Catalyst For Heck Coupling Reaction Research Articles

Support Engineering for the Stabilisation of Heterogeneous Pd3 P-Based Catalysts for Heck Coupling Reactions.

Herein we report the use of a supported Pd3 P catalyst for Heck coupling reactions. For the stabilisation of Pd3 P and Pd, as reference system, the silica support material was modified via phosphorus doping (0.5 and 1 wt % P). Through this so-called support engineering approach, the catalytic activity of Pd3 P was clearly enhanced. Whereas an iodobenzene conversion of 79 % was witnessed for Pd3 P@SiO2 in the coupling of styrene and iodobenzene in 1 h, 90 % conversion could be achieved using Pd3 P@1P-SiO2 . This improved catalytic activity probably stems from an electronic modulation of the support surface via the introduction of phosphorus. Simultaneously, the recyclability was boosted and the Pd3 P@1P-SiO2 catalyst has shown to maintain its catalytic activity over several recovery tests. Hereby, metal leaching could almost be suppressed completely to 3 % by the use of a P-modified silica support.

Fabrication of Pd NPs/Mg–Al LDH via a facile one-step hydrothermal method as highly active and stable heterogeneous catalyst for Heck coupling reaction

Fabrication of Pd NPs/Mg–Al LDH via a facile one-step hydrothermal method as highly active and stable heterogeneous catalyst for Heck coupling reaction

Anodic TiO2 nanotubes supported palladium catalysts for Heck coupling reactions: Excellent catalytic activity and reusability

A convenient method for preparing palladium nanocatalyst and its application in the Heck coupling reactions between various aryl halides and olefins are presented. Pd nanoparticles were photoreduced on anodic TiO2 nanotubes (ATNTs) to prepare the Pd@ATNTs catalyst by utilizing the large specific surface area of the ATNTs' hollow tubes. Pd nanoparticles were found to be highly dispersed on the walls of the nanotubes with an average particle size of 8.01 nm by characterization techniques. The heterogeneous Pd@ATNTs catalyst showed excellent catalytic efficiency (TOF up to 1010 h−1) due to the highly dispersed Pd within the ATNTs. Pd@ATNTs has remarkable properties of ease of separation and good reusability, allowing for at least 10 cycles of recovery and reuse without a significant decrease in catalytic activity.

N-maleyl chitosan-supported palladium catalyst for Heck coupling reaction and reduction of 4-nitrophenol

In this study, maleic anhydride-acylated chitosan (MAAC) was synthesized by modifying chitosan with maleic anhydride, and used to support palladium catalysts. N-maleyl chitosan-supported palladium (Pd/MAAC) was used as a heterogeneous catalyst for the Heck coupling reaction and reduction of 4-nitrophenol (4-NP). The chemical structure of Pd/MAAC was characterized using FT-IR XPS, XRD, XPS, TEM, SEM/EDS, N2-physisorption (adsorption–desorption), and ICP-MS. The as-synthesized catalyst exhibited high catalytic performance and could be reused up to nine runs to catalyze the cyclic reaction between iodobenzene and n-butyl acrylate with low leaching of palladium. Pd/MAAC was also used for the reduction of 4-NP to 4-aminophenol(4-AP) in 90 s at room temperature, and could be reused six times. The findings establish that Pd/MAAC catalyst is an efficient, economical, practical, and environment-friendly catalyst for the Heck reaction and reduction of 4-NP.

Palladium Loaded Dendronized Polymer as Efficient Polymeric Sustainable Catalyst for Heck Coupling Reaction

Palladium Loaded Dendronized Polymer as Efficient Polymeric Sustainable Catalyst for Heck Coupling Reaction

Shrimp shell supported palladium complex: an environmentally friendly catalyst for Heck coupling reactions

A novel shrimp shell supported palladium complex is prepared through simple processes. The new complex is well characterized through ICP, FT-IR spectra, XRD, XPS, SEM, EDX, EDS. This complex is applied as the catalyst for Heck coupling reactions between alkenes and aryl halides, and performed high catalytic activity in water as solvent under mild conditions. The cyclic utilization test revealed a stability and sustainability of this catalyst.

Alkali/alkaline earth ion-exchanged and palladium dispersed MCM-22 zeolite as a potential catalyst for eugenol isomerization and Heck coupling reactions

Alkali and alkaline earth metal ions (Na+, K+, Cs+, Mg2+) exchanged MCM-22 zeolites were prepared and subsequently palladium (2 wt.%; Pd) was dispersed on above exchanged MCM-22 zeolite materials. All the MCM-22 materials were systematically characterized by FTIR, powder X-ray diffraction, N2 sorption analysis and temperature-programmed desorption (TPD) of CO2. The XRD pattern and FTIR data confirmed the existence of the MCM-22 framework structure even after exchanging bulky metal ions and palladium loading. TPD studies using CO2 supports that the cesium and magnesium incorporated MCM-22 possess a strong and large number of basic sites. The alkali and alkaline-earth metal ions exchanged MCM-22 catalysts were explored for industrially important eugenol isomerisation, whereas the palladium containing MCM-22 materials were utilised for Heck coupling reaction of styrene with iodobenzene. The Cs-MCM-22 showed the best activity for the eugenol isomerization with the isoeugenol yield of 76%. The Cs/Pd-MCM-22 was shown as promising heterogeneous catalyst for Heck coupling reaction of styrene with iodobenzene and yield 99% stilbene. For both isomerization and Heck coupling reaction, the catalysts retain their activities even after several runs. Among different alkali and alkaline earth ion-exchanged MCM-22 materials, cesium containing MCM-22 was shown as a promising catalyst for isomerization of lignin-derived biomass model compound viz., eugenol. Subsequently, the palladium dispersed CsMCM-22 was found to be the potential catalyst for Heck coupling under ambient conditions.

Novel and efficient polymer supported copper catalyst for heck reaction

A novel polymer supported copper complex (m-PAN-Cu) is prepared by immobilizing Cuprous Iodide (CuI) on amidoxime modified Polyacrylonitrile (mPAN) and characterised by FTIR, XRD, EDX, ICP-MS and XPS analyses. This complex was further explored as a general and efficient heterogeneous catalyst for Heck coupling reaction of a series of aryl halides with olefins and afforded the corresponding coupling products in moderate to good yields. This catalyst offers easy preparation, good stability, excellent catalytic activity and reusability. This is the first study involving an amidoxime modified PAN supported copper catalyst towards greener and efficient Heck reaction.

Preparation of porous chitosan/reduced graphene oxide microspheres supported Pd nanoparticles catalysts for Heck coupling reactions

Novel porous chitosan/reduced graphene oxide microspheres supported Pd nanoparticles catalysts (Pd@CS/RGO) were prepared by a combination of silica nanoparticles etching and freeze-drying treatments of CS/RGO/silica/PdCl2 composite microspheres. The microstructure of the Pd@CS/RGO microspheres catalysts have been investigated by X-ray photo electron spectroscopy (XPS), Raman spectroscopy, high resolution transmission electron microscopy (HR-TEM), thermo-gravimetric analysis (TGA), and X-ray diffraction (XRD), etc. The results revealed that: the novel catalysts showed open porous structure; CS had good miscibility with RGO nanosheets; Pd nanoparticles were well incorporated within CS/RGO matrix; the thermal stabilities of the catalysts were improved significantly over CS. Meanwhile, the Pd@CS/RGO catalysts have been demonstrated as highly active and easily recyclable catalysts for Heck reactions. The preparation process is simple, and the structure and performance of the catalytic material can be governed by changing the mass ratios of CS/RGO/silica/PdCl2 and the pore-forming process conditions.

Tuning the Connectivity, Rigidity, and Functionality of Two-Dimensional Zr-Based Metal–Organic Frameworks

Presented herein is a group of highly stable Zr-based metal-organic frameworks with bowl-shaped dihydroanthracene-based tetratopic linkers as building blocks. Structural analysis reveals that these frameworks are all two-dimensional but comprise three distinct connectivities of Zr6 nodes. By using the steric hindrance of the nonplanar linker, the connectivity of Zr6 node can be tuned from 8-c to unusual 4-c. Further, through either one-pot synthesis or postsynthetic linker installation strategies, the connectivity of Zr6 node can be tuned from 8-c to 10-c by the insertion of a secondary linear dicarboxylate linker, from which not only the temperature-dependent flexibility of the structure can be effectively controlled with enhanced rigidity and thermal stability but also a scaffold for postsynthetic metalation of Pd(II) catalyst for Heck coupling reaction is offered.

Palladium (II) anchored on a magnetic mesoporous polymelamine–formaldehyde as new catalyst for Heck coupling reaction: optimization of reaction using response surface methodology

The paper describes synthesis of a novel mesoporous and magnetically regenerated heterogeneous nanocatalyst with high catalytic activity. The synthesis strategy includes a one-step polycondensation reaction of melamine, formaldehyde and FeCl3·6H2O in a simple and sustainable manner and followed by immobilization of Pd(II) on it. Formation and properties of nanocomposite were characterized by different techniques; the results were illustrated good surface area and a well-defined mesopore structure. Also the palladium-catalyzed C–C bond formation between aryl halides and olefins was selected to survey the activity of the synthesized nanocatalyst. Central Composite Design (CCD) strategy was used to predict the optimum synthesis conditions and identify the remarkable and effective factors including temperature, period of the reaction and amount of catalyst. These results were also verified experimentally. In order to minimize systematic error, the experimental runs as a randomized fashion were accomplished.

Terephthalic acid derived ligand‐stabilized palladium nanocomposite catalyst for Heck coupling reaction: without surface‐modified heterogeneous catalyst

A new protocol is reported for the synthesis of a heterogeneous palladium nanocomposite stabilized with a terephthalic acid‐derived ligand (N,N‐bis(4‐hydroxy‐3‐methoxybenzylidene)terephthalohydrazide). This is a highly insoluble ligand in common organic solvents, except dimethylformamide and dimethylsulfoxide. The resulting palladium nanocomposite acts as an efficient catalyst precursor for Mizoroki–Heck coupling reactions conducted under various reaction conditions. The spectral data suggest that the rate, yield and recycling of the catalyst are more effective for C–C coupling reactions. Copyright © 2016 John Wiley & Sons, Ltd.

Synthesis, crystal structure and applications of palladium thiosalicylate complexes

Three palladium thiosalicylate complexes [Pd(tb)(bipy)]·3H2O (1), [Pd2(tb)2(bipy)2]·(dtdb)2 (2) and [Pd2(tb)2(phen)2]·dtdb·H2O (3) (bipy=bipyridine; phen=phenanthroline) were prepared from the reaction of PdCl2(CH3CN)2 with dithiosalicylic acid (dtdb) which underwent cleavage to form thiobenzoate anion (tb) in DMF/MeOH. Square planar geometries of the complexes with a N2SO coordination type were proposed on the basis of single crystal X-ray structural study. The presence of trapped and uncoordinated dtdb was observed in complexes 2 and 3. Complexes 1–3 were evaluated as catalysts for Heck coupling reactions of methyl acrylate with iodobenzene, and showed moderate activities at a very low catalyst loading. Complex 1 was found to inhibit the growth of bacteria and scavenge free radicals efficiently.

ChemInform Abstract: Hybrid Au/Pd Nanoparticles as Reusable Catalysts for Heck Coupling Reactions in Water under Aerobic Conditions.

AbstractLigand‐free Heck coupling reactions of styrenes and alkyl acrylates with aryl bromides and iodides provide the corresponding products in high yields.

Fe3O4@OA–Pd and Mo10V2@NSiO2 nanoparticles: an efficient and reusable catalytic system for Heck reaction under ligand free conditions

This paper reports the use of a novel catalytic system composed of H5PMo10V2O40 supported on nano silica (Mo10V2@NSiO2) and palladium-deposited, oleic-acid-coated Fe3O4 (Fe3O4@OA–Pd) nanoparticles, as reusable catalysts for Heck coupling reaction under ligand and base free conditions. The average particle size of catalyst was measured to be about 9 nm by transmission electron microscopy. The immobilized palladium on oleic acid coated Fe3O4 was found to be effective in the Heck arylation of various aryl bromides and especially less reactive aryl chlorides with styrene in the presence of heteropoly acid. This method has the advantages of high yields, elimination of ligand and base, simple methodology and easy workup. Interestingly, the novel catalytic system could be recovered in a facile manner from the reaction mixture and recycled several times without any significant loss in catalytic activity. Structural changes of recovered Mo10V2@NSiO2 and Fe3O4@OA–Pd were investigated before reusing for the next runs. Finally, synchronized reusability of both components of our catalytic system has been investigated in the model reaction.

ChemInform Abstract: Palladium Supported on Oleic Acid‐coated Magnetic Nanoparticle as an Efficient Catalyst for Heck Coupling Reaction in Aqueous Media.

AbstractThe catalyst can be easily recovered by external magnetic field and reused several times without significant loss of activity.

Hybrid Au/Pd nanoparticles as reusable catalysts for Heck coupling reactions in water under aerobic conditions

This work reports the synthesis and application of Au/Pd nanoparticles as separable catalysts for Heck coupling reactions in water under aerobic conditions. This method provides high yields, mild reaction conditions, and an easy work-up. Catalytic efficiency remains unaltered even after several repeated cycles.

Palladium Supported on Oleic Acid-coated Magnetic Nanoparticle as an Efficient Catalyst for Heck Coupling Reaction in Aqueous Media

The catalyst can be easily recovered by external magnetic field and reused several times without significant loss of activity.

Electrochemically codeposited reduced graphene oxide and palladium nanoparticles: An efficient heterogeneous catalyst for Heck coupling reaction

The catalytic activity of electrochemically codeposited reduced graphene oxide and palladium (ERGO-Pd) was examined for Heck coupling reactions. It showed excellent catalytic activity and stability for Heck coupling reaction. The prepared catalyst (ERGO-Pd) can be used up to the 5th cycle with negligible loss in activity.

Preparation, optical properties and catalytic activity of TiO2@Pd nanoparticles as heterogeneous and reusable catalysts for ligand-free Heck coupling reaction

This paper reports the synthesis and use of TiO2@Pd nanoparticles, as reusable catalysts for Heck coupling reaction under ligand-free conditions. This method has the advantages of high yields, elimination of ligand and homogeneous catalysts, simple methodology and easy work up. Interestingly, the novel catalyst could be recovered in a facile manner from the reaction mixture and recycled several times without any significant loss in activity. The catalyst was characterized by SEM, EDS and UV–vis spectroscopy. Experimental absorbance spectra compared with results from the Mie theory.