze the borylation of arenes and heteroarenes. The resulting aminoborylated products can be converted to the corresponding boronic acid derivatives simply by treatment with suitable diols or diamines.
- Tobisu, Mamoru,Igarashi, Takuya,Chatani, Naoto
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supporting information
p. 654 - 661
(2016/07/06)
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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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- Phosphine and palladium-free synthesis of aryl and alkenyl boronates: A nano-catalytic approach
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Superparamagnetic copperferrite nanoparticle is employed as an environmentally benign and efficient catalyst to affect the borylation of aryliodides yielding the corresponding arylboronates at low catalyst loading under mild reaction conditions. This protocol tolerates various substituents present in aryl iodides and also could be extended to beta bromostyrenes in the absence of phosphine and palladium.
- Mohan, Balaji,Kang, Hyuntae,Park, Kang Hyun
-
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- Ruthenium-catalysed dehydrogenative C-H borylation of arenes with pinacolborane
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A ruthenium complex prepared in situ from [RuCl2(p-cymene)]2 and TpMe2K[TpMe2 = hydrotris(3,5-dimethylpyrazolyl)borate] is efficient for aromatic C-H borylation with pinacolborane (4,4,5,5-tetramethyl-1,3,2-dioxaborolane). Arenes were borylated at more electron-rich positions. DFT calculations and kinetic isotope effect experiments suggest that the catalytic cycle should involve an electrophilic aromatic substitution with a borenium cation.
- Murata, Miki,Ueda, Yosuke,Hyogo, Mayu,Kohari, Yoshihito,Namikoshi, Takeshi,Watanabe, Shinji
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p. 393 - 396
(2016/07/21)
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- High-Turnover Aromatic C-H Borylation Catalyzed by POCOP-Type Pincer Complexes of Iridium
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The catalytic C-H borylation of arenes with HBpin (pin = pinacolate) using POCOP-type pincer complexes of Ir has been demonstrated, with turnover numbers exceeding 10 000 in some cases. The selectivity of C-H activation was based on steric preferences and largely mirrored that found in other Ir borylation catalysts. Catalysis in the (POCOP)Ir system depends on the presence of stoichiometric quantities of sacrificial olefin, which is hydrogenated to consume the H2 equivalents generated in the borylation of C-H bonds with HBpin. Smaller olefins such as ethylene or 1-hexene were more advantageous to catalysis than sterically encumbered tert-butylethylene (TBE). Olefin hydroboration is a competing side reaction. The synthesis and isolation of multiple complexes potentially relevant to catalysis permitted examination of several key elementary reactions. These experiments indicate that the C-H activation step in catalysis ostensibly involves oxidative addition of an aromatic C-H bond to the three-coordinate (POCOP)Ir species. The olefin is mechanistically critical to gain access to this 14-electron, monovalent Ir intermediate. C-H activation at Ir(I) here is in contrast to the olefin-free catalysis with state-of-the-art Ir complexes supported by neutral bidentate ligands, where the C-H activating step is understood to involve trivalent Ir-boryl intermediates.
- Press, Loren P.,Kosanovich, Alex J.,McCulloch, Billy J.,Ozerov, Oleg V.
-
supporting information
p. 9487 - 9497
(2016/08/12)
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- Aromatic C-H borylation by nickel catalysis
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The first nickel-catalyzed aromatic C-H borylation is described. In the presence of catalytic amounts of [Ni(cod)2], tricyclopentylphosphine, and CsF, benzene and indole derivatives can be borylated with B2pin2. The N-heterocyclic carbene IPr was also found to be an effective ligand. Kinetic isotope effect experiments showed that C-H cleavage is likely involved in the rate-determining step.
- Zhang, Hua,Hagihara, Shinya,Itami, Kenichiro
-
supporting information
p. 779 - 781
(2015/06/22)
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- C-H Functionalization at Sterically Congested Positions by the Platinum-Catalyzed Borylation of Arenes
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Despite significant progress in the area of C-H bond functionalization of arenes, no general method has been reported for the functionalization of C-H bonds at the sterically encumbered positions of simple arenes, such as mesitylene. Herein, we report the development of the first platinum-based catalyst for C-H borylation of arenes and heteroarenes. Notably, this method exhibited high tolerance toward steric hindrance and provided rapid access to a series of 2,6-disubstituted phenylboronic esters, valuable building blocks for further elaborations.
- Furukawa, Takayuki,Tobisu, Mamoru,Chatani, Naoto
-
supporting information
p. 12211 - 12214
(2015/10/12)
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- Iridium-bipyridine periodic mesoporous organosilica catalyzed direct C-H borylation using a pinacolborane
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Heterogeneous catalysis for direct C-H borylation of arenes and heteroarenes in the combination of iridium (Ir) complex fixed on periodic mesoporous organosilica containing bipyridine ligands within the framework (Ir-BPy-PMO) and pinacolborane (HBpin) is reported. Ir-BPy-PMO showed higher catalytic activity toward the borylation of benzene with inexpensive HBpin compared to expensive bis(pinacolato)diboron (B2pin2). The precatalyst could be handled without the use of a glove box. The catalyst was easily recovered from reaction mixtures by simple filtration under air. The recovered catalyst still showed good catalytic activity for at least three more times for the borylation of benzene. A variety of arenes and heteroarenes were successfully borylated with high boron efficiency by Ir-BPy-PMO using HBpin, whereas almost no activity was observed for borylation of some heteroarenes with B2pin2. The system using Ir-BPy-PMO and HBpin was also utilized in syntheses of multi-boronated thiophene-based building blocks containing ladder-, acenefused-, and fused-thiophene skeletons. The combination of a stable and reusable solid catalyst and inexpensive HBpin is expected to be superior to conventional approaches for the development of industrial applications.
- Maegawa, Yoshifumi,Inagaki, Shinji
-
supporting information
p. 13007 - 13016
(2016/01/09)
-
- Pyridine-promoted dediazoniation of aryldiazonium tetrafluoroborates: Application to the synthesis of SF5-substituted phenylboronic esters and iodobenzenes
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Pyridine promotes dediazoniation of aryldiazonium tetrafluoroborates. The formed aryl radicals were trapped with B2pin2, iodine, or tetrahydrofuran to afford boronic esters, iodobenzenes and benzenes, respectively. The application to the synthesis of (pentafluorosulfanyl) phenylboronic esters, iodo(pentafluorosulfanyl)benzenes and (pentafluorosulfanyl)benzene is shown.
- Iakobson, George,Du, Junyi,Slawin, Alexandra M. Z.,Beier, Petr
-
supporting information
p. 1494 - 1502
(2016/04/09)
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- A mild carbon-boron bond formation from diaryliodonium salts
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The direct metal-free borylation of diaryliodonium salts with diboron reagents is now demonstrated to be a feasible process toward formation of aryl boronic esters without any additive or catalysts, and it can be extended to a two-step C-C coupling of both aryl groups of the initial diaryliodonium reagent.
- Miralles,Romero,Fernández,Mu?iz
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p. 14068 - 14071
(2015/09/15)
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- Efficient Rh-catalyzed C-H borylation of arene derivatives under photochemical conditions
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Photocatalysis allows innovations in organic synthesis. Among the various catalytic reactions, CH-functionalizations offer valuable possibilities for the refinement of easily available building blocks. In this respect, catalytic borylation is of interest, too. So far, most of the catalytic borylation reactions are performed under thermal conditions at comparably high temperatures. Here, we describe a new synthetic route for efficient borylation reactions of arenes using a photocatalytic pathway. This novel approach allows the synthesis of a broad variety of borylated arenes and heteroarenes under mild conditions. Applying trans-[Rh(PMe3)2(CO)Cl] as an active photocatalyst and HBPin as an boron source, we achieved high TON. A catalytic cycle that relies on a Rh(i)-Rh(iii) interconversion is proposed.
- Bheeter, Charles Beromeo,Chowdhury, Abhishek Dutta,Adam, Rosa,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 10336 - 10340
(2015/10/28)
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- NEW PROCESS FOR PREPARING ARYLBORANES BY ARYLATION OF ORGANOBORON COMPOUNDS
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The present invention relates to a new process for the preparation of an arylborane compound, by arylation of a B-H bond, which comprises a step (1) of contacting an arenediazonium salt or a heteroarenediazonium salt with an organoboron compound containing at least one B-H bond, in a reaction medium containing a solvent, in the absence of base, in the absence or in the presence of an activating agent, for the preparation of an arylborane compound, and a possible step (2) of recovery and purification of said arylborane compound obtained at the step (1), said arylborane being in particular an aminoarylborane, and a possible step (3) of refunctionalisation of said arylborane obtained at step (1) or (2) for the preparation of aryl boronic derivatives or arylborates.
- -
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Page/Page column 53-54; 67-68
(2014/02/15)
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- Borylation using group IV metallocene under mild conditions
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A borylation reaction of aromatic diazonium salts has been optimized using titanocene and zirconocene derivatives as catalysts. The reaction employs diisopropylaminoborane as a borylating agent and proceeds smoothly at room temperature to provide arylboronates after methanolysis and transesterification with pinacol. The reaction mechanism has been found to proceed via a radical pathway.
- Marciasini, Ludovic D.,Vaultier, Michel,Pucheault, Mathieu
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supporting information
p. 1702 - 1705
(2014/03/21)
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- Conversion of aromatic amino into trifluoromethyl groups through a Sandmeyer-type transformation
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A novel strategy for aromatic trifluoromethylation by converting amino into trifluoromethyl groups via a Sandmeyer-type reaction is reported. The transformation involves diazotization of the aromatic amines with tert-butyl nitrite and hydrochloric acid to form aryldiazonium chlorides, followed by trifluoromethylation with trifluoromethylsilver at low temperature. Various readily available aromatic amines are smoothly converted under mild conditions. Georg Thieme Verlag Stuttgart. New York.
- Wang, Xi,Xu, Yan,Zhou, Yujing,Zhang, Yan,Wang, Jianbo
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supporting information
p. 2143 - 2148
(2014/08/18)
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- New process for preparing arylboranes by arylation of organoboron compounds
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The present invention relates to a new process for the preparation of an arylborane compound, by arylation of a B-H bond, which comprises a step (1) of contacting an arenediazonium salt or a heteroarenediazonium salt with an organoboron compound containing at least one B-H bond, in a reaction medium containing a solvent, in the absence of base, in the absence or in the presence of an activating agent, for the preparation of an arylborane compound, and a possible step (2) of recovery and purification of said arylborane compound obtained at the step (1), said arylborane being in particular an aminoarylborane, and a possible step (3) of refunctionalisation of said arylborane obtained at step (1) or (2) for the preparation of aryl boronic derivatives or arylborates.
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Paragraph 0108; 0109; 0110; 0111; 0127; 0128
(2014/01/23)
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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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- 2-PHENYL-6-AZOLYLPYRIDINE-BASED LIGAND AND GROUP VIII TRANSITION METAL COMPLEX
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A 2-phenyl-6-azolylpyridine-based ligand is represented by the following formula (I): wherein, X represents nitrogen or C—R10; R1, R2, R3, R4, R5, R6, R7, R8 /su
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Paragraph 0066; 0067
(2013/03/26)
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- Silver-mediated trifluoromethylation of aryldiazonium salts: Conversion of amino group into trifluoromethyl group
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A novel strategy for aromatic trifluoromethylation by converting aromatic amino group into CF3 group is reported herein. This method, which can be considered as trifluoromethylation variation of the classic Sandmeyer reaction, uses readily available aromatic amines as starting materials and is performed under mild conditions.
- Wang, Xi,Xu, Yan,Mo, Fanyang,Ji, Guojing,Qiu, Di,Feng, Jiajie,Ye, Yuxuan,Zhang, Songnan,Zhang, Yan,Wang, Jianbo
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supporting information
p. 10330 - 10333
(2013/08/23)
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- Iron-catalysed borylation of arenediazonium salts to give access to arylboron derivatives via aryl(amino)boranes at room temperature
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Complementary to previously described Miyaura borylation methods, a new access to boron derivatives via aryl(amino)boranes is described. Direct coupling between aryldiazonium salts and diisopropylaminoborane is catalysed by 0.1% ferrocene leading to the formation of a carbon-boron bond. The obtained aryl(amino)boranes could eventually then be transformed into boronic acids, boronates or borates. Copyright
- Marciasini, Ludovic D.,Richy, Nicolas,Vaultier, Michel,Pucheault, Mathieu
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supporting information
p. 1083 - 1088
(2013/05/21)
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- Base metal catalysts for photochemical C-H borylation that utilize metal-metal cooperativity
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Heterobimetallic Cu-Fe and Zn-Fe complexes catalyze C-H borylation, a transformation that previously required noble metal catalysts. The optimal catalyst, (IPr)Cu-FeCp(CO)2, exhibits efficient activity at 5 mol% loading under photochemical conditions, shows only minimal decrease in activity upon reuse, and is able to catalyze borylation of a variety of arene substrates. Stoichiometric reactivity studies are consistent with a proposed mechanism that exploits metal-metal cooperativity and showcases bimetallic versions of the classical organometallic processes, oxidative addition and reductive elimination.
- Mazzacano, Thomas J.,Mankad, Neal P.
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supporting information
p. 17258 - 17261
(2014/01/06)
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- Unsaturated iridium(III) complexes supported by a quinolato-carboxylato ONO pincer-type ligand: Synthesis, reactivity, and catalytic C-H functionalization
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The unsaturated σ,π-cyclooctenyl iridium(III) pincer compound [Ir(κ3-hqca)(1-κ-4,5-η-C8H13)] (1) has been prepared by the reaction of [Ir(cod)(CH3CN) 2]BF4 with lithium 8-oxidoquinoline-2-carboxylate (Li 2hqca) and obtained as two isomers derived from the relative disposition of the pincer and the σ,π-cyclooctenyl ligands. Compound 1 can be prepared as a single isomer by reaction of 8-hydroxyquinoline-2- carboxylic acid (H2hqca) with [Ir(μ-OMe)(cod)]2. Reaction of [Ir(μ-OH)(coe)2]2 with H2hqca gave the square-pyramidal iridum(III) complex [IrH(κ3-hqca) (coe)] (3). This compound exists as dinuclear assemblies [IrH(κ 3-hqca)(coe)]2 in noncoordinating solvents and as the corresponding labile mononuclear solvates in more polar solvent solutions. The dimerization of 3 was established by 1H-DOSY NMR spectroscopy and an ESI+ mass spectrum and supported by DFT calculations. Reaction of 3 with pyridine gave the adduct [IrH(κ3-hqca)(coe)(py)] (4) and the bis-pyridine complexes [IrH(κ3-hqca)(R-py)2] (R = H (6), 2-Me (7)) by replacement of the coe ligand. Compound 4 was transformed into the bromo derivative [IrBr(κ3-hqca)(coe)(py)] (5) by reaction with N-bromosuccinimide. Carbonylation of 4 gave the cyclooctenyl complex [Ir(κ3-hqca)(1-κ-C8H 15)(CO)(py)] (8), which is stable only under a carbon monoxide atmosphere. The pincer complexes were active in the catalytic borylation of arenes under thermal conditions.
- Nguyen, Duc Hanh,Perez-Torrente, Jesus J.,Jimenez, M. Victoria,Modrego, F. Javier,Gomez-Bautista, Daniel,Lahoz, Fernando J.,Oro, Luis A.
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p. 6918 - 6930
(2014/01/06)
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- PREPARATION METHOD OF AROMATIC BORONATE COMPOUNDS
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Preparation method of aromatic boronate compound is provided, in which the is as follows: reacting aromatic amine Ar-NH2, with diboronic ester and alkyl nitrite in the presence of organic solvent, where Ar represents non-heterocyclic aryl. It enables for the first time the preparation of aromatic boronate from aromatic amine in one step by the present method.
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Page/Page column 2
(2012/07/28)
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- PREPARATION METHOD OF AROMATIC BORATE ESTER COMPOUND
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Preparation method of aromatic boronate compound is provided, in which the step is as follows: reacting aromatic amine Ar-NH2, with diboronic ester and alkyl nitrite in the presence of organic solvent, where Ar represents non-heterocyclic aryl.
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Page/Page column 4
(2012/08/08)
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- Palladium nanoparticle catalysis: Borylation of aryl and benzyl halides and one-pot biaryl synthesis via sequential borylation-Suzuki-Miyaura coupling
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Palladium nanoparticles generated in PEG catalyze the reaction of bis(pinacolato)diboron with various aryl/benzyl halides to afford aryl/benzyl boronates in high yield. Arylboronates thus prepared, have been directly used in the Suzuki-Miyaura coupling reaction with different aryl halides and benzyl halides in a convenient one-pot, two-step solvent free green synthesis of unsymmetrical biaryls and diarylmethanes. The Royal Society of Chemistry 2012.
- Bej, Ansuman,Srimani, Dipankar,Sarkar, Amitabha
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experimental part
p. 661 - 667
(2012/05/04)
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- Unsaturated iridium pyridinedicarboxylate pincer complexes with catalytic activity in borylation of arenes
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Unsaturated σ,π-cyclooctenyl and hydrido Ir(iii) complexes bearing an unusual tridentate dianionic ONO pincer-type ligand have been straightforwardly obtained from 2,6-pyridinedicarboxylic acid and standard Ir(i) starting materials. These complexes efficiently catalyzed the arene C-H borylation under thermal conditions. The Royal Society of Chemistry 2011.
- Hanh Nguyen, Duc,Perez-Torrente, Jesus J.,Lomba, Laura,Victoria Jimenez,Lahoz, Fernando J.,Oro, Luis A.
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p. 8429 - 8435
(2011/10/10)
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- POLYCYCLIC COMPOUNDS AS LYSOPHOSPHATIDIC ACID RECEPTOR ANTAGONISTS
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Described herein are compounds that are antagonists of lysophosphatidic receptor(s). Also described are pharmaceutical compositions and medicaments that include the compounds described herein, as well as methods of using such antagonists, alone and in combination with other compounds, for treating LPA-dependent or LPA-mediated conditions or diseases.
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Page/Page column 33
(2011/04/24)
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- Direct conversion of arylamines to pinacol boronates: A metal-free borylation process
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Leave the metal out: Arylboronates are produced In moderate to good yields by direct borylation of readily available aryl amines (see scheme). The reaction can be carried out under air at room temperature and transition-metal catalysis is not required. The boronate products can be used without purification in SuzukiMiyaura cross-coupling reactions. Chemical equation representation
- Mo, Fanyang,Jiang, Yubo,Qiu, Di,Zhang, Yan,Wang, Jianbo
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supporting information; experimental part
p. 1846 - 1849
(2010/06/16)
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- Development of recyclable iridium catalyst for C-H borylation
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Aromatic C-H borylation using [IrCl(COD)]2 and 2,2′-bipyridinedicarboxylic acids was studied. 2,2′-Bipyridine-4,4′-dicarboxylic acid was complexed with [IrCl(COD)]2 in the presence of bis(pinacolato)diboron. The resulting iridium catalyst could be readily separated from the reaction mixture by simple filtration, and the recovered catalyst under a nitrogen atmosphere was still active and could be reused more than 10 times.
- Tagata, Tsuyoshi,Nishida, Mayumi,Nishida, Atsushi
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scheme or table
p. 6176 - 6179
(2009/12/26)
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- Iridium complexes of N-heterocyclic carbenes in C-H borylation using energy efficient microwave technology: Influence of structure, ligand donor strength and counter ion on catalytic activity
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Bridged and unbridged N-heterocyclic carbene (NHC) ligands were metalated with [Ir(COD)Cl]2 to give iridium(i) mono- and biscarbene substituted catalysts [Ir(COD)NHC(Cl)] and [Ir(COD)(NHC)2][X] (X: I, PF 6, BF4, CF3COO, OTf). The prepared NHC-complexes were tested in the C-H borylation reaction of aromatic carbons with bis(pinacolato)diboron (B2pin2) and pinacolborane (HBpin). The use of microwave technology in this study not only facilitates a time efficient screening of a wide range of influences such as ligand σ-donor strength and structural motif as well as the effects of the complex counter ion, but also provides an energy efficient heating source. Catalyst 6TFA, which features a chelating NHC ligand, proved to be most effective catalyst and further investigations with this complex in the borylation of mono- and disubstituted benzene derivatives exploring chemo- and regioselectivity were undertaken. The Royal Society of Chemistry 2009.
- Rentzsch, Christoph F.,Tosh, Evangeline,Herrmann, Wolfgang A.,Kuehn, Fritz E.
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scheme or table
p. 1610 - 1617
(2010/05/18)
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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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- Aromatic C-H borylation catalyzed by hydrotris(pyrazolyl)borate complexes of rhodium and iridium
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Dehydrogenative coupling of 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (pinacolborane) with arenes occurred in good yield in the presence of a catalytic amount of [Rh(TpMe2)-(cod)] (TpMe2 = hydrotris(3,5-dimethylpyrazolyl)borate, cod = 1,5-cyclooctadiene), [Ir(Tp)(cod)] (Tp = hydrotris-(pyrazolyl)borate), and related (pyrazolyl)borate complexes. The catalytic activity was strongly affected by substituents on the pyrazolyl rings.
- Murata, Miki,Odajima, Hiroki,Watanabe, Shinji,Masuda, Yuzuru
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p. 1980 - 1982
(2008/02/02)
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