- Triazine-hyperbranched polymer-modified magnetic nanoparticles-supported nano-cobalt for C–C cross-coupling reactions
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Design of hyperbranched polymers (HBPs) and crafting them in catalytic systems especially in organic chemistry are a relatively unexplored domain. This paper reports the utilization of triazine-hyperbranched polymer (THBP)-coated magnetic chitosan nanoparticles (MCs) as stabilizing matrix for cobalt nanoparticles. Cobalt nanoparticles were fabricated by coordination cobalt(II) ions with amine-terminated triazine polymer and then reduced into Co(0) using sodium borohydride in aqueous medium. The Co(0)-THBP@MCs were fully characterized by FT-IR, SEM–EDX, TEM, and TGA analyses. The presence of metallic cobalt was determined by ICP and XRD techniques. This novel hyperbranched polyaromatic polymer-encapsulated cobalt nanoparticles showed high catalytic activity in Mizoroki–Heck and Suzuki–Miyaura cross-coupling reactions. Heck and Suzuki reactions were carried out using 0.35 and 0.4?mol% of cobalt nanoparticles in which the turnover number (TON) values were calculated as 271 and 225, respectively. In addition, the produced heterogeneous catalyst could be recovered and reused without considerable loss of activity. Oxygen stability and high reusability over 7 runs with trace leaching of the cobalt into the reaction media as well as moisture stability of the immobilized cobalt nanoparticles are their considerable worthwhile advantages.
- Hajipour, Abdol R.,Sadeghi, Shaghayegh
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p. 3219 - 3233
(2021/08/06)
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- A Bis (BICAAC) Palladium(II) Complex: Synthesis and Implementation as Catalyst in Heck-Mizoroki and Suzuki-Miyaura Cross Coupling Reactions
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Carbenes are one of the most appealing, well-explored, and exciting ligands in modern chemistry due to their tunable stereoelectronic properties and a wide area of applications. A palladium complex (BICAAC)2PdCl2 with a recently discovered cyclic (alkyl)(amino)carbene having bicyclo[2.2.2] octane skeleton (BICAAC) was synthesized and characterized. The enhanced σ-donating and π-accepting ability of this carbene lend a hand to form a robust Pd-carbene bond, which allowed us to probe its reactivity as a precatalyst in Heck-Mizoroki and Suzuki-Miyaura cross-coupling reactions with low catalyst loading in open-air conditions. The diverse range of substrates was explored for both the cross-coupling reactions. To get a better understanding of the catalytic reactions, several analytical techniques such as field-emission scanning electron microscopy, high-resolution transmission electron microscopy, and powder X-ray diffraction were employed in a conclusive manner.
- Chakrabortty, Soumyadeep,Kaur, Mandeep,Adhikari, Manu,Manar, Krishna K.,Singh, Sanjay
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supporting information
p. 6209 - 6217
(2021/05/06)
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- Pd salen complex@CPGO as a convenient, effective heterogeneous catalyst for Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions
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A Pd(II) Schiff base complex supported on graphene oxide nanosheets (Pd(II) salen@CPGO) has been synthesized and characterized by FT-IR, ICP-AES, XRD, SEM/EDX and TEM. The synthesized nanocatalyst has been found to be an efficient heterogeneous catalyst for Suzuki–Miyaura and Heck–Mizoroki coupling reactions. Pd(II) salen@CPGO could be separated and recovered easily from the reaction mixture and recycled several times without a discernible decrease in its catalytic activity. The construction of a solid sheet-supported Pd catalyst would be expected to be a promising system to perform heterogeneous catalytic reactions.
- Ghabdian, Mahdieh,Nasseri, Mohammad Ali,Allahresani, Ali,Motavallizadehkakhky, Alireza
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p. 1713 - 1728
(2018/05/25)
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- Palladium-Based Catalysts Supported by Unsymmetrical XYC–1 Type Pincer Ligands: C5 Arylation of Imidazoles and Synthesis of Octinoxate Utilizing the Mizoroki–Heck Reaction
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A series of new unsymmetrical (XYC–1 type) palladacycles (C1–C4) were designed and synthesized with simple anchoring ligands L1–4H (L1H = 2-((2-(4-methoxybenzylidene)-1-phenylhydrazinyl)methyl)pyridine, L2H = N,N-dimethyl-4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono)methyl)aniline, L3H = N,N-diethyl-4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono)methyl) aniline and L4H = 4-(4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono) methyl)phenyl)morpholine H = dissociable proton). Molecular structure of catalysts (C1–C4) were further established by single X-ray crystallographic studies. The catalytic performance of palladacycles (C1–C4) was explored with the direct Csp2–H arylation of imidazoles with aryl halide derivatives. These palladacycles were also applied for investigating of Mizoroki–Heck reactions with aryl halides and acrylate derivatives. During catalytic cycle in situ generated Pd(0) nanoparticles were characterized by XPS, SEM and TEM analysis and possible reaction pathways were proposed. The catalyst was employed as a pre-catalyst for the gram-scale synthesis of octinoxate, which is utilized as a UV-B sunscreen agent.
- Maji, Ankur,Singh, Ovender,Singh, Sain,Mohanty, Aurobinda,Maji, Pradip K.,Ghosh, Kaushik
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p. 1596 - 1611
(2020/04/29)
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- Pd/Cu-free Heck and Sonogashira coupling reactions applying cobalt nanoparticles supported on multifunctional porous organic hybrid
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A new heterogeneous cobalt catalyst has been synthesized by immobilizing Co species onto a nitrogen-rich porous organic polymer (Co@imine-POP). The heterogeneous catalyst synthesized was efficient in Heck and Sonogashira cross-coupling reactions in green media under mild reaction conditions without inert air and phase transfer agents. This phosphine-, copper-, and palladium-free catalyst was stable under the reaction conditions and could be reused for at least eight successive runs without a discernible decrease in its catalytic activity.
- Hajipour, Abdol R.,Khorsandi, Zahra
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- Palladium schiff base complex immobilized on magnetic nanoparticles: An efficient and recyclable catalyst for Mizoroki and Matsuda-Heck coupling
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The present work elucidates the catalytic efficiency of palladium Schiff base complex immobilized on amine functionalized magnetic nanoparticles for Heck coupling of structurally different aryl halide/arenediazonium tetrafluoroborate with styrene/acrylate/acrylonitrile. Matsuda-Heck coupling proceeds in aqueous media at room temperature whereas Mizoroki-Heck coupling was carried out at 80 °C. Both reactions were successfully furnished with low catalyst loading. The catalyst was easily separated from reaction mixture and reused up to six times without significant loss of catalytic activity.
- Vibhute, Sandip P.,Mhaldar, Pradeep M.,Shejwal, Rajendra V.,Rashinkar, Gajanan S.,Pore, Dattaprasad M.
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supporting information
(2020/03/23)
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- In situ synthesis of carbon nanotube-encapsulated cobalt nanoparticles by a novel and simple chemical treatment process: Efficient and green catalysts for the Heck reaction
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In this study, we present a novel, fast and easy method for supporting metal nanoparticles onto the internal surface of multi-walled CNTs; these CNT-encapsulated nanoparticles as heterogeneous, efficient, inexpensive and green catalysts promote the Heck cross-coupling of a large library of functional substrates under mild and sustainable conditions. Remarkably, the introduced catalytic system could be reused for at least nine successive runs without a discernible decrease in its catalytic activity.
- Hajipour, Abdol R.,Khorsandi, Zahra,Farrokhpour, Hossein
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supporting information
p. 8215 - 8219
(2019/06/07)
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- Threonine stabilizer-controlled well-dispersed small palladium nanoparticles on modified magnetic nanocatalyst for Heck cross-coupling process in water
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We report the synthesis of magnetically separable Fe3O4@Silica-Threonine-Pd0 magnetic nanoparticles with a core–shell structure. After synthesis of Fe3O4@Silica, threonine as an efficient stabilizer/ligand was bonded to the surface of Fe3O4@Silica. Then, palladium nanoparticles were generated on the threonine-modified catalyst. The threonine stabilizer helps to generate palladium nanoparticles of small size (less than 4?nm) with high dispersity and uniformity. Magnetically separable Fe3O4@Silica-Threonine-Pd0 nanocatalyst was fully characterized using various techniques. This nanocatalyst efficiently catalysed the Heck cross-coupling reaction of a variety of substrates in water medium as a green, safe and inexpensive solvent at 80°C. The Fe3O4@Silica-Threonine-Pd0 catalyst was used for at least eight successful consecutive runs with palladium leaching of only 0.05%.
- Sarvi, Iraj,Gholizadeh, Mostafa,Izadyar, Mohammad
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- Cobalt supported on dendronized magnetic nanoparticles: A new highly efficient and recyclable catalyst for the Mizoroki–Heck cross-coupling reaction
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Polyamidoamine (PAMAM) is one of the most interesting types of hyperbranched polymers that carry a large number of amino groups on its surface. PAMAM has gained significant attention from synthetic organic chemists due to its structural characteristics, controllable structure, inner porosity, and ability to trap a wide range of ions and molecules. So, in this work, the PAMAM dendrimer was synthesized, grafted onto the surface of magnetite nanoparticles, and the resulting hybrid nanoparticles were then employed as suitable host for immobilizing cobalt nanoparticles. The newly developed catalyst was well characterized by Fourier transform-infrared, X-ray diffraction, thermogravimetric analysis, field emission-scanning electron microscopy, transmission electron microscopy, atomic absorption spectroscopy, element mapping and energy-dispersive X-ray analysis. The efficiency of the as-prepared nanocatalyst was evaluated for the Mizoroki–Heck cross-coupling reactions. The MNP@PAMAM-Co represented perfect catalytic efficiency and high selectivity for the Mizoroki–Heck cross-coupling reaction compared with previously reported catalysts. The catalyst separation from the reaction mixture was easily achieved with the assistance of an external magnetic field, and its recycling was also investigated for five consecutive runs. Hot filtration confirmed no leaching of the active metal during the Heck coupling.
- Arghan, Maryam,Koukabi, Nadiya,Kolvari, Eskandar
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- Phenanthroline-based microporous organic polymer as a platform for an immobilized palladium catalyst for organic transformations
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Porous organic polymers have attracted significant attention owing to their large specific surface area, excellent chemical and thermal stability, and controllable skeletons. phenanthroline-based microporous organic polymer (Phen-MOP) has been synthesized via a cost-effective method based on the Scholl reaction. The Phen-MOP polymer exhibits high surface area and good stability. Owing to the phenanthroline skeleton embedding into the microporous polymer framework, the Phen-MOP can serve as a platform to support a transition metal catalyst. After being post-modified with palladium acetate, the synthesized Phen-Pd-MOP framework can serve as a highly efficient heterogeneous catalyst for the Suzuki-Miyaura coupling reaction and the Heck coupling reaction. Moreover, the Phen-Pd-MOP catalyst could be reused at least 10-12 times without any significant loss of the catalytic activity.
- Wang, Chang-An,Nie, Kun,Song, Guo-Dong,Li, Yan-Wei,Han, Yin-Feng
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p. 8239 - 8245
(2019/03/21)
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- PdII Immobilized on Ferromagnetic Multi-Walled Carbon Nanotubes Functionalized by Aminated 2-Chloroethylphosphonic Acid with S -Methylisothiourea (FMMWCNTs@CPA@SMTU@PdII NPs) Applied as a Highly Efficient and Recyclable Nanostructured Catalyst for Suzuki-Miyaura and Mizoroki-Heck Cross-Coupling Reactions in Solvent-Free Conditions
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The new ferromagnetic nanostructured FMMWCNTs@CPA@SMTU@PdII NPs (IV) as an eco-friendly heterogeneous nanocatalyst with a particle size of ~20-30 nm reported earlier by our group has been found to be very effective for Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions at ambient temperature. The procedure has been applied for a wide range of aryl halides, arylboronic acids, and alkenes. The magnetic separation by an external magnetic field, mild reaction conditions, and catalyst reusability up to four times without significant decrease in catalytic activity (reduced catalytic activity from 11 to 18 % in the fifth, sixth, and seventh cycles) made the present method sustainable and economically viable for C-C cross-coupling reactions.
- Ghasemzadeh, Maryam Sadat,Akhlaghinia, Batool
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p. 674 - 692
(2019/07/12)
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- Pd–Schiff base complex supported on Fe3O4 magnetic nanoparticles: A new and highly efficient reusable catalyst for C–C bond formation in water
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A protocol is introduced for the preparation of a new cage-like Pd–Schiff base organometallic complex supported on Fe3O4 nanoparticles (Fe3O4@Schiff-base-Pd). The structure of the nanomagnetic catalyst was comprehensively characterized using Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller measurements, scanning electron microscopy (SEM), transmission electron microscopy, X-ray mapping, thermogravimetric analysis, vibrating sample magnetometry and inductively coupled plasma atomic emission spectroscopy. In the second stage, the catalytic activity of this catalyst was studied in the Suzuki and Heck cross-coupling reactions in water as a green solvent. In this sense, simple preparation of the catalyst from commercially available materials, high catalytic activity, simple operation, short reaction times, high yields and use of green solvent are some advantages of this protocol. Finally, the nanocatalyst was easily recovered, using an external magnet, and reused several times without significant loss of its catalytic efficiency. In addition, the stability of the catalyst after recycling was confirmed using SEM, XRD and FT-IR techniques.
- Lei, Lei
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- Bis-quinoline-2-carboxylic acid Copper Salt as an Efficient Catalyst for Synthesis of Aryl Olefins by Heck Reaction
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Abstract: A bis-quinoline-2-carboxylic acid copper salt as a single crystal was prepared and characterized by X-ray single crystal analysis. The crystal as a catalyst was applied to the Mizoroki–Heck coupling reaction between arylboronic acids and α-olefins. A series of diarylethenes and aryl olefins were synthesized with good to excellent yields at room temperature. The catalytic system exhibited good functional group tolerance and low pollution. Graphic Abstract: A bis-quinoline-2-carboxylic acid copper salt as a single crystal was prepared and characterized by X-ray single crystal analysis. The crystal as a catalyst was applied to the Mizoroki–Heck coupling reaction between arylboronic acids and α-olefins[InlineMediaObject not available: see fulltext.].
- Zuo, Minghui,Li, Zhuofei,Fu, Wanyong,Guo, Rui,Hou, Chuanfu,Guo, Weihao,Sun, Zhizhong,Chu, Wenyi
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p. 3217 - 3223
(2019/07/17)
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- Homoleptic cis- and trans-palladium(II) bis(guanidinato) complexes derived from N-aryl-N′,N″-di(pyridin-2-yl)- and N-aryl-N′,N″-bis(6-methylpyridin-2-yl)guanidines: Catalysts for Heck-Mizoroki coupling reactions
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N-Aryl-N′,N″-di(pyridin-2-yl)- and N-aryl-N′,N″-bis(6-methylpyridin-2-yl)guanidines (1–4 and 5–7) were isolated in 75%–81% yields. Reactions of Pd(OAc)2 with guanidines 2–7 carried out separately in toluene at 60 °C for 3 h afforded 8–13 respectively in 69%–80% yields. Compounds 1–13 were characterized by elemental analyses, HR-MS, IR and NMR (1H and 13C) spectroscopy. Molecular structures of guanidines 1, 4, 5 and 6 and those of 8–13 were determined by single crystal X-ray diffraction. The Pd(II) atom in 8–10 revealed trans geometry while that in 11–13 revealed cis geometry. DFT calculations were carried out on model compounds 9a (trans) and its hypothetical cis isomer, 9b and 12a (cis) and its hypothetical trans isomer 12b which indicated a very small energy difference between the 9a/9b pair (1.28 kcal/mol) whereas a large energy difference was observed between the 12a/12b pair (26.38 kcal/mol) in CH2Cl2. The catalytic utility of 9 in Heck-Mizoroki coupling reactions involving styrene and methyl acrylate and aryl bromides/aryl chlorides in the presence of NaOAc and excess of tetrabutylammonium bromide (TBAB) at 120 °C was explored. Both activated and de-activated aryl bromides and aryl chlorides were coupled with styrene and in addition, the aryl chlorides were coupled with methyl acrylate in the presence of 9 to afford the respective coupling products in 68% ? >99% yields. Neat reaction carried out with 9 and TBAB under the optimized condition released the colloidal Pd black as verified by EDAX, PXRD and SEM techniques thereby implying the heterogeneous nature of catalysis.
- Mishra, Vishwesh,Thomas, Jisha Mary,Chinnappan, Sivasankar,Thirupathi, Natesan
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- Novel multi-dentate phosphines for Pd-catalyzed alkoxycarbonylation of alkynes promoted by H2O additive
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A series of novel multi (bi-/tri-/tetra-)-dentate phosphines with good robustness against water and oxygen were synthesized and fully characterized. It was found that the developed ionic tri-dentate phosphine (L2′) enabled Pd-catalyzed alkoxycarbonylation of alkynes most efficiently while H2O was used as an additive instead of acid. As for L2′, its unique steric configuration with two types of potential P-P chelation modes (P?P distance of 4.31 ? and 4.36 ? respectively) to Pd-centre rendered the corresponding Pd-catalyst high activity and good stability for alkoxycarbonylation of alkynes. The in situ FT-IR analysis also verified that the formation and stability of Pd–H active species were greatly facilitated with the presence of L2′ as well as H2O additive. In addition, as an ionic phosphine, L2′ based PdCl2(MeCN)2 system immobilized in RTIL of [Bmim]NTf2 could be recycled for 7 runs without obvious activity loss or metal leaching.
- Yang, Da,Liu, Lei,Wang, Dong-Liang,Lu, Yong,Zhao, Xiao-Li,Liu, Ye
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p. 236 - 244
(2019/02/19)
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- Discovery of novel piperonyl derivatives as diapophytoene desaturase inhibitors for the treatment of methicillin-, vancomycin- and linezolid-resistant Staphylococcus aureus infections
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Inhibition of S. aureus diapophytoene desaturase (CrtN) could serve as an alternative approach for addressing the tricky antibiotic resistance by blocking the biosynthesis of carotenoid pigment which shields the bacterium from host oxidant killing. In this study, we designed and synthesized 44 derivatives with piperonyl scaffold targeting CrtN and the structure-activity relationships (SARs) were examined extensively to bring out the discovery of 21b with potent efficacy and better hERG safety profile compared to the first class CrtN inhibitor benzocycloalkane derivative 2. Except the excellent pigment inhibitory activity against wild-type S. aureus, 21b also showed excellent pigment inhibition against four pigmented MRSA strains. In addition, H2O2 killing and human whole blood killing assays proved 21b could sensitize S. aureus to be killed under oxidative stress conditions. Notably, the murine study in vivo validated the efficacy of 21b against pigmented S. aureus Newman, vancomycin-intermediate S. aureus Mu50 and linezolid-resistant S. aureus NRS271.
- Wei, Hanwen,Mao, Fei,Ni, Shuaishuai,Chen, Feifei,Li, Baoli,Qiu, Xiaoxia,Hu, Linghao,Wang, Manjiong,Zheng, Xinyu,Zhu, Jin,Lan, Lefu,Li, Jian
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p. 235 - 251
(2018/01/17)
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- Pd nanoparticles immobilized on magnetic chitosan as a novel reusable catalyst for green Heck and Suzuki cross-coupling reaction: In water at room temperature
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A novel type of magnetically responsive chitosan nanocomposite was successfully synthesized as a green and high powerful palladium-based heterogeneous catalyst and its efficiency in Heck and Suzuki cross-coupling was evaluated. This catalyst promote a large library of functional substrates of these reactions under mild and sustainable conditions (water or ethanol as solvent, at room temperature, in significantly short reaction time (20?minutes)) and stand as recyclable, metal scavenging catalytic systems.
- Hajipour, Abdol R.,Sadeghi, Ali R.,Khorsandi, Zahra
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- Probing the Evolution of Palladium Species in Pd@MOF Catalysts during the Heck Coupling Reaction: An Operando X-ray Absorption Spectroscopy Study
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The mechanism of the Heck C-C coupling reaction catalyzed by Pd@MOFs has been investigated using operando X-ray absorption spectroscopy (XAS) and powder X-ray diffraction (PXRD) combined with transmission electron microscopy (TEM) analysis and nuclear magnetic resonance (1H NMR) kinetic studies. A custom-made reaction cell was used, allowing operando PXRD and XAS data collection using high-energy synchrotron radiation. By analyzing the XAS data in combination with ex situ studies, the evolution of the palladium species is followed from the as-synthesized to its deactivated form. An adaptive reaction mechanism is proposed. Mononuclear Pd(II) complexes are found to be the dominant active species at the beginning of the reaction, which then gradually transform into Pd nanoclusters with 13-20 Pd atoms on average in later catalytic turnovers. Consumption of available reagent and substrate leads to coordination of Cl- ions to their surfaces, which causes the poisoning of the active sites. By understanding the deactivation process, it was possible to tune the reaction conditions and prolong the lifetime of the catalyst.
- Yuan, Ning,Pascanu, Vlad,Huang, Zhehao,Valiente, Alejandro,Heidenreich, Niclas,Leubner, Sebastian,Inge, A. Ken,Gaar, Jakob,Stock, Norbert,Persson, Ingmar,Martín-Matute, Belén,Zou, Xiaodong
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supporting information
p. 8206 - 8217
(2018/06/22)
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- The Catalytic Asymmetric Mukaiyama–Michael Reaction of Silyl Ketene Acetals with α,β-Unsaturated Methyl Esters
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α,β-Unsaturated esters are readily available but challenging substrates to activate in asymmetric catalysis. We now describe an efficient, general, and highly enantioselective Mukaiyama–Michael reaction of silyl ketene acetals with α,β-unsaturated methyl esters that is catalyzed by a silylium imidodiphosphorimidate (IDPi) Lewis acid.
- Gatzenmeier, Tim,Kaib, Philip S. J.,Lingnau, Julia B.,Goddard, Richard,List, Benjamin
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supporting information
p. 2464 - 2468
(2018/02/06)
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- Syntheses, characterization, solution behavior and catalytic activity of trans-[(guanidine)2PdX2] (X?=?Cl and OC(O)R; R?=?Me, Ph and tBu) in Heck–Mizoroki coupling reactions involving chloroarenes/methyl acrylate
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Trans-[{(ArNH)2C[dbnd]NAr}2PdX2] (Ar = 2,5-Me2C6H3; X = Cl (1) and OC(O)R; R = Me (2), Ph (3), and tBu (4)) were isolated in high yields and characterized by elemental analysis, IR, and NMR (1H and 13C) spectroscopy. The molecular structures of the aforementioned complexes were determined by single crystal X-ray diffraction which revealed trans syn anti-anti (1·CHCl3), trans anti anti-syn (2·CHCl3 and 3·C7H8) and trans anti anti-anti (4) stereochemistry in solid state. Complexes 2·CHCl3, 3·C7H8 and 4 contain a pair of R11(8) rings stabilized by an intramolecular N–H?O hydrogen bond between the guanidine ligand and the carboxylate moiety. The influence of shape and size of the anion upon the stereochemistry of the complexes in the solid state and in solution are discussed. VT 1H NMR spectroscopic studies carried out on samples of 1 and 3 revealed the presence of a mixture of two rotamers in solution which arise due to the restricted [dbnd]C–N(H)Ar single bond rotation of the guanidine ligand in both complexes. Complexes 1–4 were shown to be active catalysts even when used in 0.001 mol% in Heck–Mizoroki coupling reactions involving chlorobenzene and methyl acrylate. The scope of 1 in Heck–Mizoroki coupling reactions involving methyl acrylate and nine distinct chloroarenes were explored at 0.01 mol% which afforded the coupling products in 81?96% yields.
- Elumalai, Palani,Ujjval, Rishabh,Nethaji, Munirathinam,Thirupathi, Natesan
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p. 313 - 322
(2018/06/20)
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- Synthesis and Characterization of C, C -Type Palladacycles and Their Catalytic Application in Mizoroki-Heck Coupling Reaction
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Two series of ligand precursors, based on imidazo[1,2-a]pyridine and C2-phenyl substituted imidazole moieties, were developed and synthesized in high yields, featuring an N-CH2(C=O)Ar substituent on the imidazole ring. Upon reacting with palladium acetate, both series of ligands underwent double C-H bond activations at the methylene and o-aryl carbon sites on the N-CH2(C=O)Ar substituent, yielding C,C-type palladacycles bearing five-membered chelate rings. A dimeric palladium complex with bridging bromides was obtained from the ligand precursor with the bromide anion, whereas an ionic palladium complex with two "throw away" pyridine ligands was formed with the precursor of the tetrafluoroborate anion. All complexes are air-stable and were characterized by 1H and 13C NMR spectroscopy and elemental analysis. The structures of three of the new complexes were further established by single-crystal X-ray diffraction studies. These complexes have been screened for catalyzing Mizoroki-Heck coupling reaction using ionic salt as solvent. The complex based on imidazo[1,2-a]pyridine, which has an electron-donating 4-methoxyphenyl ring on the ligand scaffold, was the most efficient catalyst, capable of using activated aryl chloride and sterically hindered aryl bromide as substrates. It was also successfully applied in the green process of one-pot Mizoroki-Heck coupling/trans-esterification reaction in molten ionic salt.
- Lo, Chi Hou,Lee, Hon Man
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p. 1150 - 1159
(2018/04/17)
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- Multibond Forming Tandem Reactions of Anilines via Stable Aryl Diazonium Salts: One-Pot Synthesis of 3,4-Dihydroquinolin-2-ones
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A fast and effective one-pot tandem process that generates Heck coupled products from readily available anilines via stable aryl diazonium tosylate salts was developed. The mild and simple procedure involves rapid formation of aryl diazonium salts using a polymer-supported nitrite reagent and p-tosic acid, followed by a base-free Heck-Matsuda coupling with acrylates and styrenes. Using 2-nitroanilines as substrates, the one-pot tandem process was extended for the direct synthesis of 3,4-dihydroquinolin-2-ones. In this case, following diazotization and Heck-Matsuda coupling to give methyl cinnamates, addition of hydrogen and reutilization of the palladium catalyst for reduction of the nitro group and hydrogenation of the alkene resulted in efficient formation of 3,4-dihydroquinolin-2-ones. The synthetic utility of this one-pot, four-stage process was demonstrated with the five-pot synthesis of a quinolinone-based sodium ion channel modulator.
- Faggyas, Réka J.,Grace, Megan,Williams, Lewis,Sutherland, Andrew
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p. 12595 - 12608
(2018/10/15)
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- Silica-Supported Ni(II)–DABCO Complex: An Efficient and Reusable Catalyst for the Heck Reaction
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Abstract: An interesting nickel-based catalyst supported on DABCO-functionalized silica was successfully prepared and evaluated as heterogeneous nanocatalyst in Heck cross coupling reaction of various aryl halides and methyl acrylate. The as-prepared nanocatalyst was well characterized by FT-IR, FE-SEM, TEM, XRD, SEM-EDX, ICP and TGA techniques and found to be highly efficient in the reaction system in terms of activity and recyclability. Graphical Abstract: This work provides an economical and heterogeneous catalytic system based nickel nanoparticle supported on DABCO functionalized silica for the Heck cross-coupling reaction of various aryl halides with methyl acrylate. [Figure not available: see fulltext.]
- Hajipour, Abdol R.,Abolfathi, Parisa
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p. 188 - 195
(2017/02/10)
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- Self-assembled Pd nanoparticle-containing ionic liquid: Efficient and reusable catalyst for the Heck reaction in water
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A self-assembled Pd nanoparticle-containing ionic liquid as metal–organic polymer was successfully prepared. The structure of the catalyst was characterized using Fourier transform infrared and 1H NMR spectroscopies, scanning electron microscopy and elemental analysis. The catalyst was effectively employed in the palladium-catalyzed Heck reaction in water as a green solvent. Moreover, due to its stability the catalyst can be recovered simply and effectively and reused nine times without much loss of activity.
- Zong, Yingxiao,Wang, Junke,An, Pengli,Yue, Guoren,Pan, Yi,Wang, Xicun
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p. 2389 - 2396
(2017/09/30)
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- Aminophosphine Palladium(0) Complex Supported on ZrO2 Nanoparticles (ZrO2@AEPH2-PPh2-Pd(0)) as an Efficient Heterogeneous Catalyst for Suzuki–Miyaura and Heck–Mizoroki Reactions in Green Media
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Abstract: A new aminophosphine palladium(0) complex supported on ZrO2nanoparticles (ZrO2@AEPH2-PPh2-Pd(0)) was successfully synthesized and characterized using FT-IR, XRD, XPS, SEM, TEM, EDS, TGA and ICP techniques. Characterization results revealed that the synthesized catalyst had tetragonal and monoclinic structure with spherical morphology. The prepared nanocatalyst was showed excellent reactivity in the Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions. Moreover, this nanocatalyst can be easily recovered and reused for at least six cycles without deterioration in catalytic activity. Graphical Abstract: [Figure not available: see fulltext.]
- Razavi, Nasrin,Akhlaghinia, Batool,Jahanshahi, Roya
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p. 360 - 373
(2017/02/18)
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- Thiophene Methanimine–Palladium Schiff Base Complex Anchored on Magnetic Nanoparticles: A Novel, Highly Efficient and Recoverable Nanocatalyst for Cross-Coupling Reactions in Mild and Aqueous Media: Γ-Fe2O3/AEPH2-TC-Pd Catalyzed Suzuki–Miyaura and Heck–Mizoroki Reactions
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Abstract: In this study, a novel thiophene methanimine–palladium Schiff base complex anchored on decorated γ-Fe2O3 with 2-aminoethyl dihydrogen phosphate (γ-Fe2O3/AEPH2-TC-Pd) was synthesized as a new magnetically separable nanocatalyst. Characterization of the new designed nanocatalyst was performed successfully using different techniques such as FT-IR, XRD, XPS, TEM, TGA, VSM, ICP and elemental analysis. This nanocatalyst presented a superb catalytic activity for Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions. The most important features of the prepared catalytic system which makes the current protocol more beneficial from both industrial and environmental viewpoints are its ease of recovery and reusability up to nine cycles without appreciable loss of the catalytic performance, as well as accomplishing the reactions under mild conditions in aqueous media which is a great challenge in some cross-coupling reactions. Graphical Abstract: [Figure not available: see fulltext.].
- Jahanshahi, Roya,Akhlaghinia, Batool
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p. 2640 - 2655
(2017/09/06)
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- Iron catalysis for the synthesis of ligands: Exploring the products of hydrophosphination as ligands in cross-coupling
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Catalytic hydrophosphination is a useful technique for the synthesis of phosphines, however, the phosphine products have been little exploited as ligands in catalysis. We have selected three phosphines prepared by iron catalyzed hydrophosphination and used them as ligands in a series of cross-coupling reactions: Heck, Suzuki-Miyaura and Buchwald-Hartwig. Rather than limit the chemistry to simple cross-coupling partners which are almost guaranteed to perform well in these transformations, industrially relevant substrates which are challenging from and electronic and/or steric perspective, along with substrates which contain several heteroatoms, were explored in order to gauge the true potential of these phosphine ligands.
- Espinal-Viguri, Maialen,Mahon, Mary F.,Tyler, Simon N.G.,Webster, Ruth L.
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- Efficient nickel(II) naringenin-oxime complex catalyzed Mizoroki-Heck cross-coupling reaction in the presence of hydrazine hydrate
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A novel nickel(ii) naringenin-oxime complex was designed, synthesized and characterized. Therein, the nickel(ii) naringenin oxime complex as an efficient catalyst was used in Mizoroki-Heck coupling reactions of aryl halides containing electron-rich and electron-deficient substituents with styrene, methyl acrylate and divinylbenzene (DVB), respectively. The reaction proceeded efficiently under alkaline conditions in the presence of 0.30 mol% of the Ni(ii) naringenin oxime complexand N2H4·H2O as the reductant in EtOH at 80 °C, and 32 alkene products were afforded in moderate to excellent yields, containing four new olefins. The new catalytic system not only provided an inexpensive and efficient process with greener conditions, but also broadened the reaction scope.
- Song, Jin-Yi,Liu, Yang,Zhao, Hong-Yan,Han, Hua-Tao,Li, Zhuo-Fei,Guo, Wei-Hao,Chu, Wen-Yi,Sun, Zhi-Zhong
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p. 12288 - 12292
(2017/10/16)
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- Fe3O4@Boehmite-NH2-CoII NPs: An inexpensive and highly efficient heterogeneous magnetic nanocatalyst for the Suzuki-Miyaura and Heck-Mizoroki cross-coupling reactions
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Herein we report the synthesis of a magnetically separable core-shell-like Fe3O4@Boehmite-NH2-CoII NPs as an environmentally friendly heterogeneous catalyst. The as-prepared nanocatalyst was well characterized by various techniques such as FT-IR, XRD, BET, TEM, FE-SEM, EDX, TGA, H2-TPR, VSM, ICP-OES and elemental analysis and evaluated for the Suzuki-Miyaura and Heck-Mizoroki cross-coupling reactions in a green solvent (H2O). The results of characterization studies revealed the superparamagnetic behavior of the Fe3O4 NP core encapsulated by a Boehmite NP shell. Also, it was clearly found that the size of the particles was about 13-54 nm. In comparison with previously reported catalysts, Fe3O4@Boehmite-NH2-CoII NPs exhibited perfect catalytic efficiency for the Suzuki-Miyaura and Heck-Mizoroki cross-coupling reactions under mild conditions without using toxic solvents. The concerted effects between individual components of the catalyst and also its unique egg-like nanostructure led to the high catalytic performance of Fe3O4@Boehmite-NH2-CoII NPs. Also, the introduction of Co significantly lowers the cost of the catalyst. More importantly, the longevity of the nanocatalyst was studied and it was found that the magnetic nanocatalyst was stable under the reaction conditions and could be easily reused for at least seven consecutive cycles without a discernible decrease in its catalytic activity or metal leaching.
- Mohammadinezhad, Arezou,Akhlaghinia, Batool
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p. 5625 - 5641
(2017/12/06)
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- Pd/Cu-free Heck and Sonogashira cross-coupling reaction by Co nanoparticles immobilized on magnetic chitosan as reusable catalyst
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Chitosan (CS) is a porous, self-standing, nanofibrillar microsphere that can be used as a metal carrier. Amino groups on CS enable to modulate cobalt coordination using a safe organic ligand (methyl salicylate). This catalyst efficiently promotes Heck cross-coupling of a large library of functional substrates under mild and sustainable conditions (polyethylene glycol as solvent at 80 °C in a short time (1 h)). The cobalt complex was also used as a heterogeneous, efficient, inexpensive, and green catalyst for Sonogashira cross-coupling reactions. The reactions of various aryl halides and phenylacetylene provided the corresponding products in moderate to good yields. More importantly, this phosphine, copper, and palladium-free catalyst was stable under the reaction conditions and could be easily reused using an external magnet for at least five successive runs without a discernible decrease in its catalytic activity.
- Hajipour, Abdol R.,Rezaei, Fatemeh,Khorsandi, Zahra
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supporting information
p. 1353 - 1361
(2017/08/18)
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- Hg(II) and Pd(II) complexes with a new selenoether bridged biscarbene ligand: Efficient mono- and bis-arylation of methyl acrylate with a pincer biscarbene Pd(II) precatalyst
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Two equivalents of 1-benzyl-3-bromoethylbenzimidazolium bromide couple with Na2Se to produce the first selenoether bridged bis-benzimidazolium salt (LH2)Br2. The nitrate (LH2)(NO3)2 and tetrafluoroborate (LH2)(BF4)2 salts were also synthesized from (LH2)Br2. The reaction of Hg(OAc)2 with (LH2)Br2 gave the first pseudo pincer carbene mercury complex, [Hg(L-κ2C)][HgBr4] (C1). Different complexes of Pd(ii) with selenoether bridged carbene were obtained using (LH2)Br2 and (LH2)(NO3)2. Syntheses of these complexes were dependent on the counter anion and the temperature. Thus, the pincer type ionic complex [PdBr(L-κ3CSeC)]Br (C2) was isolated at 80 °C and the pseudo pincer type neutral complex cis-[PdBr2(L-κ2C)] (C3) was isolated at room temperature from (LH2)Br2 and Pd(OAc)2 in DMSO. The nitrate precursor (LH2)(NO3)2 on palladation with Pd(OAc)2 afforded [Pd(L-κ4CBzCSeC)]NO3 (C4) showing an unprecedented intramolecular metallation at the ortho position of the benzyl wingtip of the benzimidazole moiety. The ligand salts and metal complexes have been characterized using HRMS, heteronuclear NMR and IR spectroscopy. Single crystal X-ray structures of the ligand salts (LH2)Br2 and (LH2)(BF4)2 and complexes C1-C4 have also been elucidated. Complex C2 showed good activity for C-C coupling in the mono-Heck reaction of methyl acrylate and arylbromides. Interestingly, the less common bis-arylation was also observed with deactivated arylbromides as the result of double-Heck coupling.
- Rishu,Prashanth, Billa,Bawari, Deependra,Mandal, Ushnish,Verma, Aditya,Choudhury, Angshuman Roy,Singh, Sanjay
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supporting information
p. 6291 - 6302
(2017/07/10)
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- A Pd-metalated porous organic polymer as a highly efficient heterogeneous catalyst for C-C couplings
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An efficient catalyst system based on a Pd-metalated porous organic polymer bearing phenanthroline ligands was designed and synthesized. This catalyst was applied to various C-C bond-forming reactions, including the Suzuki, Heck and Sonogashira couplings, and afforded the corresponding products while exhibiting excellent activities and selectivities. More importantly, this catalyst can be readily recycled. These features show that such catalysts have significant potential applications in the future.
- Dai, Zhifeng,Chen, Fang,Sun, Qi,Ji, Yanyan,Wang, Liang,Meng, Xiangju,Xiao, Feng-Shou
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- Regioselective Heck reaction catalyzed by Pd nanoparticles immobilized on DNA-modified MWCNTs
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This is the first report of regioselective Heck reaction of aryl iodides with 2,3-dihydrofuran using heterogonous nanocatalyst. Herein, palladium nanoparticles is immobilized on DNA-modified multi walled carbon nanotubes and characterized by FT-IR spectroscopy, UV-vis spectroscopy, field emission scanning electron microscopy, X-ray diffraction, transmission electron microscopy, inductively coupled plasma and elemental analysis. DNA as a well-defined structure and biodegradable natural polymer generate the palladium catalyst which showed high activity in common and regioselective Heck reaction in excellent yields and good selectivity under ligand-free and mild reaction conditions. Moreover, the catalyst could be recovered and reused at least nine times without any considerable loss of its catalytic activity.
- Hajipour, Abdol R.,Khorsandi, Zahra,Farrokhpour, Hossein
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p. 59124 - 59130
(2016/07/06)
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- Magnetic iron oxide nanoparticles–N-heterocyclic carbene–palladium(II): a new, efficient and robust recyclable catalyst for Mizoroki–Heck and Suzuki–Miyaura coupling reactions
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A new and efficient nanoparticle–N-heterocyclic carbene–palladium complex was synthesized and characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, field emission scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction, transmission electron microscopy, elemental analysis, inductively coupled plasma analysis and vibrating sample magnetometry. This catalytic system was found to be a highly active catalyst in the Mizoroki–Heck and Suzuki–Miyaura cross-coupling reactions. These reactions were best performed in dimethylformamide and water, respectively, in the presence of only 0.054 mol% of palladium under mild conditions. Moreover, the catalyst could be recovered easily and reused at least ten times without any considerable loss of its catalytic activity. Copyright
- Hajipour, Abdol R.,Tadayoni, Nayereh S.,Khorsandi, Zahra
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p. 590 - 595
(2016/07/16)
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- Multi walled carbon nanotubes supported N-heterocyclic carbene-cobalt (II) as a novel, efficient and inexpensive catalyst for the Mizoroki-Heck reaction
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In this paper, an N-heterocyclic carbene-cobalt complex (NHC-Co2+) was immobilized onto the surface of multi-walled carbon nanotubes (MWCNTs) via direct grafting amination approach for the first time. The resultant composite (Co - NHC@MWCNTs) was characterized by FT-IR, TGA, XRD, ICP-OES, FE-SEM, TEM and CHN analyses. It was demonstrated that Co-NHC@MWCNTs can act as an efficient and inexpensive catalyst for Heck reactions in normal conditions which provided the corresponding products in moderate to good yields. More importantly, this phosphine and palladium-free catalyst can be reused for at least six successive runs without any discernible decrease in its catalytic activity and no remarkable changes were observed in catalyst structure.
- Hajipour, Abdol R.,Khorsandi, Zahra
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- Imidazolyl-Functionalized Ordered Mesoporous Polymer from Nanocasting as an Effective Support for Highly Dispersed Palladium Nanoparticles in the Heck Reaction
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New imidazolyl-functionalized ordered mesoporous cross-linked polymers were prepared by the copolymerization of the ionic liquid 3-benzyl-1-vinyl-1H-imidazolium bromide with divinylbenzene as the cross-linker and azobisisobutyronitrile as the radical initiator in the presence of O-silylated SBA-15 as the hard template. The materials were characterized by N2 adsorption–desorption analysis, TEM, thermogravimetric analysis, elemental analysis, and FTIR spectroscopy. The material, which benefits from the use of entrapped ionic liquid in the prepared polymer matrix in combination with its ordered mesoporous structure, is an excellent environment for the stabilization of highly dispersed Pd nanoparticles to result in a recyclable catalyst system with a significant activity in the Heck coupling reaction of aryl halides. The presence of well-distributed imidazolium functionalities in the polymeric framework might be responsible for the relatively uniform and nearly atomic scale distribution of Pd nanoparticles throughout the mesoporous structure and the prevention of Pd agglomeration during the reaction, which results in high durability, high stability, and good recycling characteristics of the catalyst. Although our catalyst system operates in a homogeneous pathway, it is also very stable and recyclable.
- Karimi, Babak,Marefat, Mohammad Reza,Hasannia, Maliheh,Akhavan, Pari Fadavi,Mansouri, Fariborz,Artelli, Zahra,Mohammadi, Fariba,Vali, Hojatollah
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p. 2508 - 2515
(2016/08/25)
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- Copper Acetate Catalyzed Regio-selective Synthesis of Substituted 1,2,3-Triazoles: A Versatile Azide–Alk-ene Cycloaddition/Oxidation Approach
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A copper acetate catalyzed oxidative cycloaddition reaction of benzyl and aryl azides with terminal and internal olefins that contain electron-withdrawing groups (COOR, CONH2, CN, CHO, COR) has been developed. The reaction employs air as the oxidant and does not require any base or additives to afford 1,4-disubstituted and 1,4,5-trisubstituted 1,2,3-triazoles in good to excellent yields with high regioselectivity.
- Rohilla, Sandeep,Patel, Shyam Sunder,Jain, Nidhi
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p. 847 - 854
(2017/01/18)
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- A click strategy for the immobilization of palladium nanoparticles onto silica: Efficient and recyclable catalysts for carbon-carbon bond formation under mild reaction conditions
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An interesting silica-supported nano-palladium catalyst was successfully prepared through "click" reaction of azide-functionalized silica with methylpropargylimidazolium bromide followed by immobilization of palladium nanoparticles (NPs), in which the click-triazole as an important functional entity acts as both a stable linker and a good chelator. The palladium-NPs are stabilized by synergistic effect of coordination and electrostatic interactions. The as-prepared nanocatalyst was well characterized and found to be highly efficient in Heck and Suzuki-Miyaura coupling in terms of activity and recyclability in aqueous ethanol under phosphine-free and low Pd loading (0.1 mol%) conditions.
- Hajipour, Abdol R.,Abolfathi, Parisa,Mohammadsaleh, Fatemeh
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p. 78080 - 78089
(2018/06/22)
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- Flexible, dicationic imidazolium salts for in situ application in palladium-catalysed Mizoroki–Heck coupling of acrylates under aerobic conditions
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The synthesis, characterization and in situ catalytic performance of new unsymmetric N,N′-disubstituted imidazolium-based dicationic salts in Mizoroki–Heck coupling of acrylates with aryl bromides under aerobic conditions are described. A series of flexible dicationic salts with varying steric and electronic properties were synthesized in good to excellent yields. All the salts were well characterized using spectroscopic techniques. X-ray diffraction analysis of two salts with the same dicationic backbone and different counter anions shows that the ligand adopts two different conformations which are influenced by the nature of the anion. Thus, the ligand is capable of changing its conformation according to the change in environment due to its flexible nature. All the synthesized imidazolium salts were found to be active in in situ palladium-catalysed Mizoroki–Heck coupling under aerobic conditions. Amongst the salts, the hydroxyl-functionalized imidazolium salt, incorporating the features of both bidentate chelating O,O ligand and carbene, shows the maximum catalytic activity. A variety of aryl and heteroaryl methyl and ethyl cinnamates were synthesized using these imidazolium salts as preligands. In addition, NMR studies confirm in situ generation of normal N-heterocyclic carbenes from the C-2 position of imidazol-2-ylidene ring. The mercury poisoning test was also performed to ascertain the nature of catalytically active palladium species. Aerobic conditions, low catalytic loading (0.5?mol%), shorter reaction times, broad functional group tolerance and good to excellent isolated yields are some of the significant features of the novel catalytic systems described here. Copyright
- Milton, Marilyn Daisy,Garg, Parul
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p. 759 - 766
(2016/09/04)
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- Green and efficient procedure for Suzuki-Miyaura and Mizoroki-Heck coupling reactions using palladium catalyst supported on phosphine functionalized ZrO2 NPs (ZrO2@ECP-Pd) as a new reusable nanocatalyst
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In this article, palladium supported on phosphine functionalized ZrO2 NPs (ZrO2@ECP-Pd) has been introduced as a novel and efficient nanocatalyst for Suzuki-Miyaura and Mizoroki-Heck reactions. This new catalyst was prepared from the reaction of Pd(OAc)2 and PPh2-functionalized ZrO2 NPs, and then characterized using FT-IR, XRD, SEM, TEM, TGA and ICP techniques. The above experimental results showed that the synthesized catalyst existed as spheres with a mean size range of 10-40 nm. The prepared ZrO2@ECP-Pd nanocatalyst was shown to be highly efficient in the Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions of a wide range of aryl halides including electron-rich and electron-poor aryl iodides/bromides, and heteroaryl iodides, affording the corresponding products in good to excellent yields in short reaction times. The notable feature of the present protocol is the use of water and [bmim]PF6 as environmentally benign solvents, which eliminate the need of toxic solvent. In addition to the aforementioned favorable properties, the nanocatalyst can be recovered and reused for the subsequent reactions (at least six times) without any appreciable loss of efficiency.
- Zarghani, Monireh,Akhlaghinia, Batool
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p. 1192 - 1200
(2016/11/02)
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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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- Recyclable glucose-derived palladium(0) nanoparticles as in situ-formed catalysts for cross-coupling reactions in aqueous media
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In situ-generated, glucose-derived palladium(0) nanoparticles were shown to be convenient and effective catalysts for aqueous Mizoroki-Heck, Sonogashira and Suzuki-Miyaura cross-coupling reactions. The addition of only 4-10 mol% glucose to the reaction mixture lead to a significant increase in yield of the desired products in comparison to processes that omitted the renewable sugar. Interestingly, the Mizoroki-Heck reaction was observed to proceed in good yield even as the reaction reached acidic pH levels. Extensive analysis of the size and morphology of the in situ-formed palladium nanoparticles using advanced analytical techniques showed that the zero valent metal was surrounded by hydrophilic hydroxyl groups. The increased aqueous phase affinity afforded by these groups allowed for facile recycling of the catalyst.
- Camp, Jason E.,Dunsford, Jay J.,Dacosta, Oliver S. G.,Blundell, Rebecca K.,Adams, James,Britton, Joshua,Smith, Robert J.,Bousfield, Thomas W.,Fay, Michael W.
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p. 16115 - 16121
(2016/02/20)
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- An in Situ Generated Palladium on Aluminum Oxide: Applications in Gram-Scale Matsuda-Heck Reactions
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In situ generated palladium on aluminum oxide provides an active catalytic system for Matsuda-Heck reactions in gram-scale. The novel catalyst proceeded through a significantly higher catalytic activity compared to the classical Pd/C system. Based on the high catalytic activity the first α,β,β-triarylation of methyl acrylate in good yields could be provided in one-step.
- Pape, Simon,Dauk?ait?, Lauryna,Lucks, Sandra,Gu, Xiaoting,Brunner, Heiko
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supporting information
p. 6376 - 6379
(2016/12/23)
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- A kind of carboxylic acid with malonic acid method of esterification reaction of dimethyl ester (by machine translation)
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The invention belongs to the field of chemical synthesis and particularly relates to a carboxyl acid compound methyl etherification method. The carboxyl acid compound methyl etherification method comprises the following steps: in a polar solvent, using a carboxyl acid compound and dimethyl malonate as reactants, under the catalysis of a catalyst, and preparing an acid methyl ester compound through the methyl etherification reaction of the carboxyl acid. The method has the advantages of cheap raw materials, easiness in raw material acquisition, low toxicity, high safety, simple neutral salt catalyst and low dosage and is suitable for industrial application.
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Paragraph 0058; 0059
(2017/02/28)
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- A novel bisoxazoline/Pd composite microsphere: A highly active catalyst for Heck reactions
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A novel bisoxazoline/Pd microsphere catalyst was successfully prepared. The structure of the solid catalyst was characterized by SEM, TGA and FT-IR. The catalyst exhibits excellent activity for the Heck reaction. Moreover, the catalyst shows outstanding stability and reusability, can be recovered simply and effectively and reused six times without any activity decrease.
- Wang, Junke,Zong, Yingxiao,Yue, Guoren,Hu, Yulai,Wang, Xicun
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p. 76285 - 76290
(2015/09/28)
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- Synthesis of a cyclometalated 1,3,5-triphenylpyrazole palladium dimer and its activity towards cross coupling reactions
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A phosphine free 1,3,5-triphenylpyrazole acetate-bridged palladacycle was prepared from simple commercially available starting materials. The activity of the palladacycle in the Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions was evaluated. The palladacycle precatalyst shows a wide substrate scope, both in Mizoroki-Heck as well as in Suzuki-Miyaura cross-coupling reactions using low catalyst loadings viz., 0.2 mol% and 0.1 mol% respectively.
- Mamidala, Ramesh,Mukundam, Vanga,Dhanunjayarao, Kunchala,Venkatasubbaiah, Krishnan
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p. 5805 - 5809
(2015/03/30)
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- Fullerene-ionic-liquid conjugates: A new class of hybrid materials with unprecedented properties
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A modular approach has been followed for the synthesis of a series of fullerene-ionic-liquid (IL) hybrids in which the number of IL moieties (two or twelve), anion, and cation have been varied. The combination of C60 and IL give rise to new unique propert
- Campisciano, Vincenzo,Parola, Valeria La,Liotta, Leonarda F.,Giacalone, Francesco,Gruttadauria, Michelangelo
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supporting information
p. 3327 - 3334
(2015/03/05)
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- Silica-acetylacetone-supported palladium nanoparticles as an efficient and reusable catalyst in the Heck-Mizoroki C-C cross-coupling reaction
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The preparation of palladium nanoparticles supported on acetylacetone-modified silica gel and their catalytic application for Heck olefination of aryl halides were investigated. The catalyst was characterized using X-ray diffraction, X-ray photoelectron spectroscopy, and transmission and scanning electron microscopies. The supported palladium nanoparticles are demonstrated to be a highly active and reusable catalyst for the Heck reaction. Several reaction parameters, including type and amount of solvent and base, were evaluated. The heterogeneity of the catalytic system was investigated with results indicating that there is a slight palladium leaching into the reaction solution under the applied reaction conditions. Despite this metal leaching, the catalyst can be reused nine times without significant loss of catalytic activity.
- Hajipour, Abdolreza,Shirdashtzade, Zohre,Azizi, Ghobad
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p. 143 - 146
(2015/03/30)
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- A practical, chemoselective approach to O-methylation of carboxylic acids with dimethyl malonate
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A practical and chemoselective method is described for the O-methylation of carboxylic acids. Dimethyl malonate, a low toxic and commercially available compound was found to be an effective methylating reagent for a variety of carboxylic acids affording methyl ester products in good to high yields and with excellent chemoselectivity, without the use of strong bases as additives. A mechanism involving the utilization of potassium bromide is tentatively proposed.
- Mao, Jincheng,Liu, Defu,Li, Yongming,Zhao, Jinzhou,Rong, Guangwei,Yan, Hong,Zhang, Guoqi
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p. 9067 - 9072
(2015/11/09)
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- Matsuda-Heck reaction with arenediazonium tosylates in water
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An environmentally friendly Matsuda-Heck reaction with arenediazonium tosylates has been developed for the first time. A range of alkenes was arylated in good to quantitative yields in water. The reaction is significantly accelerated when carried out under microwave heating. The arylation of haloalkylacrylates with diazonium salts has been implemented for the first time.
- Kutonova, Ksenia V.,Trusova, Marina E.,Stankevich, Andrey V.,Postnikov, Pavel S.,Filimonov, Victor D.
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supporting information
p. 358 - 362
(2015/06/16)
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