- CuBr/H2O2-mediated oxidative coupling of N,N-dialkylarylamines in water: A practical synthesis of benzidine derivatives
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CuBr/H2O2 was deployed into mediating the oxidative coupling reaction of N,N-dialkylarylamines in water, which gave benzidine derivatives in an economically and environmentally satisfying manner. Georg Thieme Verlag Stuttgart.
- Jiang, Yanfeng,Xi, Chanjuan,Yang, Xianghua
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- Detection of the Short-Lived Radical Cation Intermediate in the Electrooxidation of N,N-Dimethylaniline by Mass Spectrometry
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The N,N-dimethylaniline (DMA) radical cation DMA.+, a long-sought transient intermediate, was detected by mass spectrometry (MS) during the electrochemical oxidation of DMA. This was accomplished by coupling desorption electrospray ionization (DESI) MS with a waterwheel working electrode setup to sample the surface of the working electrode during electrochemical analysis. This study clearly shows that DESI-based electrochemical MS is capable of capturing electrochemically generated intermediates with half-lives on the order of microseconds, which is 4–5 orders of magnitude faster than previously reported electrochemical mass spectrometry techniques.
- Brown, Timothy A.,Chen, Hao,Zare, Richard N.
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- Remarkably efficient oxidative coupling of N,N-dialkylarylamines in water mediated by cerium(IV) ammonium nitrate
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A highly effective, economical, and environmentally friendly method using of CAN as oxidant and water as solvent for oxidative coupling of N,N-dialkylarylamines was reported.
- Xi, Chanjuan,Jiang, Yanfeng,Yang, Xianghua
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- Oxidative coupling reaction of N,N-dialkylanilines with cerium(IV) ammonium nitrate in the solid state
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Oxidative coupling reactions of N,N-dialkylanilines with cerium(IV) ammonium nitrate can be achieved by grinding at room temperature in the absence of solvents. Copyright Taylor & Francis Group, LLC.
- Yang, Xianghua,Xi, Chanjuan,Jiang, Yanfeng
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- Electrochemical Thermospray Mass Spectrometry
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Thermospray ionization combined with a quadrupole mass spectrometer was used on line to detect electrochemically generated products directly from solution.To do so, an electrochemical cell was constructed and connected with the mass spectrometer in such a way that the electrolyte was forced by pressure from the working electrode into the heated capillary tube of the thermospray system.The fast response achieved allowed analysis to be performed in parallel with a cyclic voltammetry curve.The utility of the method is demonstrated by means of the electrooxidation of N, N -dimethylaniline in an aqueous medium.The potential-dependent formation of dimers and trimers is shown.
- Hambitzer, Guenther,Heitbaum, Joachim
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- Detection of the short-lived cation radical intermediate in the electrochemical oxidation of N, N -dimethylaniline by scanning electrochemical microscopy
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The short-lived intermediate N,N-dimethylaniline (DMA) cation radical, DMA?+, was detected during the oxidation of DMA in MeCN with 0.1 M tetra-n-butylammonium hexafluorophosphate. The detection was accomplished at steady state by scanning electrochemical microscopy (SECM) with ultramicroelectrodes using the tip generation/substrate collection mode. Cyclic voltammetry (CV) with a 2 mm Pt electrode indicates that DMA oxidation in acetonitrile is followed by a dimerization and two electrochemical reactions, which is consistent with previous results. The DMA?+ intermediate is detected by SECM, where the DMA?+ generated at the ca. 500 nm radius Pt tip is collected on a 5 μm radius Pt substrate when the gap between the tip and the substrate is a few hundred nanometers. Almost all of the DMA?+ is reduced at the substrate when the gap is 200 nm or less, yielding a dimerization rate constant of 2.5 × 108 M-1·s-1 based on a simulation. This is roughly 3 orders of magnitude larger than the value estimated by fast-scan CV. We attribute this discrepancy to the effects of double-layer capacitance charging and adsorbed species in the high scan rate CV.
- Cao, Fahe,Kim, Jiyeon,Bard, Allen J.
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- Electrochemical synthesis of symmetrical benzidines through dehydrogenative cross-coupling reaction
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Synthesis of diversely functionalized symmetrical benzidines through electrochemical dehydrogenative cross-coupling reaction of two N,N-disubstituted anilines, is described. The reactions conducted under mild conditions with no oxidizing reagents and transition metal catalysts.
- Liu, Xiaoying,Cai, Tian-Cheng,Guo, Dingyi,Wang, Bin-Bin,Ying, Shengneng,Wang, Huixian,Tang, Shiyun,Shen, Qinpeng,Gui, Qing-Wen
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supporting information
(2021/04/09)
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- Cobalt-catalyzed cross-coupling reactions of aryl- And alkylaluminum derivatives with (hetero)aryl and alkyl bromides
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A simple cobalt complex, such as Co(phen)Cl2, turned out to be a highly efficient and cheap precatalyst for a host of cross-coupling reactions involving aromatic and aliphatic organoaluminum reagents with aryl, heteroaryl and alkyl bromides. New C(sp2)-C(sp2) and C(sp2)-C(sp3) bonds were formed in good to excellent yields and with high chemoselectivity, under mild reaction conditions.
- Dilauro, Giuseppe,Messa, Francesco,Bona, Fabio,Perrone, Serena,Salomone, Antonio
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supporting information
p. 10564 - 10567
(2021/10/19)
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- Catalytic and Aerobic Oxidative Biaryl Coupling of Anilines Using a Recyclable Heterogeneous Catalyst for Synthesis of Benzidines and Bicarbazoles
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In this study, a heterogeneous rhodium-catalyzed oxidative homocoupling reaction of anilines utilizing molecular oxygen as the sole oxidant is reported. Employing a commercially available and recyclable Rh/C catalyst enabled the oxidative dimerization of various anilines, including N,N-disubstituted and N-monosubstituted anilines, as well as diarylamines, triarylamines, and carbazoles. Additionally, the catalytic protocol was extended to the ortho-ortho coupling of anilines, affording 2,2′-diaminobiphenyls with high regioselectivity. Notably, the developed approach provides rapid access to diversely functionalized benzidines and diaminobiphenyls in an operationally simple, practical, and environmentally friendly manner.
- Matsumoto, Kenji,Toubaru, Yasunori,Tachikawa, Shohei,Miki, Ayaka,Sakai, Kentaro,Koroki, Syota,Hirokane, Tsukasa,Shindo, Mitsuru,Yoshida, Masahiro
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p. 15154 - 15166
(2020/12/23)
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- Single-Site Cobalt-Catalyst Ligated with Pyridylimine-Functionalized Metal-Organic Frameworks for Arene and Benzylic Borylation
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We report a highly active single-site heterogeneous cobalt-catalyst based on a porous and robust pyridylimine-functionalized metal-organic frameworks (pyrim-MOF) for chemoselective borylation of arene and benzylic C-H bonds. The pyrim-MOF having UiO-68 topology, constructed from zirconium-cluster secondary building units and pyridylimine-functionalized dicarboxylate bridging linkers, was metalated with CoCl2 followed by treatment of NaEt3BH to give the cobalt-functionalized MOF-catalyst (pyrim-MOF-Co). Pyrim-MOF-Co has a broad substrate scope, allowing the C-H borylation of halogen-, alkoxy-, alkyl-substituted arenes as well as heterocyclic ring systems using B2pin2 or HBpin (pin = pinacolate) as the borylating agent to afford the corresponding arene- or alkyl-boronate esters in good yields. Pyrim-MOF-Co gave a turnover number (TON) of up to 2500 and could be recycled and reused at least 9 times. Pyrim-MOF-Co was also significantly more robust and active than its homogeneous control, highlighting the beneficial effect of active-site isolation within the MOF framework that prevents intermolecular decomposition. The experimental and computational studies suggested (pyrim?-)CoI(THF) as the active catalytic species within the MOF, which undergoes a mechanistic pathway of oxidative addition, turnover limiting σ-bond metathesis, followed by reductive elimination to afford the boronate ester.
- Akhtar, Naved,Antil, Neha,Balendra,Begum, Wahida,Kumar, Ajay,Manna, Kuntal,Newar, Rajashree,Shukla, Sakshi
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supporting information
p. 10473 - 10481
(2020/08/05)
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- Electrochemical dehydrogenative cross-coupling of two anilines: Facile synthesis of unsymmetrical biaryls
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A new, general ortho/para-selective anodic dehydrogenative cross-coupling of two aryl amines, naphthalen-2-amine derivatives and anilines, is described. This electrochemical protocol assembles a wide range of unsymmetrical biaryls in good to excellent yields under mild, additional-metal-catalyst-free, oxidant-free conditions with excellent selectivity, broad substrate scope, and wide functional group tolerance. This electrochemical technology is highlighted with facile incorporation of important pharmacophores into the resulting biaryls, and is applicable to the homocoupling of anilines for producing symmetrical biaryls.
- He, De-Liang,Li, Jin-Heng,Li, Yang,Luo, Mu-Jia,Ouyang, Xuan-Hui
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supporting information
p. 2707 - 2710
(2020/03/13)
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- Aerobic Homocoupling of Arylboronic Acids Catalyzed by Regenerable Pd(II)@MIL-88B-NH2(Cr)
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A fast and operationally simple method for the aerobic homocoupling of arylboronic acids is described. The process is catalyzed by Pd(II) complexes supported on the metal-organic framework MIL-88B-NH2(Cr). The benefits of this approach include the use of a benign oxidant/solvent mixture at room temperature with catalytic amounts of base, easy recovery of the catalyst, and easy isolation of the products. Very high conversions and good yields were achieved for a variety of substrates, and the process was also carried out on a larger scale with the same efficiency. The catalyst was found to suffer deactivation due to progressive reduction and agglomeration of palladium into inactive metal clusters/particles. An innovative procedure for the oxidative redispersion and regeneration of the active Pd(II)@MOF species is presented.
- Valiente, Alejandro,Carrasco, Sergio,Sanz-Marco, Amparo,Tai, Cheuk-Wai,Bermejo Gómez, Antonio,Martín-Matute, Belén
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p. 3933 - 3940
(2019/05/22)
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- Aerobic and Ligand-Free Manganese-Catalyzed Homocoupling of Arenes or Aryl Halides via in Situ Formation of Aryllithiums
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Ligand-free manganese-catalyzed homocoupling of arenes or aryl halides can be carried out under aerobic conditions via the in situ formation of the corresponding aryllithiums. A wide range of biaryls and derivatives has been obtained, and a mechanism involving monomeric manganese-oxo complexes has been proposed on the basis of DFT calculations.
- Liu, Yujia,Bergès, Julien,Zaid, Yassir,Chahdi, Fouad Ouazzani,Van Der Lee, Arie,Harakat, Dominique,Clot, Eric,Jaroschik, Florian,Taillefer, Marc
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p. 4413 - 4420
(2019/03/26)
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- Absolute Configuration Assignment from Optical Rotation Data by Means of Biphenyl Chiroptical Probes
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A non-empirical approach for the assignment of the absolute configuration of chiral 2-alkyl-substituted carboxylic acids and primary amines by [α]D measurements has been developed. The method requires the conversion of the chiral acids or amines into the corresponding 4,4′-disubstituted biphenylamides or biphenylazepines, respectively. In these derivatives a central-to-axial chirality transfer induces a preferred torsion in the biphenyl moiety revealed by the sign of the biphenyl A band in the ECD spectrum. By 4,4′-substitution on the biphenyl moiety a redshift of the A band is obtained, leading to an increase of its relative contribution to optical rotation. This allows to reliably establish a direct correlation between the [α]D sign, the biphenyl twist and, then, the substrate absolute configuration. This approach thus constitutes a really practical and reliable method to assign the absolute configuration of chiral carboxylic acids and primary amines by simple and straightforward [α]D measurement, readily obtainable by a routine instrumentation like the polarimeter.
- Vergura, Stefania,Scafato, Patrizia,Belviso, Sandra,Superchi, Stefano
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supporting information
p. 5682 - 5690
(2019/03/17)
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- Efficient Homocoupling of Aryl- and Alkenylboronic Acids in the Presence of Low Loadings of [{Pd(μ-OH)Cl(IPr)} 2 ]
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NHC-palladium(II) complex [{Pd(μ-OH)Cl(IPr)} 2 ] (IPr = bis(2,6-diisopropylphenyl)imidazolin-2-ylidene) catalyzes the oxidative coupling of a broad spectrum of aryl- and alkenylboronic acids at loadings down to 5 ppm. At the concentration of 0.05 mol% the catalyst permits an efficient reaction under base-free conditions.
- Ostrowska, Sylwia,Rogalski, Szymon,Lorkowski, Jan,Walkowiak, Jedrzej,Pietraszuk, Cezary
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supporting information
p. 1735 - 1740
(2018/07/21)
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- Iron(MCP) Complexes Catalyze Aziridination with Olefins As Limiting Reagents
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Herein described are the first efficient nitrogen-atom transfer reactions mediated by iron N,N′-dimethyl-N,N′-bis(2-pyridinylmethyl)cyclohexane-1,2-diamine- (MCP-) and 2-({1-[(pyridin-2-ylmethyl)pyrrolidin-2-yl]pyrrolidin-1-yl}methyl)pyridine-type (PDP-type) complexes. These catalysts affect styrene aziridination under mild conditions based on a limiting quantity of olefin substrate.
- Shehata, Mina F.,Ayer, Suraj K.,Roizen, Jennifer L.
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p. 5072 - 5081
(2018/05/15)
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- Fast, Efficient and Low E-Factor One-Pot Palladium-Catalyzed Cross-Coupling of (Hetero)Arenes
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The homocoupling of aryl halides and the heterocoupling of aryl halides with either aryl bromides or arenes bearing an ortho-lithiation directing group are presented. The use of a Pd catalyst, in combination with t-BuLi, allows for the rapid and efficient formation of a wide range of polyaromatic compounds in a one pot procedure bypassing the need for the separate preformation of an organometallic coupling partner. These polyaromatic structures are obtained in high yields, in 10 min at room temperature, with minimal waste generation (E-factors as low as 1.5) and without the need for strict inert conditions, making this process highly efficient and practical in comparison to classical methods. As illustration, several key intermediates of widely used BINOL-derived structures are readily prepared.
- Pinxterhuis, Erik B.,Visser, Paco,Esser, Iwan,Gualtierotti, Jean-Baptiste,Feringa, Ben L.
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supporting information
p. 9452 - 9455
(2017/10/23)
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- Nickel-Catalyzed Electrochemical Reductive Homocouplings of Aryl and Heteroaryl Halides: A Useful Route to Symmetrical Biaryls
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Due to their widespread presence in functional materials and pharmaceuticals, biaryls are of fundamental importance in organic chemistry. Methods for the synthesis of symmetrical biaryls generally involve both metallic reduction and transition-metal catalysis. In this work, we show that electroreduction can also constitute a very relevant way to achieve the nickel-catalyzed reductive synthesis of symmetrical biaryl compounds. Therefore, it is demonstrated that both aryl and heteroaryl halides undergo reductive coupling to furnish the corresponding symmetrical biaryls in fair to excellent yields. Reactions are performed under very mild conditions thus ensuring important functional group tolerance.
- Rahil, Rima,Sengmany, Stéphane,Le Gall, Erwan,Léonel, Eric
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p. 146 - 154
(2017/09/28)
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- Synthesis of dendrimer-type viologen and its use in Pd-mediated homocoupling of aryl halides
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Dendrimer-type viologen (V2+.D.) was prepared from mesitylene and 4.4′-bipyridyl. Electroreduction of V2+.D. gave the corresponding quinoid (V0.D.), which promoted Pd-catalyzed homocoupling of aryl bromides Ar-Br to give the corresponding biaryls Ar-Ar in moderate to good yields.
- Kuroboshi, Manabu,Kojima, Atsuki,Tanaka, Hideo
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p. 2132 - 2140
(2017/11/21)
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- Radical additions of acyclic and cyclic ethers to alkenes via an allyl transfer reaction involving phthalimido-N-oxyl radical
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Direct functionalization of rudimentary and cheap starting materials to yield complex value added products is of great interest to synthetic chemists. Particularly, direct functionalization of cheap commodity molecules that have been traditionally considered inert to known reactions are of widespread interest. We have previously demonstrated the functionalization of benzylic C–H bonds via an allyl transfer reaction using various allyl-phthalimido-N-oxyl substrates. In this work, we demonstrate the extension of our mild, metal-free, and neutral allyl transfer methodology to the direct functionalization of ethers. The C–H bond in α position to the ether oxygen in various acyclic and cyclic ethers was functionalized in high yields demonstrating wide substrate scope for this transformation. Furthermore, selective mono-functionalization of symmetrical cyclic ethers and regioselective functionalization of unsymmetrical ethers was achieved, thus demonstrating further utility of this reaction. Finally, kinetic chain length measurements were performed, which provided valuable insights into the initial rates and efficiency of the chain process involving the phthalimido-N-oxyl (PINO[rad]) radical.
- Patil, Shradha V.,Tanko, James M.
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p. 7849 - 7858
(2016/11/17)
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- Cobalt-Catalyzed Oxidative Homocoupling of Arylzinc Species
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A novel procedure for the synthesis of functionalized symmetrical biaryl compounds is described. The reaction proceeds via the oxidative homocoupling of arylzinc species formed by cobalt catalysis in the presence of air or p-benzoquinone depending on the nature of the functional group.
- Bourne-Branchu, Yann,Moncomble, Aurélien,Corpet, Martin,Danoun, Gregory,Gosmini, Corinne
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p. 3352 - 3356
(2016/09/12)
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- A symmetry biphenyltetrazole preparation method
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The invention provides a symmetric biphenyl preparation method which adopts aryl sulfinate as a substrate and palladium chloride as a catalyst for preparing the symmetric biphenyl through self-coupling reaction of aryl sulfinate. The preparation method provided by the invention does not need oxidant or additive, the reaction can be performed under a gentle condition, the reaction time is short, a product can be obtained through simple treatment, and the yield of the product is high.
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Paragraph 0036-0038
(2017/02/09)
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- Recyclable and reusable Pd(OAc)2/PPh3/PEG-2000 system for homocoupling reaction of arylboronic acids under air without base
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A stable and efficient Pd(OAc)2/PPh3/PEG-2000 catalytic system for homocoupling of arylboronic acids has been developed. In the presence of Pd(OAc)2 and PPh3, the homocoupling reaction of arylboronic acids was carried out smoothly in PEG-2000 at 70°C under air without base to afford a variety of symmetric biaryls in good to excellent yields. The isolation of the products was readily performed by extractionwith diethyl ether, and the Pd(OAc)2/PPh3/PEG-2000 systemcould be easily recycled and reused six times without significant loss of catalytic activity.
- Xia, Jianhui,Cheng, Mingzhu,Chen, Qiurong,Cai, Mingzhong
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p. 113 - 116
(2015/01/30)
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- Direct oxidative cyanation of tertiary amines promoted by in situ generated hypervalent iodine(III)-CN intermediate
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An environmentally benign and metal-free cyanation method of tertiary amines oxidated by hypervalent iodine(III) intermediate generated in situ from PIFA (or DIB) and TMSCN has been developed. A variety of substituent groups on amines are tolerated to the oxidation of α-C-H bond to form C-C bond in the absence of metal catalysts with yields of up to 74%.
- Shen, Hang,Zhang, Xiaohui,Liu, Qing,Pan, Jing,Hu, Wen,Xiong, Yan,Zhu, Xiangming
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supporting information
p. 5628 - 5631
(2015/09/21)
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- The coupling reactions of aryl halides and phenols catalyzed by palladium and MOP-type ligands
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Palladium-catalyzed coupling reactions of aryl halides and phenols are described employing the bulky and electron-rich MOP-type ligands. When K3PO4 was used as base and toluene as solvent, the catalyst system exhibited high efficiency for the coupling reaction of the activated aryl halides. When NaH was used as base and o-xylene as solvent, unactivated aryl halides can be used as substrates.
- Zhang, Yi,Ni, Gang,Li, Chengjun,Xu, Sheng,Zhang, Zhaoguo,Xie, Xiaomin
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p. 4927 - 4932
(2015/06/23)
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- Redox inactive metal ion triggered N-dealkylation by an iron catalyst with dioxygen activation: A lesson from lipoxygenases
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Utilization of dioxygen as the terminal oxidant at ambient temperature is always a challenge in redox chemistry, because it is hard to oxidize a stable redox metal ion like iron(iii) to its high oxidation state to initialize the catalytic cycle. Inspired by the dioxygenation and co-oxidase activity of lipoxygenases, herein, we introduce an alternative protocol to activate the sluggish iron(iii) species with non-redox metal ions, which can promote its oxidizing power to facilitate substrate oxidation with dioxygen, thus initializing the catalytic cycle. In oxidations of N,N-dimethylaniline and its analogues, adding Zn(OTf)2 to the [Fe(TPA)Cl2]Cl catalyst can trigger the amine oxidation with dioxygen, whereas [Fe(TPA)Cl2]Cl alone is very sluggish. In stoichiometric oxidations, it has also been confirmed that the presence of Zn(OTf)2 can apparently improve the electron transfer capability of the [Fe(TPA)Cl2]Cl complex. Experiments using different types of substrates as trapping reagents disclosed that the iron(iv) species does not occur in the catalytic cycle, suggesting that oxidation of amines is initialized by electron transfer rather than hydrogen abstraction. Combined experiments from UV-Vis, high resolution mass spectrometry, electrochemistry, EPR and oxidation kinetics support that the improved electron transfer ability of iron(iii) species originates from its interaction with added Lewis acids like Zn2+ through a plausible chloride or OTf- bridge, which has promoted the redox potential of iron(iii) species. The amine oxidation mechanism was also discussed based on the available data, which resembles the co-oxidase activity of lipoxygenases in oxidative dealkylation of xenobiotic metabolisms where an external electron donor is not essential for dioxygen activation.
- Zhang, Jisheng,Wang, Yujuan,Luo, Nengchao,Chen, Zhuqi,Wu, Kangbing,Yin, Guochuan
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p. 9847 - 9859
(2015/06/08)
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- A general method for N-methylation of amines and nitro compounds with dimethylsulfoxide
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DMSO methylates a broad range of amines in the presence of formic acid, providing a novel, green and practical method for amine methylation. The protocol also allows the one-pot transformation of aromatic nitro compounds into dimethylated amines in the presence of a simple iron catalyst. Not just a solvent: DMSO methylates a broad range of amines in the presence of formic acid, providing a novel, green and practical method for amine methylation. The protocol also allows the one-pot transformation of aromatic nitro compounds into dimethylated amines in the presence of a simple iron catalyst. Copyright
- Jiang, Xue,Wang, Chao,Wei, Yawen,Xue, Dong,Liu, Zhaotie,Xiao, Jianliang
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supporting information
p. 58 - 63
(2014/01/17)
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- Quinonediimine-induced oxidative coupling of organomagnesium reagents
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N,N′-Diphenyl-p-benzoquinonediimine, a redox-active unit of polyaniline, efficiently induced the oxidative homocoupling of various aryl- and vinylmagnesium reagents in suppressing the side reactions, such as 1,2- or 1,4-addition reaction. Copyright
- Amaya, Toru,Suzuki, Riyo,Hirao, Toshikazu
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p. 653 - 656
(2014/01/23)
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- Palladium catalytic systems with hybrid pyrazole ligands in C-C coupling reactions. Nanoparticles versus molecular complexes
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This paper reports the comparison of the chemoselectivity of two different Pd catalytic systems, namely molecular and colloidal systems, in C-C coupling reactions. For this purpose, new hybrid pyrazole derived ligands containing alkylether, alkylthioether or alkylamino moieties have been synthesized and used to form Pd(ii) complexes and to stabilize Pd nanoparticles (Pd NPs). With the aim of studying the coordination mode of the ligands and further to understand their role in catalysis, both types of Pd species were characterized by appropriate techniques. In C-C coupling reactions promoted by different Pd colloidal systems, several reports evidenced that active species are molecular catalysts leached from Pd NPs. The most important feature of this work relies on the differences observed in the output of C-C coupling reactions, depending on the colloidal or molecular nature of the catalyst employed. Thus, molecular systems carry out typical Suzuki-Miyaura cross-coupling, together with the dehalogenation of the substrate in different proportions. In contrast, Pd NPs catalyze either Suzuki-Miyaura or C-C homocoupling reactions depending on the haloderivative used. Interestingly, Pd NPs catalyze the quantitative dehalogenation of 4-iodotoluene. Differences observed in the chemoselectivity of these two catalytic systems support that reactions carried out with Pd NPs stabilized with the hybrid pyrazole ligands employed here take place on the surface of the colloids. The Royal Society of Chemistry 2013.
- Peral, Daniel,Gomez-Villarraga, Fernando,Sala, Xavier,Pons, Josefina,Carles Bayon,Ros, Josep,Guerrero, Miguel,Vendier, Laure,Lecante, Pierre,Garcia-Anton, Jordi,Philippot, Karine
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p. 475 - 489
(2013/03/14)
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- Synthesis of benzidine derivatives via FeCl3·6H 2O-promoted oxidative coupling of anilines
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Under open-flask conditions in the presence of commercially available FeCl3·6H2O, N,N-disubstituted anilines can be converted into diversely functionalized benzidines with yields of up to 99%. Oxidative coupling was extended to N-monosubstituted anilines, and the method was applied to the efficient preparation of 6,6′-biquinoline. Mechanistic investigations have also been performed to explain the observed reactivities.
- Ling, Xuege,Xiong, Yan,Huang, Ruofeng,Zhang, Xiaohui,Zhang, Shuting,Chen, Changguo
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supporting information
p. 5218 - 5226
(2013/07/25)
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- Synthesis of N,N,N',N'-tetraalkylbenzidines through oxidative coupling of N,N-dialkylarylamines induced by SbCl5
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The oxidative coupling to 4,4'-N,N,N',N'-tetraalkylbenzidines is the main reaction observed during a study on the reactivity of N,N-dialkylanilines with SbCl5. A possible reaction mechanism is presented and discussed in comparison with the N,N-dialkylanilines oxidative coupling achieved with other Lewis acids. ARKAT-USA, Inc.
- Vitale, Paola,Di Nunno, Leonardo,Scilimati, Antonio
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- Iron-catalyzed homocoupling of aryl halides and derivatives in the presence of alkyllithiums
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Direct synthesis of biaryl derivatives from aryl halides takes place under very mild temperature conditions by using a ligand-free iron catalytic system. The procedure, which proceeds via an in situ quantitative aryl halide exchange with alkyllithiums, allows for excellent control of the reactivity and is in line with the sustainable development. The method is also applicable to styryl and benzyl halides and to phenylacetylene.
- Toummini, Dounia,Ouazzani, Fouad,Taillefer, Marc
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supporting information
p. 4690 - 4693
(2013/10/08)
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- Amphiphilic viologen: Electrochemical generation of organic reductant and pd-catalyzed reductive coupling of aryl halides in water
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Electroreduction of 1,1′-bis(methoxyethoxyethoxyethyl)-4,4′- bipyridinium tosylate generated amphiphilic organic reductants, which promoted the Pd-catalyzed reductive coupling of aryl bromides in water to give the corresponding biaryls. The yields and selectivity of biaryls depended on the length of ethyleneoxy groups and substituents of the aryl bromides. Georg Thieme Verlag Stuttgart · New York.
- Kuroboshi, Manabu,Yamamoto, Takashi,Tanaka, Hideo
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p. 197 - 200
(2013/03/14)
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- The homocoupling of arylsulfonylhydrazides by palladium-catalysed desulfonation in air
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A simple and efficient preparation of biaryl derivatives from arylsulfonyl hydrazides has been developed using Pd(OAc)2 as the catalyst in a mixed solvent of DMA and THF and without the use of any ligand and base.
- Zhang, Wei,Zhao, Baoli,Li, Ke
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p. 674 - 676
(2014/01/17)
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- Electrophilic fluorination of N,N-dimethylaniline, N,N-dimethylnaphthalen- 1-amine and 1,8-bis(dimethylamino)naphthalene with N-F reagents
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Reaction of N,N-dimethylaniline, N,N-dimethylnaphthalen-1-amine and 1,8-bis(dimethylamino)- naphthalene (proton sponge) with 1-chloromethyl-4- fluorodiazonia-bicyclo[2.2.2]octane bis(tetrafluoroborate) (Selectfluor) and N-fluorobenzenesulfonimide (NFSI) h
- Sorokin, Vladimir I.,Pozharskii, Alexander F.,Ozeryanskii, Valery A.
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- Oxidant-dependent Cu-catalyzed alkynylation and aminomethylation: C-H versus C-C cleavage in TMEDA
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Oxidant-dependent Cu-catalyzed alkynylation and aminomethylation reactions have been achieved under facile and mild conditions. TMEDA coupled with various terminal alkynes via C-H bond cleavage in good yields using atmospheric oxygen as an oxidant. Switching from air to TBHP afforded aminomethylation products of terminal alkynes through C-C bond cleavage of TMEDA. The protocol provided a novel strategy to prepare bi/tridentate N-ligand.
- Shen, Qi,Zhang, Lei,Zhou, Yu-Ren,Li, Jian-Xin
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p. 6725 - 6728
(2013/11/19)
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- Ultrasound induced, copper mediated homocoupling using polymer supported aryltrifluoroborates
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Using Dowex polymer supported aryltrifluoroborates, we are able to achieve homocoupling for a variety of compounds. The reactions were completed in 6 h, while producing high yields of the desired products. The reaction proceeds under mild conditions, using ultrasound as the energy source, copper acetate as the metal co-reactant, and aqueous ethanol as solvent.
- Musolino, Bryan,Quinn, Michael,Hall, Kelly,Coltuclu, Vitali,Kabalka, George W.
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p. 4080 - 4082
(2013/07/25)
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- Replacing conventional carbon nucleophiles with electrophiles: Nickel-catalyzed reductive alkylation of aryl bromides and chlorides
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A general method is presented for the synthesis of alkylated arenes by the chemoselective combination of two electrophilic carbons. Under the optimized conditions, a variety of aryl and vinyl bromides are reductively coupled with alkyl bromides in high yields. Under similar conditions, activated aryl chlorides can also be coupled with bromoalkanes. The protocols are highly functional-group tolerant (-OH, -NHTs, -OAc, -OTs, -OTf, -COMe, -NHBoc, -NHCbz, -CN, -SO2Me), and the reactions are assembled on the benchtop with no special precautions to exclude air or moisture. The reaction displays different chemoselectivity than conventional cross-coupling reactions, such as the Suzuki-Miyaura, Stille, and Hiyama-Denmark reactions. Substrates bearing both an electrophilic and nucleophilic carbon result in selective coupling at the electrophilic carbon (R-X) and no reaction at the nucleophilic carbon (R-[M]) for organoboron (-Bpin), organotin (-SnMe3), and organosilicon (-SiMe2OH) containing organic halides (X-R-[M]). A Hammett study showed a linear correlation of σ and σ(-) parameters with the relative rate of reaction of substituted aryl bromides with bromoalkanes. The small ρ values for these correlations (1.2-1.7) indicate that oxidative addition of the bromoarene is not the turnover-frequency determining step. The rate of reaction has a positive dependence on the concentration of alkyl bromide and catalyst, no dependence upon the amount of zinc (reducing agent), and an inverse dependence upon aryl halide concentration. These results and studies with an organic reductant (TDAE) argue against the intermediacy of organozinc reagents.
- Everson, Daniel A.,Jones, Brittany A.,Weix, Daniel J.
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supporting information; experimental part
p. 6146 - 6159
(2012/05/07)
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- FeCl3 catalyzed barbier homocoupling reaction for synthesis of symmetric biaryls
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Aseries of biaryls and biheteroaryls were synthesized by the Barbier reaction of aryl bromide withmagnesium powder and 1,2-dibromoethane in the presence of FeCl3 in THF under reflux reaction condition. The catalytic system differentiates itself fromother homocoupling reactions catalyzed by iron salts in that it requires neither the preliminary preparation of Grignard reagent nor the addition of an oxidant.
- Lee, Adam Shih-Yuan,Chen, Pin-Lung,Chang, Yu-Ting,Tsai, Heng-Tser
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experimental part
p. 452 - 454
(2012/07/03)
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- Nickel-catalyzed synthesis of diarylamines via oxidatively induced C-N bond formation at room temperature
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A nickel-catalyzed oxidative coupling of zinc amides with organomagnesium compounds selectively produces diarylamines under mild reaction conditions, with tolerance for chloride, bromide, hydroxyl, ester, and ketone groups. A diamine is bis-monoarylated. A bromoaniline undergoes N-arylation followed by Kumada-Tamao-Corriu coupling in one pot. The reaction may proceed via oxidatively induced reductive elimination of a nickel species.
- Ilies, Laurean,Matsubara, Tatsuaki,Nakamura, Eiichi
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supporting information
p. 5570 - 5573,4
(2012/12/12)
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- Cobalt-xantphos-catalyzed, LiCl-mediated preparation of arylzinc reagents from aryl iodides, bromides, and chlorides
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A cobalt-Xantphos-catalyzed, LiCl-mediated system has been developed for the direct and expedient preparation of arylzinc reagents in THF from the corresponding aryl iodides, bromides, and chlorides. Owing to the use of THF as a versatile solvent, the thus-formed arylzinc reagents displayed a high degree of compatibility with a variety of conventional as well as newly emerging metal-catalyzed cross-coupling reactions.
- Jin, Meng-Yi,Yoshikai, Naohiko
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experimental part
p. 1972 - 1978
(2011/05/19)
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- Palladium(II) complexes of Y,C,Y-chelated phosphines: Synthesis, structure, and catalytic activity in Suzuki-Miyaura reaction
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The phosphines L1PPh2 (1) and L2PPh 2 (2) containing different Y,C,Y-chelating ligands, L1 = 2,6-(tBuOCH2)2C6H3 - and L2 = 2,6-(Me2NCH2) 2C6H3-, were treated with PdCl 2 and di-Aμ-chloro-bis[2-[(N,N-dimethylamino)methyl]phenyl- C,N]-dipalladium(II) and yielded complexes trans-{[2,6-(tBuOCH 2)2C6H3]PPh2} 2PdCl2 (3), {[2,6-(Me2NCH2) 2C6H3]PPh2} PdCl2 (4), {[2,6-(tBuOCH2)2C6H 3]PPh2}Pd(Cl)[2-(Me2NCH2)C 6H4] (5) and {[2,6-(Me2NCH2) 2C6H3]PPh2}Pd(Cl)[2-(Me 2NCH2)C6H4] (6) as the result of different ability of starting phosphines 1 and 2 to complex PdCl2. Compounds 3-6 were characterized by 1H, 13C, 31P NMR spectroscopy and ESI-MS. The molecular structures of 3,4 and 6 were also determined by X-ray diffraction analysis. The catalytic activity of complexes 3-6 was evaluated in the Suzuki-Miyaura cross-coupling reaction.
- Reznicek, Tomas,Dostal, Libor,Ruzicka, Ales,Kulhanek, Jiri,Bures, Filip,Jambor, Roman
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experimental part
p. 173 - 179
(2012/04/23)
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- Negishi cross-coupling reaction catalyzed by an aliphatic, phosphine based pincer complex of palladium. biaryl formation via cationic pincer-type Pd IV intermediates
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The aliphatic, phosphine-based pincer complex [(C10H 13-1,3-(CH2P(Cy2)2)Pd(Cl)] (1) is a highly active Negishi catalyst, enable to quantitatively couple various electronically activated, non-activated, deactivated, sterically hindered and functionalized aryl bromides with various diarylzinc reagents within short reaction times and low catalyst loadings. Experimental observations strongly indicate that a molecular mechanism is operative with initial chloride dissociation of 1 and formation of the cationic T-shaped 14e- complex [(C10H13-1,3-(CH2P(C6H 11)2)2)Pd]+ (B), which undergoes oxidative addition of an aryl bromide (Ar′Br) to yield the cationic, penta-coordinated aryl bromide pincer complexes of type [(C10H 13-1,3-(CH2P(Cy2)2)Pd(Br) (aryl′)]+ (C) with the metal center in the oxidation state of +IV and the aryl unit in cis position relative to the aliphatic pincer core. Subsequent transmetalation with Zn(aryl)2 result in the cationic diaryl pincer complexes of type [(C10H13-1,3-(CH 2P(Cy2)2)Pd(aryl)(aryl′)]+ (D), which reductively eliminate the coupling products, thereby regenerating the catalyst. The neutral square planar aryl pincer complex - a possible key intermediate in the catalytic cycle - was found to be reversibly formed in the reaction mixture but is not involved in the catalytic mechanism. Similarly, palladium nanoparticles as the catalytically active form of 1 could have been excluded. The Royal Society of Chemistry 2011.
- Gerber, Roman,Blacque, Olivier,Frech, Christian M.
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experimental part
p. 8996 - 9003
(2011/10/31)
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- OXIDATIVE HOMO-COUPLING REACTIONS OF ARYL BORONIC ACIDS USING A POROUS COPPER METAL-ORGANIC FRAMEWORK AS A HIGHLY EFFICIENT HETEROGENEOUS CATALYST
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The disclosure provides methods for the use of open metal frameworks to synthesize biaryls comprising contacting a metal organic framework (MOF) or metal organic polyhedral (MOP) with an aryl boronic acid compound under conditions wherein the MOF or MOP catalyze the synthesis of the biaryl through a homo-coupling reaction.
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Page/Page column 23-28
(2011/02/24)
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- Oxidative coupling of N,N-Dialkylanilines using iodic acid and sodium nitrite
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A new reagent system, a combination of iodic acid and sodium nitrite has been investigated for oxidative coupling of N,N-disubstituted anilines. A facile para-selective coupling occurs to give benzidines at room temperature in water as a solvent. A tentative mechanism is proposed with some supporting experiments.
- Huddar, Sameerana N.,Mahajan, Ulhas S.,Akamanchi, Krishnacharya G.
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experimental part
p. 808 - 809
(2011/01/07)
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- Pd/TEMPO-catalyzed electrooxidative synthesis of biaryls from arylboronic acids or arylboronic esters
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A facile electrooxidative method for synthesizing biaryls from arylboronic acids or arylboronic esters is described. In the presence of a catalytic amount of Pd(OAc)2 and TEMPO, the electrooxidation of arylboronic acids or arylboronates gave the corresponding biaryls in moderate to excellent yields.
- Mitsudo, Koichi,Shiraga, Takuya,Kagen, Daisuke,Shi, Deqing,Becker, James Y.,Tanaka, Hideo
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supporting information; experimental part
p. 8384 - 8388
(2009/12/24)
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- Homocoupling of arylboronic acids catalyzed by 1,10-phenanthroline-ligated copper complexes in air
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The efficient homocoupling of arylboronic acids was achieved by using the catalytic combination of inexpensive copper salts and 1,10-phenanthroline as aligand. The homocoupling reaction proceeds at ambient temperature in air without any additives such as base or oxidant. This method tolerates various substituents on the arylboronic acids such as halogens, carbonyls, and a nitro group. As a result, 25 symmetrical biaryls were obtained from readily available arylboronic acids in 19-92% isolated yields. A binuclear (μ- hydroxido)copper complex is assumed as the catalytically active species, which undergoes efficient transmetalation with arylboronic acids to produce dinuclear arylcopper complexes. The binuclear structure is assumed to be essential for the bimetallic reductive elimination of biaryls as well as the oxidative restoration of the catalyst. Wiley-VCH Verlag GmbH & Co, KGaA.
- Kirai, Naohiro,Yamamoto, Yoshihiko
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experimental part
p. 1864 - 1867
(2009/08/17)
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- Direct cobalt-catalyzed cross-coupling between aryl and alkyl halides
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An operationally simple cross-coupling reaction between aryl halides and alkyl halides with high selectivity has been developed. The underlying domino process utilizes CoCl2/Me4-DACH as a catalyst system. The methodology exhibits hig
- Czaplik, Waldemar Maximilian,Mayer, Matthias,Jacobi Von Wangelin, Axel
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experimental part
p. 2931 - 2934
(2010/01/21)
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- Thieme journal awardees - Where are they now? on cobalt-catalyzed biaryl coupling reactions
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An operationally simple biaryl coupling reaction has been developed. The underlying domino process involves in situ Grignard formation from aryl bromides and subsequent homocoupling with catalytic CoCl2 and 1 bar synthetic air as terminal oxidant. Georg Thieme Verlag Stuttgart.
- Mayer, Matthias,Czaplik, Waldemar Maximilian,Jacobi Von Wangelin, Axel
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experimental part
p. 2919 - 2923
(2010/01/21)
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- Manganese-catalyzed oxidative homo-coupling of aryl Grignard chlorides
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Manganese-catalyzed homo-coupling of aryl magnesium chlorides to give biphenyls was successfully achieved using manganese chloride as catalyst. A variety of aryl magnesium chlorides were efficiently converted into the corresponding symmetrical biaryls using 10 mol% MnCl2 as catalyst in the presence of a stoichiometric amount of 1,2-dichloroethane. Since the aryl chlorides, from which the Grignard reagents were prepared, are cheaper and more readily available that the corresponding bromides and iodides this procedure should become the method of choice for preparing symmetrical biaryls.
- Zhou, Zhiming,Xue, Weizhe
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supporting information; experimental part
p. 599 - 603
(2009/05/30)
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- Cobalt-catalyzed formation of symmetrical biaryls and its mechanism
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A method for cobalt-catalyzed formation of symmetrical biaryls and mechanism used for the formation, were reported. The study involved a new cobalt-catalyzed homo-coupling reaction in which cobalt was used with manganese dust as reducing agent. It was observed that the presence of allylchloride significantly reduced the amount of reduction compounds without modifying kinetics of the reactions and the reaction remained un-affected by the presence of air as oxidant. It was also found that no-reactions occurred in DMF, THF, and toluene in the presence of pyridine as co-solvent at room temperature, which indicated that MeCN acted as a ligand of the cobalt active species. The coupling process can be extended to less reactive aryl chlorides by changing some experimental conditions. DFT calculations revealed that the involvement of a CoI/CoIII couple was realistic in the case of 1,3-diazadienes as ligands.
- Moncomble, Aurelien,Floch, Pascal Le,Gosmini, Corinne
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supporting information; experimental part
p. 4770 - 4774
(2009/12/05)
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- Transition-metal-free oxidative homocoupling of aryl, alkenyl, and alkynyl Grignard reagents with TEMPO
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Oxidative homocoupling of aryl, alkenyl, and alkynyl Grignard reagents by using commercially available TEMPO as an organic oxidant is described. These coupling reactions occur highly efficiently without the presence of any transition metal. Georg Thieme Verlag Stuttgart.
- Maji, Modhu Sudan,Studer, Armido
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experimental part
p. 2467 - 2470
(2010/01/14)
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- Preparation, structure, and reactivity of nonstabilized organoiron compounds. Implications for iron-catalyzed cross coupling reactions
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A series of unprecedented organoiron complexes of the formal oxidation states -2, 0, +1, +2, and +3 is presented, which are largely devoid of stabilizing ligands and, in part, also electronically unsaturated (14-, 16-, 17- and 18-electron counts). Specifically, it is shown that nucleophiles unable to undergo β-hydride elimination, such as MeLi, PhLi, or PhMgBr, rapidly reduce Fe(3+) to Fe(2+) and then exhaustively alkylate the metal center. The resulting homoleptic organoferrate complexes [(Me4Fe)(MeLi)] [Li(OEt2)]2 (3) and [Ph4Fe][Li(Et 2O)2][Li(1,4-dioxane)] (5) could be characterized by X-ray crystal structure analysis. However, these exceptionally sensitive compounds turned out to be only moderately nucleophilic, transferring their organic ligands to activated electrophiles only, while being unable to alkylate (hetero)aryl halides unless they are very electron deficient. In striking contrast, Grignard reagents bearing alkyl residues amenable to β-hydride elimination reduce FeXn (n = 2, 3) to clusters of the formal composition [Fe(MgX)2]n. The behavior of these intermetallic species can be emulated by structurally well-defined lithium ferrate complexes of the type [Fe(C2H4) 4][Li(tmeda)]2 (8), [Fe(cod)2][Li(dme)] 2 (9), [CpFe(C2H4)2][Li(tmeda)] (7), [CpFe(cod)][Li(dme)] (11), or [Cp*Fe(C2H4) 2][Li(tmeda)] (14). Such electron-rich complexes, which are distinguished by short intermetallic Fe-Li bonds, were shown to react with aryl chlorides and allyl halides; the structures and reactivity patterns of the resulting organoiron compounds provide first insights into the elementary steps of low valent iron-catalyzed cross coupling reactions of aryl, alkyl, allyl, benzyl, and propargyl halides with organomagnesium reagents. However, the acquired data suggest that such C-C bond formations can occur, a priori, along different catalytic cycles shuttling between metal centers of the formal oxidation states Fe(+1)/Fe(+3), Fe(0)/Fe(+2), and Fe(-2)/Fe(0). Since these different manifolds are likely interconnected, an unambiguous decision as to which redox cycle dominates in solution remains difficult, even though iron complexes of the lowest accessible formal oxidation states promote the reactions most effectively.
- Fuerstner, Alois,Martin, Ruben,Krause, Helga,Seidel, Guenter,Goddard, Richard,Lehmann, Christian W.
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p. 8773 - 8787
(2008/12/23)
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