Catalyst For Suzuki Coupling Reactions Research Articles

Highly effective photoativation Pd catalyst for Suzuki coupling reaction

Suzuki coupling reaction is widely applied for constructing biaryl skeletons in various fields. Designing and developing highly effective catalysts are essential regarding the Suzuki coupling reaction. Here, we report a simple light irradiation approach to achieve the highly efficient Suzuki coupling reaction via the application of low valence Pd homogeneous catalyst. The catalyst exhibited a TOF value of 76,000 h−1. We systematically investigated the impact of various experimental conditions on catalytic performance and further clarify the evolution of Pd species during the light irradiation and catalytic reaction process. This work provides a facile strategy for designing highly effective catalysts for the Suzuki coupling reaction and understanding the detailed evolution process of Pd during the reaction process.

Catalytic activity of the two magnetic nanoparticles-supported palladium catalysts for Suzuki coupling reaction under green conditions

Two palladium Schiff base complexes supported on magnetic nanoparticles, namely, P,N-Pd-Fe3O4 and CPS-MNPs-NNN-Pd, were successfully used as efficient heterogeneous catalysts for the Suzuki coupling reaction under mild and green conditions. We compared the catalytic activity of these two catalysts and the results indicated that the CPS-MNPs-NNN-Pd catalyst promoted the reaction more efficiently due to its structure. Only 0.1 mol% of CPS-MNPs-NNN-Pd catalyst was required to promote the Suzuki reactions and these reactions were performed efficiently for aryl iodides, bromides, and also chlorides. Notably, this catalyst had higher TON and TOF numbers than most of the previously reported catalysts. Moreover, the catalyst could be easily separated from the reaction mixture under the outer or external magnetic field and reused at least for 4 times without appreciable loss of its catalytic activity.

Fe3O4-carbon spheres core–shell supported palladium nanoparticles: A robust and recyclable catalyst for suzuki coupling reaction

Suzuki-Miyaura (S-M) is regarded the most powerful way for synthesis biaryls, triaryls, or incorporating of substituted aryl moieties in organic preparation by the cross-coupling of aryl boronic acid with aryl halides using the Pd catalyst. This work reports the combining of the hydrothermal and microwave-assisted protocol to convert the glucose to magnetic carbon spheres (Fe3O4-CSPs) decorated with Pd nanoparticles (NPs) as the catalyst for Suzuki-Miyaura cross-coupling reactions. The physicochemical properties in the produced composite were examined using FESEM, HRTEM, nitrogen isotherms, Raman spectroscopy, FTIR, XPS, and XRD. The as-fabricated composite Pd/Fe3O4-CSPs is mostly spherical with a core–shell structure and possesses a great surface area of 253.2 m2·g−1. Its catalytic performance demonstrates that the composite has excellent stability and high tolerance Suzuki-Miyaura cross-coupling reactions in 30 min at 80 °C. Both activated and deactivated aryl halides provided excellent yield. The as-fabricated catalyst was recycled for up to four catalytic cycles without a substantial decline in performance. Moreover, this research offers a facile roadmap for synthesizing Pd/Fe3O4-CSPs composites and promoting the practical implementation of Pd/Fe3O4-CSPs catalysts for organic transformation processes.

High-Power and High-Performance Catalyst for Suzuki Coupling Reaction

In this project, the aim was to carry out the Suzuki reaction using a new and unique catalyst with a base of Fe3O4 magnetic nanoparticles coated using a new ligand. In fact, this magnetic catalyst has an inhomogeneous surface to create a connection between the organic and aqueous phases so that the carbon–carbon coupling reaction is completely performed on its large surface. The structure of this catalyst uses two metals, nickel and cobalt, which are coated on a bed of amino linkers and propel the Suzuki coupling reaction at high speed on the catalyst surface. The products obtained are from ideal and optimal conditions with an efficiency of over 98%. The catalyst has a recovery power of over 96% and has enough power to perform several coupling reactions several times. Lastly, the magnetic nanocatalyst is easily separated from the reaction medium by an external field and has 100% power when performing other reactions.

Rapid synthesis of Pd single-atom/cluster as highly active catalysts for Suzuki coupling reactions

Palladium (Pd)-based catalysts are essential to drive high-performance Suzuki coupling reactions, which are powerful tools for the synthesis of functional organic compounds. Herein, we developed a solution-rapid-annealing process to stabilize nitrogen-mesoporous carbon supported Pd single-atom/cluster (Pd/NMC) material, which provided a catalyst with superior performance for Suzuki coupling reactions. In comparison with commercial palladium/carbon (Pd/C) catalysts, the Pd/NMC catalyst exhibited significantly boosted activity (100% selectivity and 95% yield) and excellent stability (almost no decay in activity after 10 reuse cycles) for the Suzuki coupling reactions of chlorobenzenes, together with superior yield and excellent selectivity in the fields of the board scope of the reactants. Moreover, our newly developed rapid annealing process of precursor solutions is applied as a generalized method to stabilize metal clusters (e.g. Pd, Pt, Ru), opening new possibilities in the construction of efficient highly dispersed metal atom and sub-nanometer cluster catalysts with high performance.

Green synthesis of Pd/Fe3O4 nanoparticles using Chamomile extract as highly active and recyclable catalyst for Suzuki coupling reaction

In the present study, we demonstrate the synthesis of a novel biogenic nanocomposite by adorning in situ green synthesized Pd nanoparticles (Pd NPs) over the surface of magnetic nanoparticles by using Chamomileflower extract. It was physicochemically assigned by a number of analytical techniques. The as developed material was catalytically exploited in the synthesis of diverse biaryls via classical Suzuki-Miyaura coupling. Rigourness of the material was further validated by the study of reusability, hot-filtration and leaching test.

Decorated palladium nanoparticles on chitosan/δ-FeOOH microspheres: A highly active and recyclable catalyst for Suzuki coupling reaction and cyanation of aryl halides

In this study, an eco-friendly and low cost magnetic nanocomposite consisting of chitosan/δ-FeOOH microspheres (CS/δ-FeOOH) was fabricated as a stabilizer by using a simple method. Pd nanoparticles (Pd NPs) were decorated on the designed CS/δ-FeOOH, and the resulting Pd NPs@CS/δ-FeOOH microspheres were employed as a heterogeneous catalyst in the construction of biaryl and benzonitriles. Pd NPs@CS/δ-FeOOH microspheres efficiently catalyzed the conversion of aryl iodides and bromides to the desired biaryls within 3 h. Moreover, Pd NPs@CS/δ-FeOOH microspheres showed high catalytic potential against synthesis of benzonitriles by providing yields up to of 99% within 4 h. More importantly, it was proved that Pd NPs@CS/δ-FeOOH microspheres were able to be easily recycled and reused up to eight runs for both reactions. This study reveals that Pd NPs@CS/δ-FeOOH microspheres are useful and recyclable nanocatalysts, which catalyze the synthesis of biaryl and benzonitriles with good reaction yields.

Palladium metal embedded on mesoposrous graphene oxide as an efficient heterogeneous catalyst for Suzuki coupling reaction

A novel method for the synthesis of Graphene Oxide (GO) decorated palladium nanocomposite (Pd NC) as a highly efficient heterogeneous catalyst has been developed. The resulting GO-PdNC acts as a catalyst precursor for the Suzuki coupling reaction. The catalytic reaction was conducted by varying reaction conditions, like reaction temperature, time, solvent and the catalyst loading. The catalyst was reused for Suzuki reaction up to 5 reaction cycles. Spectral data of the catalytic product suggest that the purity, rate, yield and recycling of catalyst are more effective for the C–C coupling reaction.

Anchored PdCl2 on fish scale: an efficient and recyclable catalyst for Suzuki coupling reaction in aqueous media

PdCl2 anchored on fish scale (FS) complex were intended to a heterogeneous catalyst for ligand-free Suzuki coupling reaction in aqueous media. The catalyst FS-PdCl2 was characterized by FT-IR, powder XRD, XPS and SEM. FS-PdCl2 complex has been successfully implemented for Suzuki coupling reactions of various halogenated aromatics with arylboronic acid to provide the corresponding biaryl compounds under environmentally friendly conditions (40 °C, water solvent). Moreover, the efficient catalyst shows excellent stability and recyclability, and its catalytic activity without any decrease after 8 times consecutive reused.

Si-thiol supported atomic-scale palladium as efficient and recyclable catalyst for Suzuki coupling reaction

Atomic-scale catalysts leverage the advantages of both heterogeneous catalysts for their stability and reusability and homogeneous catalysts for their isolated active sites. Here, a palladium catalyst supported by Si-thiol, a commercially available mercaptopropyl-modified and TMS-passivated amorphous silica, was synthesized and characterized by SEM,TEM, aberration-corrected STEM-HAADF, XRD, FT-IR and XPS. Statistical analysis revealed that the catalytic Pd species predominantly consisted of intermediate sized nanoparticles (<2 nm), small amounts of essentially isolated atoms (ca. 0.1 nm), and limited amounts of somewhat larger nanoparticles (<5 nm). The nanoscale atomic clusters dominated the reactivity and served as the key active sites for Suzuki coupling. The outcomes of the reaction were greatly affected by the choice of solvents, and Pd/Si-thiol was demonstrated to be reusable for more than three times without a noticeable loss of catalytic activity.

Facile fabrication of magnetically separable palladium nanoparticles supported on modified kaolin as a highly active heterogeneous catalyst for Suzuki coupling reactions

In this study, Fe3O4 loaded Schiff base modified kaolin was prepared as a new support and palladium nanoparticles were anchored on it without any additional reducing agent (Pd NPs@Kao/Fe3O4/Pyr). Characterization studies demonstrated that Pd NPs@Kao/Fe3O4/Pyr was successfully designed and the size of particles was about 25 nm. Pd NPs@Kao/Fe3O4/Pyr was then utilized as catalyst in the preparation of biaryl compounds via Suzuki cross coupling reactions. Catalytic tests showed that Pd NPs@Kao/Fe3O4/Pyr acted as a highly active heterogeneous nanocatalyst in the coupling reaction of aryl iodides, bromides and chlorides containing different functional groups. Moreover, it was found that Pd NPs@Kao/Fe3O4/Pyr was successfully used in consecutive recycling tests and gave an 89% yield even after ten runs. In addition to the high catalytic behavior and reusability, Pd NPs@Kao/Fe3O4/Pyr have some advantages such as i) capability of application for various halides containing different functional groups, ii) ease of purification of final product and iii) simple work-up.

N-heterocyclic carbene bearing thermoresponsive poly(NIPAM) supported palladium (II) complex: Synthetic strategy and application

In this article, we have reported the synthesis of thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) bearing N-heterocyclic carbene (NHC) based palladium complex through carbene formation. The complex was synthesized from the polymer, which was obtained by SET-LRP (Single Electron Transfer - Living Radical Polymerization) technique using suitable N-heterocyclic carbene (NHC) based initiator. The single-crystal X-ray diffraction (XRD) confirms the structure of the initiator. Furthermore, NMR, FTIR and XPS studies confirmed the formation of the NHC–Pd (II) complex. Our complex possessed unique thermoresponsive characteristics in water i.e, water-soluble at below lower critical solution temperature (LCST) and water-insoluble at LCST. Hence, it can be used as a smart catalyst for Suzuki coupling reactions of various aryl halides in water medium at ambient temperature (30 °C). Due to its thermoresponsive behavior, it can be easily recovered from the reaction medium simply by the elevation of temperature and reused for several cycles.

Strategy used to synthesize high activity and low Pd catalyst for Suzuki coupling reaction: an experimental and theoretical investigation.

Unveiling the reaction mechanism is significant for developing high-performance catalysts. In this paper, a series of precisely controlled PdxM147-x (M = Cu, Pt, Au, Rh, Ru) dendrimer encapsulated nanoparticles (DENs) has been successfully synthesized. The mechanisms of PdxM147-x as catalysts for Suzuki cross-coupling reactions were investigated by combining experimental and theoretical methods. The experimental results indicate that Pd74Cu73 DEN shows similar activity to Pd147 DEN and excellent substrate adaptability under mild reaction conditions. Moreover, the Cu component can play an important role in tuning the catalytic activity of PdxCu147-x DEN. Density functional theory (DFT) calculations illustrate that the similar activities of the Pd147 and Pd74Cu73 DENs originate from the comparable energy barriers of the rate-determining steps. The partial density of states (PDOS) and electron density differences demonstrate that Cu decreases the intensities of the valence orbitals of the top and edge Pd atoms and weakens orbital interactions between the intermediates and Pd74Cu73 DEN, leading to low desorption energies of the products. This work can provide a promising strategy to reduce the cost of Pd catalysts in Suzuki cross-coupling reactions.

Nanoporous phenanthroline polymer locked Pd as highly efficient catalyst for Suzuki‐Miyaura Coupling reaction at room temperature

Because of the intrinsic advantages, Suzuki coupling reactions have been one of the most popular coupling reactions in organic synthesis, however developing a high‐performance heterogeneous catalyst for Suzuki coupling reactions in aqueous media at low temperature (e.g. room temperature) is still a challenge. Herein, a heterogeneous catalyst with coordinated Pd as active site and a designed conjugated phenanthroline based porous polymer (CPP) as support was fabricated. Systematically investigation on CPP support by Fourier transform infrared spectroscopy (FT‐IR), Thermogravimetric analysis (TGA), Transmission electron microscopy (TEM), N2 adsorption–desorption isotherm and Scanning electron microscopy (SEM) show that the derived CPP catalyst support owns a porous structure, moderately good surface area (141 m2/g) and an excellent thermal stability. As a heterogeneous catalyst for the synthesis of biphenyl derivatives via Suzuki coupling, Pd/CPP achieves an excellent catalytic performance and recycling ability towards Suzuki reaction of various reactants at room temperature in ethanol‐water medium.

Controlled synthesis of three dimensional mesoporous C3N4 with ordered porous structure for room temperature Suzuki coupling reaction

We report on the synthesis of mesoporous graphitic C3N4 (MGCN-6) with 3D porous structure and Ia3d symmetry and controllable surface properties through a simple polymerization of an environmentally benign and non-toxic guanidine hydrochloride as a C and N precursor using KIT-6 with variable pore sizes as templates for Suzuki coupling reaction. The pore diameters (3.1–4.2 nm), specific surface areas (207–303 m2 g−1), and the specific pore volumes (0.58–0.71 cm3 g−1) of the MGCN-6 materials are finely controlled by varying the pore size of the templates used. The nano cavities of MGCN-6 with the highest specific surface area and a free amine groups are effectively utilized to chelate with Pd(OAC)2 and applied the prepared catalysts for Suzuki coupling reaction between aryl halides with phenylboronic acid derivatives under very mild and sustainable reaction conditions. The Pd(OAC)2/MGCN-6 is found to be very active and stable and exhibits an excellent reactivity and selectivity for all of substrates regardless of aryl halides with electron-withdrawing and electron donating groups at room temperature. The activity of the Pd(OAC)2/MGCN-6 is much higher than that of non-porous bulk graphitic carbon nitride and 2D mesoporous carbon nitride.

Palladium nanoparticles decorated on a novel polyazomethine as a highly productive and recyclable catalyst for Suzuki coupling reactions and 4-nitrophenol reduction

This report displays the procedure in preparation of fast, highly productive, reusable, and easily retrievable Pd nanoparticles (NPs) as a heterogeneous catalyst (Pd NPs@P(3-MPAP)) immobilized on a novel polyazomethine with phenol group, Poly(3-methyl-4-((pyridin-2-ylmethylene)amino)phenol) (P(3-MPAP)), and the investigation of its catalytic efficiency in fabrication of several biaryl compounds by Suzuki coupling reactions and reduction of 4-nitrophenol to 4-aminophenol. The structures of the synthesized monomer, polymer support material and nanocatalyst were identified by UV–Vis, FT-IR, 1H NMR, TGA, XRD, SEM and EDS methods. The catalytic activity of Pd NPs@P(3-MPAP) catalyst in the synthesis of various biaryls by Suzuki coupling reactions was explored using microwave irradiation, which is rapid, easy, solventless and environmentally friendly method. The nanocatalyst presented outstanding advantageous methodology containing easy work-up with high reaction yield (99%) at very short reaction time (5 min) in solventless media using very low catalyst loading (0.007 mol%) in the synthesis of biaryls. Additionally, the harmful 4-nitrophenol was completely reduced to industrially useful 4-aminophenol in the presence of Pd NPs@P(3-MPAP) with low catalyst amount (1 mg), at very short reaction time (60s) without any toxic solvent (in water) at room temperature. Additionally, reproducibility test results for both catalytic reactions show that the highly productive nanocatalyst was easily retrievable and reusable for six and five sequential cycles, respectively, for Suzuki coupling reactions and reduction of 4-NP without any notable loss in its catalytic activity.

Heterogeneous High-Loading Hyperbranched Polyglycidol with Peripheral NHC–Pd Complex: Synthesis and Application as Catalyst in Suzuki Coupling Reaction

A new polymer-supported highly functionalized dendritic polyether with peripheral NHC–Pd complex was developed by the simple anionic ring opening polymerization of glycidol on bis(3-hydroxypropyl) amine grafted Merrifield resin and its subsequent functional modification of hydroxyl group to NHC–Pd complex. The polymeric material had high stability and swelling capacity in a wide range of solvents, even in water. Similar to supported higher generation dendrimer, the newly developed system showed high palladium content with uniformly distributed and well isolated metal nanocentres. The palladium content was found to be 2.02 mmol/g which was comparatively higher than other heterogeneous NHC–Pd based catalysts and the polymer was used as heterogeneous palladium catalyst for Suzuki coupling reaction. Various factors affecting the catalyst’s performance were studied. The high availability and increased accessibility of catalytic sites, stability and dendrimer like property of the polymeric support, reusability, better resistance to metal leaching, easy synthesis etc. are the important features of this newly synthesized catalytic system.

A Graphene Oxide Nanosheet Supported NHC–Palladium Complex as a Highly Efficient and Recyclable Suzuki Coupling Catalyst

A practical heterogeneous catalyst was prepared by anchoring a triazine-tethered N-heterocyclic carbene (NHC)–palladium complex on the surface of graphene oxide (GO) nanosheets. The immobilized complex was characterized by X-ray photoelectron spectroscopy, field-emission transmission electron microscopy, energy-dispersive X-ray spectroscopy, and surface area analysis. It proved to be a highly active and durable heterogeneous catalyst for Suzuki coupling reactions. At room temperature, the use of this catalyst enabled the preparation of various biaryls and heterobiaryls in short reaction times. The catalytic system could be recycled at least 10 times with almost consistent activity. The results reveal that the stable palladium complex is strongly anchored on the surface of GO nanosheets. Interestingly, an open planar network of the GO nanosheet support plays a role during the catalytic process in enhancing the catalytic activity.

Carbon Nanofibers Supported Ultra-Small Palladium Oxide Nanoclusters as an Efficient and Continuable Catalyst for Suzuki Coupling Reaction

This work reports a very facile method to fabricate ultra-small PdO nanoclusters supported on carbon nanofibers (CNFs) which performed outstanding catalytic activity for Suzuki coupling reaction under the mild reaction conditions. The catalyst developed in this paper showed several advantages compared with our group previous jobs, such as simpler procedure to prepare the catalyst, lower active species loading and higher performance in Suzuki coupling reactions. Importantly, the catalyst could be recycled at least up to ten times and without any loss in activity. The reaction mechanism in this system was also explored by our group. Ultra-small palladium oxide nanoclusters supported on carbon nanofibers (PdO@CNFs) were successfully obtained through the facile process of electrospinning technology and high-temperature carbonization. The fabricated composite catalyst exhibited a better catalytic activity for Suzuki coupling reaction under mild conditions, especially in recycle ability (at least ten times). According to the experiment results, a plausible reaction mechanism was proposed by our group. We had an idea that the active species was palladium oxide, and the first step involved the reaction between bromobenzene and palladium oxide nanoclusters generated organo-oxopalladium species. This step was a rate-determining step and slightly different from the traditional mechanism.

Iron pincer complex and its graphene oxide composite as catalysts for Suzuki coupling reaction

We report the synthesis of Fe-NCN pincer complex as homogenous catalyst and its composite by immobilizing the complex on amino functionalized graphene oxide as a heterogeneous catalyst for Suzuki coupling reactions. Both the complex and the composite were employed in catalyzing the Suzuki-Miyaura cross-coupling reaction between the aryl halide and phenyl boronic acid in acetonitrile solvent media with Cs2CO3 as a base. Effect of substitution over aryl halide was also investigated. Immobilization of the pincer complex had advantageous recovery and reuse of the catalyst as compared to its homogenous analog with no significant decrease in the catalytic efficiency.