- Ligand-free copper-catalyzed coupling of phenols with nitroarenes by using a metal-organic framework as a robust and recoverable catalyst
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A highly porous metal-organic framework Cu2(BDC)2(DABCO) (H2BDC=1,4-benzenedicarboxylic acid, DABCO=1,4-diazabicyclo[2.2.2]octane) was synthesized and used as an efficient recyclable heterogeneous catalyst for the coupling reaction of phenols with nitroarenes to form diaryl ethers without using a ligand. Physical characterization of the MOF was obtained by using XRD, SEM, TEM, thermogravimetric analysis (TGA), FTIR spectroscopy, atomic absorption spectrophotometry (AAS), H2 temperature-programmed reduction (H2-TPR), and N2 physisorption measurements. The Cu2(BDC)2(DABCO)-catalyzed coupling reaction offers several advantages compared to the conventional Ullmann reaction for the synthesis of unsymmetrical diaryl ethers. To the best of our knowledge, the ligand-free Cu-catalyzed O-arylation reaction of phenols with nitroarenes that uses a heterogeneous catalyst has not been mentioned previously in the literature.
- Phan, Nam T. S.,Nguyen, Tung T.,Nguyen, Vu T.,Nguyen, Khoa D.
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Read Online
- Reductively activated "Polar" nucleophilic aromatic substitution. II. The reaction of p-dinitrobenzene and p-nitrobenzonitrile with charged and neutral nucleophiles
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Electrochemical studies indicate that although the reactions of p-dinitrobenzene and p-nitrobenzonitrile with phenolate or phenol in DMF show radical features, they can not be attributed to the direct reaction of the nucleophile on the substrate radical anion. Reductive activation is feasible in certain cases (reaction of p-dinitrobenzene with phenol). However, substrate radical anion formation is not responsible for it.
- Mir, Miquel,Espin, Martirio,Marquet, Jorge,Gallardo, Iluminada,Tomasi, Chiara
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Read Online
- Palladium-catalyzed formation of diaryl ethers from aryl bromides. Electron poor phosphines enhance reaction yields
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Aryl bromides were converted to diaryl ethers with sodium aryl oxides in the presence of catalytic amounts of Pd(DBA)2 and DPPF. Isolated yields of over 90% were achieved in reactions with electron deficient aryl bromides and electron rich sodium aryl oxides. Electron poor DPPF derivatives led to increased reaction yields.
- Mann, Grace,Hartwig, John F.
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Read Online
- Nickel-Catalyzed Etherification of Phenols and Aryl Halides through Visible-Light-Induced Energy Transfer
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Notwithstanding some progress in nickel-catalyzed etherification of alkanols and arylhalides, the ability of such a Ni-catalyzed transformation employing phenols to diaryl ethers is unsuccessful due to phenolates with much lower reduction potentials, which suppress the oxidation of nickel(II) intermediates into requisite Ni(III) species. We herein report visible-light-initiated, nickel-catalyzed O-arylation of phenols with arylhalides using t-BuNH(i-Pr) as the base and thioxanthen-9-one as the photosensitizer under visible light. This photocoupling exhibits a broad substrate scope.
- Zhu, Da-Liang,Jiang, Shan,Wu, Qi,Wang, Hao,Li, Hai-Yan,Li, Hong-Xi
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supporting information
p. 8327 - 8332
(2021/10/25)
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- L-Proline N-oxide dihydrazides as an efficient ligand for cross-coupling reactions of aryl iodides and bromides with amines and phenols
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A novel catalytic system based on L-proline N-oxide/CuI was developed and applied to the cross-coupling reactions of various N- and O- nucleophilic reagents with aryl iodides and bromides. This strategy featured in the employment of an-proline derived dihydrazides N-oxide compound as the superior supporting ligand. By using this protocol, a variety of products, including N-arylimidazoles, N-arylpyrazoles, N-arylpyrroles, N-arylamines, and aryl ethers, were synthesized with up to 99% yield.
- Ding, Zhiqiang,Nie, Nan,Chen, Tian,Meng, Lingxin,Wang, Gongshu,Chen, Zhangpei,Hu, Jianshe
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supporting information
(2020/12/21)
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- Solvent-free palladium-catalyzed C–O cross-coupling of aryl bromides with phenols
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A new solvent-free procedure for C–O cross-coupling between phenols and aryl bromides comprising of Pd2(dba)3/ButBrettPhos catalytic system is efficient for substrates bearing donor or acceptor, as well as bulky substituents.
- Asachenko, Andrey F.,Bogachev, Vasilii N.,Cherkashchenko, Ilia R.,Lavrov, Konstantin V.,Minaeva, Lidiya I.,Nechaev, Mikhail S.,Rzhevskiy, Sergey A.,Sterligov, Grigorii K.,Topchiy, Maxim A.
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p. 409 - 411
(2021/06/07)
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- Lipophilic tail modifications of 2-(hydroxymethyl)pyrrolidine scaffold reveal dual sphingosine kinase 1 and 2 inhibitors
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The sphingosine 1-phosphate (S1P) signaling pathway is an attractive target for pharmacological manipulation due to its involvement in cancer progression and immune cell chemotaxis. The synthesis of S1P is catalyzed by the action of sphingosine kinase 1 or 2 (SphK1 or SphK2) on sphingosine and ATP. While potent and selective inhibitors of SphK1 or SphK2 have been reported, development of potent dual SphK1/SphK2 inhibitors are still needed. Towards this end, we report the structure–activity relationship profiling of 2-(hydroxymethyl)pyrrolidine-based inhibitors with 22d being the most potent dual SphK1/SphK2 inhibitor (SphK1 Ki = 0.679 μM, SphK2 Ki = 0.951 μM) reported in this series. 22d inhibited the growth of engineered Saccharomyces cerevisiae and decreased S1P levels in histiocytic lymphoma myeloid cell line (U937 cells), demonstrating inhibition of SphK1 and 2 in vitro. Molecular modeling studies of 22d docked inside the Sph binding pocket of both SphK1 and SphK2 indicate essential hydrogen bond between the 2-(hydroxymethyl)pyrrolidine head to interact with aspartic acid and serine residues near the ATP binding pocket, which provide the basis for dual inhibition. In addition, the dodecyl tail adopts a “J-shape” conformation found in crystal structure of sphingosine bound to SphK1. Collectively, these studies provide insight into the intermolecular interactions in the SphK1 and 2 active sites to achieve maximal dual inhibitory activity.
- Li, Hao,Sibley, Christopher D.,Kharel, Yugesh,Huang, Tao,Brown, Anne M.,Wonilowicz, Laura G.,Bevan, David R.,Lynch, Kevin R.,Santos, Webster L.
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- Light-emitting diode light–enabled denitrative etherification of 4-nitrobenzonitrile under catalyst-free conditions at room temperature
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In this study, we have developed a catalyst-free procedure for denitrative etherification of electron-deficient nitroarenes. In this method, the reaction failed in the dark but was enabled by white light-emitting diode light (6 W) in the presence of NaOH/dimethylformamide at room temperature with short reaction times. Interestingly, the reaction in the dark is completed almost immediately once a small quantity of water is added to the reaction mixture. Ultraviolet irradiation (λ = 254 nm) was not effective for this reaction to proceed.
- Soltani, Roghaye,Abdollahi, Fatemeh,Ghaderi, Arash
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- SO2F2-mediated oxidation of primary and tertiary amines with 30% aqueous H2O2 solution
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A highly efficient and selective oxidation of primary and tertiary amines employing SO2F2/H2O2/base system was described. Anilines were converted to the corresponding azoxybenzenes, while primary benzylamines were transformed into nitriles and secondary benzylamines were rearranged to amides. For tertiary amine substrates quinolines, isoquinolines and pyridines, their oxidation products were the corresponding N-oxides. The reaction conditions are very mild and just involve SO2F2, amines, 30% aqueous H2O2 solution, and inorganic base at room temperature. One unique advantage is that this oxidation system is just composed of inexpensive inorganic compounds without the use of any metal and organic compounds.
- Liao, Xudong,Zhou, Yi,Ai, Chengmei,Ye, Cuijiao,Chen, Guanghui,Yan, Zhaohua,Lin, Sen
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supporting information
(2021/11/01)
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- Nickel-Catalyzed Cyanation of Aryl Thioethers
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A nickel-catalyzed cyanation of aryl thioethers using Zn(CN)2 as a cyanide source has been developed to access functionalized aryl nitriles. The ligand dcype (1,2-bis(dicyclohexylphosphino)ethane) in combination with the base KOAc (potassium acetate) is essential for achieving this transformation efficiently. This reaction involves both a C-S bond activation and a C-C bond formation. The scalability, low catalyst and reagents loadings, and high functional group tolerance have enabled both late-stage derivatization and polymer recycling, demonstrating the reaction's utility across organic chemistry.
- Delcaillau, Tristan,Woenckhaus-Alvarez, Adrian,Morandi, Bill
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supporting information
p. 7018 - 7022
(2021/09/13)
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- Nickel-Catalyzed Reversible Functional Group Metathesis between Aryl Nitriles and Aryl Thioethers
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We describe a new functional group metathesis between aryl nitriles and aryl thioethers. The catalytic system nickel/dcype is essential to achieve this fully reversible transformation in good to excellent yields. Furthermore, the cyanide- and thiol-free reaction shows high functional group tolerance and great efficiency for the late-stage derivatization of commercial molecules. Finally, synthetic applications demonstrate its versatility and utility in multistep synthesis.
- Delcaillau, Tristan,Boehm, Philip,Morandi, Bill
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supporting information
p. 3723 - 3728
(2021/04/07)
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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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- A novel magnetic polyacrylonotrile-based palladium Core?Shell complex: A highly efficientcatalyst for Synthesis of Diaryl ethers
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The present article describes the synthesis of a new magnetic polyacrylonitrile-based Pd catalyst involving polyacrylonitrile modified via 2-aminopyridine as an efficient support to immobilize Pd nanoparticles. The simple reusability, easy separation and high stability of this Pd complex make it an excellent candidate to generate a C–O bond via Ph-X activation which is a really important subject in achieving biologically active compounds. It is worth to note access to good and high yields as well as broad substrate scope have resulted from superior reactivity of this catalyst complex. Furthermore, the structure of the magnetic polyacrylonitrile-based heterogeneous catalyst was characterized by fourier transmission infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM), X-ray diffraction (XRD). Also, its thermal properties were studied by thermogravimetric analysis (TGA).
- Eslami, Mohammad,Jarahiyan, Atefeh,Moghaddam, Firouz Matloubi,Pourjavadi, Ali
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- Catalysis with magnetically retrievable and recyclable nanoparticles layered with Pd(0) for C-C/C-O coupling in water
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Nanoparticles layered with palladium(0) were prepared from nano-sized magnetic Fe3O4 by coating it with silica and then reacting sequentially with phenylselenyl chloride under an N2 atmosphere and palladium(ii) chloride in water. The resulting Fe3O4?SiO2?SePh?Pd(0) NPs are magnetically retrievable and the first example of NPs in which the outermost layer of Pd(0) is mainly held by selenium. The weight percentage of Pd in the NPs was found to be 1.96 by ICP-AES. The NPs were authenticated via TEM, SEM-EDX, XPS, and powder XRD and found to be efficient as catalysts for the C-O and C-C (Suzuki-Miyaura) coupling reactions of ArBr/Cl in water. The oxidation state of Pd in the NPs having size distribution from ~12 to 18 nm was inferred as zero by XPS. They can be recycled more than seven times. The main features of the proposed protocols are their mild reaction conditions, simplicity, and efficiency as the catalyst can be separated easily from the reaction mixture by an external magnet and reused for a new reaction cycle. The optimum loading (in mol% of Pd) was found to be 0.1-1.0 and 0.01-1.0 for O-arylation and Suzuki-Miyaura coupling, respectively. For ArCl, the required amount of NPs was more as compared to that needed for ArBr. The nature of catalysis is largely heterogeneous.
- Joshi, Hemant,Sharma, Alpesh K.,Singh, Ajai K.
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p. 6452 - 6459
(2020/02/25)
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- Palladium complexes of chalcogenoethanamine (S/Se) bidentate ligands: Applications in catalytic arylation of C[sbnd]H and O[sbnd]H bonds
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This report describes the syntheses of N,E (E = S, Se) coordinated bidentate palladium complexes, by the reaction of N-(2-bromobenzyl)-2-(phenylthio/selanyl)ethanamine (3, 4) with [PdCl2(CH3CN)2]. The new ligands and palladium complexes were characterized by techniques like 1H, 13C{1H} NMR, IR, and elemental analysis. The coordination modes of ligand with palladium precursor in complexes 5 and 6 were authenticated by single crystal X-ray diffraction. The complexes possess distorted square planar geometry around palladium center. Thermally robust and air stable complexes 5 and 6 were used as catalyst for regioselective arylation of imidazole and O-arylation of phenol. In case of regioselective arylation of imidazole, the reaction proceeds smoothly under mild reaction conditions, only 2.0 mol% of catalyst loading is required to achieve high yield (76–92%). This protocol is applicable to a broad substrate scope showing excellent tolerance towards different functional groups. Whereas for O-arylation of phenol also only 2.0 mol% catalyst loading is sufficient to give good yield (71–92%) with excellent tolerance towards a broad range of functional groups. Among sulfur and selenium coordinated ligands, selenium ligand coordinated complex, was found to outperform the catalytic reactions in both cases as compare to sulfur ligand. The mercury and triphenylphosphine poisoning tests suggest homogeneous nature of catalysis.
- Bhatt, Ramprasad,Bhuvanesh, Nattamai,Himanshi,Joshi, Hemant,Sharma, Alpesh K.
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- Ni(II) complexes of tripodal N4 ligands as catalysts for alkane hydroxylation and O-arylation of phenol: Structural and reactivity effects induced by fluoro substitution
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Nickel(II) complexes [NiII(L1-2)(OAc)(H2O)][BPh4] (1–2) and [NiII(L3)(OAc)][BPh4] (3) derived from fluorinated tripodal ligands viz. N-((6-fluoropyridin-2-yl)methyl)(pyridin-2-yl)-N-(pyridin-2-ylmethyl)methanamine (L1 or FTPA), N,N′-bis((6-fluoropyridin-2-yl)methyl)(pyridin-2-yl)methanamine (L2 or F2TPA) and tris((6-fluoropyridin-2-yl)methyl)amine (L3 or F3TPA) have been synthesized and characterized by spectroscopic (UV–visible, FT-IR, paramagnetic NMR), elemental analysis, electrochemistry and X-ray diffraction techniques. In structurally similar complexes 1 and 2, Ni(II) center has a distorted octahedral coordination geometry constituted by all the four N atoms of the ligands, one acetate group and a water molecule. Complex 3 has different structural aspects. It does not have the water molecule in the coordination sphere and contains one acetate group bound with metal center in a bidentate mode. All the complexes exhibit a one-electron oxidation corresponding to the NiII/NiIII redox couple, the potential of which is influenced by the donor functionalities of ligand. These complexes catalyze the oxidation of cyclohexane efficiently (turn over number: 586–698) and selectively (alcohol to ketone ratio: 7.9:1 to 8.4:1). The study also includes the catalysis of adamantane oxidation to a mixture of ketones and alcohols. Catalytic potential of all the three complexes (1–3) has also been screened for C–O coupling reactions of phenol with aryl halides. Among them, complex 1 is more efficient than 2 and 3 for such reactions.
- Kerbib, Wissame,Kumar, Arun,Kumar, Sushil,Nautiyal, Divyanshu,Singh, Siddhant
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- HETEROCYCLIC COMPOUNDS AS MUTANT IDH INHIBITORS
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The present disclosure relates generally to compounds useful in treatment of conditions associated with mutant isocitrate dehydrogenase (mt-IDH), particularly mutant IDH1 enzymes. Specifically, the present invention discloses compound of formula (IA), which exhibits inhibitory activity against mutant IDH1 enzymes. Method of treating conditions associated with excessive activity of mutant IDH1 enzymes with such compound is disclosed. Uses thereof, pharmaceutical composition, and kits are also disclosed.
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Paragraph 0591-0592
(2020/07/16)
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- Method for preparing diarylether compound
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The invention relates to a method for preparing a diarylether compound. The method comprises the following steps: dispersing an aromatic heterocyclic borate compound, a nitrobenzene compound, a coppercatalyst, an alkaline compound and an additive in an organic solvent, heating and stirring, and extracting, separating and purifying the obtained reaction solution by using an organic solvent after the reaction is completed to obtain the diarylether compound. Compared with the prior art, the method has the following advantages: the efficient preparation of the diarylether compound can be realizedunder the catalysis of bivalent copper with stable properties and low price; extra protection of inert gas is not needed, and the reaction is carried out under a heating condition in the air, so environmental friendliness is achieved; and expensive catalysis and ligands are not needed in the reaction, the reaction selectivity is high, the functional group tolerance of a substrate is good, the whole reaction process is simple and easy to implement, and the method is a brand-new synthesis method of the diarylether compound.
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Paragraph 0114-0122
(2020/06/02)
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- Palladium-Catalyzed Cyanation of Aryl Halides Using Formamide and Cyanuric Chloride as a New “CN” Source
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A new source of “CN” employing formamide and cyanuric chloride is introduced for the cyanation reactions. The treatment of formamide and 2,4,6-trichloro-1,3,5-triazine (TCT; cyanuric chloride) afforded an efficient cyanating agent which it can be used as a nontoxic, readily available, and non-expensive reagent in the cyanation transformations. In this study, palladium-catalyzed cyanation of aryl halides was successfully accomplished using this new “CN” source in high yields.
- Niknam, Esmaeil,Panahi, Farhad,Khalafi-Nezhad, Ali
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p. 2699 - 2707
(2020/04/08)
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- Nickel-Catalyzed Cyanation of Aryl Halides and Hydrocyanation of Alkynes via C-CN Bond Cleavage and Cyano Transfer
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We report nickel-catalyzed cyanation and hydrocyanation methods to prepare aryl nitriles and vinyl nitriles from aryl halides and alkynes, respectively. Using inexpensive and nontoxic 4-cyanopyridine N-oxide as the cyano shuttle, the methods provide an efficient approach to prepare aryl cyanides and vinyl nitriles under mild and operationally simple reaction conditions with a broad range of functional group tolerances. In hydrocyanation of alkynes, the method demonstrated good regioselectivity, producing predominantly E- or Z-alkenyl nitriles in a controlled manner and exclusively Markovnikov vinyl nitriles when internal diaryl alkynes and terminal alkynes were applied as the substrates, respectively. The preliminary mechanistic investigation indicated that the C-CN bond cleavage process is promoted by oxidative addition to the nickel(I) complex in the cyanation of aryl halides, and further studies via a series of deuterium exchange experiments indicated that water serves as the hydrogen source for the hydrocyanation of alkynes.
- Chen, Hui,Sun, Shuhao,Liu, Yahu A.,Liao, Xuebin
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p. 1397 - 1405
(2020/02/04)
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- An aerobic and green C-H cyanation of terminal alkynes
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This study describes a benign C-H cyanation of terminal alkynes with α-cyanoesters serving as a nontoxic cyanide source. In situ generation of the key copper cyanide intermediate is proposed by a sequence of α-C-H oxidation and copper-mediated β-carbon elimination of α-cyanoesters, releasing the α-ketoester byproduct observed experimentally. The ensuing reaction of copper cyanide with terminal alkynes delivers preferentially cyanoalkynes and surpasses the possible Glaser type dimerization of terminal alkynes or the undesired accumulation of HCN under protic conditions. The presence of the co-oxidant K2S2O8 is crucial to this selectivity, probably by promoting oxidative transmetalation and the resulting formation of the Cu(iii)(acetylide)(CN) intermediate. All the reagents and salts used are commercially available, cheap and nontoxic, avoiding the use of highly toxic cyanide salts typically required in cyanation studies. The scope of this reaction is demonstrated with a set of alkynes and α-cyanoesters. The application of this method to late-stage functionalization of the terminal alkyne group in an estrone derivative is also feasible, showing its practical value for drug design.
- Si, Yi-Xin,Zhang, Song-Lin,Zhu, Peng-Fei
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supporting information
p. 9216 - 9220
(2020/12/03)
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- A convenient reagent for the conversion of aldoximes into nitriles and isonitriles
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For the dehydroxylation of aldoximes with 4-nitro-1-((trifluoromethyl)sulfonyl)-imidazole (NTSI), slight modifications of reaction conditions resulted in significantly different reaction paths to provide either nitriles or isonitriles. The challenging conversion of aldoximes into isonitriles was achieved under mild conditions.
- Zhang, Wei,Lin, Jin-Hong,Zhang, Pengfei,Xiao, Ji-Chang
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supporting information
p. 6221 - 6224
(2020/06/29)
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- Ni-Catalyzed Reductive Cyanation of Aryl Halides and Phenol Derivatives via Transnitrilation
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Herein, we report a Ni-catalyzed reductive coupling for the synthesis of benzonitriles from aryl (pseudo)halides and an electrophilic cyanating reagent, 2-methyl-2-phenyl malononitrile (MPMN). MPMN is a bench-stable, carbon-bound electrophilic CN reagent that does not release cyanide under the reaction conditions. A variety of medicinally relevant benzonitriles can be made in good yields. Addition of NaBr to the reaction mixture allows for the use of more challenging aryl electrophiles such as aryl chlorides, tosylates, and triflates. Mechanistic investigations suggest that NaBr plays a role in facilitating oxidative addition with these substrates.
- Mills, L. Reginald,Graham, Joshua M.,Patel, Purvish,Rousseaux, Sophie A. L.
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p. 19257 - 19262
(2019/12/02)
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- Base-Mediated O-Arylation of Alcohols and Phenols by Triarylsulfonium Triflates
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A mild and efficient protocol for O-arylation of alcohols and phenols (ROH) by triarylsulfonium triflates was developed under transition-metal-free conditions. Various alcohols, including primary, secondary and tertiary, and phenols bearing either electron-donating or electron-withdrawing groups on the aryl rings were smoothly converted to form the corresponding aromatic ethers in moderate to excellent yields. The reactions were conducted at 50 or 80 °C for 24 h in the presence of a certain base and showed good functional group tolerance. The base-mediated arylation with asymmetric triarylsulfonium salts could selectively transfer the aryl groups of sulfoniums to ROH, depending on their inherent electronic nature. The mechanistic studies revealed that the reaction might proceed through the nucleophilic attack of the in situ formed alkoxy or phenoxy anions at the aromatic carbon atoms of the C?S bonds of triarylsulfonium cations to furnish the target products.
- Ming, Xiao-Xia,Tian, Ze-Yu,Zhang, Cheng-Pan
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supporting information
p. 3370 - 3379
(2019/11/03)
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- Transformation of aromatic bromides into aromatic nitriles with n-BuLi, pivalonitrile, and iodine under metal cyanide-free conditions
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Various aromatic nitriles could be obtained in good yields by the treatment of aryl bromides with n-butyllithium and then pivalonitrile, followed by the treatment with molecular iodine at 70 °C, without metal cyanides under transition-metal-free conditions. The present reaction proceeds through the radical β-elimination of imino-nitrogen-centered radicals formed from the reactions of imines and N-iodoimines under warming conditions.
- Uchida, Ko,Togo, Hideo
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- Fe3O4@SiO2-copper sucrose xanthate as a green nanocatalyst for N-, O- and S-arylation
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Formation of C(sp2)–X bonds was carried out using a Fe3O4@SiO2-copper(I) sucrose xanthate nanoparticle catalyst with the aid of the copper(I) xanthate moiety in the catalyst which was prepared from the reaction between sucrose and carbon disulfide through an alkaline medium via the traditional Zeise approach. Various techniques were employed for the characterization of these novel nanoparticles. Three sorts of heteroatoms, N, O and S, successfully underwent heteroatom arylation to produce secondary or tertiary amines, ethers and thioethers, respectively.
- Radfar, Iman,Kazemi Miraki, Maryam,Esfandiary, Naghmeh,Ghandi, Leila,Heydari, Akbar
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- Nickel-catalyzed denitrative etherification of activated nitrobenzenes
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Electron-deficient nitrobenzenes were coupled with phenols/alcohols to form diaryl/alkyl aryl ethers by the aid of NiCl2 as the catalyst. The reactions were conducted under ligand- and oxidant-free conditions without the exclusion of air or moisture. The initial studies upon the mechanism of the reaction revealed two solvent-dependent approaches. In molten TBAB, SNAr mechanism seems to be predominated, while, in DMF, the reaction might include the radical species.
- Zamiran, Fatemeh,Ghaderi, Arash
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p. 293 - 299
(2019/01/28)
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- A diaryl ether compounds of the novel preparation method and application thereof
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The invention relates to a diaryl ether compounds of the novel preparation method, in particular compound is added to the reactor in sequence 1, dimethyl sulfoxide, cesium carbonate, compound 2, stirring at room temperature 10 - 60 minutes; then placing the reaction temperature is set to 70 - 120 °C the pot of the oil bath, and incandescent lamp for irradiation, the course of the reaction by TLC detection, to be after the reaction, the reaction solution by filtration, extraction and column chromatography, to obtain the target compound, the completion of the diaryl ether compound preparation. The technical scheme of the present invention visible under light induction, does not add any transition metal catalyst and ligand firmly oxidation reducing agent, aryl halide with phenol derivatives in photocatalytic C - O cross-coupling reaction. Preparation of mild conditions, green, high efficiency, low cost, simple and convenient operation. The preparation of this compound is a biological, medical, in the field of organic synthesis in particular pharmaceutical synthesis of important synthetic intermediate.
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Paragraph 0023-0032
(2019/07/01)
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- Novel EDA transient electron donor-acceptor complex, and preparation method and applications thereof
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The invention relates to a novel EDA transient electron donor-acceptor complex, and a preparation method and applications thereof. The structure of the complex is represented in the description, wherein R1 represents an electron-withdrawing group such as cyano, nitro, acetyl, trifluoromethyl, and the like; R2 represents any one substituent group such as hydrogen, an alkyl group (methyl, ethyl, etc.), chlorine, bromine, iodine, methoxyl, nitro, and the like; and the position of the substituent group can be an o-position, m-position, or p-position. According to the synthesis method, under the induction of visible light, phenol derivatives and electron deficient aryl halide carry out reactions under the action of basic cesium carbonate to generate the complex, and no transition metal catalyst, transition metal ligand, or photo oxidation-reduction agent is added. Through the reaction mechanism, a series of diaryl ether derivatives is prepared. The preparation method has the advantages of mild conditions, greenness, high efficiency, low cost, and simple operation.
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Paragraph 0042; 0044-0048
(2019/07/04)
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- EDA (electronic design automation) transient electron donor-acceptor complex as well as preparation method and application thereof
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The invention relates to an EDA (electronic design automation) transient electron donor-acceptor complex as well as a preparation method and application thereof. The compound has a structural formulashown in the specification, in the formula, R1 is an electron withdrawing group such as cyan, nitryl, acetyl and trifluoromethyl; R2 is any one of arbitrary substituent groups such as hydrogen, methyl, ethyl and other alkyl groups, chloro, bromo, iodo, methoxyl and nitryl; and the position relationship of the substituent groups is any one of an ortho-position, a meta-position and a para-position.According to a synthesis method, under induction of visible light, without addition of any transition metal catalyst, ligand or photoredox agent, the complex is prepared from a phenol derivative and an electron-deficient aryl halide under the action of alkali cesium carbonate through reactions. In addition, a series of diaryl ether derivatives are prepared through the reaction mechanism. The condition is gentle and green, the efficiency is high, the cost is low and operation is simple and convenient.
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Paragraph 0036-0042
(2019/09/13)
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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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- Method for preparing diaryl ether compound
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The invention relates to a novel preparation method of a diaryl ether compound. The novel preparation method specifically comprises the following steps: sequentially putting a derivative of benzene, dimethyl sulfoxide, cesium carbonate and a phenol derivative into a reactor, and carrying out stirring for 30-60 minutes at room temperature; putting the mixture into an oil bath pot of which the reaction temperature is set as 70-120 DEG C, lighting the mixture with an incandescent light bulb, detecting the reaction process with TLC (thin layer chromatography), after the reaction is completed, carrying out filtering on a reaction liquid, and carrying out extraction and column chromatography, so as to obtain a target compound and complete preparation of the diaryl ether compound. By adopting thetechnical scheme of the invention, under induction of visible light, without addition of any transition metal catalyst, ligand or photoredox agent, an aryl halide and a phenol derivative are subjected to a photocatalytic C-O cross coupling reaction. The preparation method is mild in condition, green, efficient, low in cost and simple and convenient in operation. The prepared compound is a significant synthesis intermediate in fields such as biologics, medicines and organic synthesis, particularly in medicine synthesis.
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Paragraph 0024-0029; 0030; 0031; 0032; 0033
(2019/09/13)
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- From Anilines to Aryl Ethers: A Facile, Efficient, and Versatile Synthetic Method Employing Mild Conditions
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We have developed a simple and direct method for the synthesis of aryl ethers by reacting alcohols/phenols (ROH) with aryl ammonium salts (ArNMe3+), which are readily prepared from anilines (ArNR′2, R′=H or Me). This reaction proceeds smoothly and rapidly (within a few hours) at room temperature in the presence of a commercially available base, such as KOtBu or KHMDS, and has a broad substrate scope with respect to both ROH and ArNR′2. It is scalable and compatible with a wide range of functional groups.
- Wang, Dong-Yu,Yang, Ze-Kun,Wang, Chao,Zhang, Ao,Uchiyama, Masanobu
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p. 3641 - 3645
(2018/03/13)
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- CuCl heterogenized on metformine-modified multi walled carbon nanotubes as a recyclable nanocatalyst for Ullmann-type C-O and C-N coupling reactions
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Herein, a novel MWCNTs-Met/CuCl nanocatalyst synthesis method by metformine covalent grafting on the surface of carbon nanotubes and subsequent coordination with a CuCl catalyst is described. The nanocatalyst formation was analyzed by FTIR, energy dispersive spectroscopy (EDS), Raman spectroscopy and ICP analysis. The nanocatalyst morphology was examined by transmission and scanning electron microscopies (TEM and SEM). Moreover, in the N-arylation of anilines and indole, the nanocatalyst (MWCNTs-Met/CuCl) could be successfully used by formation of intermolecular C(aryl)-N bonds of the relevant aryl halides (Ar-I, Ar-Br, Ar-Cl) with amines by coupling reactions of Ullmann-type. The O-arylation of substituted phenols is also promoted by this heterogeneous copper catalyst with different aryl iodides and bromides. Additionally, without any considerable loss in activity, the novel catalyst was recovered and recycled several times.
- Akhavan, Elham,Hemmati, Saba,Hekmati, Malak,Veisi, Hojat
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p. 2782 - 2789
(2018/02/19)
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- 4-(Phenoxy) and 4-(benzyloxy)benzamides as potent and selective inhibitors of mono-ADP-ribosyltransferase PARP10/ARTD10
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Human Diphtheria toxin-like ADP-ribosyltranferases (ARTD) 10 is an enzyme carrying out mono-ADP-ribosylation of a range of cellular proteins and affecting their activities. It shuttles between cytoplasm and nucleus and influences signaling events in both compartments, such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling and S phase DNA repair. Furthermore, overexpression of ARTD10 induces cell death. We recently reported on the discovery of a hit compound, OUL35 (compound 1), with 330 nM potency and remarkable selectivity towards ARTD10 over other enzymes in the human protein family. Here we aimed at establishing a structure-activity relationship of the OUL35 scaffold, by evaluating an array of 4-phenoxybenzamide derivatives. By exploring modifications on the linker between the aromatic rings, we identified also a 4-(benzyloxy)benzamide derivative, compound 32, which is potent (IC50 = 230 nM) and selective, and like OUL35 was able to rescue HeLa cells from ARTD10-induced cell death. Evaluation of an enlarged series of derivatives produced detailed knowledge on the structural requirements for ARTD10 inhibition and allowed the discovery of further tool compounds with submicromolar cellular potency that will help in understanding the roles of ARTD10 in biological systems.
- Murthy, Sudarshan,Desantis, Jenny,Verheugd, Patricia,Maksimainen, Mirko M.,Venkannagari, Harikanth,Massari, Serena,Ashok, Yashwanth,Obaji, Ezeogo,Nkizinkinko, Yves,Lüscher, Bernhard,Tabarrini, Oriana,Lehti?, Lari
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- Immobilized palladium nanoparticles on MNPs@A-N-AEB as an efficient catalyst for C-O bond formation in water as a green Solvent
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Palladium nanoparticles immobilized on the magnetic nanoparticles@2-amino-N-(2-aminoethyl) benzamide (MNPs@A-N-AEB.Pd0) have been presented as an efficient, and reusable magnetically heterogeneous catalyst for the C-O coupling reaction, namely Ullmann condensation reactions in an aqueous medium. This heterogeneous catalyst shows superior reactivity for the C-O arylation of different aryl halide (chloride, bromide, and iodide) with phenol derivatives to afford the desired products in good to excellent yields within short reaction time. Moreover, the catalyst can be easily recovered and reused for seven runs without loss of catalytic activity. The catalyst was characterized by several techniques, such as FT-IR, SEM, TEM, EDS, XRD, TGA and ICP-OES.
- Moghaddam, Firouz Matloubi,Eslami, Mohammad
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- Cellulose-supported N-heterocyclic carbene silver complex with pendant ferrocenyl group for diaryl ether synthesis
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A cellulose-supported N-heterocyclic carbene Ag(I) complex has been synthesized by covalent grafting of ferrocenyl ionic liquid in the matrix of cellulose followed by metallation with silver oxide. The complex was employed as a heterogeneous catalyst in the synthesis of diaryl ethers. Reactions of a variety of phenols with aryl halides afford corresponding diaryl ethers in moderate to good yields. Recyclability experiments were executed successfully for five consecutive runs.
- Jagadale, Megha,Salunkhe, Rajashri,Kumbhar, Arjun,Gajare, Shivanand,Rajmane, Mohan,Rashinkar, Gajanan
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- Palladacycles of sulfated and selenated Schiff bases of ferrocene-carboxaldehyde as catalysts for O-arylation and Suzuki-Miyaura coupling
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Schiff base ligands (L1: sulfated and L2: selenated) having a ferrocene core synthesized by reacting ferrocene-carboxaldehyde with 2-(phenylthio/seleno)ethylamine on treatment with Na2PdCl4 in the presence of NaOAc give cyclopalladated complexes [Pd(L1/L2-H)Cl] (1/2). Complex 1 of a sulfated Schiff base L1, on reacting with one equivalent of triphenylphosphine gives complex [Pd(L1-H)PPh3Cl] (3), formed due to cleavage of a Pd-S bond. With 2 such a reaction does not occur, as a Pd-Se bond being stronger than that of its sulfur analogue does not get cleaved. L1, L2 and their complexes 1-3 were authenticated with HR-MS, 1H, 13C{1H} and 77Se{1H} NMR spectroscopy. The single crystal structures of 1-3 were determined with X-ray diffraction. Palladium in all three complexes has nearly a square planar geometry. The Pd-S, Pd-Se and Pd-P bond distances are 2.4249(12), 2.5058(14) and 2.2445(17) ? respectively. The catalytic activity of complexes 1-3 was explored for O-arylation of phenol and Suzuki-Miyaura coupling (SMC) of phenylboronic acid with aryl bromides and chlorides. The optimum reaction time for SMC of ArBr is 3 h whereas for ArCl it is 6 h. The TON values of O-arylation catalyzed with complexes 1-3 are up to ~170 (TOF, 28 h?1) and SMC ~9300 (TOF, 3100 h?1) for the reaction time of the order of 3 and 6 h respectively. The catalytic process is somewhat more efficient with 2 (Pd bonded with a selenoether group), than 3, followed by 1.
- Sharma, Alpesh K.,Joshi, Hemant,Bhaskar, Renu,Kumar, Satyendra,Singh, Ajai K.
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p. 2485 - 2496
(2017/03/08)
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- Palladium(II) complexes of N, N-diphenylacetamide based thio/selenoethers and flower shaped Pd16S7 and prismatic Pd17Se15 nano-particles tailored as catalysts for C-C and C-O coupling
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2-Bromo-N,N-diphenylacetamide (P1) prepared by reacting diphenylamine with α-bromoacetyl bromide, on treatment with Na2S and Na2Se generated in situ, has resulted in thio and selenoether ligands, L1 ((Ph2NCOCH2)2S) and L2 ((Ph2NCOCH2)2Se), respectively. Reacting these ligands with Na2PdCl4 in ethanol at room temperature resulted in their complexes [Pd(L1/L2)2Cl2] (C1/C2). P1, L1, L2, C1 and C2 were characterized by 1H, 13C{1H} and 77Se{1H} NMR spectroscopy, IR spectroscopy and High resolution mass spectrometry (HR-MS). Single crystal structures of all the five compounds were determined by X-ray diffraction. In both C1 and C2 the geometry of Pd is nearly square planar. Flower shaped Pd16S7 (size 26-50 nm) and prismatic Pd17Se15 NPs (size 20-55 nm) were synthesized by a single source precursor route (thermolysis at ~280 °C in trioctylphosphine) from air and moisture insensitive C1 and C2, respectively. These shapes of the two nanophases were unknown hitherto. They were characterized by powder X-ray diffraction (PXRD), SEM-EDX and HR-TEM and found to show good catalytic activity for Suzuki-Miyaura (Pd loading 0.5 mol%; yield up to 96%) and C-O (Pd loading 0.5 mol%; yield up to 96%) coupling reactions (at 100 °C) of aryl bromides with phenylboronic acid and phenol, respectively. The complexes C1 and C2 were found very efficient for Suzuki-Miyaura and C-O coupling as revealed by their optimum loading of 0.0001-0.01 and 0.1 mol% of Pd, respectively, for the two reactions. The reuse of the complexes or NPs as a catalyst is demonstrated.
- Singh, Poornima,Singh, Ajai K.
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supporting information
p. 10037 - 10049
(2017/08/10)
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- Cyanation of aromatic/vinylic boronic acids with α-cyanoacetates
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A friendly protocol is reported to achieve cyanation of aromatic and vinylic boronic acids using nontoxic and readily available α-cyanoacetates as a cyano source under aerobic conditions. Many aryl/vinyl boronic acids (as well as some iodides and bromides) are amenable substrates to give aryl nitriles and acrylonitriles. This cyanation method provides a safe and operationally convenient alternative to traditional ones requiring toxic cyanide salts.
- Wang, Xian-Jin,Zhang, Song-Lin
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supporting information
p. 14826 - 14830
(2017/12/15)
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- Direct C-H Cyanation of Arenes via Organic Photoredox Catalysis
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Methods for the direct C-H functionalization of aromatic compounds are in demand for a variety of applications, including the synthesis of agrochemicals, pharmaceuticals, and materials. Herein, we disclose the construction of aromatic nitriles via direct C-H functionalization using an acridinium photoredox catalyst and trimethylsilyl cyanide under an aerobic atmosphere. The reaction proceeds at room temperature under mild conditions and has proven to be compatible with a variety of electron-donating and -withdrawing groups, halogens, and nitrogen- and oxygen-containing heterocycles, as well as aromatic-containing pharmaceutical agents.
- McManus, Joshua B.,Nicewicz, David A.
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supporting information
p. 2880 - 2883
(2017/03/11)
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- Highly efficient heterogeneous copper-catalysed O-arylation of phenols by nitroarenes leading to diaryl ethers
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The heterogeneous O-arylation of phenols by nitroarenes was achieved in DMF at 100 °C by using an MCM-41-immobilised bidentate nitrogen copper(II) complex [MCM-41-2N-Cu(OAc)2] as catalyst, yielding a variety of unsymmetrical diaryl ethers in good to excellent yields. This heterogeneous copper catalyst can be easily prepared by a simple procedure from commercially readily available and inexpensive reagents, recovered by filtration of the reaction solution and recycled at least seven times without significant loss of activity.
- Du, Yingying,Yao, Fang,Tuo, Yuxin,Cai, Mingzhong
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p. 725 - 729
(2018/01/08)
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- Synthesis of copper nanoparticles supported on a microporous covalent triazine polymer: An efficient and reusable catalyst for O-arylation reaction
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Copper nanoparticles were supported on a microporous covalent triazine polymer prepared by the Friedel-Crafts reaction (Cu@MCTP-1). The resulting material was characterized by powder X-ray diffraction, thermogravimetric analysis, N2 adsorption-desorption isotherms at 77 K, transmission electron microscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma optical emission spectroscopy, and Cu particles with an average size of 3.0 nm and a BET total surface area of ca. 1002 m2 g-1 were obtained. Cu@MCTP-1 was evaluated as a heterogeneous catalyst for the Ullmann coupling of O-arylation over a series of aryl halides and phenols without employing expensive ligands or inert atmosphere, which produced an excellent yield of the corresponding diaryl ethers. The catalyst could be recovered by simple centrifugation and was reusable at least five times with only a slight decrease in catalytic activity.
- Puthiaraj, Pillaiyar,Ahn, Wha-Seung
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p. 1701 - 1709
(2016/04/05)
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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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- Rhodium-Catalyzed Transnitrilation of Aryl Boronic Acids with Dimethylmalononitrile
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An efficient transnitrilation of aryl boronic acids with dimethylmalononitrile (DMMN) is described. This rhodium-catalyzed electrophilic cyanation presents a novel approach to prepare aryl nitriles by using a carbon-bound cyanating reagent which undergoes cross-coupling with the aryl boronic acid. The reaction expands the degree of functional-group compatibility exhibited by the transnitrilation of aryl Grignard and aryllithium reagents. A variety of aryl boronic acid derivatives and dialkylmalononitriles were amenable to the transnitrilation.
- Malapit, Christian A.,Reeves, Jonathan T.,Busacca, Carl A.,Howell, Amy R.,Senanayake, Chris H.
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supporting information
p. 326 - 330
(2016/01/25)
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- Aerobic Copper-Promoted Radical-Type Cleavage of Coordinated Cyanide Anion: Nitrogen Transfer to Aldehydes to Form Nitriles
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We have disclosed for the first time the copper-promoted C≡N triple bond cleavage of coordinated cyanide anion under a dioxygen atmosphere, which enables a nitrogen transfer to various aldehydes. Mechanistic study of this unprecedented transformation suggests that the single electron-transfer process could be involved in the overall course. This protocol provides a new cleavage pattern for the cyanide ion and would eventually lead to a more useful synthetic pathway to nitriles from aldehydes.
- Wu, Qian,Luo, Yi,Lei, Aiwen,You, Jingsong
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supporting information
p. 2885 - 2888
(2016/03/19)
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- Simple N-Heterocyclic Carbenes as Ligands in Ullmann-Type Ether and Thioether Formations
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A simple N-heterocyclic carbene (NHC) derived from 1-methyl-3-ethylimidazolium tetrafluoroborate was found to be an efficient ligand for a range of copper-catalyzed cross-coupling reactions, leading to the formation of aromatic ethers and thioethers. (Figure presented.) .
- Wu, Jiang-Ping,Saha, Anjan K.,Haddad, Nizar,Busacca, Carl A.,Lorenz, Jon C.,Lee, Heewon,Senanayake, Chris H.
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supporting information
p. 1924 - 1928
(2016/07/06)
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- CsF/clinoptilolite: An efficient solid base in SNAr and copper-catalyzed Ullmann reactions
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CsF/clinoptilolite was found to be an efficient solid base catalyst for both SNAr and Ullmann ether reactions. A general and efficient one-step procedure was developed for the synthesis of biaryl ethers via direct coupling of electron-deficient aryl halides to phenols using CsF/clinoptilolite. The protocol was also applied to electron-rich aryl halides by addition of a catalytic amount of copper oxide nanoparticles. Both SNAr and Ullmann reactions were rapid and provided good to excellent yields.
- Keipour, Hoda,Hosseini, Abolfazl,Afsari, Amir,Oladee, Razieh,Khalilzadeh, Mohammad A.,Ollevier, Thierry
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- Barberry fruit extract assisted in situ green synthesis of Cu nanoparticles supported on a reduced graphene oxide-Fe3O4 nanocomposite as a magnetically separable and reusable catalyst for the O-arylation of phenols with aryl halides under ligand-free conditions
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In situ synthesis of copper nanoparticles (NPs) supported on a reduced graphene oxide (RGO)-Fe3O4 nanocomposite was carried out with barberry fruit extract as a reducing and stabilizing agent. The morphology and structure of the Cu/RGO-Fe3O4 nanocomposite was fully characterized by means of X-ray diffraction (XRD), Fourier transformed infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FE-SEM), Raman, energy dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). Cu/RGO-Fe3O4 was a promising catalyst for the O-arylation of phenols with aryl halides under ligand-free conditions. A diverse range of diaryl ethers were obtained in a good to high yield. Furthermore, due to the magnetic separability and high stability of the composite the catalyst could be separated conveniently from the reaction mixtures by an external permanent magnet and recycled multiple times without loss of catalytic activity.
- Nasrollahzadeh, Mahmoud,Maham, Mehdi,Rostami-Vartooni, Akbar,Bagherzadeh, Mojtaba,Sajadi, S. Mohammad
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p. 64769 - 64780
(2015/08/18)
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- Microwave assisted synthesis of selected diaryl ethers under Cu(I)-catalysis
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A practical synthesis of diaryl ethers has been achieved from cross coupling reaction between aryl halides and phenols under Cu(I)-catalysis and using ACHN as a ligand. The presence of catalysis and microwave-assistance benefitted the synthesis by increasing the yield of diaryl ethers with a reduction of reaction time.
- Navarro, Lorena,Pujol, M. Dolors
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supporting information
p. 1812 - 1815
(2015/03/30)
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- Structure-activity relationship for the oxadiazole class of antibiotics
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The structure-activity relationship (SAR) for the newly discovered oxadiazole class of antibiotics is described with evaluation of 120 derivatives of the lead structure. This class of antibiotics was discovered by in silico docking and scoring against the crystal structure of a penicillin-binding protein. They impair cell-wall biosynthesis and exhibit activities against the Gram-positive bacterium Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA) and vancomycin-resistant and linezolid-resistant S. aureus. 5-(1H-Indol-5-yl)-3-(4-(4-(trifluoromethyl)phenoxy)phenyl)-1,2,4-oxadiazole (antibiotic 75b) was efficacious in a mouse model of MRSA infection, exhibiting a long half-life, a high volume of distribution, and low clearance. This antibiotic is bactericidal and is orally bioavailable in mice. This class of antibiotics holds great promise in recourse against infections by MRSA.
- Spink, Edward,Ding, Derong,Peng, Zhihong,Boudreau, Marc A.,Leemans, Erika,Lastochkin, Elena,Song, Wei,Lichtenwalter, Katerina,O'Daniel, Peter I.,Testero, Sebastian A.,Pi, Hualiang,Schroeder, Valerie A.,Wolter, William R.,Antunes, Nuno T.,Suckow, Mark A.,Vakulenko, Sergei,Chang, Mayland,Mobashery, Shahriar
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supporting information
p. 1380 - 1389
(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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- Iridium-catalyzed synthesis of diaryl ethers by means of chemoselective C-F bond activation and the formation of B-F bonds
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Transition-metal-catalyzed C-F activation, in comparison with C-H activation, is more difficult to achieve and therefore less fully understood, mainly because carbon-fluorine bonds are the strongest known single bonds to carbon and have been very difficult to cleave. Transition-metal complexes are often more effective at cleaving stronger bonds, such as C(sp2)-X versus C(sp2)-X. Here, the iridium-catalyzed C-F activation of fluorarenes was achieved through the use of bis(pinacolato)diboron with the formation of the B-F bond and self-coupling. This strategy provides a convenient method with which to convert fluoride aromatic compounds into symmetrical diaryl ether compounds. Moreover, the chemoselective products of the C-F bond cleavage were obtained at high yields with the C-Br and C-Cl bonds remaining.
- Chen, Jianping,Zhao, Keyan,Ge, Bingyang,Xu, Chongying,Wang, Dawei,Ding, Yuqiang
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supporting information
p. 468 - 473
(2015/02/05)
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