- Miniaturized catalysis: monolithic, highly porous, large surface area capillary flow reactors constructed in situ from polyhedral oligomeric silsesquioxanes (POSS)
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A single-step molding process utilizing free-radical cross-linking reaction of vinyl POSS in microliter-sized dimensions leads to hierarchically-structured, mechanically robust, porous hybrid structures. Functional variants show excellent performance in Suzuki-type coupling reactions. Due to their small volume, long-term operational robustness, and potential chemical diversity, these materials are promising candidates for catalyst screening applications.
- Scholder,Nischang
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Read Online
- N-Aroylsulfonamide-Photofragmentation (ASAP)-A Versatile Route to Biaryls
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The photochemical fragmentation of N-aroylsulfonamides 9 (ASAP) is a powerful method for the preparation of various biaryls. Compounds 9 are easily accessible in two steps from amines by treatment with arenesulfonyl chlorides and aroyl chlorides. Many of these compounds were prepared for the first time. The irradiation takes place in a previously developed continuous-flow reactor using inexpensive UVB or UVC fluorescent lamps. Isocyanates and sulphur dioxide are formed as the only by-products. The ASAP tolerates a variety of functional groups and is even suited for the preparation of phenylnaphthalenes and terphenyls. The ASAP mechanism was elucidated by interaction of photophysical and quantum chemical (DFT) methods and revealed a spirocyclic biradical as key intermediate.
- Wessig, Pablo,Krebs, Saskia
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supporting information
p. 6367 - 6374
(2021/09/29)
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- Micellar catalysis of the Suzuki Miyaura reaction using biogenic Pd nanoparticles fromDesulfovibrio alaskensis
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Microorganisms produce metal nanoparticles (MNPs) upon exposure to toxic metal ions. However, the catalytic activity of biosynthesised MNPs remains underexplored, despite the potential of these biological processes to be used for the sustainable recovery of critical metals, including palladium. Herein we report that biogenic palladium nanoparticles generated by the sulfate-reducing bacteriumDesulfovibrio alaskensisG20 catalyse the ligand-free Suzuki Miyaura reaction of abiotic substrates. The reaction is highly efficient (>99% yield, 0.5 mol% Pd), occurs under mild conditions (37 °C, aqueous media) and can be accelerated within biocompatible micelles at the cell membrane to yield products containing challenging biaryl bonds. This work highlights how native metabolic processes in anaerobic bacteria can be combined with green chemical technologies to produce highly efficient catalytic reactions for use in sustainable organic synthesis.
- Dennis, Jonathan A.,Era, Yuta,Horsfall, Louise E.,Wallace, Stephen
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supporting information
p. 8886 - 8890
(2021/11/23)
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- Cobalt-catalyzed C(sp2)?CN bond activation: Cross-electrophile coupling for biaryl formation and mechanistic insight
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Herein, we report a cross-electrophile coupling of benzonitrile derivatives and aryl halides with a simple cobalt-based catalytic system under mild conditions to form biaryl compounds. Even though the cobalt catalyst is able to activate the C(sp2)?CN bond alone, the use of the AlMe3 Lewis acid enhances the reactivity of benzonitriles and improves the cross-selectivity with barely any influence on the functional group compatibility. X-ray structure determination of an original low-valent cobalt species combined with catalytic and stoichiometric reactions reveals a catalytically active cobalt(I) species toward the aryl halide partner. On the other hand, experimental insights, including cyclic voltammetry experiments, suggest the involvement of a cobalt complex of a lower oxidation state to activate the benzonitrile derivative. Finally, density functional theory calculations support the proposed mechanistic cycle involving two low-valent cobalt species of different oxidation states to perform the reaction.
- Dorval, Céline,Tricoire, Maxime,Begouin, Jeanne-Marie,Gandon, Vincent,Gosmini, Corinne
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p. 12819 - 12827
(2020/11/18)
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- para-Selective arylation and alkenylation of monosubstituted arenes using thianthreneS-oxide as a transient mediator
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Using thianthreneS-oxide (TTSO) as a transient mediator,para-arylation and alkenylation of mono-substituted arenes have been demonstratedviaapara-selective thianthrenation/Pd-catalyzed thio-Suzuki-Miyaura coupling sequence under mild conditions. This reaction features a broad substrate scope, and functional group and heterocycle tolerance. The versatility of this approach was further demonstrated by late-stage functionalization of complex bioactive scaffolds, and direct synthesis of some pharmaceuticals, including Tetriprofen, Ibuprofen, Bifonazole, and LJ570.
- Chen, Xiao-Yue,Nie, Xiao-Xue,Wu, Yichen,Wang, Peng
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supporting information
p. 5058 - 5061
(2020/05/18)
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- Preparation method of para-substituted aryl compound
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The invention discloses a preparation method of a para-substituted aryl compound shown as a formula (I) which is described in the specfication. The preparation method is characterized by comprising the following step of: subjecting an aryl sulfonium salt shown as a formula (II) which is described in the specfication and boride to a coupling reaction in a solvent in an inert atmosphere under the action of alkali and a palladium catalyst to obtain the para-substituted aryl compound. According to the method, mono-substituted aromatic hydrocarbon is taken as a substrate, the aryl sulfonium salt isconstructed in situ, and the palladium catalyst catalyzes the aryl sulfonium salt constructed in situ to undergo the Suzuki-Miyaura coupling reaction, so a mono-substituted aromatic hydrocarbon para-arylation or alkenylation product is constructed quickly and efficiently. The method is mild in conditions, high in substrate universality and wide in tolerance of a heterocyclic coupling substrate.
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Paragraph 0151-0165; 0212-0220
(2020/06/09)
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- Nickel versus Palladium in Cross-Coupling Catalysis: On the Role of Substrate Coordination to Zerovalent Metal Complexes
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A detailed comparison of the effect of coordinating functional groups on the performance of Suzuki-Miyaura reactions catalysed by nickel and palladium is reported, using competition experiments, robustness screening, and density functional theory calculations. Nickel can interact with a variety of functional groups, which manifests as selectivity in competitive cross-coupling reactions. The presence of these functional groups on exogenous additives has effects on cross-coupling reactions that range from a slight improvement in yield to the complete cessation of the reaction. In contrast, palladium does not interact sufficiently strongly with these functional groups to induce selectivity in cross-coupling reactions; the selectivity of palladium-catalysed cross-coupling reactions is predominantly governed by aryl halide electronic properties.
- Burton, Paul M.,Cooper, Alasdair K.,Nelson, David J.
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p. 565 - 573
(2020/02/13)
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- Dual Nickel-/Palladium-Catalyzed Reductive Cross-Coupling Reactions between Two Phenol Derivatives
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Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance of phenols. Here, we report a dual nickel-/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2′-disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allows for straightforward late-stage functionalization, illustrated with examples such as ezetimibe and tyrosine.
- Xiong, Baojian,Li, Yue,Wei, Yin,Kramer, S?ren,Lian, Zhong
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supporting information
p. 6334 - 6338
(2020/09/02)
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- meta-Selective C?H Arylation of Fluoroarenes and Simple Arenes
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Fluorine is known to promote ortho-C?H metalation. Based upon this reactivity, we employed an activated norbornene that traps the ortho-palladation intermediate and is then relayed to the meta position, leading to meta-selective C?H arylation of fluoroarenes. Deuterium experiment suggests that this meta-arylation is initiated by ortho C?H activation and the catalytic cycle is terminated by C-2 protonation. A dual-ligand system is crucial for the observed high reactivity and site selectivity. Applying this approach to simple benzene or other arenes also affords arylation products with good yield and site selectivity.
- Liu, Luo-Yan,Qiao, Jennifer X.,Yeung, Kap-Sun,Ewing, William R.,Yu, Jin-Quan
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supporting information
p. 13831 - 13835
(2020/07/13)
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- METHOD FOR THE METAL-FREE PREPARATION OF A BIARYL BY A PHOTOSPLICING REACTION AND THEIR USES
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The present invention relates to a method for the metal-free preparation of a biaryl compound by a photosplicing reaction and its use in the preparation of chemical compounds, preferably of active ingredients e.g. in the fields of pharmaceuticals and agrochemicals. In particular, it refers to a method for the regiocontrolled preparation of a biaryl compound of formula (I): Ar-Ar' by photochemically reacting a precursor compound of formula (II): Ar-L-Ar' to form a biaryl compound of general formula: Ar-L-Ar' (II) → Ar-Ar' (I) wherein Ar and Ar', independently of each other, represent an unsubstituted or substituted C6-C20 aryl group or a heteroaryl group with 5–20 ring atoms selected from carbon, nitrogen, oxygen and sulfur, and L represents a group –X–Y–Z– as defined herein. The biaryl compounds are generally suitable as intermediates or key building blocks in a very broad spectrum of organic chemical syntheses and their respective utilities. Their use within the field of synthesis of active ingredients is an aspect of the invention, and their use in the preparation of pharmaceutically active ingredients is particularly preferred.
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Page/Page column 39; 41; 42
(2019/06/11)
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- Metal-Free Aryl Cross-Coupling Directed by Traceless Linkers
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The metal-free, highly selective synthesis of biaryls poses a major challenge in organic synthesis. The scope and mechanism of a promising new approach to (hetero)biaryls by the photochemical fusion of aryl substituents tethered to a traceless sulfonamide linker (photosplicing) are reported. Interrogating photosplicing with varying reaction conditions and comparison of diverse synthetic probes (40 examples, including a suite of heterocycles) showed that the reaction has a surprisingly broad scope and involves neither metals nor radicals. Quantum chemical calculations revealed that the C?C bond is formed by an intramolecular photochemical process that involves an excited singlet state and traversal of a five-membered transition state, and thus consistent ipso–ipso coupling results. These results demonstrate that photosplicing is a unique aryl cross-coupling method in the excited state that can be applied to synthesize a broad range of biaryls.
- Haensch, Veit G.,Neuwirth, Toni,Steinmetzer, Johannes,Kloss, Florian,Beckert, Rainer,Gr?fe, Stefanie,Kupfer, Stephan,Hertweck, Christian
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p. 16068 - 16073
(2019/11/28)
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- Metal-Free Synthesis of Pharmaceutically Important Biaryls by Photosplicing
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Many pharmaceuticals feature biaryl motifs that are crucial for their binding to the target. Yet, benchmark methods for selective cross-couplings rely on highly toxic heavy metal catalysts, which are unfavorable in the synthesis of pharmaceuticals. Metal-free coupling reactions, on the other hand, may require harsh conditions and lack selectivity. We report a novel, metal-free cross-coupling reaction that involves the tethering of two phenyl groups by a temporary, traceless sulfonamide linker that directs a photochemical aryl fusion into a single coupling product. The perfect regio- and chemoselectivity of the reaction could be rationalized by a cyclic intermediate, which fragments into the biaryl and volatile side products. Using a flow reactor, we synthesized numerous substituted biaryl building blocks for important therapeutics in high yields, such as antibiotics, antitumor, neuroprotective and cholesterol-lowering agents as well as antiarthritic non-steroidal antiinflammatory drugs (NSAIDs). The new method was successfully employed in a total synthesis of cannabinol, an important analgesic and antiemetic therapeutic. We also report a metal-free synthesis of key building blocks used for the preparation of sartans, antihypertensive agents that rank among the top blockbuster drugs worldwide. This safe and convenient protocol is a valuable alternative for the widely used metal-dependent aryl cross-coupling methods.
- Kloss, Florian,Neuwirth, Toni,Haensch, Veit G.,Hertweck, Christian
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supporting information
p. 14476 - 14481
(2018/09/06)
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- Cyrene as a Bio-Based Solvent for the Suzuki-Miyaura Cross-Coupling
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The Suzuki-Miyaura (SM) cross-coupling is the most broadly utilized Pd-catalyzed C-C bond-forming reaction in the chemical industry. A large proportion of SM couplings employ dipolar aprotic solvents; however, current sustainability initiatives and increasingly stringent regulations advocate the use of alternatives that exhibit more desirable properties. Here we describe the scope and utility of the bio-derived solvent Cyrene in SM cross-couplings and evaluate its suitability as a reaction medium for this benchmark transformation from discovery to gram scale.
- Wilson, Kirsty L.,Murray, Jane,Jamieson, Craig,Watson, Allan J. B.
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supporting information
p. 650 - 654
(2017/12/26)
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- GOLD-CATALYZED C-C CROSS-COUPLING OF BORON- AND SILICON-CONTAINING ARYL COMPOUNDS AND ARYLDIAZONIUM COMPOUNDS BY VISIBLE-LIGHT
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The present invention relates to a method for producing (functionalized) biaryls by employing a visible-light-driven, gold-catalyzed C-C cross-coupling reaction system involving boron- and silicon-containing aryl compounds and aryldiazonium compounds. Moreover, the present invention relates to the use of such boron- and silicon-containing aryl compounds and aryldiazonium compounds, as well as related gold catalysts, in the manufacture of (functionalized) biaryls.
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Page/Page column 24; 25; 30; 41; 42
(2018/07/29)
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- Molecular Design of Donor-Acceptor-Type Organic Photocatalysts for Metal-free Aromatic C?C Bond Formations under Visible Light
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Metal-free and photocatalytic radical-mediated aromatic C?C bond formations offer a promising alternative pathway to the conventional transition metal-catalyzed cross-coupling reactions. However, the formation of aryl radicals from common precursors such as aryl halides is highly challenging due to their extremely high reductive potential. Here, we report a structural design strategy of donor-acceptor-type organic photocatalysts for visible light-driven C?C bond formations through the reductive dehalogenation of aryl halides. The reduction potential of the photocatalysts could be systematically aligned to be ?2.04 V vs. SCE via a simple heteroatom engineering of the donor-acceptor moieties. The high reductive potential of the molecular photocatalyst could reduce various aryl halides into aryl radicals to form the C?C bond with heteroarenes. The designability of the molecular photocatalyst further allowed the synthesis of a high LUMO (lowest unoccupied molecular orbital) polymer photocatalyst by a self-initiated free radical polymerization without compromising its LUMO level. (Figure presented.).
- Wang, Lei,Byun, Jeehye,Li, Run,Huang, Wei,Zhang, Kai A. I.
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p. 4312 - 4318
(2018/10/02)
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- 1, 3, 5 - cyclohexanetriol - cis - or organic boronic acid-stable siloxy inositol complex and organic synthetic reaction using a reagent art
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PROBLEM TO BE SOLVED: To provide a stable ate-type complex of an organoboronic acid as a reagent for organic synthesis reaction; and manufacturing techniques thereof.SOLUTION: A stable ate-type complex of an organoboronic acid with scyllo-inositol or 1,3,5-cis-cyclohexanetriol comprises an anion represented by the specified general formula (I) or (II) as a constituent. In the formula, Rand Reach represent an alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group or aralkyl group which may have substituents.
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Paragraph 0138; 0139
(2017/06/02)
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- AROMATIC ESTERS AND POLYESTERS, PRODUCTION WITHOUT ESTERIFICATION CATALYST, AND USE
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This disclosure relates to methods for production of aromatic esters useful as plasticizers without using esterification catalyst, to the aromatic esters, and to polymer compositions containing the aromatic esters. It also relates to producing aromatic polyesters without using esterification catalyst. The aromatic esters and polyesters can be produced catalyst-free by esterifying carboxylic acids with alcohol(s) at high temperature and high pressure, namely at a temperature from 100°C to 350°C and a pressure ≥ 100 psig, preferably ≥ 600 psig. The aromatic esters and polyesters can also be produced by esterifying without esterification catalyst carboxylic acids with methyl or ethyl alcohol, separating the resulting methyl or ethyl esters from the carboxylic acid and any byproduct impurities, and then transesterifying with or without esterification catalyst the methyl or ethyl esters with alcohols and/or diols.
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Paragraph 0058
(2018/04/12)
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- Immobilized boronic acid for Suzuki-Miyaura coupling: Application to the generation of pharmacologically relevant molecules
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An synthetic strategy for the generation of a variety of biaryl and related derivatives, based on Suzuki-Miyaura coupling using immobilized boronic acid, is described. The importance of the methodology was demonstrated by its further application to biologically interesting compounds such as 4-biaryl-β-lactams, descripted as cholesterol absorption inhibitors and anti-MRSA active agents, neoflavonoids, imidazoles, isoxazolines, among others.
- Martinez-Amezaga,Delpiccolo,Mata
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p. 34994 - 35003
(2017/07/24)
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- Photosensitizer-Free, Gold-Catalyzed C–C Cross-Coupling of Boronic Acids and Diazonium Salts Enabled by Visible Light
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The first photosensitizer-free visible light-driven, gold-catalyzed C–C cross-couplings of arylboronic acids and aryldiazonium salts are reported. The reactions can be conducted under very mild conditions, using a catalytic amount of tris(4-trifluoromethyl)phosphinegold(I) chloride [(4-CF3-C6H4)3PAuCl] with methanol as the solvent allowing an alternative access to a variety of substituted biaryls in moderate to excellent yields with broad functional group tolerance. (Figure presented.).
- Witzel, Sina,Xie, Jin,Rudolph, Matthias,Hashmi, A. Stephen K.
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supporting information
p. 1522 - 1528
(2017/05/05)
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- Amide-ligand-controlled highly para-selective arylation of monosubstituted simple arenes with arylboronic acids
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Pd-catalyzed highly para-selective arylations of monosubstituted simple arenes with arylboronic acids to widely existed biaryls have been developed. Inspired by requisite amide-directing groups in reported selective oxidative couplings, amide ligands, especially DMF, are designed and found to be critical for the selectivity control in current arylations.
- Luan, Yu-Xin,Zhang, Tao,Yao, Wei-Wei,Lu, Ke,Kong, Lu-Yao,Lin, Yu-Tong,Ye, Mengchun
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supporting information
p. 1786 - 1789
(2017/02/15)
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- New telmisartan-derived PPARγ agonists: Impact of the 3D-binding mode on the pharmacological profile
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In previous studies, the 4′-((2-propyl-1H-benzo[d]imidazol-1-yl)methyl)-[1,1′-biphenyl]-2-carboxylic acid was identified as pharmacophoric core for PPARγ activation. In this structure-activity relationship study the C2-alkyl chain was elongated and the 2-COOH group was changed to a carbamide/carbonitrile or shifted to the 3- or 4-position. Furthermore, the benzo[d]imidazole was exchanged by 2,3-dihydrobenzo[d]thiazole or 1H-indole. C2-propyl derivatives showed the profile of partial agonists, while elongation of the C2-chain to that of an n-heptyl group or a 4-COOH shift changed the pharmacological profile to that of a potent full agonist. This finding can be explained by binding to the LBD in different ligand conformations. Two anchoring points (Tyr473 and Arg288) exist in the LBD, which have to be contacted to achieve receptor activation. In a crystal violet chemosensitivity assay using COS-7?cells and LNCaP cells expressing PPARγ only the carbamide derivatives influenced the cell growth, independently on the presence of the PPARγ. Therefore, receptor mediated cytotoxicity can be excluded.
- Obermoser, Victoria,Urban, Margarethe E.,Murgueitio, Manuela S.,Wolber, Gerhard,Kintscher, Ulrich,Gust, Ronald
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supporting information
p. 138 - 152
(2016/08/30)
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- Transition-Metal-Free Cross-Coupling of Aryl Halides with Arylstannanes
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Transition-metal-free LiCl-promoted cross-coupling reactions of tetraphenyltin, trichlorophenyl-, dichlorodiphenyl-, and chlorotriphenylstannanes with aryl halides in DMF provided access to biaryls in good to high yields. Up to four phenyl groups were transferred from the organostannanes substrates. The aryls bearing electron-withdrawing groups in either halides or organotin substrates gave coupling products in higher yields. The methodology has been applied for the efficient synthesis of ipriflavones.
- He, Qing,Wang, Liwen,Liang, Yong,Zhang, Zunting,Wnuk, Stanislaw F.
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p. 9422 - 9427
(2016/10/17)
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- An Indefinitely Air-Stable σ-NiII Precatalyst for Quantitative Cross-Coupling of Unreactive Aryl Halides and Mesylates with Aryl Neopentylglycolboronates
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Three classes of Ni precatalysts based on π-NiII, π-Ni0 and σ-NiII complexes have been elaborated and employed in different laboratories for the functionalization and cross-coupling of otherwise inert aryl C-O, C-Cl, and C-F electrophiles. Various Ni precatalysts, ligands, boron sources, and reaction conditions that were developed in various research groups, necessitated the selection of the most suitable conditions for desired cross-coupling partners. Here a universal, bench-stable, easily prepared NiIICl(1-naphthyl)(PCy3)2/PCy3 σ-complex, for efficient and quantitative cross-coupling of aryl chlorides, bromides, iodides, mesylates, and fluorides with aryl neopentylglycolboronates is reported. This precatalyst will most probably help to advance the applications of Ni catalysis in organic, supramolecular, and macromolecular synthesis and will provide an easier access to the selection of reaction conditions for various transformations.
- Malineni, Jagadeesh,Jezorek, Ryan L.,Zhang, Na,Percec, Virgil
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supporting information
p. 2795 - 2807
(2016/08/31)
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- Gold-catalysed cross-coupling between aryldiazonium salts and arylboronic acids: Probing the usefulness of photoredox conditions
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The synthesis of biaryl compounds from aryldiazonium salts and arylboronic acids was achieved using PPh3AuCl as catalyst, CsF as base and acetonitrile as solvent. Combined to photosensitizers, irradiation by blue LEDs allowed accelerating the reaction and expanding its scope. Various functional groups were compatible including bromoaryls, iodoaryls, aldehydes and alcohols. A 2-iodobenzyl alcohol moiety was smoothly introduced by this method, enabling its consecutive isotopic labelling by a Pd-catalysed alkoxycarbonylation.
- Cornilleau, Thomas,Hermange, Philippe,Fouquet, Eric
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p. 10040 - 10043
(2016/08/15)
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- A self-assembled bisoxazoline/Pd composite microsphere as an excellent catalyst for Suzuki-Miyaura coupling reactions
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A palladium complex based on a novel oxazoline, a solid microsphere catalyst, was successfully prepared. The structure and composition of the solid catalyst were characterized by SEM, 1H NMR, TGA and FT-IR. This catalyst exhibits high catalytic activity for Suzuki-Miyaura cross-coupling reactions of various aryl halides and arylboronic acids in aqueous media. Moreover, the catalyst shows outstanding stability and reusability, and it can be recovered simply and effectively and reused eight times without any activity decrease.
- Wang, Junke,Zong, Yingxiao,Wang, Xicun,Hu, Yulai,Yue, Guoren,Pan, Yi
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supporting information
p. 967 - 973
(2016/02/27)
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- An imidazolium ionic compound-supported palladium complex as an efficient catalyst for Suzuki-Miyaura reactions in aqueous media
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A water soluble and efficient ionic compound-supported palladium complex was prepared. The structure and composition of the complex was characterized by FT-IR, NMR, ICP-OES and mass spectrometry. The complex exhibits high catalytic activity for Suzuki-Miyaura reactions in aqueous media. Moreover, the catalyst shows outstanding stability and reusability, and it can be recovered simply and effectively and reused six times without much activity decrease.
- Zong, Yingxiao,Wang, Junke,He, Yubi,Yue, Guoren,Wang, Xicun,Pan, Yi
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p. 89621 - 89626
(2016/10/03)
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- Copper-Catalyzed Coupling of Triaryl- and Trialkylindium Reagents with Aryl Iodides and Bromides through Consecutive Transmetalations
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An efficient copper(I)-catalyzed coupling of triaryl and trialkylindium reagents with aryl iodides and bromides is reported. The reaction proceeds at low catalyst loadings (2 mol %) and generally only requires 0.33 equivalents of the triorganoindium reagent with respect to the aryl halide as all three organic nucleophilic moieties of the reagent are transferred to the products through consecutive transmetalations. The reaction tolerates a variety of functional groups and sterically hindered substrates. Furthermore, preliminary mechanistic studies that entailed the synthesis and characterization of potential reaction intermediates offered a glimpse of the elementary steps that constitute the catalytic cycle.
- Thapa, Surendra,Gurung, Santosh K.,Dickie, Diane A.,Giri, Ramesh
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supporting information
p. 11620 - 11624
(2016/02/19)
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- Pincer-Nickel-Catalyzed Cross-Coupling of Aryl Sulfamates with Arylzinc Chlorides
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The nickel N,N,N-pincer complex 2 was demonstrated to effectively catalyze the cross-coupling of aryl sulfamates with arylzinc chlorides under mild conditions. The reaction is suitable for a wide range of substrates, and tolerates various functional groups. A nickel N,N,N-pincer complex effectively catalyzes the cross-coupling of aryl sulfamates with arylzinc chlorides under mild conditions. The reaction is suitable for a wide range of substrates, and tolerates various functional groups.
- Tao, Jian-Long,Wang, Zhong-Xia
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p. 6534 - 6540
(2015/10/19)
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- Metal-free oxidative decarbonylative coupling of aromatic aldehydes with arenes: Direct access to biaryls
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A metal-free oxidative decarbonylative coupling of aromatic aldehydes with electron-rich or electron-deficient arenes to produce biaryl compounds was developed. This novel coupling was proposed to proceed via a non-chain radical homolytic aromatic substitution (HAS) type mechanism, based on the substrate scope, ortho-regioselectivity, radical trapping experiments and DFT calculation studies. With the ready availability of aromatic aldehydes and arenes, metal-free conditions should make this coupling attractive for the biaryl synthesis.
- Tang, Ren-Jin,He, Qing,Yang, Luo
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supporting information
p. 5925 - 5928
(2015/03/30)
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- Very efficient and broad-in-scope palladium-catalyzed Hiyama cross-coupling. the role of water and copper(I) salts
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A very high-yielding Pd-catalyzed cross-coupling between aryl halides and aryl(trialkoxy)silanes is achieved in the presence of Cu(i) and a measured amount of water. This novel methodology is useful for the generation of a wide range of biaryls, particularly non-para substituted derivatives, which are usually less reported.
- Traficante, Carla I.,Mata, Ernesto G.,Delpiccolo, Carina M. L.
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p. 26796 - 26800
(2015/03/30)
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- Palladium-catalyzed cross-coupling reactions of arylsiloxanes with aryl halides: Application to solid-supported organic synthesis
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The solid-phase version of the Pd-catalyzed Hiyama reaction between a variety of aryltriethoxysilanes and immobilized aryl halides was developed. Smooth cross-coupling was achieved to afford the corresponding biaryl products in moderate to excellent yields. The described protocol would be particularly useful for the construction of 4′-substituted 1,1′-biphenyl derivatives.
- Traficante, Carla I.,Delpiccolo, Carina M. L.,Mata, Ernesto G.
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supporting information
p. 211 - 214
(2014/06/09)
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- Metal-free iodination of arylboronic acids and the synthesis of biaryl derivatives
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A simple, general and efficient method is developed for the metal-free iodination of arylboronic acids. The protocol uses very cheap molecular iodine as the halide source and potassium carbonate as the base. The method is highly tolerant of various functional groups present in the substrates. Importantly, the iodination strategy can also be applied very effectively in the one-pot, two-step synthesis of biaryl derivatives. Georg Thieme Verlag Stuttgart New York.
- Niu, Liting,Zhang, Hao,Yang, Haijun,Fu, Hua
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supporting information
p. 995 - 1000
(2014/05/06)
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- N-heterocyclic carbene-assisted, Bis(phosphine)nickel-catalyzed cross-couplings of diarylborinic acids with aryl chlorides, tosylates, and sulfamates
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Efficient bis(phosphine)nickel-catalyzed cross-couplings of diarylborinic acids with aryl chlorides, tosylates, and sulfamates have been effected with an assistance of N-heterocyclic carbene (NHC) generated in situ from N,N′-dialkylimidazoliums, e.g., N-butyl-N′-methylimidazolium bromide ([Bmim]Br), in toluene using K3PO4·3H2O as base. In contrast to bis(NHC)nickel-catalyzed conventional Suzuki coupling of arylboronic acids, mono(NHC)bis(phosphine)nickel species generated in situ from Ni(PPh3)2Cl2/[Bmim]Br displayed high catalytic activities in the cross-couplings of diarylborinic acids. The structural influences from diarylborinic acids were found to be rather small, while electronic factors from aryl chlorides, tosylates, and sulfamates affected the couplings remarkably. The couplings of electronically activated aryl chlorides, tosylates, and sulfamates could be efficiently effected with 1.5 mol % NiCl2(PPh3)2/[Bmim]Br as catalyst precursor to give the biaryl products in excellent yields, while 3-5 mol % loadings had to be used for the couplings of non- and deactivated ones. A small ortho-substitutent on the aromatic ring of aryl chlorides, tosylates, and sulfamates was tolerable. Applicability of the nickel-catalyzed cross-couplings in practical synthesis of fine chemicals has been demonstrated in process development for a third-generation topical retinoid, Adapalene.
- Ke, Haihua,Chen, Xiaofeng,Zou, Gang
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p. 7132 - 7140
(2014/08/18)
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- Nickel-catalyzed cross-coupling of diarylborinic acids with aryl chlorides
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A highly efficient nickel/triarylphosphine catalyst system, Ni[P(4-MeOPh)3]2Cl2/2P(4-MeOPh)3, has been developed for cross-coupling of diarylborinic acids with a wide range of aryl chlorides. A variety of unsymmetrical biaryl and heterobiaryl compounds with various functional groups and steric hindrance could be obtained in good to excellent yields using 0.5-2 mol % catalyst loadings in the presence of K 3PO4·3H2O in toluene. The high atom economy of diarylborinic acids and cost-effectiveness of the nickel/phosphine catalyst system make the cross-coupling truly practical in the production of biaryl fine chemicals. Usefulness of the nickel/phosphine catalyzed cross-coupling of diarylborinic acids with aryl chlorides has been demonstrated in the development of a scalable and economical process for synthesis of 4′-methyl-2-cyanobiphenyl, Sartan biphenyl.
- Chen, Xiaofeng,Ke, Haihua,Zou, Gang
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p. 379 - 385
(2014/03/21)
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- Scyllo-inositol as a convenient protecting group for aryl boronic acids in Suzuki-Miyaura cross-coupling reactions
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Herein, we report air-and water-stable borate complexes between scyllo-inositol and aryl boronic acids. The complexes were less reactive than free aryl boronic acids under Suzuki-Miyaura cross-coupling reaction conditions; thus, the borate complexes were used as protected boronic acids. Although protecting groups for organoboronic acids are useful in coupling reactions, especially those used to produce π-conjugated molecules, only a few reports describing the use of protecting groups for boronic acids have been published. The proposed unique structural borate complex provides a novel protective method for aryl boronic acids.
- Kuno, Shinichi,Kimura, Tomoyuki,Yamaguchi, Masanori
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p. 720 - 724
(2014/01/23)
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- Synthesis of aryl trimethylstannanes from aryl amines: A sandmeyer-type stannylation reaction
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Sandmeyer-type stannylation: Stille coupling is one of the most powerful coupling reactions for C-C bond formation, whereas there are only limited methods to access aryl stannane compounds. A mild stannylation process based on a Sandmeyer-type transformation using aromatic amines as the starting materials is described. DCE: 1,2-dichloroethane. Copyright
- Qiu, Di,Meng, He,Jin, Liang,Wang, Shuai,Tang, Shengbo,Wang, Xi,Mo, Fanyang,Zhang, Yan,Wang, Jianbo
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p. 11581 - 11584
(2013/11/06)
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- Synthesis and evaluation of quinazoline derivatives as phosphodiesterase 7 inhibitors
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The latest scientific findings concerning PDE7 and PDE4 inhibition suggest that selective small-molecule inhibitors of both enzymes could provide a novel approach to treat a variety of immunological diseases. In this context, we describe a new series of quinazoline derivatives from quinazolin-4-thiones which include a substituted biphenyl fragment. Some of these compounds show inhibitory potencies at sub-micromolar levels against the catalytic domain of PDE7.
- Sánchez, Ana I.,Martínez-Barrasa, Valentín,Burgos, Carolina,Vaquero, Juan J.,Alvarez-Builla, Julio,Terricabras, Emma,Segarra, Víctor
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p. 2370 - 2378
(2013/05/09)
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- NHC-Pd(II)-Im (NHC = N-heterocyclic carbene; Im = 1-methylimidazole) complex catalyzed Hiyama reaction of aryl chlorides with aryltrimethoxysilanes
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A well-defined NHC-Pd(II)-Im complex was proved to be an efficient catalyst for the Hiyama reaction of a variety of aryl chlorides with aryltrimethoxysilanes. Under the optimal conditions, all reactions took place smoothly to give the corresponding coupling products in moderate to high yields.
- Gu, Zheng-Song,Shao, Li-Xiong,Lu, Jian-Mei
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experimental part
p. 132 - 134
(2012/03/11)
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- Palladium-catalyzed one-pot cross-coupling of phenols using nonafluorobutanesulfonyl fluoride
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Palladium-catalyzed coupling reactions, such as the Suzuki-Miyaura, Sonogashira, Stille, and Buchwald-Hartwig couplings, of phenols using nonafluorobutanesulfonyl fluoride (NfF) are described. These reactions proceeded through the in situ nonaflation of p
- Ikawa, Takashi,Saito, Kozumo,Akai, Shuji
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supporting information
p. 2241 - 2246
(2012/10/29)
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- Nickel-catalyzed Suzuki-Miyaura reaction of aryl fluorides
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Two protocols for the nickel-catalyzed cross-coupling of aryl fluorides with aryl boronic esters have been developed. The first employs metal fluoride cocatalysts, such as ZrF4 and TiF4, which enable Suzuki-Miyaura reactions of aryl fluorides bearing electron-withdrawing (ketones, esters, and CF3), aryl and alkenyl groups as well as those comprising fused aromatic rings, such as fluoronaphthalenes and fluoroquinolines. The second protocol employs aryl fluorides bearing ortho-directing groups, which facilitate the difficult C-F bond activation process via cyclometalation. N-heterocycles, such as pyridines, quinolines, pyrazoles, and oxazolines, can successfully promote cross-coupling with an array of organoboronic esters. A study into the substituent effects with respect to both coupling components has provided fundamental insights into the mechanism of the nickel-catalyzed cross-coupling of aryl fluorides.
- Tobisu, Mamoru,Xu, Tian,Shimasaki, Toshiaki,Chatani, Naoto
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supporting information; experimental part
p. 19505 - 19511
(2012/01/31)
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- Nanocrystalline titania-supported palladium(0) nanoparticles for Suzuki-Miyaura cross-coupling of aryl and heteroaryl halides
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The Suzuki cross-coupling reaction of various aryl and heteroaryl halides with arylboronic and heteroarylboronic acids was studied using a titania-supported palladium(0) catalyst at room temperature under air. The conversion and selectivity results obtained for many substrates were excellent and similar to those provided by more active or even homogeneous catalysts. The methodology is similarly effective using 2-bromo-3,4,5-trimethoxybenzaldehyde as the coupling partner and gave products in good yield. Furthermore, it has been shown that it is useful for the synthesis of terphenyl and tetraphenyls. The catalyst is quantitatively recovered from the reaction by simple filtration and reused for a number of cycles without significant loss of activity. Inductively coupled plasma (ICP) mass-spectrometric analysis of the filtrate from the reaction mixture demonstrated that the palladium metal hardly leached into the solution within the limits of the detector (1 ppm), thus suggesting that the present Suzuki-Miyaura reaction proceeded by heterogeneous catalysis. Copyright
- Sreedhar,Yada, Divya,Reddy, P. Surendra
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experimental part
p. 2823 - 2836
(2011/12/01)
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- A highly active and recyclable catalyst: Phosphine dendrimer-stabilized nickel nanoparticles for the Suzuki coupling reaction
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We report here the first dendritic phosphine-stabilized nickel nanoparticles, which can be prepared from nickel(II) chloride, a third generation phosphine dendrimer and the surfactant tetraoctylammonium bromide (TOABr) by two-phase reduction using sodium borohydride. The resulting nickel nanoparticles are found to be a highly active and recyclable catalyst for Suzuki coupling reactions, especially those extended to aryl chloride substrates, affording the biaryls in moderate to good yields. Copyright
- Wu, Lei,Ling, Jie,Wu, Zong-Quan
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supporting information; experimental part
p. 1452 - 1456
(2011/08/03)
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- A simple, efficient and recyclable phosphine-free catalytic system for Suzuki-Miyaura reaction of aryl bromides
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The Suzuki-Miyaura reaction of aryl bromides using 3-(2-aminoethylamino) propyl-functionalized MCM-41-immobilized palladium(II) complex [MCM-41-2N-Pd(II)] as an efficient heterogeneous catalyst is described. Developed catalytic system is found to be effective for the Suzuki-Miyaura reaction of aryl bromides with arylboronic acids providing good to excellent yield of the desired products. This heterogeneous palladium catalyst can be reused at least 10 times without any decrease in activity. Our system not only avoids the use of phosphine ligands, but also solves the basic problem of palladium catalyst recovery and reuse.
- Zhao, Hong,Peng, Jian,Xiao, Ruian,Cai, Mingzhong
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experimental part
p. 56 - 60
(2011/04/26)
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- Palladium nanoparticles in ionic liquid by sputter deposition as catalysts for suzuki-miyaura coupling in water
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Palladium nanoparticles in an ionic liquid prepared readily by sputter deposition efficiently catalyze the Suzuki-Miyaura coupling of hydrophobic as well as hydrophilic aryl halides in water.
- Oda, Yoshiro,Hirano, Koji,Yoshii, Kazuki,Kuwabata, Susumu,Torimoto, Tsukasa,Miura, Masahiro
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supporting information; experimental part
p. 1069 - 1071
(2011/01/09)
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- Aryl phosphoramides: useful electrophiles for suzuki-miyaura coupling catalyzed by a NiCl2/dppp system (dppp=1,3-bis(diphenylphosphino) propane)
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Chemical Equation presantation Suzuki-Miyaura coupling: We disclose a new strategy for phenol activation in the first Suzuki-Miyaura coupling of phenol derivatives activated by forming aryl bis(2-oxo-3-oxazolidinyl)phosphines as a highly efficient and broadly applicable methodology for the diverse synthesis of biaryls and heterobiaryls (see scheme). The use of readily available, stable NiCl2/dppp as the catalyst system also provides an important advance.
- Zhao, Yu-Long,Li, You,Li, Yu,Gao, Lian-Xun,Han, Fu-She
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supporting information; experimental part
p. 4991 - 4994
(2010/08/05)
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- Synthesis of unsymmetrically substituted biaryls via sequential lithiation of dibromobiaryls using integrated microflow systems
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A microflow system consisting of micromixers and microtube reactors provides an effective method for the introduction of two electrophiles onto dibromobiaryls. Selective monolithiation of dibromobiaryls, such as 2,2'-dibromobiphenyl, 4,4'-dibromobiphenyl, 2,7-dibromo-9,9-dioctylfluorene, 2,2'-dibromo-1,1'-binaphthyl, and 2,2'-dibromobibenzyl with 1 equiv of n-butyllithium followed by the reaction with electrophiles was achieved using a microflow system by virtue of fast micromixing and precise temperature control. Sequential introduction of two different electrophiles was achieved using an integrated microflow system composed of four micromixers and four microtube reactors to obtain unsymmetrically substituted biaryl compounds.
- Nagaki, Aiichiro,Takabayashi, Naofumi,Tomida, Yutaka,Yoshida, Jun-Ichi
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supporting information; experimental part
(2010/04/22)
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- Solvent-free microwave-assisted Suzuki-Miyaura coupling catalyzed by PEPPSI-iPr
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We have developed a new method for Suzuki coupling using an NHC-stabilized palladium catalyst under solvent-free conditions using microwave activation. Georg Thieme Verlag Stuttgart.
- Nun, Pierrick,Martinez, Jean,Lamaty, Frédéric
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experimental part
p. 1761 - 1764
(2009/12/04)
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- PROCESSES FOR THE PREPARATION OF BIPHENYL COMPOUNDS
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The invention concerns processes for the synthesis of a compound of the formula: wherein: R1 and R2 are each, independently, C1-C12 alkyl, CO2R3, OR4, R5(OR6), or C6-C18 aiyl; R3 -R6 are each, independently, C1-C12 alkyl or C6-C12 aryl; and n and m are each, independently, O or an integer from 1-5; said process comprising: — contacting a compound of the formula H0-R7-0H with BH3 and a compound of the formula in the presence of a nickel-containing catalyst to produce a first product, where R7 is a C2-C12 hydrocarbon group and X is a halogen, OMs or OTs; — contacting the first product in situ with a compound of the formula: in the presence of a nickel-containing catalyst to produce a compound of formula I, where Z is a halogen.
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Page/Page column 19
(2010/01/29)
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- Sequential Ni-catalyzed borylation and cross-coupling of aryl halides via in situ prepared neopentylglycolborane
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(Chemical Equation Presented) A procedure for NiCl2(dppp)- catalyzed pinacolborylation and neopentylglycolborylation that utilizes in situ prepared inexpensive pinacolborane and neopentylglycolborane is reported. The scope of this reaction was demonstrated with a variety of aryl bromides and iodides. The resulting aryl neopentylglycolboronic esters undergo a NiCl 2(dppe)-catalyzed cross-coupling with aryl halides, resulting in an extremely efficient and cost-effective method for the synthesis of functional biaryls, dendritic building blocks, and other complex architectures.
- Rosen, Brad M.,Huang, Chenghong,Percec, Virgil
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supporting information; experimental part
p. 2597 - 2600
(2009/05/27)
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- Palladium-catalyzed reactions of arylindium reagents prepared directly from aryl iodides and indium metal
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(Chemical Equation Presented) Treatment of aryl iodides with indium metal in the presence of lithium chloride leads to the formation of an organoindium reagent capable of participating in cross-coupling reactions under transition-metal catalysis. Combination with aryl halides in the presence of 5 mol % Cl2Pd(dppf) furnishes biaryl compounds in good yields; similarly, reaction with acyl halides or allylic acetates/carbonates in the presence of 5-10 mol % palladium catalyst leads to arylketones and allylic substitution products, respectively, in moderate yields. The reactions are tolerant of the presence of protic solvents, and ~85% of the indium metal employed can be recovered by reduction of the residual indium salts with zinc(0).
- Papoian, Vardan,Minehan, Thomas
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supporting information; experimental part
p. 7376 - 7379
(2009/05/07)
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