- Pd nanoparticles in silica hollow spheres with mesoporous walls: A nanoreactor with extremely high activity
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A true nanoreactor composed of mesoporous silica hollow spheres and Pd nanoparticles residing inside the spheres shows superior activity in Suzuki coupling reactions with 99.5% yield in 3 min.
- Chen, Zhe,Cui, Zhi-Min,Niu, Fang,Jiang, Lei,Song, Wei-Guo
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- Magnetic Nanoparticle-Supported N-Heterocyclic Carbene-Palladium(II): A Convenient, Efficient and Recyclable Catalyst for Suzuki–Miyaura Cross-Coupling Reactions
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Abstract: A new magnetic nanoparticle-supported N-heterocyclic carbene-palladium(II) nanomagnetic catalyst was synthesized and appropriately characterized using attenuated total reflectance infrared spectroscopy (ATR-IR), ultraviolet–visible spectroscopy (UV–Visible), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), energy-dispersive X-ray spectroscopy (EDS), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and Brunauer–Emmett–Teller surface area analysis (BET). The nanomagnetic catalyst was used as convenient and efficient catalyst for the Suzuki–Miyaura cross-coupling reaction of various aryl bromides/chlorides/iodide with phenylboronic acid. The effects of varying solvents, bases, temperature, time and catalytic ratios on the performance of the Suzuki–Miyaura cross-coupling reaction were investigated. The notable advantages of this heterogeneous nanomagnetic catalyst are excellent yields, mild reaction conditions, short reaction times and easy work-up. Moreover, the new nanomagnetic catalyst could be easily recovered with an external magnet and could be reused at least five times without loss of its catalytic activity. Graphical Abstract: [Figure not available: see fulltext.]
- Vishal,Fahlman, Bradley D.,Sasidhar,Patil, Shivaputra A.,Patil, Siddappa A.
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- An efficient heterogeneous Pd catalyst for the Suzuki coupling: Pd/Al 2O3
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PdII-loading alumina catalyst, which is simply prepared through impregnation of γ-alumina with Pd(OAc)2 followed by calcination in the air, shows a high catalytic activity for the Suzuki coupling of aryl bromides with arylboronic acids under phosphine ligand-free conditions. Only 0.25 mol% of palladium is sufficient for the promotion of the couplings in ethanol. Copyright
- Kudo, Daisuke,Masui, Yoichi,Onaka, Makoto
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- Method for synthesizing biphenyl compounds by adopting microchannel reactor
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The invention relates to a method for synthesizing biphenyl compounds by adopting a microchannel reactor. The method comprises the following steps: mixing a compound shown in a formula (1), a compound shown in a formula (2), a compound shown in a formula (3) and a copper catalyst in the microchannel reactor, carrying out diazotization coupling reaction, and purifying the obtained reaction product to obtain a compound shown in a formula (4). Compared with the prior art, the micro-channel reactor is adopted, so that the diazotization coupling reaction time is effectively shortened, the reaction stability and efficiency are improved, the reaction yield and purity are improved, and the method has the advantages of environmental protection, safety, simple process, low cost, continuous industrial production and the like.
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Paragraph 0045-0050
(2021/11/10)
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- Photoelectric properties of aromatic triangular tri-palladium complexes and their catalytic applications in the Suzuki-Miyaura coupling reaction
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The photoelectric properties and catalytic activities of substituted triphenylphosphine and sulfur/selenium ligand supported aromatic triangular tri-palladium complexes1-4, abbreviated as [Pd3]+, were investigated. The cyclic voltammogram of [Pd3]+in CH3CN-nBu4NPF6showed a single quasi-reversible wave which was consistent with their robust property and provided preliminary proof for their electron transfer processes in catalysis. With excitation at 267 nm, [Pd3]+exhibited strong ratiometric fluorescence at 550 and 780 nm at a temperature gradient from 77 K to 287 K. These peculiar triangular tri-palladium complexes showed excellent catalytic activities and exclusive reactivity with aryl iodides over the other halogenated aromatics in the Suzuki-Miyaura coupling reaction. The electronic and steric hindrance effects of substituents on the aryl iodides and aryl boronic acids including heteroaromatics like pyridine, pyrazine and thiophenes were explored and most substrates achieved up to 99% of yields. (2-[1,1′-Biphenyl]-2-ylbenzothiazole) which was analogous to the selective cyclooxygenase-2 (COX-2) inhibitors was also synthesized with our tri-palladium catalyst and gave good isolated yield (94%). The study of the catalytic process revealed that the mechanism of the reaction may involve the replacement of the sulphur ligand on [Pd3]+by iodine from aryl iodides, which was beneficial for the matching of C-I bond energy.
- Li, Jia,Li, Xujun,Liu, Xiang,Maestri, Giovanni,Malacria, Max,Wang, Xiaoshuang,Wang, Yanlan,Wu, Lingang
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supporting information
p. 11834 - 11842
(2021/09/06)
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- Palladium (II)–Salan Complexes as Catalysts for Suzuki–Miyaura C–C Cross-Coupling in Water and Air. Effect of the Various Bridging Units within the Diamine Moieties on the Catalytic Performance
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Water-soluble salan ligands were synthesized by hydrogenation and subsequent sulfonation of salens (N,N’-bis(slicylidene)ethylenediamine and analogues) with various bridging units (linkers) connecting the nitrogen atoms. Pd (II) complexes were obtained in reactions of sulfosalans and [PdCl4]2?. Characterization of the ligands and complexes included extensive X-ray diffraction studies, too. The Pd (II) complexes proved highly active catalysts of the Suzuki–Miyaura reaction of aryl halides and arylboronic acid derivatives at 80 ?C in water and air. A comparative study of the Pd (II)–sulfosalan catalysts showed that the catalytic activity largely increased with increasing linker length and with increasing steric congestion around the N donor atoms of the ligands; the highest specific activity was 40,000 (mol substrate) (mol catalyst × h)?1. The substrate scope was explored with the use of the two most active catalysts, containing 1,4-butylene and 1,2-diphenylethylene linkers, respectively.
- Bunda, Szilvia,Joó, Ferenc,Kathó, ágnes,Udvardy, Antal,Voronova, Krisztina
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supporting information
(2020/09/18)
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- Recombinant Peptide Fusion Protein-Templated Palladium Nanoparticles for Suzuki-Miyaura and Stille Coupling Reactions
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This study examined the use of nanoparticles created with recombinant 45-amino acid long peptides fused to green fluorescent protein (GFPuv) to catalyze twelve representative Suzuki-Miyaura and Stille coupling reactions. A method was developed to prepare powders (Pd@GFP) containing protein and synthesized nanoparticles. Next, coupling reactions were performed in a green solvent without nanoparticle purification. Pd@GFP had high turnover frequencies for the synthesis of model compounds including lapatinib (Tykerb) and could be recycled. This study establishes a potentially cost-effective approach to prepare heterogeneous catalysts containing well-defined nanoparticles enabling key C?C bond formation leading to synthetically and pharmaceutically interesting compounds.
- Mosleh, Imann,Shahsavari, Hamid R.,Beitle, Robert,Beyzavi, M. Hassan
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p. 2942 - 2946
(2020/03/26)
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- Catalytic reduction of aryl trialkylammonium salts to aryl silanes and arenes
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A new approach for the reduction of aryl ammonium salts to arenes or aryl silanes using nickel catalysis is reported. This method displays excellent ligand-controlled selectivity based on the N-heterocyclic carbene (NHC) ligand employed. Utilizing a large NHC in non-polar solvents generates aryl silanes, while small NHCs in polar solvents promote reduction to arenes. Several classes of aryl silanes can be accessed from simple aniline building blocks, including those useful for cross-couplings, oxidations, and halogenations. The reaction conditions are mild, functional group tolerant, and provide efficient access to a variety of benzene derivatives.
- Rand, Alexander W.,Montgomery, John
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p. 5338 - 5344
(2019/05/29)
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- Pd-nanoparticles catalyzed denitrogenative coupling of aryl halides with arylhydrazines: Greener approach for biaryls synthesis under ligand-free condition
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The greener approach for the synthesis of biaryl using palladium nanoparticle (Pd–NPs) catalyzed denitrogenative coupling between aryl hydrazine and aryl halides under ligand-free condition has been described. The phytochemicals of the black pepper extract plays a dual role in reduction of PdII to Pd0 and acts as stabilizing agent for Pd–NPs. The electronically diver's arylhydrazines and commercially available aryl halides are used for the synthesis of symmetrical and unsymmetrical biaryls in good to excellent yield. The mechanism is well supported by control experiment and the recyclability, turnover number and turnover frequency of biogenically synthesized Pd–NPs is studied.
- Hegde, Rajeev V.,Ghosh, Arnab,Patil, Siddappa A.,Dateer, Ramesh B.
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supporting information
(2019/12/09)
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- Magnetite tethered mesoionic carbene-palladium (II): An efficient and reusable nanomagnetic catalyst for Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions in aqueous medium
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In this paper, a highly active, air- and moisture-stable and easily recoverable magnetic nanoparticles tethered mesoionic carbene palladium (II) complex (MNPs-MIC-Pd) as nanomagnetic catalyst was successfully synthesized by a simplistic multistep synthesis under aerobic conditions using commercially available inexpensive chemicals for the first time. The synthesized MNPs-MIC-Pd nanomagnetic catalyst was in-depth characterized by numerous physicochemical techniques such as FT-IR, ICP-AES, FESEM, EDS, TEM, p-XRD, XPS, TGA and BET surface area analysis. The prepared MNPs-MIC-Pd nanomagnetic catalyst was used to catalyze the Suzuki–Miyaura and Mizoroki–Heck cross-coupling reactions and exhibited excellent catalytic activity for various substrates under mild reaction conditions. Moreover, MNPs-MIC-Pd nanomagnetic catalyst could be easily and rapidly recovered by applying an external magnet. The recovered MNPs-MIC-Pd nanomagnetic catalyst exhibited very good catalytic activity up to ten times in Suzuki–Miyaura and five times in Mizoroki–Heck cross-coupling reactions without considerable loss of its catalytic activity. However, MNPs-MIC-Pd nanomagnetic catalyst shows notable advantages such as heterogeneous nature, efficient catalytic activity, mild reaction conditions, easy magnetic work up and recyclability.
- Kempasiddhaiah, Manjunatha,Kandathil, Vishal,Dateer, Ramesh B.,Sasidhar, Balappa S.,Patil, Shivaputra A.,Patil, Siddappa A.
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- From agriculture residue to catalyst support; A green and sustainable cellulose-based dip catalyst for C–C coupling and direct arylation
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The core characteristics of a perfect catalyst include good activity, simple design, excellent stability, easy recovery from reaction mixture, recyclability, and have the provision for easy scale up. The ease in synthesis, recyclability and scale up makes the dip catalyst a major contender in this regard which possess most of the aforementioned characteristics. In this work, we report a dip catalyst made of cellulose, isolated from agriculture residue (sugarcane bagasse), in which biogenically synthesized palladium nanoparticles were dispersed. The prepared dip catalyst was characterized by FESEM, EDS, XRD, ATR-IR, TGA, TEM, XPS and ICP-OES analysis. Also, the activity of the dip catalyst was studied in the Suzuki-Miyaura cross-coupling reaction and was found to give excellent conversion with 15 recycles. Further, the activity of dip catalyst in C5-arylation of 2-substituted thiophenes was evaluated for which promising yields were obtained.
- Kandathil, Vishal,Kempasiddaiah, Manjunatha,B. S., Sasidhar,Patil, Siddappa A.
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- Green Synthesis of Palladium Nanoparticles: Applications in Aryl Halide Cyanation and Hiyama Cross-Coupling Reaction Under Ligand Free Conditions
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Abstract: In the current work, palladium nanoparticles (Pd NPs) were prepared from palladium acetate biogenically using the aqueous-ethanolic extract of black pepper (Piper nigrum) and characterized by various analytical techniques like XRD, FE-SEM, EDS, TEM, ATR-IR, UV–Vis spectroscopy, BET, TGA and ICP-OES analysis. The reduction of Pd(II)?to?Pd(0) is achieved by the action of various phytochemicals present in the black pepper extract like phenols, acids, pellitorine, ethyl piperonyl cyanoacetate, piperine and N-isobutyl-tetradeca-2,4-dienamide. The biosynthesized Pd NPs shown excellent catalytic activity in aryl halide cyanation and Hiyama cross-coupling reactions. Also, less toxic potassium hexacyanoferrate(II) trihydrate was used as cyanide source in aryl halide cyanation and Hiyama cross-coupling was performed under fluoride free condition. Both reactions proceeded well with Pd NPs under ligand free circumstances to give good to excellent yields. The Pd NPs were recovered after each reaction and recycled up to five times in aryl halide cyanation and ten times in Hiyama cross-coupling without considerable loss in the activity. Graphical Abstract: Green synthesis of palladium nanoparticles: applications in aryl halide cyanation and Hiyama cross-coupling reaction under ligand free conditions. [Figure not available: see fulltext.].
- Kandathil, Vishal,Dateer, Ramesh B.,Sasidhar,Patil, Shivaputra A.,Patil, Siddappa A.
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p. 1562 - 1578
(2018/04/02)
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- A new magnetically recyclable heterogeneous palladium(II) as a green catalyst for Suzuki-Miyaura cross-coupling and reduction of nitroarenes in aqueous medium at room temperature
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In the current work, a new stable and powerful magnetic nanoparticle supported Schiff base-palladium(II) (MNPs@SB-Pd) nanomagnetic catalyst was synthesized. The structural feature of the MNPs@SB-Pd nanomagnetic catalyst was properly characterized using a combination of attenuated total reflectance infrared spectroscopy (ATR-IR), ultraviolet–visible spectroscopy (UV–Visible), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), energy-dispersive X-ray spectroscopy (EDS), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller surface area analysis (BET). The air- and moisture stable prepared MNPs@SB-Pd nanomagnetic catalyst was applied in C–C bond formation through Suzuki-Miyaura cross-coupling reactions and reduction of nitroarenes. Use of green medium, eco-friendly, waste-free, efficient preparation leading to high yield of products, short reaction time and cost effective catalyst are the major benefits of the method presented. In addition, the MNPs@SB-Pd nanomagnetic catalyst was easily separated from the reaction mixture with the help of an external magnetic field and reused for five consecutive cycles in Suzuki-Miyaura cross-coupling and ten consecutive cycles in reduction of nitroarene reactions with no significant loss of catalytic efficiency.
- Kandathil, Vishal,Koley, Tuhin S.,Manjunatha,Dateer, Ramesh B.,Keri, Rangappa S.,Sasidhar,Patil, Shivaputra A.,Patil, Siddappa A.
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p. 195 - 210
(2018/04/23)
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- Magnetic nanoparticle-tethered Schiff base–palladium(II): Highly active and reusable heterogeneous catalyst for Suzuki–Miyaura cross-coupling and reduction of nitroarenes in aqueous medium at room temperature
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As a continuation of our efforts to develop new heterogeneous nanomagnetic catalysts for greener reactions, we identified a Schiff base–palladium(II) complex anchored on magnetic nanoparticles (SB-Pd@MNPs) as a highly active nanomagnetic catalyst for Suzuki–Miyaura cross-coupling reactions between phenylboronic acid and aryl halides and for the reduction of nitroarenes using sodium borohydride in an aqueous medium at room temperature. The SB-Pd@MNPs nanomagnetic catalyst shows notable advantages such as simplicity of operation, excellent yields, short reaction times, heterogeneous nature, easy magnetic work up and recyclability. Characterization of the synthesized SB-Pd@MNPs nanomagnetic catalyst was performed with various physicochemical methods such as attenuated total reflectance infrared spectroscopy, UV–visible spectroscopy, inductively coupled plasma atomic emission spectroscopy, energy-dispersive X-ray spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, powder X-ray powder diffraction, thermogravimetric analysis and Brunauer–Emmett–Teller surface area analysis.
- Manjunatha,Koley, Tuhin S.,Kandathil, Vishal,Dateer, Ramesh B.,Balakrishna, Geetha,Sasidhar,Patil, Shivaputra A.,Patil, Siddappa A.
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- A convenient, efficient and reusable N-heterocyclic carbene-palladium(II) based catalyst supported on magnetite for Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions
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In the present work, a new magnetic nanoparticle supported N-heterocyclic carbene-palladium(ii) (NO2-NHC-Pd@Fe3O4) nanomagnetic catalyst was synthesized by a facile multistep synthesis under aerobic conditions using inexpensive chemicals. The NO2-NHC-Pd@Fe3O4 nanomagnetic catalyst was characterized by various analytical techniques such as attenuated total reflectance infrared spectroscopy (ATR-IR), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), energy-dispersive X-ray spectroscopy (EDS), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller surface area analysis (BET). The synthesized NO2-NHC-Pd@Fe3O4 nanomagnetic catalyst showed excellent catalytic activity in both Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions for various substrates under mild reaction conditions. Recovery of the NO2-NHC-Pd@Fe3O4 nanomagnetic catalyst from the reaction mixture was easily accomplished by applying an external magnet. The recovered NO2-NHC-Pd@Fe3O4 nanomagnetic catalyst exhibited very good catalytic activity up to seven recycles in Suzuki-Miyaura and five recycles in Mizoroki-Heck cross-coupling reactions without considerable loss of its catalytic activity.
- Kandathil, Vishal,Fahlman, Bradley D.,Sasidhar,Patil, Siddappa A.,Patil, Shivaputra A.
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p. 9531 - 9545
(2017/08/29)
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- Electron-Poor, Fluoro-Containing Arylboronic Acids as Efficient Coupling Partners for Bis(1,5-cyclooctadiene)nickel(0)/Tricyclohexylphosphine-Catalyzed Cross-Coupling Reactions of Aryl Arenesulfonates
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The use of electron-poor, fluoro-containing arylboronic acids as general coupling partners for nickel(0)/tricyclohexylphosphine-catalyzed cross-coupling of aryl arenesulfonates is described. Electron-poor fluoro-containing arylboronic acids were found to react faster than electron-rich/neutral arylboronic acids, with (4-methoxyphenyl)(4-methylbenzenesulfonato-κO)bis(tricyclohexylphosphine)nickel. Bis(1,5-cyclooctadiene)nickel(0)/tricyclohexylphosphine, (4-methoxyphenyl)(4-methylbenzenesulfonato-κO)bis(tricyclohexylphosphine)nickel and bis(tricyclohexylphosphine)nickel(II) bromide were all found to be efficient catalysts/catalyst precursors. (Figure presented.) .
- Chen, Wen-Bo,Xing, Chun-Hui,Dong, Jie,Hu, Qiao-Sheng
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supporting information
p. 2072 - 2076
(2016/07/16)
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- Highly Active and Stable Palladium Nanoparticles Encapsulated in a Mesoporous Silica Yolk-Shell Nanoreactor for Suzuki-Miyaura Reactions
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A yolk-shell nanoreactor with nitrogen-doped carbon spheres as the yolk and mesoporous silica (mSiO2) as the shell, together with Pd nanoparticles uniformly encapsulated in the void space, were prepared. They showed excellent catalytic activity and stability in the Suzuki-Miyaura reaction between bromobenzene and phenylboronic acid with 99% yield in 5 min. Core catalysis: A yolk-shell nanoreactor with nitrogen-doped carbon spheres as the yolk and mesoporous silica (mSiO2) as the shell, together with Pd nanoparticles uniformly encapsulated in the void space, showed excellent catalytic activity and stability in the Suzuki-Miyaura reaction. CTAB=Hexadecyl trimethyl ammonium bromide, PDA=Polydopamine, TEOS=Tetraethyl orthosilicate.
- Wei, Fang,Cao, Changyan,Sun, Yongbin,Yang, Shuliang,Huang, Peipei,Song, Weiguo
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p. 2475 - 2479
(2015/08/24)
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- Palladium-catalyzed cross-coupling of polyfluoroarenes with simple arenes
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The most efficient method to construct biaryls is the direct dehydrogenative cross-coupling of two different aromatic rings. Such an ideal cross arylation starting from distinct polyfluoroarenes and simple arenes was presented. The selectivity of the cross-coupling was controlled by both of the electronic property of fluoroarenes and steric hindrance of simple arenes. Diisopropyl sulfide was essential to promote the efficacy.
- Li, Hu,Liu, Jia,Sun, Chang-Liang,Li, Bi-Jie,Shi, Zhang-Jie
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supporting information; experimental part
p. 276 - 279
(2011/04/17)
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- ARYL-PHENYL-SULFONAMIDE-PHENYLENE COMPOUNDS AND THEIR USE
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The present invention pertains generally to the field of therapeutic compounds, and more specifically to certain aryl-phenyl-sulfonamido-phenylene compounds of the following formula (I) (collectively referred to herein as "APSAP compounds"). The present invention also pertains to pharmaceutical compositions comprising such compounds, and the use of such compounds and compositions, both in vitro and in vivo, in treatment, for example, of inflammation and/or joint destruction and/or bone loss; of disorders mediated by excessive and/or inappropriate and/or prolonged activation of the immune system; of inflammatory and autoimmune disorders, for example, rheumatoid arthritis, psoriasis, psoriatic arthritis, chronic obstructive pulmonary disease (COPD), atherosclerosis, inflammatory bowel disease, ankylosing spondylitis, and the like; of disorders associated with bone loss, such as bone loss associated with excessive osteoclast activity in rheumatoid arthritis, osteoporosis, cancer-associated bone disease, Paget's disease and the like, etc.; and of cancer, such as a haematological malignancy, a solid tumour, etc.
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Page/Page column 86
(2010/04/25)
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- ARYL-PHENYL-SULFONAMIDO-CYCLOALKYL COMPOUNDS AND THEIR USE
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The present invention pertains generally to the field of therapeutic compounds, and more specifically to certain aryl-phenyl-sulfonamido-cycloalkyl compounds of the following formula (collectively referred to herein as "APSAC compounds"). The present invention also pertains to pharmaceutical compositions comprising such compounds, and the use of such compounds and compositions, both in vitro and in vivo, in treatment, for example, of inflammation and/or joint destruction and/or bone loss; of disorders mediated by excessive and/or inappropriate and/or prolonged activation of the immune system; of inflammatory and autoimmune disorders, for example, rheumatoid arthritis, psoriasis, psoriatic arthritis, chronic obstructive pulmonary disease (COPD), atherosclerosis, inflammatory bowel disease, ankylosing spondylitis, and the like; of disorders associated with bone loss, such as bone loss associated with excessive osteoclast activity in rheumatoid arthritis, osteoporosis, cancer-associated bone disease, Paget's disease and the like, etc.; and of cancer, such as a haematological malignancy, a solid tumour, etc. Formula (I).
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Page/Page column 90
(2010/04/25)
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- Stille cross-coupling reactions with tin reagents supported on ionic liquids
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New ionic-liquid-supported tin reagents were synthesized and used in Stille cross-coupling reactions. High yields of biaryls were obtained under low-temperature, solvent-free, ligand-free conditions, with simple purification techniques. Moreover, the tin compound could be recycled up to five times without significant loss of reactivity. An expanded catalytic cycle for the Stille cross coupling reaction is proposed in order to explain side products that were formed under certain reaction conditions.
- Pham, Phuoc Dien,Vitz, Juergen,Chamignon, Cecile,Martel, Arnaud,Legoupy, Stephanie
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experimental part
p. 3249 - 3257
(2009/12/24)
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- The synthesis and application of fluorous boronates without perfluorinated solvents
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The synthesis of a fluorous diol 4 bearing a perfluorodecyl chain was described. A series of boronic acid were attached to 4 by esterification. The purification of the products was fulfilled by facile filtration instead of expensive and environmental troublesome fluorous liquid-liquid extraction. The Suzuki cross-coupling reactions of the formed fluorous boronates 5 underwent smoothly and the fluorous diol 4 was recycled in good yields.
- Wang, Chun-Yan,Meng, Wei-Dong,Huang, Yan-Gen,Qing, Feng-Ling
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p. 996 - 1001
(2007/10/03)
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- PROCESS FOR PRODUCING BIARYL COMPOUND
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A process for producing a biaryl compound, characterized by reacting an arylhydrazine compound, hydrogen peroxide and an aryl compound. When the reaction is conducted in the presence of a given metal or a compound of the metal or in the presence of a metal oxide obtained by reacting the given metal or a compound of the metal with hydrogen peroxide, then the yield of the biaryl compound is improved.
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- Manganese(III) acetate-mediated oxidative coupling of phenylhydrazines with benzene: A novel method for biaryl coupling
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The reaction of phenylhydrazines with benzene in the presence of manganese(III) acetate affords biaryls in good yields. The same reaction was carried out with similar oxidants, such as CoIII, CeIV and PbIV; among these oxidants MnIII acetate shows higher efficiency and selectivity.
- Demir,Reis,Oezguel-Karaaslan
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p. 3042 - 3045
(2007/10/03)
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- Synthesis of Biaryls from Aryltriazenes
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Aryltriazenes react with aromatic solvents in the presence of trifluoroacetic acid to produce biaryls.The mechanism of the reaction involves the formation of arenediazonium trifluoroacetates which lose nitrogen to give mainly aryl radicals.
- Patrick, Timothy B.,Willaredt, Richard P.,DeGonia, David J.
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p. 2232 - 2235
(2007/10/02)
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- Process for preparing biaryl compounds via coupling of an arylamine with an arene
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Improvement in the process for preparing biaryl compounds via coupling of an arylamine with an arene in the presence of a nitrite, an acid and copper metal or a derivative thereof; the improvement is consisting in adding to the reaction mixture a trialkylorthoformate. The process may be used for preparing drugs such as Flurbiprofen and Xenbucin or intermediate compounds particularly useful for preparing Flurbiprofen, Flufenisal, Chlordimorin, Xenbucin, Xenysalate, Xenyhexenic acid and the like.
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- Homolytic Reactions of Polyfluoroaromatic Compounds. Part 16. Competitive Phenylation of Polyfluorobenzenes
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Pairs of polyfluorobenzenes were allowed to compete for phenyl radicals generated by thermolysis of benzoyl peroxide at 80 deg C.From the relative yields of biaryl, and the yields of each biaryl formed upon arylation of each arene individually, the relative rates of attack of each site in each arene were deduced.Neither iron(III) benzoate nor trichloroacetic acid uniformly improved yields of biaryl, although in some cases the isomer distribution altered, when decomposition of benzoyl peroxide was carried out in the presence of such additives, to favour products of aryldehydrogenation or of aryldefluorination, respectively.Competition did not usually affect the distribution of attack of a particular arene, except when hexafluorobenzene was used, in which case greater selectivity of attack of the second arene occured.This suggested the formation of a 'stabilised' phenyl radical, and supported an earlier suggestion of species such as >; other evidence also supported the postulate.
- Allen, Kim J.,Bolton, Roger,Williams, Gareth H.
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p. 691 - 696
(2007/10/02)
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- Process for preparing 4-(2,4-difluorophenyl)-salicyclic acid
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5-(2,4-difluorophenyl)salicylic acid, an anti-inflammatory, anti-pyretic, analgesic agent is prepared by: (1) diazotizing 2,4-difluoroaniline in the presence of benzene to yield 2,4-difluorobiphenyl; (2) Friedel-Crafts acylation to produce 2',4'-difluoro-4-alkanoylbiphenyl; (3) oxidation of the alkanoyl group to produce 2',4'-difluoro-4-alkanoyloxybiphenyl; (4) hydrolysis of the alkanoyl group to produce 4-(2,4-difluorophenyl)phenol; and (5) Kolbe-Schmitt carboxylation to produce the final product.
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- Araliphatic dihalogen compounds and process for their preparation
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Compounds of the formula STR1 wherein R1 and R2 are the same or different and are F, Cl or Br; Q is --CH(CH3)-CH2 --, --C(OH) (CH3)-CH2 -- or --C(CH3) =CH--; Y is COOH, COOR3, CH2 OH or CH2 OAc; n is 0 or 1; R3 is alkyl or aryl of up to 8 carbon atoms or C6 H4 NHCOCH3 ; and Ac is acyl of 1-8 carbon atoms; And physiologically acceptable salts thereof, are anti-inflammatory agents, which can be made from compounds of the formula Z -- X, wherein Z is STR2 AND X can be converted to --Q-Y.
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- 2-(Substituted biphenylyl) propionic acids
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2-(Substituted biphenylyl)propionic acids and salts and esters thereof, said substituents being selected from fluorine and bromine atoms, useful as anti-inflammatory agents, and their preparation.
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- Preparation of biphenyl compounds
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Biaryl coupling, particularly to form 2,4-difluorobiphenyl, is accomplished by diazotizing an aniline and coupling the benzenediazonium salt with a second aromatic component in the presence of a strong acid, an inert finely divided solid and copper powder or a copper salt.
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