Polyethylene glycol-supported recyclable NC palladacycle catalyst for Heck cross-coupling reactions

Karami, Kazem; Moghadam, Zohreh; Hosseini-Kharat, Mahboubeh

doi:10.1016/j.catcom.2013.08.027

Cited by 25 publications

(13 citation statements)

References 22 publications

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“…Nevertheless, C-Br bond can be activated by substitution of strong electron-absorbing group such as m -COCH 3 (entry 10). Clearly, the catalytic activity of Pd 0 @MMT/PEO is much higher than PEO-supported recyclable NC palladacycle catalysts [28]. And it is also comparable to recent other reported heterogeneous catalysts for Heck reactions [39,40].…”

Section: Resultssupporting

confidence: 75%

“…Also, PEO is known as an effective stabilizer for transition metal nanoparticles in reducing of their agglomeration to form big-sized particles [24,25]. PEO itself has been used as a polymer support for Pd catalysts in Heck reactions [26,27,28]. For example, PEO-supported recyclable NC palladacycle catalysts were developed by Karami and co-workers [28] by blending of dimeric NC palladacycle with PEO melts at 85 °C.…”

Section: Introductionmentioning

confidence: 99%

“…PEO itself has been used as a polymer support for Pd catalysts in Heck reactions [26,27,28]. For example, PEO-supported recyclable NC palladacycle catalysts were developed by Karami and co-workers [28] by blending of dimeric NC palladacycle with PEO melts at 85 °C. However, the size of the prepared Pd nanoparticles is too large (bigger than 50 nm) and it just showed moderate catalysis efficiency (up to 80% yield) for Heck reactions.…”

Section: Introductionmentioning

confidence: 99%

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Modification of Montmorillonite with Polyethylene Oxide and Its Use as Support for Pd0 Nanoparticle Catalysts

et al. 2019

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In this study, montmorillonite (MMT) was modified by intercalating polyethylene oxide (PEO) macromolecules between the interlayer spaces in an MMT-water suspension system. X-ray diffraction results revealed that the galleries of MMT were expanded significantly after intercalation of different loading of PEO. MMT/PEO 80/20 composite was chosen as the support platform for immobilization of Pd species in preparing novel heterogeneous catalysts. After immobilization of Pd species, the interlayer spacing of MMT/PEO (80/20) (1.52 nm) was further increased to 1.72 nm (Pd2+@MMT/PEO) and 1.73 nm (Pd0@MMT/PEO), confirming the well-immobilization of the Pd species in the interlayer spaces of PEO-modified MMT. High-resolution transmission electron microscopy (HR-TEM) observation results confirmed that Pd nanoparticles were confined inside the interlayer space of MMT and/or dispersed well on the outer surface of MMT. The conversion of Pd2+ to Pd0 species was evidenced by binding energy characterization with X-ray photo electron spectroscopy (XPS). The microstructure variation caused by the Pd immobilization was sensitively detected by positron annihilation lifetime spectroscopy (PALS) studies. The prepared Pd0@MMT/PEO (0.2/80/20) catalytic composite exhibits good thermal stability up to around 200 °C, and it showed high activities for Heck reactions between aryl iodides and butyl acrylates and could be recycled for five times. The correlations between the microstructure and properties of the Pd@MMT/PEO catalytic composites were discussed.

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Section: Resultssupporting

confidence: 75%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Modification of Montmorillonite with Polyethylene Oxide and Its Use as Support for Pd0 Nanoparticle Catalysts

et al. 2019

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“…However, these homogeneous catalysts often have catalyst separation and recycling problems. To overcome these problems, palladium complexes have been immobilized onto various inorganic or organic supports such as polymers, silica, SBA‐15/16, MCM‐41, alumina, zeolite, carbon, clay, poly(ethylene glycol) and TiO 2 to make available heterogeneous catalysts, which are easier for product separation and catalyst recycling. Earlier, we have also studied the oxidation of alcohols using palladium complexes …”

Section: Introductionmentioning

confidence: 99%

Investigation of catalytic properties of two new orthopalladated complexes supported on montmorillonite: Synthesis, characterization and application in aerobic oxidation of alcohols

Karami

Hashemi

Dinari

2016

Applied Organom Chemis

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Two new complexes, [Pd(L1)(C,N)]NO3 (1) and [Pd(L2)(C,N)]NO3 (2) (L1 = 5‐nitro‐1,10‐phenanthroline, L2 = 4‐methyl‐1,10‐phenanthroline, C,N = benzylamine), have been synthesized and characterized using infrared and NMR spectroscopies and elemental analysis. Montmorillonite (MMT‐K10 clay) was used as a solid support for incorporating the cationic part of complexes 1 and 2 to produce catalysts 1 and 2, respectively, as heterogeneous catalysts. Catalyst 1 was identified using powder X‐ray diffraction and scanning and transmission electron microscopies, and the content of palladium obtained from inductively coupled plasma analysis. By changing the electron‐donating group on the L1 ligand with an electron‐withdrawing one, a minor improvement was observed in the catalytic properties. Catalyst 1 showed better efficiency for oxidation of benzyl alcohol in comparison with catalyst 2, so catalyst 1 was used for the aerobic oxidation of alcohols to corresponding aldehydes or ketones without over‐oxidation (with and without bubbling of air). This catalytic system showed high activity towards alcohols under mild conditions. Finally, the reusability of catalyst 1 was investigated with multiple reuses of the supported catalyst in subsequent alcohol oxidation reactions.

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“…7,8 However, phosphane ligands are sensitive to air oxidation, as well as being toxic, expensive, and unstable at high temperatures. Box 16315-1618, Tehran, Iran, Fax: +98-21-22853650; Tel: +98-21-23064323; E-mail: movassagh@kntu.ac.ir ionic liquids, 15 multi-walled carbon nanotubes [16][17][18] and polymers such as polystyrene, [19][20][21] polyethylene glycol, 22 polyvinyl chloride-polyethylene, 23 and polysaccharides. 9,10 Moreover, many catalysts used in the Heck reactions are homogeneous, which are impossible to be recovered and the residual palladium left in the product, confines the reaction; therefore, in recent years, the development of heterogeneous catalytic systems has increased.…”

Section: Introductionmentioning

confidence: 99%

A magnetic porous chitosan-based palladium catalyst: a green, highly efficient and reusable catalyst for Mizoroki–Heck reaction in aqueous media

Movassagh

Rezaei

2015

New J. Chem.

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A novel, biodegradable and environmentally benign magnetic porous chitosan-thienyl imine palladium(II) complex, MPCS-TI/Pd, was prepared and characterized by FT-IR, SEM, TEM, EDX, XRD, BET, VSM and TG-DTA analysis. This complex, with high surface areas and low catalyst loading, was found to be a highly active and robust heterogeneous catalyst for the Mizoroki-Heck reactions of aryl bromides and chlorides with various terminal olefins in aqueous media in good to excellent yields. The catalyst was easily separated by an external magnet and the recovered catalyst was reused in seven cycles without significant loss of catalytic activity.

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Polyethylene glycol-supported recyclable NC palladacycle catalyst for Heck cross-coupling reactions

Cited by 25 publications

References 22 publications

Modification of Montmorillonite with Polyethylene Oxide and Its Use as Support for Pd0 Nanoparticle Catalysts

Modification of Montmorillonite with Polyethylene Oxide and Its Use as Support for Pd0 Nanoparticle Catalysts

Investigation of catalytic properties of two new orthopalladated complexes supported on montmorillonite: Synthesis, characterization and application in aerobic oxidation of alcohols

A magnetic porous chitosan-based palladium catalyst: a green, highly efficient and reusable catalyst for Mizoroki–Heck reaction in aqueous media

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