- Functionalized NHC-incorporated Te?Fe?Cu clusters: Facile synthesis, electrochemistry, and catalytic reaction
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Two novel TeFe3(CO)9-containing functionalized NHC dicopper complexes, [TeFe3(CO)9{Cu(Me2-bimy)}2] (1) and [TeFe3(CO)9{Cu(iPr2-bimy)}2] (2), were prepared from the reaction of the ternary Te?Fe?Cu complex [TeFe3(CO)9{Cu(MeCN)}2] with bis-N-methyl- or bis-N-isopropyl-substituted benzimidazol-2-ylidene (Me2-bimy or iPr2-bimy) under appropriate conditions, respectively. X-ray analysis showed that Me2-bimy-introduced complex 1 displayed a TeFe3(CO)9Cu(Me2-bimy) trigonal-bipyramidal core geometry having the Fe2Cu face capped by a Cu(Me2-bimy) fragment with the two bonded Cu atoms, whereas the bulkier iPr2-bimy-incorporated complex 2 exhibited a similar TeFe3(CO)9Cu(iPr2-bimy) core having the Fe3 triangle coordinated by a Cu(iPr2-bimy) fragment with the two unbonded Cu atoms. On the other hand, when [TeFe3(CO)9{Cu(MeCN)}2] reacted with the 4,5-dichloro-substituted 1,3-dimethylimidazolium salt (Me2-Cl2-imy·HI) in the presence of KOtBu, a different type of [TeFe3(CO)9{Cu(Me2-Cl2-imy)}2] (3) was produced in good yields. Cluster 3 was shown to possess a tetrahedral TeFe3 core geometry in which the two Fe?Fe edges were each bridged by a Cu(Me2-Cl2-imy) group. According to solid-state packings, complex 1 revealed a cluster-based 3D-supramolecular framework and complexes 2 and 3 each formed a 1D-supramolecular chain, which was stabilized by intermolecular C?H…O interactions between COs and CH moieties of the corresponding NHC ligands. Further, these di-Cu(I) based complexes 1?3 exhibited catalytic activities toward the homocoupling of arylboronic acid with high yields. Importantly, the catalytic efficiencies of this series of functionalized NHC-incorporated TeFe3(CO)9Cu2-based complexes perfectly paralleled the ease of their first oxidation and the greater electron density of the carbene atom in the NHC ligands, which was elucidated by electrochemistry, 13C NMR, and DFT calculations.
- Shieh, Minghuey,Liu, Yu-Hsin,Li, Yu-Huei,Lin, Chien-Nan,Wang, Chih-Chin
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Read Online
- Pd-Catalyzed desulfitative arylation of olefins by: N -methoxysulfonamide
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A novel Pd-catalyzed protocol for the desulfitative Heck-type reaction of N-methoxy aryl sulfonamides with alkenes was reported. The cross-coupling reaction was performed successfully with a variety of olefins to obtain aryl alkenes. Different substituents on the aromatic ring of N-methoxysulfonamides were also found to be compatible with the reaction conditions. Expectedly, the reaction proceeds through CuCl2-promoted generation of the nitrogen radical and subsequent desulfonylation under thermal conditions to afford the aryl radical for the Pd-catalyzed coupling reaction. N-Methoxysulfonamide was further exploited for the synthesis of symmetrical biaryls in the presence of CuCl2. This journal is
- Ojha, Subhadra,Panda, Niranjan
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supporting information
p. 1292 - 1298
(2022/02/19)
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- Silk?Fibroin-Supported Palladium Catalyst for Suzuki-Miyaura and Ullmann Coupling Reactions of Aryl Chlorides
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Recently, we have reported the preparation of a silk fibroin-supported Palladium catalyst (Pd/SF) and its use in the Suzuki-Miyaura cross-coupling of aryl iodides. Since its synthetic applicability and structural features are still far from being fully ex
- Albano, Gianluigi,Farinola, Gianluca M.,Giannini, Cinzia,Musio, Roberta,Omenetto, Fiorenzo G.,Rizzo, Giorgio,Sibillano, Teresa
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supporting information
(2022/02/03)
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- Pd-catalyzed oxidative homocoupling of arylboronic acids in WEPA: A sustainable access to symmetrical biaryls under added base and ligand-free ambient conditions
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Symmetrical and unsymmetrical biaryls comprises a diverse class of biologically eloquent organic compounds. We herein report, a quick and eco-friendly protocol for the synthesis of biaryls by an oxidative (aerobic) homocoupling of arylboronic acids (ABAs) using Pd(OAc)2 in water extract of pomogranate ash (WEPA) as an efficient agro-waste(bio)-derived aqueous (basic) media. The reactions were executed at ambient aerobic conditions in the absence of external base and ligand to result symmetrical biaryls in excellent yields. The use of renewable media with an effective exploitation of waste, short reaction times, excellent yields of products, easy separation of the products, unnecessating the external base, oxidant, ligand or volatile organic solvents and ambient reaction conditions are the vital insights of the present protocol.
- Appa, Rama Moorthy,Lakshmidevi, Jangam,Naidu, Bandameeda Ramesh,Venkateswarlu, Katta
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- "benchtop" Biaryl Coupling Using Pd/Cu Cocatalysis: Application to the Synthesis of Conjugated Polymers
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Typically, Suzuki couplings used in polymerizations are performed at raised temperatures in inert atmospheres. As a result, the synthesis of aromatic materials that utilize this chemistry often demands expensive and specialized equipment on an industrial scale. Herein, we describe a bimetallic methodology that exploits the distinct reactivities of palladium and copper to perform high yielding aryl-aryl dimerizations and polymerizations that can be performed on a benchtop under ambient conditions. These couplings are facile and can be performed by simple mixing in the open vessel. To demonstrate the utility of this method in the context of polymer synthesis: polyfluorene, polycarbazole, polysilafluorene, and poly(6,12-dihydro-dithienoindacenodithiophene) were created at ambient temperature and open to air.
- Minus, Matthew B.,Moor, Sarah R.,Pary, Fathima F.,Nirmani,Chwatko, Malgorzata,Okeke, Brandon,Singleton, Josh E.,Nelson, Toby L.,Lynd, Nathaniel A.,Anslyn, Eric V.
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supporting information
p. 2873 - 2877
(2021/05/05)
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- N-Methylphenothiazine S-Oxide Enabled Oxidative C(sp2)–C(sp2) Coupling of Boronic Acids with Organolithiums via Phenothiaziniums
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Herein, we report the development of a transition-metal-free oxidative C(sp2)–C(sp2) coupling of readily available boronic acids and organolithiums via phenothiazinium ions. Various biaryl, styrene, and diene derivatives were obtained using this reaction system. The key to this process is N-methylphenothiazine S-oxide (PTZSO), which allows efficient conversion of boronic acids to phenothiazinium ions. The mechanism of phenothiazinium formation using PTZSO was investigated using theoretical calculations and experiments, which provided insight into the unique reactivity of PTZSO.
- Yoshida, Tatsuki,Honda, Yuki,Morofuji, Tatsuya,Kano, Naokazu
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p. 9664 - 9668
(2021/12/17)
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- Porphyrin n-pincer pd(Ii)-complexes in water: A base-free and nature-inspired protocol for the oxidative self-coupling of potassium aryltrifluoroborates in open-air
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Metalloporphyrins (and porphyrins) are well known as pigments of life in nature, since representatives of this group include chlorophylls (Mg-porphyrins) and heme (Fe-porphyrins). Hence, the construction of chemistry based on these substances can be based on the imitation of biological systems. Inspired by nature, in this article we present the preparation of five different porphyrin, meso-tetraphenylporphyrin (TPP), meso-tetra(p-anisyl)porphyrin (TpAP), tetra-sodium meso-tetra(p-sulfonatophenyl)porphyrin (TSTpSPP), meso-tetra(m-hydroxyphenyl)porphyrin (TmHPP), and meso-tetra(m-carboxyphenyl)porphyrin (TmCPP) as well as their N-pincer Pd(II)-complexes such as Pd(II)-meso-tetraphenylporphyrin (PdTPP), Pd(II)-meso-tetra(p-anisyl)porphyrin (PdTpAP), Pd(II)-tetrasodium meso-tetra(p-sulfonatophenyl)porphyrin (PdTSTpSPP), Pd(II)-meso-tetra(m-hydroxyphenyl)porphyrin (PdTmHPP), and Pd(II)-meso-tetra(m-carboxyphenyl)porphyrin (PdTmCPP). These porphyrin N-pincer Pd(II)-complexes were studied and found to be effective in the base-free self-coupling reactions of potassium aryltrifluoroborates (PATFBs) in water at ambient conditions. The catalysts and the products (symmetrical biaryls) were characterized using their spectral data. The high yields of the biaryls, the bio-mimicking conditions, good substrate feasibility, evading the use of base, easy preparation and handling of catalysts, and the application of aqueous media, all make this protocol very attractive from a sustainability and cost-effective standpoint.
- Hanafiah, Marlia M.,Lakkaboyana, Sivarama Krishna,Lakshmidevi, Jangam,Marella, Ravi Kumar,Naidu, Bandameeda Ramesh,Prasad, Sana Siva,Venkateswarlu, Katta
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- Triptycenyl Sulfide: A Practical and Active Catalyst for Electrophilic Aromatic Halogenation Using N-Halosuccinimides
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A Lewis base catalyst Trip-SMe (Trip = triptycenyl) for electrophilic aromatic halogenation using N-halosuccinimides (NXS) is introduced. In the presence of an appropriate activator (as a noncoordinating-anion source), a series of unactivated aromatic compounds were halogenated at ambient temperature using NXS. This catalytic system was applicable to transformations that are currently unachievable except for the use of Br2 or Cl2: e.g., multihalogenation of naphthalene, regioselective bromination of BINOL, etc. Controlled experiments revealed that the triptycenyl substituent exerts a crucial role for the catalytic activity, and kinetic experiments implied the occurrence of a sulfonium salt [Trip-S(Me)Br][SbF6] as an active species. Compared to simple dialkyl sulfides, Trip-SMe exhibited a significant charge-separated ion pair character within the halonium complex whose structural information was obtained by the single-crystal X-ray analysis. A preliminary computational study disclosed that the πsystem of the triptycenyl functionality is a key motif to consolidate the enhancement of electrophilicity.
- Nishii, Yuji,Ikeda, Mitsuhiro,Hayashi, Yoshihiro,Kawauchi, Susumu,Miura, Masahiro
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supporting information
p. 1621 - 1629
(2020/02/04)
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- Exploring the coordination confinement effect of divalent palladium/zero palladium doped polyaniline-networking: As an excellent-performance nanocomposite catalyst for C-C coupling reactions
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A pre-formed catalyst Pd2+/PANI composite for C-C coupling reaction was synthesized by combining the self-stabilized dispersion polymerization method with the in-situ composite material. Experiments have confirmed that the relatively high reduced structure (75%) in the polyaniline carrier is more favorable for the coupling reaction. Raman spectroscopy, solid nuclear magnetic, and X-ray photoelectron spectroscopy were performed to characterize the structures. The pre-formed catalyst has uniform coordination of divalent palladium and nitrogen in different valence states of the carrier polyaniline, which shows a good synergistic effect in the catalytic Ullmann reaction, and greatly reduces the use of reducing agents such as hydrazine hydrate. Compared with other studies, we analyzed the catalytic reaction mechanism in detail through real-time online infrared and XPS characterization. The results show that the divalent palladium in the catalyst and the zero-valent palladium generated by the in-situ reaction synergistically promote the reaction, while the polyaniline support acts as a stabilizer and dispersant, which prevents the agglomeration of the metal particles and prolongs increased catalyst life. The prepared Pd2+/PANI composites will become the most attractive alternative to traditional organic materials due to their wide applicability, high catalytic activity, stable recycling and relatively low price. This work provides a new theoretical basis for the understanding of the essential driving force of PANI catalytic activity and the cognition of the micro mechanism of action.
- Liang, Yanping,Liu, Wanyi,Song, Manrong,Sun, Yanyan,Wang, Gang,Wu, Zhiqiang,Zhan, Haijuan
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p. 177 - 188
(2020/03/17)
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- Green-Synthesized Nickel Nanoparticles on Reduced Graphene Oxide as an Active and Selective Catalyst for Suzuki and Glaser-Hay Coupling Reactions
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A mild and benign methodology to syntheses biaryls and 1,3-diynes has been demonstrated using the nickel nanoparticles supported on reduced graphene oxide (RGO-Ni) as a heterogeneous catalyst which is prepared using green reagents. A series of substituted biaryls and 1,3-diynes has been synthesised in good to excellent yields through C-C homocoupling reaction of arylboronic acids and terminal alkynes respectively using 1,4-dioxane as a benign solvent. The present ligand-free catalytic system proceeds smoothly under mild conditions, avoids noble and stoichiometric metal reagents and tolerates sensitive functional groups. Also has a wide substrate scope and feasible with other nitrogen and sulphur containing heteroaryl boronic acids. Hot filtration test unambiguously proves the true heterogeneity of the catalyst and which support for the further reusability of the catalyst for several times without any change in the activity. The easy preparation and simple magnetic separation, stability and reusability reveal that as-prepared RGO-Ni as a versatile catalyst for the synthesis of polyaromatic compounds both in academia and industries. Highlights: Green-synthesized RGO-Ni nanocomposite used as a heterogeneous catalyst for Suzuki type (C-C) and Glaser–Hay (C ≡ C) homocoupling coupling reactions. Ligand-free catalytic system and avoids noble and stoichiometric metal reagents Short reaction time with a minimum catalyst (nickel) loading RGO-Ni nanocomposite is highly stable, reusable, and magnetically retrievable.
- Murugan, Karthik,Nainamalai, Devarajan,Kanagaraj, Pavithara,Nagappan, Saravana Ganesan,Palaniswamy, Suresh
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- Efficient Pd-catalyzed oxidative homocoupling of arylboronic acids in aqueous NaClO
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An efficient, mild and practical method was developed for the synthesis of biaryls via the Pd-catalyzed oxidative homocoupling of aromatic/heteroaromatic boronic acids in aqueous NaClO.
- Li, Min-Xin,Tang, Yan-Ling,Gao, Hui,Mao, Ze-Wei
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supporting information
(2020/03/04)
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- Arylation of aryllithiums with: S-arylphenothiazinium ions for biaryl synthesis
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Aryllithiums are one of the most common and important aryl nucleophiles; nevertheless, methods for arylation of aryllithums to produce biaryls have been limited. Herein, we report arylation of aryllithiums with S-arylphenothiazinium ions through selective
- Morofuji, Tatsuya,Yoshida, Tatsuki,Tsutsumi, Ryosuke,Yamanaka, Masahiro,Kano, Naokazu
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p. 13995 - 13998
(2020/11/21)
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- Modular and Selective Arylation of Aryl Germanes (C?GeEt3) over C?Bpin, C?SiR3 and Halogens Enabled by Light-Activated Gold Catalysis
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Selective C (Formula presented.) –C (Formula presented.) couplings are powerful strategies for the rapid and programmable construction of bi- or multiaryls. To this end, the next frontier of synthetic modularity will likely arise from harnessing the coupling space that is orthogonal to the powerful Pd-catalyzed coupling regime. This report details the realization of this concept and presents the fully selective arylation of aryl germanes (which are inert under Pd0/PdII catalysis) in the presence of the valuable functionalities C?BPin, C?SiMe3, C?I, C?Br, C?Cl, which in turn offer versatile opportunities for diversification. The protocol makes use of visible light activation combined with gold catalysis, which facilitates the selective coupling of C?Ge with aryl diazonium salts. Contrary to previous light-/gold-catalyzed couplings of Ar–N2+, which were specialized in Ar–N2+ scope, we present conditions to efficiently couple electron-rich, electron-poor, heterocyclic and sterically hindered aryl diazonium salts. Our computational data suggest that while electron-poor Ar–N2+ salts are readily activated by gold under blue-light irradiation, there is a competing dissociative deactivation pathway for excited electron-rich Ar–N2+, which requires an alternative photo-redox approach to enable productive couplings.
- Dahiya, Amit,Fricke, Christoph,Funes-Ardoiz, Ignacio,Gevondian, Avetik G.,Schoenebeck, Franziska,Sherborne, Grant J.
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supporting information
p. 15543 - 15548
(2020/06/22)
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- Band Gap Modification of TiO2 Nanoparticles by Ascorbic Acid-Stabilized Pd Nanoparticles for Photocatalytic Suzuki–Miyaura and Ullmann Coupling Reactions
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In this study, synthesis, characterization and photocatalytic performance of surface-modified TiO2 nanoparticles with ascorbic acid-stabilized Pd nanoparticles are presented. The structure, composition and morphology of as-prepared nanophotocatalyst were characterized by UV-DRS, FT-IR, ICP-AES, TEM and XPS analysis. Ascorbic acid-stabilized Pd nanoparticles induced visible light driven photocatalytic property on the surface of TiO2 which are otherwise insensitive to visible light owing to the wide band gap. The catalytic system worked well for the Suzuki–Miyaura cross-coupling and Ullmann homocoupling under compact fluorescent light as a visible source with significant activity, selectivity and recyclability. Good to excellent yields of biaryl products were obtained for various aryl halides having different electronic demands and even aryl chlorides. Our results proposed that the improved photoactivity predominantly benefits from the synergistic effects of ascorbic acid-stabilized Pd nanoparticles on TiO2 nanoparticles that cause efficient separation and photoexcited charge carriers and photoredox capability of nanocatalyst. Thus, tuning of band gap of TiO2 making a visible light sensitive photocatalyst, demonstrates a significant advancement in the photocatalytic Suzuki–Miyaura and Ullmann coupling reactions. Graphical Abstract: [Figure not available: see fulltext.].
- Feizpour, Fahimeh,Jafarpour, Maasoumeh,Rezaeifard, Abdolreza
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- Ligand-free palladium catalyzed Ullmann biaryl synthesis: 'Household' reagents and mild reaction conditions
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A palladium catalysed Ullmann biaryl synthesis has been developed using hydrazine hydrate as the reducing reagent at room temperature. The combination of Pd(OAc)2 and hydrazine hydrate works smoothly for the coupling of both electron-rich and electron-deficient aryl iodides, as well as hetero-aryl iodides, leading to a wide range of biaryls in good to excellent yields. The reaction requires only 1 mol% Pd(OAc)2 and the in situ generated palladium naoparticles are found to be active catalysts.
- Gong, Xinchi,Wu, Jie,Meng, Yunge,Zhang, Yulan,Ye, Long-Wu,Zhu, Chunyin
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supporting information
p. 995 - 999
(2019/03/12)
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- Copper-catalyzed Mizoroki-Heck coupling reaction using an efficient and magnetically reusable Fe3O4@SiO2@PrNCu catalyst
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This study intends to design and prepare a new magnetic copper catalyst and its activity was assessed by carbon-carbon coupling reactions. For this purpose, 1-[3-(trimethoxysilyl) propyl] urea (TMSPU), hydrazine and CuI were used sequentially to modify Fe3O4@SiO2 core-shell magnetic nanoparticles to obtain an efficient magnetic transition metal catalyst. Various analytical techniques were used to characterize the catalyst to show that the achieved structure and its properties are well-suited for coupling reactions. Finally, Mizoroki-Heck and Ullmann coupling reactions were performed using Fe3O4@SiO2@PrNCu catalyst. The new catalyst offer simple synthetic procedure, convenient use for routine casework and low price. The Fe3O4@SiO2@PrNCu catalyst was easily separated by means of a permanent and ordinary magnet and the recovered catalyst was reused in six cycles without any significant loss of activity.
- Yavari, Issa,Mobaraki, Akbar,Hosseinzadeh, Zhila,Sakhaee, Nader
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supporting information
p. 236 - 246
(2019/07/19)
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- A comparative study on NHC-functionalized ternary Se/Te-Fe-Cu compounds: Synthesis, catalysis, and the effect of chalcogens
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A novel family of N-heterocyclic carbene (NHC)-incorporated Se-Fe-Cu compounds, bis-1,3-dimethylimidazol-2-ylidene (bis-Me2-imy)-containing compound [(μ4-Se)Fe3(CO)9{Cu(Me2-imy)}2] (2), bis-N-methyl- or bis-N-isopropyl-substituted benzimidazol-2-ylidene (bis-Me2-bimy or bis-iPr2-bimy)-incorporated compounds [(μ4-Se)Fe3(CO)9{Cu(Me2-bimy)}2] (3) or [(μ4-Se)Fe3(CO)9{Cu(iPr2-bimy)}2] (4), and a bis-1,3-dimethyl-4,5-dichloroimidazol-2-ylidene (bis-Me2-Cl2-imy)-containing compound [(μ3-Se)Fe3(CO)9{Cu(Me2-Cl2-imy)}2] (5), were synthesized in moderate yields in facile one-pot reactions of the ternary pre-designed compound [(μ3-Se)Fe3(CO)9{Cu(MeCN)}2] (1) with the corresponding imidazolium salts and KOtBu in THF in an ice-water bath. Single-crystal X-ray analyses revealed that the Me2-imy compound 2 or the Me2-bimy compound 3 each exhibited a trigonal bipyramidal SeFe3(CO)9Cu geometry with an Fe2Cu plane further capped by a Cu(Me2-imy) or Cu(Me2-bimy) fragment, respectively, with one long Cu-Cu covalent bond. In addition, compound 4 also comprised a trigonal bipyramidal SeFe3(CO)9Cu core structure, but the second Cu(iPr2-bimy) group bridged the equatorial Fe-Fe edge with two unbonded Cu atoms, due to the presence of a sterically bulky iPr2-bimy fragment. On the other hand, the strong electron-withdrawing chloro-containing NHC compound 5 showed a comparatively open tetrahedral SeFe3(CO)9 metal core, where two Fe-Fe edges each were further bridged by a Cu(Me2-Cl2-imy) fragment. Due to the nonclassical C-H?O(carbonyl) hydrogen bonds between the CO groups of the SeFe3(CO)9Cu2 core and CH moieties of the neighboring NHC ligands, both compounds 2 and 3 comprised a one-dimensional network, while compounds 4 and 5 each were made up of a two-dimensional framework in the solid state, which efficiently enhanced the stability of these Se-Fe-Cu NHC compounds. Importantly, all of these synthesized Se-Fe-Cu NHC compounds 2-5 had pronounced catalytic activities for the homocoupling of arylboronic acids with high catalytic yields. Finally, these Se-containing Fe-Cu NHC compounds further represented excellent models for studying chalcogen effects in comparison to their Te analogs, as demonstrated by their catalytic performances and electrochemical behaviors, and by DFT calculations.
- Shieh, Minghuey,Liu, Yu-Hsin,Wang, Chih-Chin,Jian, Si-Huan,Lin, Chien-Nan,Chen, Yen-Ming,Huang, Chung-Yi
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p. 11832 - 11843
(2019/08/07)
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- Homocoupling of arylboronic acids catalyzed by dinuclear copper(I) complexes under mild conditions
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An efficient protocol for C–C coupling has been developed using three iodo-bridged copper(I) complexes as catalysts. Complexes [CuI(bpy)]2 (1), [CuI(phen)]2·DMF (2), and [CuI(Mephen)]2 (3) were successfully synthesized via solvothermal method (bpy = 2,2′-dipyridyl, phen = 1,10-phenanthroline, and Mephen = 2,9-dimethylphenanthroline). The self-coupling reaction of phenylboronic acid was selected as a model reaction to evaluate the catalytic property of the complexes. Moreover, this method tolerates various substituents on the arylboronic acids such as halogens, carbonyls, and nitro groups. It shows that the iodo-bridged Cu(I) center serves as the active site to activate molecular oxygen during the catalytic process. The result illustrates that these complexes were found to be excellent catalysts for self-coupling of arylboronic acids under mild conditions.
- Long, Bing-Fan,Qin, Gui-Fang,Huang, Qin,Xiong, Ting,Mi, Yan,Hu, Fei-Long,Yin, Xian-Hong
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p. 2639 - 2646
(2019/07/17)
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- Palladium nanoparticles immobilized on the magnetic few layer graphene support as a highly efficient catalyst for ligand free Suzuki cross coupling and homo coupling reactions
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In this study, we prepared a magnetic metal–graphene nanocomposite for the synthesis of substituted biaryls via Suzuki cross coupling and homo coupling reaction of aryl halides. The magnetic few layer graphene composite was synthesized by using one-step electrochemical exfoliation of graphite foil in aqueous iron (II) ammonium sulfate as electrolyte without using of any additive or corrosive media. Then, Fe2O3@FLG composite was used an efficient support for the immobilization and suitable dispersing of palladium nanoparticles. The obtained Fe2O3@FLG@Pd0 nanocomposite was characterized using FT-IR, SEM, TEM, EDS, XRD, VSM and ICP-AES analysis. Very low loading of this catalyst was displayed high activity in the producing substituted biaryls. It simply recovered from the reaction mixture and reused without any pre-activation in six consecutive runs with no loss of its catalytic activity or the observation of any detectable palladium leaching process.
- Rafiee, Fatemeh,Khavari, Parvaneh,Payami, Zahra,Ansari, Narges
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- Desulfurization of Diaryl(heteroaryl) Sulfoxides with Benzyne
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Two benzyne-enabled desulfurization reactions have been demonstrated which convert diaryl sulfoxides and heteroaryl sulfoxides to biaryls and desulfurized heteroarenes, respectively. The reaction accessing biaryls tolerates a variety of functional groups, such as halides, pseudohalides, and carbonyls. Mechanistic studies reveal that both reactions proceed via a common assembly process but divergent disassemblies of the generated tetraaryl(heteroaryl) sulfuranes.
- Chen, De-Li,Sun, Yan,Chen, Mengyuan,Li, Xiaojin,Zhang, Lei,Huang, Xin,Bai, Yihui,Luo, Fang,Peng, Bo
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- Method for directly synthesizing biarene compounds without metal catalysis
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The invention discloses a method for directly synthesizing biarene compounds without metal catalysis. The method is characterized in that one diaryl sulfoxide represented by a structural formula (I) shown in the description and trimethylsilyl phenyl trifluoromethanesulfonate represented by a structural formula (II) are subjected to a reaction in the presence of cesium fluoride to obtain one corresponding biarene compound represented by a formula (III) shown in the description. The method provided by the invention does not require to add any expensive metal catalyst during the reaction, therebyreducing the production costs; and the compounds have better compatibility with a substrate containing better leaving groups (such as halogen and OTs) on an aromatic ring.
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Paragraph 0026-0029
(2019/08/20)
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- Salen-porphyrin-based conjugated microporous polymer supported Pd nanoparticles: Highly efficient heterogeneous catalysts for aqueous C-C coupling reactions
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The salen-porphyrin based conjugated microporous polymer (SP-CMP) was first constructed by polycondensation reaction of a salen-dialdehyde derivative and pyrrole. Due to the outstanding chemical and thermal stability, abundant micropores with a reasonable pore size, and ordered salen-porphyrin arrays in the A4B4-type polymer framework, the functional CMP was further applied as a Pd nanoparticle support by the coordinate interactions between the polydentate chelating sites with Pd(OAc)2 and subsequent reduction with NaBH4. The as-synthesized composite material (Pd@SP-CMP) was fully characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and solid-state 13C nuclear magnetic resonance (NMR). The porous property of Pd@SP-CMP was also characterized by N2 adsorption/desorption isotherms and the obtained material exhibited a Brunauer-Emmett-Teller (BET) surface area of 266 m2 g-1, together with a pore volume of 0.192 cm3 g-1. The microscopic morphology of Pd@SP-CMP was further evaluated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The Pd@SP-CMP material with highly dispersed Pd nanoparticles exhibited excellent catalytic activity towards Suzuki-Miyaura and Heck-Mizoroki coupling reactions in water or in the dioxane/water mixture. In addition, Pd@SP-CMP also displayed outstanding stability and recyclability, and it can be reused without loss of activity in ten successive reactions. More importantly, the salen-porphyrin based CMPs could be the promising candidates for developing high-performance heterogeneous catalysts.
- Ju, Pengyao,Wu, Shujie,Su, Qing,Li, Xiaodong,Liu, Ziqian,Li, Guanghua,Wu, Qiaolin
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supporting information
p. 2660 - 2666
(2019/02/12)
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- Synergistic Activities in the Ullmann Coupling of Chloroarenes at Ambient Temperature by Pd-Supported Calcined Ferrocenated La2O3
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Novel palladium-doped nanoparticles have been explored to serve as the first metal oxide-derived heterogeneous catalyst for Ullmann reaction of chloroarenes under mild condition (34?°C). This heterogeneous catalyst exhibited high catalytic activity towards the Ullmann homocoupling of chloroarenes into a series of useful symmetrically biaryl products with good to excellent yields in the presence of ethanol and NaOH, thereby leading to green and economical Ullmann reaction. The produced nanoparticles were successfully characterized by various techniques including PXRD, XPS, HRTEM, SEM-EDS, BET, TGA techniques, elemental mapping analysis and ICP-OES. Interestingly, based on characterization and experimental data, a reasonable mechanism has been proposed. Also, the formation of aryl methyl ketone as a by-product has been further confirmed by isotopic labelling experiments that the acetyl moiety is derived from ethanol. Moreover, the catalyst was stable and could be easily reused up to 5 times under atmospheric air without suffering significant loss in catalytic activity.
- Chumkaeo, Peerapong,Poonsawat, Thinnaphat,Meechai, Titiya,Somsook, Ekasith
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- C?I-Selective Cross-Coupling Enabled by a Cationic Palladium Trimer
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While there is a growing interest in harnessing synergistic effects of more than one metal in catalysis, relatively little is known beyond bimetallic systems. This report describes the straightforward access to an air-stable Pd trimer and presents unambiguous reactivity data of its privileged capability to differentiate C?I over C?Br bonds in C?C bond formations (arylation and alkylation) of polyhalogenated arenes, which typical Pd0 and PdI-PdI catalysts fail to deliver. Experimental and computational reactivity data, including the first location of a transition state for bond activation by the trimer, are presented, supporting direct trimer reactivity to be feasible.
- Diehl, Claudia J.,Scattolin, Thomas,Englert, Ulli,Schoenebeck, Franziska
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supporting information
p. 211 - 215
(2018/12/13)
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- Palladium Niacin Complex Immobilized on Starch-Coated Maghemite Nanoparticles as an Efficient Homo- and Cross-coupling Catalyst for the Synthesis of Symmetrical and Unsymmetrical Biaryls
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Abstract: In this work, catalytic efficiency of palladium niacin complex immobilized on starch-coated maghemite nanoparticles successfully exploited for homo- and cross-coupling reactions such as Suzuki–Miyaura, Sonogashira-, and Ullmann coupling reactions. The solid catalyst characterized by different methods such as FT-IR, TGA, XPS, EDS and ICP-AES. TEM images revealed a nanosize structure for catalyst and vibrating sample magnetometer (VSM) demonstrated its magnetic property. The reactions proceeded well in the absence of commonly used additives with high selectivity. Potential reusability of magnetically separable palladium catalyst and performing the reactions at environmentally conditions are notable features of the present methods making great potential for practical applications. Graphical Abstract: [Figure not available: see fulltext.].
- Rezapour, Elham,Jafarpour, Maasoumeh,Rezaeifard, Abdolreza
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p. 3165 - 3177
(2018/08/22)
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- Efficient Homocoupling of Aryl- and Alkenylboronic Acids in the Presence of Low Loadings of [{Pd(μ-OH)Cl(IPr)} 2 ]
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NHC-palladium(II) complex [{Pd(μ-OH)Cl(IPr)} 2 ] (IPr = bis(2,6-diisopropylphenyl)imidazolin-2-ylidene) catalyzes the oxidative coupling of a broad spectrum of aryl- and alkenylboronic acids at loadings down to 5 ppm. At the concentration of 0.05 mol% the catalyst permits an efficient reaction under base-free conditions.
- Ostrowska, Sylwia,Rogalski, Szymon,Lorkowski, Jan,Walkowiak, Jedrzej,Pietraszuk, Cezary
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supporting information
p. 1735 - 1740
(2018/07/21)
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- Water-soluble superbulky (η6- p -cymene) ruthenium(ii) amine: An active catalyst in the oxidative homocoupling of arylboronic acids and the hydration of organonitriles
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A phosphine free water-soluble superbulky amine-ruthenium-arene complex (2) encompassing 2,6-bis(diphenylmethyl)-4-methylaniline was synthesised in good yield. 2 was characterized by FT-IR, 1H NMR, and 13C NMR spectroscopies, TGA and elemental analyses. The structure of 2 was confirmed by a single-crystal X-ray diffraction study. The ruthenium centre in 2 adopts the pseudo-octahedral geometry due to the η6-p-cymene ring and bulky aniline ligand along with two chloro groups. Besides, complex 2 was efficaciously employed as a catalyst in the hydration of organonitriles to amides. This reaction proceeds efficiently for a wide range of substrates in an environmentally benign medium and is an economically reasonable synthetic route to amides in good yields. In addition, 2 acts as an excellent catalyst in the oxidative homocoupling of arylboronic acids in water. A range of arylboronic acids undergo a homocoupling reaction in the presence of catalyst 2 to yield symmetrical biaryls in reasonable to good yields.
- Nirmala, Muthukumaran,Adinarayana, Mannem,Ramesh, Karupnaswamy,Maruthupandi, Mannarsamy,Vaddamanu, Moulali,Raju, Gembali,Prabusankar, Ganesan
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supporting information
p. 15221 - 15230
(2018/09/29)
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- Bipolar luminescent material based on bis-heteroaromatic ring-fused-3,7-S,S-dioxodibenzothiophene unit, and preparation method and application thereof
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The invention discloses a bipolar luminescent material based on a bis-heteroaromatic ring-fused-3,7-S,S-dioxodibenzothiophene unit, and a preparation method and an application thereof. In the invention, with the bis-heteroaromatic ring-fused-3,7-S,S-dioxodibenzothiophene unit as a nucleus, a donor unit is connected to the bis-heteroaromatic ring-fused-3,7-S,S-dioxodibenzothiophene unit through a Suzuki coupling reaction to prepare the bipolar luminescent material based on the bis-heteroaromatic ring-fused-3,7-S,S-dioxodibenzothiophene unit. The bipolar luminescent material has good solubility; when being dissolved in an organic solvent, the bipolar luminescent material can be used for preparing a luminous layer of a light emitting diode through spin-coating, ink-jet printing or printing film forming. The bipolar luminescent material contains both an electron transport unit and a hole transport unit, so that efficiency of an OLED based on the material is improved.
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Paragraph 0042; 0043; 0044; 0046
(2017/08/30)
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- based on fragrant heterocyclic and - 3 - S, S - two oxygen benzoin and thiophene unit double-polar small molecular light-emitting material and its preparation and use (by machine translation)
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The invention discloses based on fragrant heterocyclic and - 3 - S, S - two oxygen benzoin and thiophene unit double-polar small molecular light-emitting material and its preparation and use. The invention through the Suzuki coupling reaction, the electronic donor unit connected to the heterocycle and - 3 - S, S - two oxygen benzoin and thiophene prepared by the sides of the two units. The invention of based on fragrant heterocyclic and - 3 - S, S - two oxygen benzoin and thiophene unit double-polar small molecular light-emitting material has good solubility, film-forming property and thin membrane shape stability, while at the same time has good electron and hole transmission performance, can balance the carrier injection with the transmission, so that the more electron and hole effectively composite generating excitons, and avoid the hole/electron transport layer with the interface between the mixing phenomenon, thereby improving the efficiency of the light emitting device; based on the material of the luminescent layer in the electroluminescent light-emitting device can be used without the annealing treatment, so that the simple preparation process. (by machine translation)
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Paragraph 0044
(2017/08/30)
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- Ullmann homocoupling of aryl iodides catalyzed by gold nanoparticles stabilized on magnetic mesoporous silica
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Abstract: We demonstrated a convenient new procedure of the Ullmann homocoupling reaction for the synthesis of symmetrical biaryls via homocoupling of aryl iodides over a recyclable gold catalyst comprising Au nanoparticles supported on functional magnetic mesoporous silica (α-Fe2O3)-MCM-41-HS-Au. The catalyst was easily separated by an external magnet, and the recovered catalyst was reused in six successive reaction cycles without any significant loss of activity. So, using this catalyst is affordable. Also, the reaction time is much shorter than a few previously reported work. Graphical Abstract: [Figure not available: see fulltext.]
- Rostamizadeh, Shahnaz,Estiri, Hamid,Azad, Mohammad
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p. 1005 - 1010
(2017/03/11)
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- Carbon-carbon bond forming reactions via Pd-catalyzed detellurative homocoupling of diorganyl tellurides
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A simple and highly efficient method for the constructions of Csp-Csp, Csp2-Csp2 and Csp3-Csp3 bonds is reported. The symmetrical diaryl tellurides undergo detellurative homocouplings to afford symmetrical biaryl products. The reactions are carried out at ambient temperature using PdCl2 as a catalyst in the presence of Ag2O and Na2CO3. Similarly, the detellurative homocouplings of dibenzyl telluride and bis(phenylethynyl)telluride give bibenzyl and the conjugated diyne, respectively.
- Zhang, Shaozhong,Kolluru, Lalitha,Vedula, Souseelya K.,Whippie, Drew,Jin, Jin
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p. 3594 - 3597
(2017/08/23)
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- Rapid Ligand-Free Base-Accelerated Copper-Catalyzed Homocoupling Reaction of Arylboronic Acids
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A rapid, ligand-free, base-accelerated, copper-catalyzed homocoupling reaction of (het)arylboronic acids is presented. A -CuCl2·2H2O/Na2CO3-based catalyst enabled the formation of bi(het)aryl compounds by a homocoupling process in moderate to excellent yields (72-97%) within 15 minutes. A mechanism for the copper-catalyzed base-accelerated reaction is proposed.
- Cao, Ya-Nan,Tian, Xin-Chuan,Chen, Xing-Xiu,Yao, Yun-Xin,Gao, Feng,Zhou, Xian-Li
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supporting information
p. 601 - 606
(2017/03/11)
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- Synthesis, characterization and crystal structure of Cu(II) complex of trans-cyclohexane-1,2-diamine: Application in synthesis of symmetrical biaryls
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A new Cu(II) complex [Cu(cyhxn)2(H2O)2][OTf]2 was synthesised by the reaction of ligand cyhxn (cyhxn?=?trans-cyclohexane-1,2-diamine) with Cu(OTf)2 in methanol at room temperature. The complex was fully characterized by elemental analysis (CHN), FT-IR, UV–Vis and EPR spectroscopic techniques. The structure of the complex was confirmed by single crystal X-ray diffraction study. The EPR spectrum is isotropic type having giso?=?2.078, which indicates a distorted octahedral geometry of the complex. The complex was found to be an active homogeneous catalyst for the homocoupling reactions of arylboronic acid to obtain symmetrical biaryls at room temperature in methanol without the use of any additives such as a base and or an oxidant.
- Agrahari, Bhumika,Layek, Samaresh,Kumari, Shweta,Anuradha,Ganguly, Rakesh,Pathak, Devendra D.
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- Reductive Homocoupling of Organohalides Using Nickel(II) Chloride and Samarium Metal
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A homocoupling method for organohalides and organosulfonates promoted by samarium metal and HMPA, and catalyzed by NiCl2 has been developed. Various organohalides (benzyl, aryl, heterocyclic, alkenyl and alkyl halides), α-haloacetophenones, and phenyl organosulfonates were tolerated, and the reaction afforded coupling products with high efficiency. Excellent chemoselectivity was exhibited between halides and other groups, such as ?COOH, ?NO2, halogen, heterocyclic ring, ester, and ketone groups. The stereoselectivity suggested that the reaction mechanism might involve an organosamarium species.
- Liu, Yongjun,Xiao, Shuhuan,Qi, Yan,Du, Feng
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p. 673 - 678
(2017/03/22)
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- Oxidative homocoupling reaction of aryltrimethylsilanes by Pd/o-chloranil catalysis
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A practical oxidative homocoupling reaction of aryltri-methylsilanes has been achieved by Pd/o-chloranil catalytic system. The reaction shows the good functional group tolerability toward bromo, fluoro, ester, and methoxy groups to give a series of biaryls bearing electron-withdrawing and -donating groups. The boronate group is also retained on biaryls without any ArB bond cleavage, which is highly advantageous for orthogonal coupling.
- Shibata, Mari,Ito, Hideto,Itami, Kenichiro
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supporting information
p. 1701 - 1704
(2017/11/23)
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- Heck arylation of allyl alcohol catalyzed by Pd(0) nanoparticles
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Pd(0) nanoparticles ca. 2 nm in diameter were obtained by the reduction of PdCl2 and Pd(OAc)2 in water at 80 °C in the presence of a PVP-stabilizing polymer. Pd(0) NPs were successfully used in the Heck coupling of allyl alcohol with iodo- and bromobenzenes. Iodobenzenes reacted under solventless conditions or in DMF solution producing 3-arylpropanals and 2-arylpropanals as the main products. The same products were obtained in the reaction of bromobenzene in TBAB as the reaction medium. The stability of Pd(0) NPs was evidenced in recycling experiments. Similar Heck coupling results were also obtained with the palladium compounds PdCl2(cod) and Pd(OAc)2 under the same conditions.
- Tarnowicz, Stanis?awa,Alsalahi, Waleed,Mieczyńska, Ewa,Trzeciak, Anna M.
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p. 5605 - 5612
(2017/08/26)
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- Palladium-catalyzed reductive homocoupling of aryl sulfonates via cleavage of C─O bond at room temperature
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Palladium-catalyzed reductive homocoupling of aryl sulfonates has been successfully achieved under mild conditions. This transformation is a new method for the homocoupling reaction of aryl sulfonates at room temperature via the cleavage of C─O bonds, thus providing an alternative synthesis of symmetric biaryls. The reported reductive homocoupling reaction is tolerant of many common functional groups regardless of electron-donating or electron-withdrawing nature, making this newly developed transformation important for complementing Ullmann coupling. Experimental Section. Typical procedure for the products.
- Zhong, Shuangling,Chen, Mengxin,Liu, Ge,Sun, Chenggang,Liu, Wencong
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- Copper-free palladium-catalysed desulfinative homocoupling of sodium arylsulfinates under mild and aerobic conditions
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A Pd(II)-catalysed homocoupling of sodium arylsulfinates has been successfully achieved under mild conditions. This transformation is a new method for the homocoupling reaction of sodium arylsulfinates, thus providing an alternative synthesis of symmetric biaryls. The reported homocoupling reaction is tolerant to many common functional groups, such as ester, halo, cyano and nitro and works well in the presence of electron-donating and electron-withdrawing substituents. Notably, the reported desulfinative homocoupling does not require Cu salts, ligands and bases, making this newly developed transformation attractive.
- Zhang, Wei
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- Bipolar micromolecular luminescent material based on 4-(9H-carbazole-9-yl) aniline and preparation method and application thereof
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The invention discloses a bipolar micromolecular luminescent material based on 4-(9H-carbazole-9-yl) aniline and a preparation method and application thereof. The material is mainly characterized in that the 4-(9H-carbazole-9-yl) aniline is used as a hole transport center unit, and bipolar micromolecules with the 4-(9H-carbazole-9-yl) aniline as the center are obtained by selecting groups with an electron transmission function. The bipolar micromolecules prepared through the method can be used for making a luminescent layer of an organic light emitting diode.
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Paragraph 0070; 0072
(2016/10/09)
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- Homocoupling of iodoarenes and bromoalkanes using photoredox gold catalysis: A light enabled Au(III) reductive elimination
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The formation of homocoupled alkane byproducts have been identified in the reduction of bromoalkanes via photoredox gold catalysis with dimeric Au(I) complexes. This prompted further investigation into the mechanism of formation of these byproducts and the diversity of C-X bonds amenable to this transformation. Examples were found when considering bromoalkanes while a wide variety of iodoarenes underwent this process in good to excellent yields. The light enabled homocoupling of iodoarenes made possible by photoredox gold catalysis is reported.
- Tran, Huy,McCallum, Terry,Morin, Mathieu,Barriault, Louis
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supporting information
p. 4308 - 4311
(2016/09/09)
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- Homocoupling reactions of terminal alkynes and arylboronic compounds catalyzed by in situ formed Al(OH)3-supported palladium nanoparticles
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Palladium nanoparticles supported on newly generated Al(OH)3was found to be a highly efficient catalyst in oxidative homo-couplings of (Het)aryl alkynes, (Het)arylboronic acids and potassium (Het)aryltrifluoroborates, respectively. Moderate to excellent yields of symmetrical 1,3-diynes and biaryls were obtained under mild conditions.
- Li, Xing,Li, Dongjun,Bai, Yana,Zhang, Congxia,Chang, Honghong,Gao, Wenchao,Wei, Wenlong
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supporting information
p. 6996 - 7002
(2016/10/14)
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- A synthetic N, N ', , N N' -tetra (3-bromophenyl)-benzidine method
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The invention discloses a method for synthesizing N, N, N', N'-tetra(3-bromophenyl)-benzidine. The method comprises the following steps of respectively weighting 3-p-aldehyde bromobenzene, bromine and butanedioic anhydride and jointly adding into DMC/water to obtain a solution; heating for 20 hours and adding 1,4-dibromobenzene, butanedioic anhydride, bromine, copper powder and sodium hydrogen sulfite into the solution; after thoroughly dissolving, dropwise adding diluted sulfuric acid, standing, heating a reaction flask to 150-200 DEG C and reacting while stirring for 20 hours; cooling the solution to 70 DEG C, dissolving the solution in toluene, uniformly stirring and filtering to obtain a filtrate, at 50 DEG C, adding activated carbon and methanol to the filtrate to adsorb impurity, filtering, refluxing for 0.5 hour at 45 DEG C, cooling, filtering, adding 160g of methanol and washing, removing a solvent under reduced pressure to obtain a crude product and rapidly loading the crude product to a silica gel column to obtain 18.56g of target product having a yield of 53.9%. The problems of complex processes and complicated steps of the traditional method for synthesizing benzidine are avoided and N, N, N', N'-tetra(3-bromophenyl)-benzidine synthesized by the method has the advantages of high yield and high melting point.
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Paragraph 0012; 0013
(2017/04/03)
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- Ligand- and Base-Free Access to Diverse Biaryls by the Reductive Coupling of Diaryliodonium Salts
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A ligand- and base-free, Pd-catalyzed protocol to access a wide range of symmetrical and unsymmetrical biaryls from stable diaryliodonium salts was developed. The reaction involved the use of an effective and recyclable Pd/polyethylene glycol-400 catalyst system to harness the aryl moieties of two diaryliodonium salts; the ensuing biaryls may be utilized to synthesize an array of useful compounds, including 5-aryluracils, carbazoles, chromenones, fluorenones, phenathridines, and boscalid analogues.
- Arun,Reddy, P. O. Venkataramana,Pilania, Meenakshi,Kumar, Dalip
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supporting information
p. 2096 - 2100
(2016/05/09)
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- Hydrogen Peroxide Promoted Mizoroki-Heck Reactions of Phenyldiazenes with Acrylates, Acrylamides, and Styrenes
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Mizoroki-Heck reactions, which are well-known for aryldiazonium salts and which have recently been described for arylhydrazines, have now been extended to phenyldiazenes. In situ generation of phenyldiazenes from azocarboxylates allowed clean and selective reactions with styrenes, acrylates, and acrylamides using palladium(II) acetate in the presence of silver(I) acetate or hydrogen peroxide as oxidant. Hydrogen peroxide was thereby shown to be a cheap and broadly applicable alternative for the established palladium-silver(I) system.
- Lasch, Roman,Fehler, Stefanie K.,Heinrich, Markus R.
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supporting information
p. 1586 - 1589
(2016/05/02)
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- A method of compounding aromatic hydrazine synthesis symmetry biphenyl
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The invention discloses a method for synthesizing symmetrical biphenyl from aromatic hydrazine, which belongs to the field of organic synthesis. The method comprises the following steps: separately adding the aromatic hydrazine, inorganic base and a palladium catalyst into a reaction tube filled with a proper amount of a solvent, wherein the mol ratio of the aromatic hydrazine to the inorganic base to the palladium catalyst is 50: 50: 1; carrying out heating to 50 DEG C and magnetic stirring for 3 h; after completion of a reaction, carrying out cooling to room temperature; and then carrying out filtering, subjecting the solvent to spinning drying and carrying out recrystallization so as to obtain the symmetrical biphenyl. According to the method, reactive denitrification groups are removed in the form of nitrogen, which is green and free of pollution; the reaction takes air as an oxidation agent to promote oxidation denitrification, does not need any gas protection, and can be performed very well in the air without producing any by-product; and symmetrical biphenyl compounds can be prepared from cheap and easily-available aromatic hydrazine, so the method has high practicability and selectivity, and the product yield is normally much higher than the product yield reported in the literature.
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Paragraph 0026-0028
(2018/01/14)
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- Pd(OAc)2 catalyzed homocoupling of arenediazonium salts in ionic liquids: Synthesis of symmetrical biaryls
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A facile, high yielding, and simple method for the synthesis of a library of symmetrical biaryls by homocoupling of arenediazonium salts is reported, employing catalytic amounts of Pd(OAc)2 and the readily available imidazolium ionic liquids (ILs), without oxidants, ligands, additives, or volatile solvents. Simple product isolation and recycling/reuse of the IL represent additional advantages of this method.
- Savanur, Hemantkumar M.,Kalkhambkar, Rajesh G.,Laali, Kenneth K.
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p. 663 - 667
(2016/01/26)
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- Three-coordinate copper(I) 2-hydroxy-1,10-phenanthroline dinuclear complex catalyzed homocoupling of arylboronic acids towards biphenyls under air condition
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An efficient synthesis of biphenyls via three-coordinate planar dinuclear Cu2(ophen)2 complex catalyzed homocoupling of arylboronic acids under air condition and in the condition of alkali-free was demonstrated. Uniquely, this catalyst shows high selectivity towards biphenyls when the reaction was conducted in aqueous solution, which is significantly different from selectivity towards phenols in related Cu-catalysts. Utilization of environmentally friendly water as main solvent, reaction at room temperature and in the absence of base, cheapness, low loading and easy bulk preparation of catalyst make it potential in green synthesis of biphenyls.
- Wang, Yan-Hong,Xu, Mei-Chen,Liu, Jie,Zhang, Ling-Juan,Zhang, Xian-Ming
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p. 9598 - 9601
(2015/12/04)
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- Pd(OAc)2/PPh3-catalyzed desulfonylative homocoupling of arylsulfonyl chlorides
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The Pd-catalyzed homodimerization with respect to arylsulfonyl chlorides as an efficient method for the synthesis of biaryls has been developed. This desulfonylative reaction which was performed at reflux in 1,4-dioxane for 4 h under air afforded the desired products in good to excellent yields. The Pd(OAc)2/PPh3-catalyzed desulfonylative homodimerization of arenesulfonyl chlorides as an efficient method for the synthesis of biaryls was described. The corresponding products were obtained in good to excellent yields.
- Zhao, Qiao,Chen, Liangshun,Lang, Hongyue,Wu, Shengying,Wang, Limin
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p. 535 - 538
(2015/05/27)
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- Synthesis of substituted 4,4′-dihalobiphenyls and their use for the preparation of isomeric bis(carbazolyl)biphenyls
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Model compounds of some polychlorobiphenyl congeners, viz., 4,4′-dihalobiphenyls, were synthesized. These compounds can be successfully utilized by a chemical method for the in situ generation of arynes followed by the reaction with carbazole in order to prepare appropriate bis(carbazolyl)biphenyls as components for molecular electronics and OLED devices.
- Kovalev,Pavlyuk,Zaripov,Zyryanov,Kopchuk,Rusinov,Chupakhin
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p. 1978 - 1981
(2016/05/11)
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- Immobilization of Pd(II) on MOFs as a highly active heterogeneous catalyst for Suzuki-Miyaura and Ullmann-type coupling reactions
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Palladium chloride was successfully immobilized on MOF-253, a MOF material with un-coordinated 2,2′-bipyridine moieties, through post-synthetic modification. The coordination interaction between the 2,2′-bipyridine moieties and Pd cations in the MOF-253·PdCl2 material was demonstrated by X-ray photoelectron spectroscopy (XPS) analysis. The prepared MOF-253·0.05PdCl2 was shown to be highly active, selective, and recyclable for the Suzuki-Miyaura cross-coupling and Ullmann homocoupling of a wide range of aryl halides including electron-rich and electron-poor aryl iodides/bromides, heteroaryl iodides, and even aryl chlorides, affording the corresponding biaryl compounds in good to excellent yields under mild reaction conditions. It is suggested that the 2,2′-bipyridine moieties in MOF-253 provide electron-rich environment for Pd(II) cations, and thus facilitate the initial adsorption and insertion of aryl halides molecules to Pd active sites during the carbon-carbon coupling reactions. Moreover, MOF-253·PdCl2 showed remarkably higher activity than the homogeneous Pd(bpy)Cl2 and PdCl2(CH3CN)2, which might be due to the presence of charge transfers between adjacent ligands and metals in the MOF catalyst. The superior catalytic performances of metal ions immobilized on MOFs to their homogenous counterparts might bring new opportunities in the development of highly efficient metal catalysts combining advantages of both homogeneous and heterogeneous catalysis.
- Chen, Liyu,Gao, Zhiqiang,Li, Yingwei
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p. 122 - 128
(2015/03/04)
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