- Diarylamine Synthesis via Desulfinylative Smiles Rearrangement
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Diarylamines are obtained directly from sulfinamides through a novel rearrangement sequence. The transformation is transition metal-free and proceeds under mild conditions, providing facile access to highly sterically hindered diarylamines that are otherw
- Sephton, Thomas,Large, Jonathan M.,Butterworth, Sam,Greaney, Michael F.
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p. 1132 - 1135
(2022/02/09)
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- Method for synthesizing diarylamine through N-arylation reaction of arylamine under copper catalysis
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The invention provides a method for synthesizing diarylamine through an N-arylation reaction of arylamine under copper catalysis. The method comprises the following steps: S1, selecting a proper amount of a reaction reagent, a catalyst, a solvent and the like; S2, sequentially adding a reaction reagent, a catalyst, a solvent and the like into a reaction tube with a magnetic bar; S3, selecting a proper amount of AcOH, and adding the AcOH into the reaction tube; S4, heating the reaction tube; S5, performing oil bath treatment; S6, cooling to room temperature, and diluting; S7, extracting by using ethyl acetate; S8, washing the organic layer with saline water; S9, drying on anhydrous Na2SO4; S10, evaporating under vacuum; and S11, purifying the residues into the pure product through silica gel chromatography. A scheme that arylamine and an environmentally-friendly and stable aryl silicon reagent are subjected to an N-arylation reaction under the catalysis of a cheap copper reagent is provided, Cu(OAc)2 is used as a catalyst to react in DMSO in the atmosphere of O2, the conversion reactivity is good, the substrate range is wide, and the method has good tolerance to reaction substrates with various functional groups under mild reaction conditions.
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Paragraph 0062-0063; 0076; 0077; 0080; 0081
(2021/07/14)
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- A quinoxaline-based porous organic polymer containing copper nanoparticles CuNPs@Q-POP as a robust nanocatalyst toward C-N coupling reaction
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A novel porous organic polymer (denoted by Q-POP) was successfully fabricated by free-radical copolymerization of allyl-substituted 2,3-di(2-hydroxyphenyl)1,2-dihydroquinoxaline, and divinylbenzene under solvothermal conditions and used as a new platform for immobilization of copper nanoparticles. The CuNPs@Q-POP nanocatalyst was prepared via incorporating of Cu(NO3)2 into the polymeric network, followed by the reduction of Cu2+ ion with hydrazine hydrate. The obtained materials were characterized through FT-IR, XRD, N2 adsorption-desorption isotherms, ICP, TGA, SEM, HR-TEM, EDX, and the single-crystal X-ray crystallography. The results displayed that Q-POP and CuNPs@Q-POP possessed high surface area, hierarchical porosity, and excellent thermal and chemical stability. The as-synthesized catalyst was utilized for the Ullmann C-N coupling reaction of aromatic amines and different aryl halides to prepare various diarylamine derivatives. All types of aryl halides (except aryl fluorides) were screened in the Ullmann C-N coupling reaction with aromatic amines to produce diaryl amines in good to excellent yields (50-98%), and it turned out that aryl iodides have the best results. Besides, due to the strong interactions between CuNPs, N, and O-atoms of quinoxaline moiety existing in the polymeric framework, the copper leaching from the support was not observed. Furthermore, the catalyst was recycled and reused for five consecutive runs without significant activity loss.
- Gorginpour, Forough,Zali-Boeini, Hassan,Rudbari, Hadi Amiri
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p. 3655 - 3665
(2021/02/03)
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- Copper nanoparticle anchored biguanidine-modified Zr-UiO-66 MOFs: a competent heterogeneous and reusable nanocatalyst in Buchwald-Hartwig and Ullmann type coupling reactions
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We have designed a functionalized metal-organic framework (MOF) of UiO topology as a support, with an extremely high surface area, adjustable pore sizes and stable crystalline coordination polymeric structure and implanted copper (Cu) nanoparticles thereon. The core three dimensional Zr-derived MOF (UiO-66-NH2) was modified with a biguanidine moiety following a covalent post-functionalization approach. The morphological and physicochemical features of the material were determined using analytical methods such as FT-IR, SEM, TEM, EDX, atomic mapping, XRD and ICP-OES. The SEM and XRD results justified the unaffected morphology of Zr-MOF after structural modifications. The as-synthesized UiO-66-biguanidine/Cu nanocomposite was catalytically explored in the aryl and heteroaryl Buchwald-Hartwig C-N and Ullmann type C-O cross coupling reactions with excellent yields. A library of biaryl amine and biaryl ethers was synthesized over the catalyst under mild and green conditions. Furthermore, the catalyst was isolated by centrifugation and recycled 11 times with no significant copper leaching or change in its activity.
- Veisi, Hojat,Neyestani, Narges,Pirhayati, Mozhgan,Ahany Kamangar, Sheida,Lotfi, Shahram,Tamoradi, Taiebeh,Karmakar, Bikash
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p. 22278 - 22286
(2021/07/02)
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- Schiff bases-titanium (III) & (IV) complex compounds: Novel photocatalysts in Buchwald-Hartwig C–N cross-coupling reaction
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Nine novel Schiff bases were derived from salicylic aldehyde and oxalic aldehyde, isolated, and their molecular and spatial structure were explored by a set of experiments (IR, CNMR, HNMR, CHN, SEM, XRD) and theoretical simulation (DFT def2-TZVP). A high potential was predicted in metal cations chelating. The isolated organic species were applied as the ligands in the reaction of complex formation with titanium (III) chloride and (IV) bromide and 12 novel complexes were synthesized and studied experimentally and theoretically. Using the UV–vis spectroscopic titration, the solution stability of the complexes was indicated. Depending on the nature of the Schiff base ligand, their formation constants were calculated in the range of 6.84–17.32. Using the DFT def2-TZVP theoretical method together with the experimental spectroscopic data, the coordination types of the ligands were investigated, and the structure of the complexes was proposed. The photocatalytic ability of the isolated complexes was tested in the C-N cross-coupling reaction under sunlight. Complexes exhibited high visible-light photocatalytic activity for a wide range of aromatic and benzylic amines including electron-withdrawing and electron-donating groups from moderate to good yields ranging in 50–85 %. The use of an inexpensive, clean, and renewable energy source (visible light) is the superiority of the developed photocatalytic systems.
- Absalan, Yahya,Ghandi, Khashayar,Gholizadeh, Mostafa,Kovalchukova, Olga,Mahmoudi, Ghodrat,Sarvestani, Hossein Sabet,Shad, Nazanin Noroozi,Strashnov, Pavel
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- Copper anchored on phosphorus g-C3N4as a highly efficient photocatalyst for the synthesis ofN-arylpyridin-2-amines
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A heterogeneous photocatalyst based on copper modified phosphorus doped g-C3N4(Cu/P-CN) has been prepared and characterized. This recyclable catalyst exhibited high photocatalytic activity for the synthesis ofN-arylpyridin-2-amine derivatives by the reaction of 2-aminopyridine and aryl boronic acid at room temperature under the irradiation of blue light. Importantly, the range of substrates for this coupling reaction has been expanded to include aryl boronic acids with strong electron-withdrawing groups as viable raw materials. In addition, this heterogeneous catalyst can be used at least 6 times while maintaining its catalytic activity.
- Di, Jia-Qi,Zhang, Mo,Chen, Yu-Xuan,Wang, Jin-Xin,Geng, Shan-Shan,Tang, Jia-Qi,Zhang, Zhan-Hui
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p. 1041 - 1049
(2021/02/09)
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- Cu(OAc)2-porphyrins as an efficient catalytic system for base-free, nature mimicking Chan–Lam coupling in water
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The use of porphyrins as ligands in organic synthesis reveals the natural process, because these are the constituent motifs of catalysts in many bio-organic reactions. This article presents the synthesis of two N-pincer tetradentate porphyrins; tetrasodium meso-tetra(p-sulfonatophenyl)phorphyrin (H2TSTpSPP) and meso-tetra(m-carboxyphenyl)porphyrin (H2TmCPP), and study on their aptness for Cu-catalyzed C–N coupling reactions of arylboronic acids and amines (Chan–Lam coupling reaction) in water under external base free conditions. The porphyrins and Chan–Lam coupling products were well characterized by their spectral analysis. The high product yields, application of nature-inspired conditions, large extent of substrates, ease of making and handling the ligands, avoidance of base, and use of water as reaction media are the attractive attributes of this finding.
- Venkateswarlu, Katta,Rao, Kanusu Umamaheswara
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- A terphenyl phosphine as a highly efficient ligand for palladium-catalysed amination of aryl halides with 1° anilines
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A terphenyl phosphine ligand (2,6-bis(2,4,6-triisopropylphenyl)phenyl-dicyclohexylphosphine, TXPhos) and its supported palladium complex [(TXPhos)(allyl)PdCl] have been developed and the catalyst system is highly efficient in amination of aryl halides with 1° anilines, especially effective for densely functionalized substrates including both partners possessing ortho-ester, acetyl, nitrile and nitro groups. With the TXPhos-supported catalyst system, many partner combinations have been unprecedentedly realized and the base scope has been even extended to KOAc, which is even the best choice in the amination of 2-nitrochlorobenzene.
- Shi, Ji-cheng,Zhang, Lixue,Zhou, Fabin
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p. 238 - 243
(2021/09/07)
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- Preparation method of secondary aromatic amine
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The invention provides a method for preparing secondary aromatic amine by performing a palladium-catalyzed C-N coupling reaction on (pseudo)aryl halide and (pseudo)heterocyclic aryl halide and primary(heterocyclic)aromatic amine. The method is characterized in that an alkali for promoting the reaction is an alkali metal carboxylate or an alkali metal bicarbonate.
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Paragraph 0024
(2021/03/31)
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- N-(4-indolyl) N-heterocyclic carbene palladium complex and application thereof
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The invention discloses N-(4-indolyl) N-heterocyclic carbene palladium complexes of which the chemical structural general formula is shown in the specification. The palladium complex provided by the invention can be used for catalyzing cross coupling reactions such as Suzuki-Miyaura coupling, Buchwald-Hartwig reaction and the like.
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Paragraph 0115-0120
(2021/06/02)
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- Integrating CuO?Fe2O3 Nanocomposites and Supramolecular Assemblies of Phenazine for Visible-Light Photoredox Catalysis
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A photoredox catalytic ensemble consisting of CuO-Fe2O3 nanocomposites and oligomeric derivative of phenazine has been developed. The prepared system acts as an efficient photoredox catalyst for C?N bond formation reaction via SET mechanism under ‘green’ conditions (aerial environment, mixed aqueous media, recyclable), requiring less equivalents of base and amine substrate. The present study demonstrates the significant role of supramolecular assemblies as photooxidants and reductants upon irradiation and their important contribution towards the activation of the metallic centre through energy transfer and electron transfer pathways. The potential of oligomer 4: CuO-Fe2O3 has also been explored for C?C bond formation reactions via the Sonogashira protocol.
- Kaur, Lovjot,Deol, Harnimarta,Kumar, Manoj,Bhalla, Vandana
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supporting information
p. 892 - 898
(2020/03/04)
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- Design, preparation and characterization of aerogel NiO-CuO-CoO/SiO2 nanocomposite as a reusable catalyst for C-N cross-coupling reaction
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Aerogels are porous, non-crystalline solid materials with high specific surface space, plentiful three-dimensional (3D) porous construction, ultra-low density and significant porosity. The aerogel nanocomposite is produced using sol-gel and supercritical drying processes. CO2 supercritical drying (SCD) is the most powerful process, ensuring optimal product properties such as high porosity, low density, and high thermal conductivity. On this account, we used the CO2 supercritical drying method to produce NiO-CuO-CoO/SiO2 nanocomposite aerogels and applied it as a reusable catalyst for the C-N cross-coupling reaction (Buchwald-Hartwig amination). Powerful catalytic activity for the C-N cross-coupling reaction was obtained for the new nanocomposite aerogel, that is, NiO-CuO-CoO/SiO2. The catalyst was characterized by X-ray Powder Diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), elemental mapping and Brunauer-Emmett-Teller (BET). Also, organic compounds were identified by melting point, Fourier-transform infrared spectroscopy (FT-IR) and hydrogen-1 nuclear magnetic resonance (1H NMR) analyses.
- Ghasemi, Amir Hossein,Naeimi, Hossein
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supporting information
p. 5056 - 5063
(2020/04/09)
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- Phenazine-Based Donor Acceptor Systems as Organic Photocatalysts for "metal-free" C-N/C-C Cross-Coupling
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With an aim to achieve a balance between ground-state and excited-state reduction potential of donor acceptor systems for efficient C-N/C-C cross-coupling, a series of donor acceptor systems DA1-DA4 have been synthesized by varying the donor strength and connecting positions. With an increase in donor strength, systematic elevation in the ground-state reduction potential and decrease in the HOMO-LUMO gap was observed. Interestingly, all the derivatives DA1-DA4 could catalyze the C-N bond formation reaction between activated aryl halides and amines at low catalytic loading under metal-free conditions without the need of any external base upon irradiation with white LED. A balance was realized in the case of derivative DA2, which exhibits high efficiency in C-N couplings. Different control experiments support the validity of the energy as well as electron transfer pathways in the visible light-mediated C-N bond formation. This study further reveals the potential of derivative DA1 in "metal-free"Sonogashira coupling involving activated aryl halides which is attributed to its high excited-state reduction potential.
- Deol, Harnimarta,Singh, Gurpreet,Kumar, Manoj,Bhalla, Vandana
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p. 11080 - 11093
(2020/10/12)
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- Synthesis and Characterization of a Tetradentate, N-Heterocyclic Carbene Copper(II) Complex and Its Use as a Chan-Evans-Lam Coupling Catalyst
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Copper N-heterocyclic carbenes (NHCs) are an emerging area of focus for catalysis and other applications. Using a straightforward methodology, a new and highly modifiable tetradentate copper(II) NHC complex was generated and characterized using X-ray crystallography, UV-vis and EPR spectroscopy, cyclic voltammetry, and ESI-MS. This copper(II) NHC complex adopted a distorted 4-coordinate coordination mode and demonstrates a unique absorption spectrum for a copper(II) species, but more interestingly, its redox properties indicate that it can readily access all three common copper oxidation states under atmospheric conditions. The tetradentate copper(II) NHC complex was used to catalytically generate new C-N bonds from a series of phenylboronic acids and amines. Once this CEL methodology was refined, moderate to high yields were achieved using catalytic amounts of the copper(II) complex to couple phenylboronic acids to a series of aniline derivatives. Substituted phenylboronic acids and anilines had minimal impact on the catalytic capabilities of this copper complex; however, there is some indication that steric interactions between catalyst and substrates may have an impact on efficient catalysis. The straightforward synthesis of this framework and the utilization of an inexpensive, first-row transition metal center in this system highlight the usefulness of copper(II) NHCs as catalyst for cross-coupling reactions.
- Cope, James D.,Sheridan, Patrick E.,Galloway, Christopher J.,Awoyemi, Raymond Femi,Stokes, Sean L.,Emerson, Joseph P.
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p. 4457 - 4464
(2021/01/09)
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- Cu-ACP-Am-Fe3O4@SiO2: an efficient and recyclable heterogeneous catalyst for the Chan–Lam coupling reaction of boronic acids and amines
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Abstract: We have developed an efficient method for Cu-ACP-Am-Fe3O4@SiO2 catalyzed Chan–Lam coupling of phenylboronic acid with primary amine furnished secondary amines. The catalyst offered virtues like mild reaction conditions, magnetically separable, and reusable and exhibits excellent performance in terms of good product yield and high turnover number. Graphic abstract: [Figure not available: see fulltext.]
- Vibhute, Sandip P.,Mhaldar, Pradeep M.,Gaikwad, Dipak S.,Shejwal, Rajendra V.,Pore, Dattaprasad M.
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- Copper complexes of 1,4-diazabutadiene ligands: Tuning of metal oxidation state and, application in catalytic C-C and C-N bond formation
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Reaction of 1,4-diazabutadiene (p-RC6H4N = C(H)(H)C = NC6H4R-p; R = OCH3, CH3, H and Cl; abbreviated as L-R) with CuCl2·2H2O in methanol at ambient temperature (25 °C) affords a group of doubly chloro-bridged dicopper complexes of type [{CuI(L-R)Cl}2], designated as 1-R. Similar reaction carried out in acetonitrile furnishes a family of doubly chloro-bridged dicopper complexes of type [{CuII(L-R)Cl2}2], designated as 2-R. Molecular structures of 1-OCH3 and 2-OCH3 have been determined by X-ray crystallography. While copper(I) is having a nearly tetrahedral N2Cl2 coordination sphere in 1-OCH3, the N2Cl3 coordination sphere around copper(II) is distorted square pyramidal in nature in 2-OCH3. Isolated 2-R complexes, on dissolution in methanol, are found to undergo facile reduction of the metal center to generate the corresponding 1-R complexes. The 1-R and 2-R complexes show intense absorptions in the visible and ultraviolet regions. Cyclic voltammetry on the 1-R and 2-R complexes shows both metal-centered and ligand centered redox responses. The 1-R complexes are found to efficiently catalyze C-N cross-coupling reactions between arylboronic acids and aryl amines; while the 2-R complexes display notable catalytic efficiency for nitroaldol reactions.
- Mukherjee, Aparajita,Basu, Semanti,Bhattacharya, Samaresh
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- Chan-Evans-Lam C?N Coupling Promoted by a Dinuclear Positively Charged Cu(II) Complex. Catalytic Performance and Some Evidence for the Mechanism of CEL Reaction Obviating Cu(III)/Cu(I) Catalytic Cycle
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In the present study, we report the synthesis of a series of copper(II) complexes with a wide range of ligands and their testing in the copper catalyzed Chan-Evans-Lam (CEL) coupling of aniline and phenylboronic acid. The efficiency of the coupling was directly connected with the ease of the reduction of Cu(II) to Cu(I) of the complexes. The most efficient catalyst was derived from 4-t-butyl-2,5-bis[(quinolinylimino)methyl]phenolate and two Cu(II) ions. Depending on the counter-anion nature and the concentration of the reaction mixture, the reaction can be directed to predominant C?N-bond formation. Forty-three derivatives of diphenylamine were prepared under the optimized conditions. The proposed mechanism of the catalysis was based on the reduction potential of a series of complexes, molecular weight measurements of the catalytic complex in MeOH and the kinetic studies of aniline and phenylboronic acid coupling. In addition, an 1H NMR experiment in a sealed NMR tube, without external oxygen supply available, proved that no complete Cu(II) to Cu(I) conversion was observed under the condition, ruling out the usually accepted mechanism of the C?N coupling, which included the oxygenation of the intermediately formed Cu(I) complexes after the key step of C?N conversion had already been completed. Instead, a mechanism was proposed, involving an oxygen molecule coordinated to two copper ions in the key C?N bond formation without any detectable conversion of the Cu(II) complexes to Cu(I).
- Akatyev, Nikolay,Il'in, Mikhail,Il'in, Mikhail,Peregudova, Svetlana,Peregudov, Alexander,Buyanovskaya, Anastasiya,Kudryavtsev, Kirill,Dubovik, Alexander,Grinberg, Valerij,Orlov, Victor,Pavlov, Alexander,Novikov, Valentin,Volkov, Ilya,Belokon, Yuri
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p. 3010 - 3021
(2020/04/29)
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- Cp*Co(iii) and Cu(OAc)2bimetallic catalysis for Buchwald-type C-N cross coupling of aryl chlorides and amines under base, inert gas & solvent-free conditions
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A strategy involving bimetallic catalysis with a combination of Cp?Co(CO)I2 and Cu(OAc)2 was used for performing Buchwald-type C-N coupling reactions of aryl chlorides with amines. The reactions proceeded at 100 °C to produce excellent yields of many of the desired C-N coupled products, in 4 h, under aerobic reaction conditions. The reactions were shown to run under base-free and solvent-free conditions, enabling this strategy to work efficiently for electron-withdrawing and base-sensitive functionalities. The presented methodology was found to be equally efficient for electron-donating functionalities as well as for primary (1°) and secondary (2°) aromatic and aliphatic amines. Moreover, the products were easily separated through the extractions of the organic aqueous layer, with this process chromatographic separations is not required.
- Srivastava, Avinash K.,Sharma, Charu,Joshi, Raj K.
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supporting information
p. 8248 - 8253
(2020/12/29)
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- Half-sandwich (η5-Cp?)Rh(iii) complexes of pyrazolated organo-sulfur/selenium/tellurium ligands: Efficient catalysts for base/solvent free C-N coupling of chloroarenes under aerobic conditions
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Three new pyrazolated chalcogenoether ligated Rh(iii) half-sandwich complexes (1-3) were synthesised by the thermal reaction of chalcogenoether (S, Se and Te) substituted 1H-pyrazole ligands (L1-L3) and [(η5-C5Me5)RhCl]2 in methanol. The complexes were fully characterised by various spectroscopic techniques, and the molecular structures of complexes 1 and2 were also established through single crystal X-ray crystallographic analysis, which indicates a pseudo-octahedral half-sandwich piano-stool geometry around the rhodium metal. All three complexes were found to be thermally stable and insensitive towards air and moisture. One mol% of Rh(iii) complexes (1-3) along with 10 mol% of Cu(OAc)2 were explored for the Buchwald-Hartwig type C-N coupling reactions of amine and aryl chloride. Good to excellent yields (89-92%) of the coupling products were obtained with seleno- and thio-ether functionalised pyrazolated Rh(iii) complexes (1 and 2), while an average yield (39%) was obtained with the telluro-ether functionalised complex (3). In contrast to the previously reported C-N coupling reactions the present reaction works under solvent- and base-free conditions, and the coupling reaction is accomplished in just 6 h with a high yield of the coupling product. The present methodology was also found to be efficient for a wide variety of functionalised aryl halides, and aliphatic or aromatic amines (1° and 2°). Moreover, the reaction also enables the C-N coupling of electron-withdrawing substrates and base-sensitive functionalities.
- Joshi, Raj Kumar,Sharma, Charu,Sharma, Kamal Nayan,Srivastava, Avinash Kumar
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supporting information
p. 3599 - 3606
(2020/06/10)
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- C–N Cross-coupling Reactions of Amines with Aryl Halides Using Amide-Based Pincer Nickel(II) Catalyst
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Abstract: An approach to C–N cross-coupling reactions of aryl halides with amines in the presence of an amide-based pincer nickel(II) catalyst (2) is described. For 3?h reactions at 110?°C with 0.2?mol% catalyst, aryl bromides gave higher turnover numbers (TON) than the corresponding chlorides or iodides. Both primary and secondary amines could be used with the former giving higher TON. However, sterically hindered amines showed lower TON. In elucidating the mechanism of this nickel complex-catalyzed C–N cross coupling reaction it was found that the rate of reaction was unchanged in the presence of radical quenchers and a plausible Ni(I)–Ni(III) pathway is proposed. Graphic Abstract: [Figure not available: see fulltext.]Nickel pincer catalyst proved to be excellent catalyst for the C-N cross-coupling reaction with the high turnover number (TON) for 1° and 2° amines and different nonactivated aryl halides under optimum conditions.
- Albkuri, Yahya M.,RanguMagar, Ambar B.,Brandt, Andrew,Wayland, Hunter A.,Chhetri, Bijay P.,Parnell, Charlette M.,Szwedo, Peter,Parameswaran-Thankam, Anil,Ghosh, Anindya
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p. 1669 - 1678
(2019/12/27)
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- One-way valveN-Preparation method of aryl substituted heterocyclic compound (by machine translation)
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The invention relates to the technical field of organic chemical synthesis, in particular to an organic chemical synthesis technology. NThe preparation method comprises ?timetime?: 3 molar ratio, reaction 30 - 60 minutes at normal temperature and normal pressure, water adding quenching after reaction, organic solvent extraction 1:1-1 and column chromatography separation (V). Petroleum ether : VEthyl acetate =40:1 - 20:1). NAryl substituted heterocyclic derivatives. Nitrobenzene is used as Ar-H source. N-methylaniline. N-ethylaniline. N-methyl-heterocycles, tetrahydroquinoline, and the like can be used as the amine source. t- BuBuBuBuBuBuBuONa/DMSO/O2 In the system, a direct arylamine reaction of the aromatic ring is achieved. This process has the advantage that the process is simple and high in atomic economy, avoiding the use of expensive transition metals, mild reaction conditions, and environmental-friendly by-products. (by machine translation)
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Paragraph 0022
(2020/11/01)
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- Continuous Synthesis of Aryl Amines from Phenols Utilizing Integrated Packed-Bed Flow Systems
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Aryl amines are important pharmaceutical intermediates among other numerous applications. Herein, an environmentally benign route and novel approach to aryl amine synthesis using dehydrative amination of phenols with amines and styrene under continuous-flow conditions was developed. Inexpensive and readily available phenols were efficiently converted into the corresponding aryl amines, with small amounts of easily removable co-products (i.e., H2O and alkanes), in multistep continuous-flow reactors in the presence of heterogeneous Pd catalysts. The high product selectivity and functional-group tolerance of this method allowed aryl amines with diverse functional groups to be selectively obtained in high yields over a continuous operation time of one week.
- Ichitsuka, Tomohiro,Kobayashi, Shū,Koumura, Nagatoshi,Sato, Kazuhiko,Takahashi, Ikko
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p. 15891 - 15896
(2020/07/13)
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- A Novel Modified Cross-Coupling of Phenols and Amines Using Dichloroimidazolidinedione (DCID)
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Phenols are considered as an ideal alternative to aryl halides as coupling partners in cross-coupling reactions. In the present work a copper-catalyzed cross-coupling of phenols with various aromatic and aliphatic amines for the synthesis of secondary aryl amines using dichloroimidazolidinedione (DCID) as a new and efficient activating agent has been developed. Substituted phenols were compatible with the standard reaction conditions. The two proposed mechanisms, which are based on the oxidation addition of copper with Ar-OMCID (MCID: Monochloroimidazolidinedione), are also discussed.
- Madankar, Kamelia,Mokhtari, Javad,Mirjafary, Zohreh
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supporting information
p. 1725 - 1729
(2020/09/01)
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- A new copper complex on graphene oxide: A heterogeneous catalyst for N-arylation and C-H activation
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Graphene oxide supported Cu (II) ligand complex (GO?AP/L-Cu) has been synthesized and characterized by FT-IR, Raman, PXRD, UV–Visible, TGA, XPS, FESEM, TEM, EDAX, Elemental mapping, BET, CHNS and AAS analysis. The complex has been found to be efficient and reusable heterogeneous catalyst for the N-arylation and C-H activation reactions, both the catalytic reactions were found to be simple, cleaner and give high yields (~ 90%) of product. The catalyst can be easily filtered out from the reaction mixture and reused up to four times without significant loss of catalytic activity. The reported method is economical and novel in the sense that aqueous medium was used for both the reactions and for the stability of the catalyst. All isolated organic products were fully characterized on the basis of their physical and spectral data.
- Mittal, Ayushi,Kumari, Shweta,Parmanand,Yadav, Deepak,Sharma, Sunil K.
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- Diaza crown-type macromocycle (kryptofix 22) functionalised carbon nanotube for efficient Ni2+ loading; A unique catalyst for cross-coupling reactions
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Raising the capability of supporting and suppressing the leaching possibility to a very insignificant level has still remained challenging for some class of transition metals, i.e. Ni2+. Here we present the covalent functionalisation of macrocyclic ligand, 4,13-diaza-18-crown-6 (kryptofix 22), on the surface of carbon nanotube (CNT), leading to a unique adsorptive capability for supporting Ni2+. This material was incorporated as a promising catalyst in coupling reactions including C[sbnd]C, CN, and CO[sbnd][sbnd] cross-coupling reactions. We demonstrate that the kryptofix 22 functionalisation on the surface of CNT has a key role in the enhancement of the adsorption capability Ni2+ and subsequent catalytic activity. We further prove that this ligand causes a significant boost in the recyclability of the reactions due to the extremely trivial Ni2+ leaching from the CNT's surface during the reactions.
- Aalinejad, Michael,Doustkhah, Esmail,Pesyan, Nader Noroozi
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- Preparation method of 4-nitrodiphenylamine and 4-nitrosodiphenylamine
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The invention provides a preparation method of 4-nitrodiphenylamine and 4-nitrosodiphenylamine. The preparation method comprises the following steps: (1) dissolving anhydride and/or aromatic dibasic acid as well as aniline into an organic solvent and performing ammonolysis or acylation reaction; and (2) adding nitrobenzene and a catalyst into the solution obtained in the step (1) and performing condensation reaction to generate the 4-nitrodiphenylamine and the 4-nitrosodiphenylamine. A reaction product of the aniline and the anhydride and/or the aromatic dibasic acid is used for replacing theaniline to react with the nitrobenzene, so on one hand, the steric hindrance of the reaction product and nitrobenzene ortho-reaction is increased and generation of ortho-reaction byproducts is effectively inhibited; and on the other hand, the protective effect on amino is achieved and the side reaction that two molecule aniline are condense to generate azobenzene is avoided, so that the yield of the target product is increased and energy consumption in the separation and purification link is reduced. Furthermore, the cost of the raw materials such as the anhydride and the aromatic dibasic acidis low, and the method is suitable for industrialized production.
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Paragraph 0049-0090
(2019/02/04)
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- Copper(ii)-catalyzed c-n coupling of aryl halides and n-nucleophiles promoted by quebrachitol or diethylene glycol
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Herein, we report the natural ligand quebrachitol (QCT) as a promoter for a Cu(II) catalyst, which is highly effective for N-Arylation of various amines and related aryl halides. A series of diarylamine derivatives were obtained in high yields by using diethylene glycol (DEG) as both ligand and solvent. The C-N coupling reactions proceed under mild conditions and exhibit good functional group tolerance.
- Chen, Guoliang,Chen, Yuanguang,Du, Fangyu,Fu, Yang,Wu, Ying,Zhou, Qifan
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p. 2161 - 2168
(2019/11/25)
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- Ligand-Enabled Gold-Catalyzed C(sp2)-N Cross-Coupling Reactions of Aryl Iodides with Amines
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The first example of ancillary (P,N)-ligand-enabled gold-catalyzed C-N cross-coupling reactions of aryl iodides with amines is reported. The high generality of the reaction in de novo synthesis, late-stage modifications, and cascade processes to access functionalized indolinones and carbazoles underscores the synthetic potential of the presented strategy. Monitoring the reaction with ESI-HRMS and NMR provided strong evidence for the in situ formation of putative high valent Au(III) intermediates.
- Akram, Manjur O.,Das, Avishek,Chakrabarty, Indradweep,Patil, Nitin T.
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supporting information
p. 8101 - 8105
(2019/10/11)
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- CoII immobilized on an aminated magnetic metal-organic framework catalyzed C-N and C-S bond forming reactions: A journey for the mild and efficient synthesis of arylamines and arylsulfides
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In this work, we report a simple and versatile method for the modification of a metal-organic framework (NH2-MIL53(Al)) in a step-wise manner. To characterize the synthesized nanostructured catalyst, a variety of spectroscopic and microscopic techniques including FT-IR, XRD, BET, TEM, FE-SEM, EDX, EDX-mapping, TGA, XPS, VSM, ICP-OES and CHN have been employed. Fe3O4@AMCA-MIL53(Al)-NH2-CoII NPs, which benefit from small nanocrystalline size (10-30 nm, according to the XRD and TEM data) in combination with the coexistence of magnetic nanoparticles, a metal-organic framework, and cobalt species, were found to be an excellent environment catalyst to promote the C-N and C-S cross coupling reactions. A wide range of functional substrates including electron-withdrawing and electron-donating aryl halides underwent the coupling reaction with aromatic/heteroaromatic/benzylic and aliphatic amines and sulfides. The results demonstrated that the yields of the target products were good to excellent and the catalyst can be recycled for at least seven recycling runs without a discernible decrease in its catalytic activity. Furthermore, the heterogeneity studies (such as hot filtration and poisoning tests) efficiently confirmed that the as-synthesized nanostructured catalyst is heterogeneous and completely stable under the reaction conditions. We hope that our study inspires more interest in designing novel catalysts based on using low-cost metal ions (such as cobalt) in the field of cross coupling reactions.
- Mohammadinezhad, Arezou,Akhlaghinia, Batool
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supporting information
p. 15525 - 15538
(2019/10/19)
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- A new strategy to design a graphene oxide supported palladium complex as a new heterogeneous nanocatalyst and application in carbon–carbon and carbon-heteroatom cross-coupling reactions
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The palladium nanoparticles were successfully stabilized with an average diameter of 6–7?nm through the coordination of palladium and terpyridine-based ligands grafted on graphene oxide surface. The graphene oxide supported palladium nanoparticles were thoroughly characterized and applied as an efficient heterogeneous catalyst in carbon–carbon (Suzuki-Miyaura, Mizoroki-Heck coupling reactions) and carbon–heteroatom (C-N and C-O) bond-forming reactions. The catalyst was simply recycled from the reaction mixture and was reused consecutive four times with small drop in catalytic activity.
- Bahrami, Kiumars,Targhan, Homa
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- Design of BNPs-TAPC Palladium Complex as a Reusable Heterogeneous Nanocatalyst for the O-Arylation of Phenols and N-Arylation of Amines
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The thermally stable new heterogenous nanocatalyst BNPs@SiO2(CH2)3-TAPC-O-CH2CH2NH2-Pd(0) was synthesized, characterized and successfully applied in carbon-heteroatom (C–O and C–N) coupling reactions of aryl halides with phenols and amines. The formation of resultant nanocatalyst was approved by FT-IR, XRD, TGA, XPS and EDX techniques. The morphology of BNPs@SiO2(CH2)3-TAPC-O-CH2CH2NH2-Pd(0) was characterized using scanning and transmission electron microscopes. The leaching of palladium from the surface of the catalyst was studid by ICP-OES technique. Noteworthy, the highly active BNPs@SiO2(CH2)3-TAPC-O-CH2CH2NH2-Pd(0) can be easily recycled and reused for six times with negligible loss in its activity. Some remarkable advantages of this method are the shorter reaction times, milder conditions, no needs for an inert atmosphere, high yields and easy separation. Graphical Abstract: [Figure not available: see fulltext.].
- Bahrami, Kiumars,Khodamorady, Minoo
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p. 688 - 698
(2019/01/04)
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- Recyclable bimetallic CuMoO4 nanoparticles for C-N cross-coupling reaction under mild conditions
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Herein we disclosed inexpensive copper(ii) bimetallic CuMoO4 nanoparticles for the C-N cross-coupling reaction of alkyl and aryl amines with haloarenes. The reaction proceeds under mild and ligand free conditions. The catalyst is recyclable and effective for a wide range of amines and haloarenes. Here, the efficiency of the Cu(ii) catalyst is increased by doping molybdenum metal. The bimetallic nanoparticles are anticipated to proceed via normal oxidative addition and reductive eliminations.
- Panigrahi, Reba,Panda, Subhalaxmi,Behera, Pradyota Kumar,Sahu, Santosh Kumar,Rout, Laxmidhar
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supporting information
p. 19274 - 19278
(2019/12/24)
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- C?N Cross-Coupling Reactions Under Mild Conditions Using Singlet Di-Radical Nickel(II)-Complexes as Catalyst: N-Arylation and Quinazoline Synthesis
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Herein we report a cost-effective synthetic approach for C?N cross-coupling reactions of a broad array of nitrogen nucleophiles and aryl halides under mild conditions. These reactions are catalyzed by an inexpensive, air-stable, earth-abundant and easy-to-prepare singlet di-radical nickel(II)-catalyst containing two antiferromagnetically coupled single-electron oxidized diiminosemiquinonato type ligands. This protocol provides an alternative method for C?N cross-coupling reactions avoiding nickel(0)/nickel(II) or nickel(I)/nickel(III) redox processes via cooperative participation of metal and ligand-centered redox events. Besides a wide range of N-arylation reactions, by judicious choice of aryl halides and nitrogen nucleophiles the synthesis of a variety of polysubstituted quinazolines has been achieved in moderate to good yields under relatively mild reaction conditions. Our catalyst has been found to be almost equally effective in quinazoline synthesis via C?N cross-coupling of (i) 2-bromobenzylamine with benzamide, and (ii) 2-bromobenzylbromide with amidine. Control experiments and DFT studies were performed to improve the understanding of the cooperative participation of ligand and metal (nickel)-centered redox events during oxidative addition/reductive elimination processes of the catalytic cycle and to shed light on the plausible mechanistic pathway of the C?N cross-coupling reactions. (Figure presented.).
- Sikari, Rina,Sinha, Suman,Chakraborty, Gargi,Das, Siuli,van Leest, Nicolaas Petrus,Paul, Nanda D.
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supporting information
p. 4342 - 4353
(2019/08/21)
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- CuCl2 heterogenized on metformine-modified polystyrene resin as an antibacterial agent and recyclable nanocatalyst for Ullmann-type C-N coupling reactions
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Merrifield Resin was functionalized with metformine and applied as a solid support to immobilize the CuCl2. The Ps-Met/CuCl2 was characterized by several techniques including Fourier transform infrared (FTIR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), wavelength-dispersive X-ray spectroscopy (WDX) and inductively coupled plasma (ICP). The Ps-Met/CuCl2 was used as an efficient recyclable solid nanocatalyst for N-arylation of indole and aniline through coupling reactions of Ullmann-type C-N. The advantages of this method are easy workup, improved yields, and simple recovery via filtration. Ultimately, the Ps-Met/CuCl2 antibacterial property was examined against two bacteria (Staphylococcus aureus (Staph. aureus) and Escherichia coli (E. coli)) and indicated its antibacterial performance against gram negative (E. coli) bacteria and gram positive (Staph. aureus).
- Veisi, Hojat,Ahmadian, Hossein,Mirshokraie, Seyed Ahmad,Didehban, Khadijeh,Zangeneh, Mohammad Mahdi
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- Amination of Aromatic Halides and Exploration of the Reactivity Sequence of Aromatic Halides
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A base-promoted amination of aromatic halides has been developed using a limited amount of dimethylformamide (DMF) or amine as an amino source. Various aryl halides, including F, Cl, Br, and I, have been successfully aminated in good to excellent yields. Although the amination of aromatic halides with amines or DMF is usually considered as an aromatic nucleophilic substitution (SNAr) process, and the reactivity of an aromatic halide is F > Cl > Br > I, the reactivity of aromatic halides in this system was found to be I > Br a‰ F > Cl. This protocol also showed a good regioselectivity for multihalogenated aromatics. This protocol is valuable for industrial application due to the simplicity of operation, the unrestricted availability of amino sources and aromatic halides, transition metal-free conditions, no requirement for solvent, and scalability.
- Yang, Chu,Zhang, Feng,Deng, Guo-Jun,Gong, Hang
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p. 181 - 190
(2019/01/10)
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- Preparation and characterization of isatin complexed with Cu supported on 4-(aminomethyl) benzoic acid-functionalized Fe3O4 nanoparticles as a novel magnetic catalyst for the Ullmann coupling reaction
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Isatin complexed with Cu supported on 4-(aminomethyl) benzoic acid-functionalized Fe3O4 nanoparticles (Cu-IS-AMBA-MNPs) as a new catalyst was designed, prepared and characterized by appropriate analyses. The heterogeneous reusable catalyst was successfully used for the efficient and widespread syntheses of diaryl ethers and diarylamines via the Ullmann coupling reaction. This green catalyst was easily removed, reused several times with no significant loss of its activity, and provided a clean synthesis with excellent yield and reduced time.
- Khodaei, Mohammad Mehdi,Alizadeh, Abdolhamid,Haghipour, Maryam
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p. 2727 - 2747
(2019/02/13)
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- URJC-1-MOF as New Heterogeneous Recyclable Catalyst for C-Heteroatom Coupling Reactions
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Guillermo Calleja and co-workers from @urjc describe URJC-1-MOF as a new heterogeneous recyclable catalyst for c-heteroatom coupling reactions. The capacity of copper-based URJC-1-MOF as a MOF catalyst in cross-coupling reactions has been evaluated, focusing on the Chan-Lam-Evans arylation-type reactions on amines and alcohols without extra additives or ligands. The extraordinary chemical and structural stability of URJC-1-MOF and its good specific surface, make this material a promising alternative to homogeneous Cu (II) catalysts for cross-coupling reactions. URJC-1-MOF showed a remarkable catalytic activity for cross-coupling C?N and C?O reactions, higher than other heterogeneous and homogeneous copper-based catalyst, such as CuO, HKUST-1, Cu?MOF-74, Cu(OAc)2 and CuSO4?5H2O. Moreover, its easy recovery by simple filtration and reusability in successive runs without any loss of activity and stability, demonstrates the potential of URJC-1-MOF as an alternative catalyst for this kind of reactions in different chemical media of industrial interest.
- Mu?oz, Antonio,Leo, Pedro,Orcajo, Gisela,Martínez, Fernando,Calleja, Guillermo
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p. 3376 - 3380
(2019/07/04)
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- Nickel-catalyzed N-arylation of amines with arylboronic acids under open air
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In this study, a well-defined, novel NHC-Ni complex was developed and used to catalyze the N-arylation of alkyl- and arylamines with arylboronic acids in a rare version of Chan-Lam coupling. Although the same coupling using copper catalysts has been widely studied, the nickel-catalyzed version is rare and normally requires 10–20 mol% catalyst loading. This novel NHC-Ni complex in combination with 4,4′-dimethyl-2,2′-bipyridine, however, proved to be an effective catalyst that lowered the required catalyst loading to only 2.0 mol%.
- Ando, Shin,Hirota, Yurina,Matsunaga, Hirofumi,Ishizuka, Tadao
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supporting information
p. 1277 - 1280
(2019/04/10)
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- Diamines as interparticle linkers for silica-titania supported PdCu bimetallic nanoparticles in Chan-Lam and Suzuki cross-coupling reactions
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A series of highly efficient amine functionalized SiO2-TiO2 supported bimetallic PdCu catalysts with varied metal composition have been synthesized. Ethane-1,2-diamine, butane-1,4-diamine and hexane-1,6-diamine were employed as interparticle linkers for amine functionalization of a SiO2-TiO2 support material so as to study the effect of pendant chain length on stabilization and immobilization of bimetallic nanoparticles. The shortest carbon chain length on the support provided the best results, which may be due to the trapping of metal nanoparticles more efficiently by the basic nitrogen sites. The catalytic activities of these materials were evaluated for C-N and C-C coupling reactions. The most active catalyst, Pd1Cu1@12DA-STS, was characterized by various techniques including SEM, HR-TEM, ICP-AES, XRD, FTIR, EDX, CHN analysis and TGA studies. Moreover, the synthesized catalyst was found to be recyclable for up to five runs without significant loss of activity.
- Jamwal, Babita,Kaur, Manpreet,Sharma, Harsha,Khajuria, Chhavi,Paul, Satya,Clark
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p. 4919 - 4928
(2019/03/26)
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- Copper-Catalyzed NaBAr 4-Based N-Arylation of Amines
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Using NaBAr 4 as an arylating agent, the formation of carbon-heteroatom bonds by a Cham-Lam cross-coupling reaction in the presence of catalytic copper(II) acetate monohydrate in acetonitrile at room temperature under air is described. The investigation of reaction scope suggests that several aliphatic and aromatic amines are compatible. In particular, the reaction of alkylamine and NaBAr 4 proceeds smoothly to offer the corresponding products in good to excellent yields.
- Yang, Qin,Lei, Xiaoli,Yin, Zhijian,Deng, Zhihong,Peng, Yiyuan
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supporting information
p. 538 - 544
(2019/01/10)
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- Ullmann-type: N-arylation of anilines with alkyl(aryl)sulfonium salts
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A palladium/copper-cocatalyzed Ullmann-type N-arylation of anilines using alkyl(aryl)sulfonium triflates as arylation reagents has been accomplished. The reaction enabled Caryl-S bond cleavage over Calkyl-S bond breakage of alkyl(aryl)sulfoniums by Pd(P(tBu)3)2/CuI and gave the corresponding N-arylated products in good to high yields. It was also significant that the reactions of aniline with asymmetric butyl(mesityl)(aryl)sulfonium triflates showed excellent selectivity, in which the aryl groups other than the bulky and electron-rich mesityl moieties were transformed.
- Tian, Ze-Yu,Zhang, Cheng-Pan
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supporting information
p. 11936 - 11939
(2019/10/11)
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- Reductive Molybdenum-Catalyzed Direct Amination of Boronic Acids with Nitro Compounds
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The synthesis of aromatic amines is of utmost importance in a wide range of chemical contexts. We report a direct amination of boronic acids with nitro compounds to yield (hetero)aryl amines. The novel combination of a dioxomolybdenum(VI) catalyst and triphenylphosphine as inexpensive reductant has revealed to be decisive to achieve this new C?N coupling. Our methodology has proven to be scalable, air and moisture tolerant, highly chemoselective and engages both aliphatic and aromatic nitro compounds. Moreover, this general and step-economical synthesis of aromatic secondary amines showcases orthogonality to other aromatic amine syntheses as it tolerates aryl halides and carbonyl compounds.
- Suárez-Pantiga, Samuel,Hernández-Ruiz, Raquel,Virumbrales, Cintia,Pedrosa, María R.,Sanz, Roberto
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supporting information
p. 2129 - 2133
(2019/01/25)
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- Peptide Nanofiber Templated Zinc Oxide Nanostructures as Non-precious Metal Catalyzed N-Arylation of Amines, One-Pot Synthesis of ImidazoHeterocycles and Fused Quinazolines
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In the present study, peptide nanofiber was used to immobilize zinc oxide. This nanoparticle was prepared through self-assembly in an aqueous solution. The structural properties of the prepared catalyst were examined by a series of techniques, such as FT-IR, EDS, SEM, TEM, XRD, ICP-OES (inductively coupled plasma optical emission spectrometry), and ultraviolet–visible (UV–Vis) spectroscopy. TEM images showed the necklace model for peptide nanofiber decorated with zinc oxide. The versatility of the method was investigated by N-arylation using reaction of amines with hydroxybenzotriazole as a novel phenylating reagent, one-pot synthesis of imidazoheterocycles by a three-component reaction of 2-aminopyridine, aldehyde, terminal alkyne and preparation of tetracyclic quinazolinone ring by one-pot reaction of isatoic anhydride, amine, and ninhydrin. High yields, low cost of catalyst, environmental friendliness, efficient recovery and recyclability of catalyst are the most important features of this catalytic system.
- Taherinia, Zahra,Ghorbani-Choghamarani, Arash,Hajjami, Maryam
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p. 151 - 168
(2018/10/26)
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- Electrochemically Enabled Chan-Lam Couplings of Aryl Boronic Acids and Anilines
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The Chan-Lam reaction remains a highly utilized transformation for C-N bond formation. However, anilines remain problematic substrates due to their lower nucleophilicity. To address this problem, we developed an electrochemically mediated Chan-Lam coupling of aryl boronic acids and amines utilizing a dual copper anode/cathode system. The mild conditions identified have enabled the preparation of a wide range of functionalized biarylanilines in good yields and chemoselectivities.
- Wexler, Ryan P.,Nuhant, Philippe,Senter, Timothy J.,Gale-Day, Zachary J.
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supporting information
p. 4540 - 4543
(2019/06/27)
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- Methyl-α-d-glucopyranoside as Green Ligand for Selective Copper-Catalyzed N-Arylation
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In the selective N-arylation of amines or azoles with aryl halidesa-, methyl-α-d-glucopyranoside (MG) was found to function as a green ligand of copper powder. In addition, nitrogen heterocyclic amine compounds can also undergo the N-arylation coupling with heterocyclic aryl chlorides. This process allows access to a variety of aromatic amines and aryl azoles under mild reaction conditions, has good tolerance, and proceeds in moderate to high yield.
- Chen, Fengyang,Chen, Guoliang,Chen, Yuanguang,Du, Fangyu,Zhou, Qifan
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p. 4590 - 4600
(2019/12/11)
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- Transition-metal-free synthesis of aromatic amines via the reaction of benzynes with isocyanates
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An unexpected reaction between benzynes and isocyanates to generate aromatic amines has been developed under transition-metal-free conditions. The in situ prepared anions formed through cleavage of the N–C bond in isocyanates, reacted with aryne precursor
- Seo, Jeong Hoon,Ko, Haye Min
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supporting information
p. 671 - 674
(2018/01/19)
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- "on Water" Promoted Ullmann-Type C-N Bond-Forming Reactions: Application to Carbazole Alkaloids by Selective N-Arylation of Aminophenols
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The Ullmann-type cross coupling of a variety of aromatic, aliphatic amines with aryl halides is reported using a CuI-based catalytic system in combination with an easily accessible prolinamide ligand in aqueous media. The method is mild and tolerant to air, moisture, and a wide range of functional groups, providing a novel way to access a variety of aminated products. Secondary amines like heteroaromatic amines and nucleobases have also been used, affording the corresponding coupling products in good to excellent yields. Moreover, this method has been employed for chemoselective C-N arylation of aminophenols and further utilized for the synthesis of carbazole natural products, avoiding the protection and deprotection steps.
- Chakraborti, Gargi,Paladhi, Sushovan,Mandal, Tirtha,Dash, Jyotirmayee
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p. 7347 - 7359
(2018/07/29)
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- A new diphosphine-carbonyl complex of ruthenium: an efficient precursor for C-C and C-N bond coupling catalysis
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Reaction of 1,2-bis(diphenylphosphino)benzene (dppbz) with [{Ru(CO)2Cl2}n] affords [Ru(dppbz)(CO)2Cl2], where the two carbonyls are mutually cis and the two chlorides are trans. The molecular structure of [Ru(dppbz)(CO)2Cl2], has been determined by X-ray crystallography, and the stability of the different available stereoisomers has been computationally evaluated. [Ru(dppbz)(CO)2Cl2] has been found to serve as an excellent pre-catalyst for catalytic Suzuki-type C-C coupling and Buchwald-type C-N coupling reactions.
- Mukherjee, Aparajita,Hrovat, David A.,Richmond, Michael G.,Bhattacharya, Samaresh
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p. 10264 - 10272
(2018/08/06)
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- Ultrafine hybrid Cu2O-Fe2O3 nanoparticles stabilized by hexaphenylbenzene-based supramolecular assemblies: A photocatalytic system for the Ullmann-Goldberg coupling reaction
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Ultrafine hybrid Cu2O-Fe2O3 NPs have been prepared using the supramolecular assemblies of hexaphenylbenzene (HPB) derivative 3 as nanoreactors and stabilizers. The as-prepared hybrid Cu2O-Fe2O3 NPs serve as an efficient and recyclable photocatalytic system for carrying out C-N coupling between aryl halides and various amines (aliphatic, aromatic and N-heterocyclic) at room temperature in mixed aqueous media under visible light irradiation. Amazingly, Cu2O-Fe2O3 NPs also exhibited high efficiency in the reactions involving the synthesis of biologically important N-substituted carbazole derivatives. The work being presented in this article demonstrates the preparation of a 'dip strip' coated with the as-prepared catalytic system and utilization of this paper strip as a recyclable and portable heterocatalytic system for carrying out the Ullmann-Goldberg coupling.
- Singh, Gurpreet,Kumar, Manoj,Bhalla, Vandana
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p. 5346 - 5357
(2018/12/05)
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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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