- Oxalohydrazide Ligands for Copper-Catalyzed C?O Coupling Reactions with High Turnover Numbers
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Here, we report a class of ligands based on oxalohydrazide cores and N-amino pyrrole and N-amino indole units that generates long-lived copper catalysts for couplings that form the C?O bonds in biaryl ethers. These Cu-catalyzed coupling of phenols with aryl bromides occurred with turnovers up to 8000, a value which is nearly two orders of magnitude higher than those of prior couplings to form biaryl ethers and nearly an order of magnitude higher than those of any prior copper-catalyzed coupling of aryl bromides and chlorides. This ligand also led to copper systems that catalyze the coupling of aryl chlorides with phenols and the coupling of aryl bromides and iodides with primary benzylic and aliphatic alcohols. A wide variety of functional groups including nitriles, halides, ethers, ketones, amines, esters, amides, vinylarenes, alcohols and boronic acid esters were tolerated, and reactions occurred with aryl bromides in pharmaceutically related structures.
- Ray, Ritwika,Hartwig, John F.
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supporting information
p. 8203 - 8211
(2021/03/08)
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- Preparation method of substituted phenoxy benzylamine compound and preparation method of pyrazole carboxamide compound
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The invention discloses a preparation method of a substituted phenoxy benzylamine compound. P-halobenzonitrile is taken as an initial raw material, R'OH is taken as a solvent in the presence of R'OM, the substituted phenoxy benzylamine compound is obtained through hydrogen reduction, and the preparation method has the advantages of high yield and high purity. The invention also discloses a preparation method of pyrazole carboxamide. The preparation method of pyrazole carboxamide comprises the following steps: salifying the substituted phenoxy benzylamine compound, and reacting with a substituted pyrazole acyl chloride compound to prepare the pyrazole carboxamide compound at an expected high yield. The preparation methods provided by the invention have the advantages of high product purity, high yield, low solvent loss and low production cost.
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Paragraph 0028-0031
(2021/06/26)
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- Thermally stable and robust gadolinium-based metal-organic framework: Synthesis, structure and heterogeneous catalytic O-arylation reaction
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Hydrothermal treatment of gadolinium nitrate and 2,6-naphthalenedicarboxylic acid (H2NDC) afforded a new metal-organic framework compound, {[Gd4(NDC)6(H2O)6]·2H2O}n(1). Compound 1 has been characterized by single-crystal X-ray crystallography, elemental analysis, FT-IR spectroscopy, therrmogravimetric analysis (TGA) and powder X-ray diffraction analysis. It is crystallized in the monoclinic system with the P21/n space group. Four crystallographically distinct Gd (III) centres are interconnected with each other through bridged carboxylato oxygen atoms and water molecules to form tetranuclear secondary building units, which are further connected through the carboxylato ligand and the network propagates along the crystallographic ac plane to form a 2D structure. Subsequent reinforcement from the remaining carboxylato oxygen atoms gives rise to a robust 3D framework structure. Thermogravimetric analysis demonstrates that compound 1 is fairly stable after dehydration under a nitrogen atmosphere. Notably, compound 1 is capable of catalyzing the O-arylation reaction efficiently between substituted phenols and bromoarene under heterogeneous conditions at 80 °C to afford unsymmetrical diarylethers.
- Ghosh, Pameli,Maity, Tanmoy,Biswas, Saptarshi,Debnath, Rakesh,Koner, Subratanath
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- CoII Immobilized on Aminated Magnetic-Based Metal–Organic Framework: An Efficient Heterogeneous Nanostructured Catalyst for the C–O Cross-Coupling Reaction in Solvent-Free Conditions
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Abstract: In this paper, we report the synthesis of Fe3O4?AMCA-MIL53(Al)-NH2-CoII NPs based on the metal–organic framework structures as a magnetically separable and environmentally friendly heterogeneous nanocatalyst. The prepared nanostructured catalyst efficiently promotes the C–O cross-coupling reaction in solvent-free conditions without the need for using toxic solvents and/or expensive palladium catalyst. Graphic Abstract: [Figure not available: see fulltext.].
- Mohammadinezhad, Arezou,Akhlaghinia, Batool
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p. 332 - 352
(2020/01/11)
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- Design, synthesis, insecticidal, and acaricidal activities of novel pyrimidinamine derivatives containing a biphenyl ether
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A series of original pyrimidinamine derivatives containing a biphenyl ether moiety were designed and synthesized. Their structures were confirmed by 1H NMR, MS, and elemental analyses. Their insecticidal activities against lepidopteran and hemiptera insects and acaricidal activities were tested. The results of bioassay demonstrated that 9k showed the best activity (LC50 = 2.08 mg/L) against Tetranychus urticae, which is comparable with the positive control, spirotetramat (LC50 = 2.27 mg/L), and 9g showed better activity (LC50 = 0.52 mg/L) against Aphis fabae than the positive control, imidacloprid (LC50 = 1.02 mg/L), and relatively good activity (LC50 = 2.49 mg/L) against T urticae. Their structure-activity relationships indicated that both an ethyl group on the 4-position of the pyrimidine ring and alkyl chain as a para-substituent group of the benzene ring showed good biological activity.
- Li, Lizhong,Zhou, Chunge,Liu, Minhua,Zhang, Ping,Zhang, Ning,Li, Jianming,Li, Tao,Liu, Xingping,Cheng, Shufen,Li, Qianhe,Liu, Aiping
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p. 3206 - 3214
(2019/11/13)
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- Structure-Activity Relationship Studies of Tolfenpyrad Reveal Subnanomolar Inhibitors of Haemonchus contortus Development
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Recently, we have discovered that the registered pesticide, tolfenpyrad, unexpectedly and potently inhibits the development of the L4 larval stage of the parasitic nematode Haemonchus contortus with an IC50 value of 0.03 μM while displaying good selectivity, with an IC50 of 37.9 μM for cytotoxicity. As a promising molecular template for medicinal chemistry optimization, we undertook anthelmintic structure-activity relationships for this chemical. Modifications of the left-hand side (LHS), right-hand side (RHS), and middle section of the scaffold were explored to produce a set of 57 analogues. Analogues 25, 29, and 33 were shown to be the most potent compounds of the series, with IC50 values at a subnanomolar level of potency against the chemotherapeutically relevant fourth larval (L4) stage of H. contortus. Selected compounds from the series also showed promising activity against a panel of other different parasitic nematodes, such as hookworms and whipworms.
- Le, Thuy G.,Kundu, Abhijit,Ghoshal, Atanu,Nguyen, Nghi H.,Preston, Sarah,Jiao, Yaqing,Ruan, Banfeng,Xue, Lian,Huang, Fei,Keiser, Jennifer,Hofmann, Andreas,Chang, Bill C. H.,Garcia-Bustos, Jose,Wells, Timothy N. C.,Palmer, Michael J.,Jabbar, Abdul,Gasser, Robin B.,Baell, Jonathan B.
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p. 1036 - 1053
(2019/01/14)
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- Novel cobalt-valine catalyzed O-arylation of phenols with electron deficient aryl iodides
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Abstract: A Novel cobalt-catalyzed O-arylation of phenols with electron deficient aryl iodides is described. The reaction employs cheap and easy-to-handle cobalt acetate tetrahydrate as the catalyst precursor and naturally occurring l-valine as the ligand without the use of any transmetallating or reducing agents. The new protocol offers a wide scope for a variety of phenols towards O-arylation with moderate to excellent yields with electron deficient aryl iodides.
- Ujwaldev, Sankuviruthiyil M.,Saranya, Salim,Harry, Nissy Ann,Anilkumar, Gopinathan
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p. 339 - 346
(2019/01/18)
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- Probing the Azaaurone Scaffold against the Hepatic and Erythrocytic Stages of Malaria Parasites
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The potential of azaaurones as dual-stage antimalarial agents was investigated by assessing the effect of a small library of azaaurones on the inhibition of liver and intraerythrocytic lifecycle stages of the malaria parasite. The whole series was screened against the blood stage of a chloroquine-resistant Plasmodium falciparum strain and the liver stage of P. berghei, yielding compounds with dual-stage activity and sub-micromolar potency against erythrocytic parasites. Studies with genetically modified parasites, using a phenotypic assay based on the P. falciparum Dd2-ScDHODH line, which expresses yeast dihydroorotate dehydrogenase (DHODH), showed that one of the azaaurone derivatives has the potential to inhibit the parasite mitochondrial electron-transport chain. The global urgency in finding new therapies for malaria, especially against the underexplored liver stage, associated with chemical tractability of azaaurones, warrants further development of this chemotype. Overall, these results emphasize the azaaurone chemotype as a promising scaffold for dual-stage antimalarials.
- Carrasco, Marta P.,Machado, Marta,Gon?alves, Lídia,Sharma, Moni,Gut, Jiri,Lukens, Amanda K.,Wirth, Dyann F.,André, Vania,Duarte, Maria Teresa,Guedes, Rita C.,dos Santos, Daniel J. V. A.,Rosenthal, Philip J.,Mazitschek, Ralph,Prudêncio, Miguel,Moreira, Rui
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supporting information
p. 2194 - 2204
(2016/10/19)
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- Heterogeneous O -arylation of nitroarenes with substituted phenols over a copper immobilized mesoporous silica catalyst
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Highly porous and robust mesoporous silica, SBA-15 has been subjected to post-synthesis modification for the anchoring of copper through Schiff base moiety formation using the silicon alkoxide route. The hybrid porous material has been fully characterized by powder-XRD, electronic spectra, EPR, thermogravimetric analysis, N2 sorption measurements, and TEM and SEM/EDS studies. The efficiency of the catalyst has been assessed in the O-arylation reaction using various substituted phenols and nitroarenes in heterogeneous conditions. The catalytic coupling reaction efficiently produces unsymmetrical diaryl ethers. The impressive capability to activate substrates having electron-donating or electron-withdrawing substituents and to have a high turnover frequency in the catalytic reactions made the catalyst highly desirable.
- Maity, Tanmoy,Bhunia, Susmita,Das, Soma,Koner, Subratanath
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p. 33380 - 33386
(2016/05/09)
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- Copper mediated formation of carbon-heteroatom bonds using organoboron reagents and ultrasound
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This report summarizes research efforts focused on copper acetate mediated reactions to form new carbon-heteroatom bonds using organoboron reagents under ultrasound irradiation. The method involves the application of ultrasound irradiation to the Chan-Evans-Lam reaction to achieve O-arylation of phenols, N-arylation of anilines and indoles, and S-arylation of thiols. Ultrasound irradiation was found to decrease reaction times from 72 hours to 4 hours while improving the product yields an average of 20%.1 Representative C-O, C-N, and C-S coupling reactions were successfully scaled-up from the milligram to gram levels while maintaining good product yields offering potential applications in industrial processes.
- Musolino, Bryan J.,Kabalka, George W.
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p. 271 - 297
(2015/03/04)
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- Design and Synthesis of a Focused Library of Diamino Triazines as Potential Mycobacterium tuberculosis DHFR Inhibitors
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We report design of a series of 2,4-diamino triazines as Mycobacterium tuberculosis (Mtb) dihydrofolate reductase inhibitors. The synthesized compounds were evaluated against Mtb (H37Rv and Dormant stage H37Ra), their cytotoxicity was assessed (HepG2 and A549 cell lines), and selectivity toward Mtb was evaluated by testing against other bacterial strains. Some derivatives showed promising activity along with low cytotoxicity. The most potent compound in the whole cell assay (MIC 0.325 μM against H37Rv) showed selectivity in the enzyme assay and exhibited synergy with second line anti-TB agent p-amino salicylic acid. This study therefore provides promising molecules for further development as antituberculosis DHFR inhibitors.
- Lele, Arundhati C.,Raju, Archana,Khambete, Mihir P.,Ray,Rajan,Arkile, Manisha A.,Jadhav, Nandadeep J.,Sarkar, Dhiman,Degani, Mariam S.
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p. 1140 - 1144
(2015/11/24)
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- A family of ligand and anion dependent structurally diverse Cu(II) Schiff-base complexes and their catalytic efficacy in an O-arylation reaction in ethanolic media
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Two nitrato bridged dinuclear systems [Cu2(L1)2(NO3)3]NO3·H2O (1) and [Cu2(L2)2(NO3)3]NO3·MeOH (2), five monomeric complexes viz. [Cu(L3)(NO3)]NO3 (3), [Cu(L4)(NO3)]NO3 (4), [Cu(L5)(NO3)]NO3 (5), [Cu(L6)(NO3)NO3] (7), [Cu(L7)(NO3)]NO3 (8) and one hetero bi-bridged (phenoxido and water) dinuclear complex [Cu2(L2)2(H2O)2](ClO4)4·4H2O (6) have been synthesized and characterized using several physicochemical methods (L1 = 1-(N-3-methoxysalicylideneimino)-ethane-2-piperazine, L2 = 1-(N-3-ethoxysalicylideneimino)-ethane-2-piperazine, L3 = 1-(N-4′-ethoxy-α-methylasalicylideneimino)-ethane-2-piperazine, L4 = 1-(N-5′-chloro-α-methylasalicylideneimino)-ethane-2-piperazine, L5 = 1-(N-5-chlorosalicylideneimino)-ethane-2-piperazine, L6 = 1-(N-4-methoxysalicylideneimino)-ethane-2-piperazine and L7 = 1-(N-4′-methoxy-α-methylasalicylideneimino)-ethane-2-piperazine). X-ray structural analysis showed that complexes 1 and 2 are discrete dinuclear species where the pentacoordinated metal centers are bridged through a nitrate ion. In 3, 4, 5 and 8 the monomeric copper center displays a square pyramidal geometry with a weak axial Cu-O bond. In 7, the monomeric copper center shows a distorted octahedral geometry with two coordinated nitrate anions. However, in 6 the two copper centers coordinate in different manners (one is square-pyramidal and the other is distorted octahedral) and are bridged through a phenoxido group and a water molecule. All complexes efficiently catalyze the C-O coupling reaction under homogeneous conditions at 80 °C to afford unsymmetrical diaryl ethers using nitroarenes to act as an excellent electrophile. Notably, the reaction is carried out in ethanol media which facilitates the avoidance of toxic wastes. Structurally diverse copper(ii) Schiff-base complexes have rarely been used systematically in catalytic C-O coupling reactions.
- Maity, Tanmoy,Saha, Debraj,Bhunia, Susmita,Brand?o, Paula,Das, Soma,Koner, Subratanath
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p. 82179 - 82191
(2015/10/12)
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- Probing the aurone scaffold against Plasmodium falciparum: Design, synthesis and antimalarial activity
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A library comprising 44 diversely substituted aurones derivatives was synthesized by straightforward aldol condensation reactions of benzofuranones and the appropriately substituted benzaldehydes. Microwave enhanced synthesis using palladium catalyzed protocols was introduced as a powerful strategy for extending the chemical space around the aurone scaffold. Additionally, Mannich-base derivatives, containing a 7-aminomethyl-6-hydroxy substitution pattern at ring A, were also prepared. Screening against the chloroquine resistant Plasmodium falciparum W2 strain identified novel aurones with IC 50 values in the low micromolar range. The most potent compounds contained a basic moiety, with the ability to accumulate in acidic digestive vacuole of the malaria parasite. However, none of those aurones revealed significant activity against hemozoin formation and falcipain-2, two validated targets expressed during the blood stage of P. falciparum infection and functional in digestive vacuole of the parasite. Overall, this study highlight (i) the usefulness of aurones as platforms for synthetic procedures using palladium catalyzed protocols to rapidly deliver lead compounds for further optimization and (ii) the potential of novel aurone derivatives as promising antimalarial compounds.
- Carrasco, Marta P.,Newton, Ana S.,Gon?alves, Lídia,Góis, Ana,Machado, Marta,Gut, Jiri,Nogueira, Fátima,H?nscheid, Thomas,Guedes, Rita C.,Dos Santos, Daniel J.V.A.,Rosenthal, Philip J.,Moreira, Rui
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supporting information
p. 523 - 534
(2014/05/20)
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- Highly active recyclable heterogeneous Pd/ZnO nanoparticle catalyst: Sustainable developments for the C-O and C-N bond cross-coupling reactions of aryl halides under ligand-free conditions
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Efficient Pd supported on ZnO nanoparticles for the ligand-free O-arylation and N-arylation of phenols and various N-H heterocycles with aryl chlorides, bromides, and iodides were readily synthesized and characterized. The amount of palladium on ZnO is 9.84 wt% (0.005 g of the catalyst contains 462 × 10-8 mol% of Pd) which was determined by ICP analysis. This nano sized Pd/ZnO with an average particle size of 20-25 nm and specific surface area 40.61 m2 g-1 was used as a new reusable heterogeneous catalyst for the formation of C-O and C-N bonds in organic synthesis. This protocol gives the arylated product in satisfactory yields without any N2 or Ar flow. The catalyst can be recovered and recycled several times without marked loss of activity.
- Hosseini-Sarvari, Mona,Razmi, Zahra
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p. 44105 - 44116
(2014/12/10)
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- First palladium-catalyzed denitrated coupling reaction of nitroarenes with phenols
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The first palladium-catalyzed protocol for the denitrated coupling reaction of nitroarenes with phenols has been developed, achieving unsymmetrical diaryl ethers in moderate to excellent yields. The cyclopalladated ferrocenylimine (catalyst Ic) exhibited highly catalytic activity for this transformation with low catalyst loading (0.75 mol%) and short reaction time (2 h). The efficiency of this reaction was demonstrated by its compatibility with a range of groups. Moreover, the rigorous exclusion of air or moisture was not required in these transformations. Copyright
- Wang, Hailei,Yu, Ajuan,Cao, Aijuan,Chang, Junbiao,Wu, Yangjie
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p. 611 - 614
(2013/10/21)
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- Metal- and ligand-free Ullmann-type C-O and C-N coupling reactions promoted by potassium tert-butoxide
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A simple, metal- and ligand-free procedure for the Ullmann-type C-O coupling reactions has been achieved by allowing aryl bromides to react with a variety of phenols in the presence of t-BuOK. Moderate to excellent yields of O-arylation products are obtained under mild conditions in a short time. In addition, two examples of C-N coupling reactions are also reported. A benzyne mechanism is proposed according to the experiment data.
- Yang, Shuliang,Wu, Cunqi,Ruan, Mingbo,Yang, Yanqin,Zhao, Yongxia,Niu, Jiajia,Yang, Wei,Xu, Jingwei
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supporting information; experimental part
p. 4288 - 4292
(2012/09/22)
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- Ligand-free copper-catalyzed O-arylation of nitroarenes with phenols
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The first example of ligand-free copper-catalyzed O-arylation of nitroarenes with phenols was developed, achieving unsymmetrical diaryl ethers in moderate to excellent yields. This arylation proceeded smoothly without promotion of the ligands, and displayed great functional group compatibility. Thus, the method represents a new, facile, and cost-effective approach to access unsymmetrical diaryl ethers.
- Chen, Jiuxi,Wang, Xingyong,Zheng, Xingwang,Ding, Jinchang,Liu, Miaochang,Wu, Huayue
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supporting information
p. 8905 - 8907
(2012/10/29)
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- The coupling of arylboronic acids with nitroarenes catalyzed by rhodium
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The coupling of arylboronic acids with electron-deficient nitroarenes was realized for the first time by using a rhodium(I) catalyst under an air atmosphere, achieving unsymmetrical diaryl ethers with yields ranging from poor to good. From a deuterium labeling experiment, the oxygen atom is derived from ambient water. The efficiency of this reaction was demonstrated by its compatibility with fluoro, bromo, chloro, and trifluoromethyl groups.
- Zheng, Xingwang,Ding, Jinchang,Chen, Jiuxi,Gao, Wenxiao,Liu, Miaochang,Wu, Huayue
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supporting information; experimental part
p. 1726 - 1729
(2011/05/06)
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- Selective one-pot access to symmetrical or unsymmetrical diaryl ethers by copper-catalyzed double arylation of a simple oxygen source
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Great CO-mbination: A novel method is reported for the controlled one-pot synthesis of various symmetrical or unsymmetrical diaryl ethers by double arylation of a simple inorganic oxygen source (see scheme). This versatile and highly selective process is based on the use of a cheap and low toxicity copper catalytic system.
- Tlili, Anis,Monnier, Florian,Taillefer, Marc
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supporting information; experimental part
p. 12299 - 12302
(2011/02/16)
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- COMPOSITION FOR AGRICULTURAL USE FOR CONTROLLING OR PREVENTING PLANT DISEASES CAUSED BY PLANT PATHOGENS
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Disclosed is a composition for agricultural use, which is used for controlling or preventing plant diseases caused by plant pathogens. The composition for agricultural use contains a compound represented by formula (1), a salt thereof or a hydrate of the compound or the salt. (1) [In the formula, Z represents an oxygen atom, a sulfur atom or NRz; and E represents a furyl group, a thienyl group, a pyrrolyl group, a tetrazolyl group, a thiazolyl group, a pyrazolyl group, a phenyl group or the like.]
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Page/Page column 264
(2010/11/19)
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- Copper(I)-catalyzed C-C and C-O coupling reactions using hydrazone ligands
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Copper-catalyzed C-C coupling reaction of aryl iodides with diethylmalonate in toluene at 90C gave arylated malonates using 5 mol% of CuI with hydrazone 1a as a ligand in good yields under an aerobic atmosphere. We also found CuI/hydrazone 1b in toluene to be an efficient catalytic system for C-O coupling reactions of aryl bromides with phenols to give aryl ethers in good yields at 110C under an aerobic atmosphere.
- Mino, Takashi,Yagishita, Fumitoshi,Shibuya, Masanori,Kajiwara, Kenji,Shindo, Hiroaki,Sakamoto, Masami,Fujita, Tsutomu
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experimental part
p. 2457 - 2460
(2010/01/07)
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- Immobilization of copper in organic-inorganic hybrid materials: a highly efficient and reusable catalyst for the Ullmann diaryl etherification
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The immobilization of copper in organic-inorganic hybrid materials catalyzing the Ullmann reaction has been described. Phenols reacted with aryl iodides, aryl bromides and aryl chlorides smoothly in the presence of a 3-(2-aminoethylamino)propyl functionalized silica gel immobilized copper catalyst. The protocol involved the use of DMSO as the solvent, and potassium fluoride as the base. The reactions generated the corresponding cross-coupling products in good to excellent yields. Furthermore, the silica-supported copper could be recovered and recycled by a simple filtration of the reaction solution and used for 10 consecutive trials without loss of its reactivity.
- Miao, Tao,Wang, Lei
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- Correlation between molecular dipole moment and centrosymmetry in some crystalline diphenyl ethers
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The presence of a large molecular dipole moment in diphenyl ethers leads unequivocally to a centrosymmetric crystal structure. The Royal Society of Chemistry 2005.
- Dey, Archan,Desiraju, Gautam R.
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p. 2486 - 2488
(2007/10/03)
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- Synthesis of diaryl ethers using an easy-to-prepare, air-stable, soluble copper(I) catalyst
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We have found that bromo(triphenylphosphine)copper(I), an air-stable and soluble copper(I) complex, can be used as a catalyst in the synthesis of diaryl ethers. Using this catalyst, we have synthesized diaryl ethers from electron-rich aryl bromides and electron-rich phenols in the presence of cesium carbonate, in 17-24 h, in NMP. We also found that electron-deficient aryl bromides couple with phenols in the presence of cesium carbonate, in 6 h in NMP at 70°C, without the catalyst.
- Gujadhur,Venkataraman
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p. 2865 - 2879
(2007/10/03)
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