Catalyst For Suzuki-Miyaura Cross-coupling Reaction Research Articles

Suzuki-Miyaura Cross-Coupling Reaction Using Palladium Catalysts Supported on Phosphine Periodic Mesoporous Organosilica.

Phosphine periodic mesoporous organosilicas (R-P-PMO-TMS: R=Ph, tBu), which possess electron-donating alkyl substituents on the phosphorus atom, were synthesized using bifunctional compounds with alkoxysilyl- and phosphino groups, bis[3-(triethoxysilyl)propyl]phenylphosphine borane (1 a) and bis[3-(triethoxysilyl)propyl]-tert-butylphosphine borane (1 b). Immobilization of Pd(0) species was performed to give R-P-Pd-PMO-TMS: R=Ph (2 a), tBu (3 a), respectively. The Pd(0) immobilized 2 a and 3 a were applicable as catalysts for Suzuki-Miyaura cross-coupling reactions of aryl chlorides with phenylboronic acid. It was revealed that 3 a bearing more electron-donating tBu groups exhibited higher catalytic activity. Various functional groups including both electron withdrawing and donating substituents were compatible in the system. The recyclability of 3 a was examined to support its moderate utility for the recycle use.

Hierarchical NiZn Solid Solution as a Highly Efficient Palladium Free Heterogeneous Catalyst for Suzuki-Miyaura Cross-Coupling Reaction.

In this report, surfactant free solid solution of NiZn with a hierarchical architecture was synthesized via a one-pot colloidal approach. Evidence supporting hierarchical crystal growth and alloying of metals at the atomic level was obtained from field emission scanning electron microscopy and transmission electron microscopy-energy-dispersive X-ray data. Lattice sites of face-centered metallic Ni were found to be occupied by Zn as evident from powder X-ray diffraction where a gradual shift in the peak position and increase in the average lattice parameter upon reduction of the Ni content in the alloy samples can be observed. This well-alloyed, magnetically separable, non-noble metal-based solid solution has the potential to replace the palladium-based catalyst in the Suzuki-Miyaura cross-coupling of aryl halides (-Cl/-Br) and phenylboronic acid. The nanostructured catalyst was formed through the assembly of a triangular spiked and sheet-like structure and is magnetically well separable that is stable enough under the catalytic reaction condition. The developed heterogeneous catalyst and the designed economical catalytic model are the first ever reported work. The catalytic results outperformed most of the reported state-of-the-art works involving the transition metal-based catalyst.

Pd Immobilization Phenanthroline-2,9-Dicarbaldehyde Modified Magnetic CuBDC MOF as a Reusable Heterogeneous Catalyst for Suzuki-Miyaura Cross-Coupling Reactions

A porous magnetic multifunctional copper-based metal-organic framework (MOF) was developed through combined covalent and dative post-synthetic modification (PSM) of the CuBDC. In this regard, a novel magnetic metal-organic framework (MMOF) consisting of supported 1,10-phenanthroline-2,9-dicarbaldehyde (Fe3O4@Cu(BDC)-NH2-PHD) has been fabricated by post-synthetic modifications of Fe3O4@Cu(BDC)-NH2. Subsequently, the prepared nanocomposites were modified using palladium chloride ions (Fe3O4@Cu(BDC)-NH2-PdPHD) to impart catalytic sites. As a result, the fabricated magnetic porous catalyst exhibited great catalytic activity in Suzuki-Miyaura cross-coupling reactions. Some of the essential advantages of the synthesized catalyst are; high catalytic activity, short reaction times, mild conditions, high thermal stability, and reusability. Moreover, his porous magnetic nanomaterial can be used as a new support to immobilize other metals in different catalytic reactions.

Hierarchically structured and highly active palladium-loaded Al-MIL-53-linked hybrid periodic mesoporous silica catalysts for Suzuki-Miyaura cross-coupling reaction

The rational design and precise preparation of hierarchically structured catalysts (HSCs) with an enhanced catalytic activity and reusability are still enormous challenges in material science and catalysis. Herein, a HSC Pd/Al-MIL-53@HOOC-SBA-15 was successfully prepared by the oriented growth of metal-organic framework Al-MIL-53 into/onto HOOC-SBA-15 via a hydrothermal technique and in-situ deposition of Pd nanoparticles reduced by NaBH4. Such a heterogeneous catalyst was applied to Suzuki-Miyaura cross-coupling reaction (CCR) of various aryl halides and phenylboronic acid. The results showed a highly catalytic performance over 99% conversion/yield, thanks to the crucial role of functional group, the synergistic effect of microporous-mesoporous structure, mesoporous confinement effect and microporous confinement effect. As a comparison, Pd/HOOC-SBA-15 and Pd/SBA-15 were also fabricated for C-C CCR, showing characteristic functional group-protected effect ensuring the stability and redeposition of Pd during catalysis. Based on experimental results, an order on catalytic activity and recyclability is Pd/Al-MIL-53@HOOC-SBA-15 > Pd/HOOC-SBA-15 > Pd/SBA-15 > Pd/Al2O3-C@SBA-15, revealing an excellent catalytic activity and high reusability of Pd/Al-MIL-53@HOOC-SBA-15. Combining with structure and composition of all catalysts, the leaching-redeposition mechanism can well explain highly catalytic performance and deactivation behavior in C-C CCR. This study provides an efficient strategy to prepare large-scale multi-composite HSCs for multi-functionalized catalytic applications.

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.

Zeolite-encaged palladium catalysts for heterogeneous Suzuki-Miyaura cross-coupling reactions

Suzuki-Miyaura cross-coupling reaction by homogeneous Pd complex is a powerful route to construct carbon-carbon bond and is now widely applied in the synthesis of functional organic compounds. Heterogeneous Pd catalysts are highly desired as alternatives to homogeneous ones due to their facile reusability and good compatibility. Herein, zeolite-encaged Pd particles, namely Pd@MFI, have been successfully prepared via an in-situ hydrothermal strategy and investigated as promising heterogeneous catalysts for Suzuki-Miyaura cross-coupling reactions. Characterization results demonstrate that high dispersed Pd particles with apparent sizes of 1–2 nm have been encaged in and efficiently stabilized by the matrix of MFI zeolite. The as-prepared Pd@MFI catalysts are active in the Suzuki-Miyaura coupling reaction between bromobenzene and phenylboronic acid, and the presence of basic sites adjacent to Pd sites are crucial to achieving high catalytic activity via effective cooperation. Pd@K-ZSM-5 can be optimized for the coupling between bromobenzene and phenylboronic acid and can catalyze the reaction with a low apparent activation energy value of 41.2 kJ/mol. Pd@K-ZSM-5 also shows good stability and can be recycled for at least five times without obvious loss in activity, demonstrating its great potential as a heterogeneous catalyst for Suzuki-Miyaura cross-coupling reactions. Encapsulation of metal species in zeolite matrix offers a big opportunity to the heterogenization of homogeneous metal catalysts for practical chemical transformations.

Hierarchically Structured and Highly Active Palladium-Loaded Al-Mil-53-Linked Hybrid Periodic Mesoporous Silica Catalysts for Suzuki-Miyaura Cross-Coupling Reaction

Hierarchically Structured and Highly Active Palladium-Loaded Al-Mil-53-Linked Hybrid Periodic Mesoporous Silica Catalysts for Suzuki-Miyaura Cross-Coupling Reaction

N-functionalized mesoporous carbon supported Pd nanoparticles as highly active nanocatalyst for Suzuki-Miyaura reaction, reduction of 4-nitrophenol and hydrodechlorination of chlorobenzene

A series of nanocatalysts derived from immobilization of palladium nanoparticles (Pd NPs) into three dimensional (3D) tube-type architecture of nitrogen (N) functionalized and without functionalized mesoporous carbon CMK-9 is developed by dual agents chemical reduction approach. Herein, for the first time N-functionalized CMK-9 is explored as supports to immobilize Pd NPs and use as multifunctional catalysts for Suzuki-Miyaura cross-coupling reaction, reduction of 4-nitrophenol and hydrodechlorination of chlorobenzene. The Pd@N-CMK-9 catalysts show excellent activities with 100% conversion for Suzuki-Miyaura reaction between iodobenzene and phenylboronic acid and turnover frequency up to 1992 h−1. When use as catalyst for reduction of 4-nitrophenol to 4-aminophenol, it delivers an outstanding rate constant of 4.22 × 10-2 s−1 with activity parameter of 51719 s-1g−1 with respect to only Pd content. The nanocatalysts also demonstrate 100% conversion of chlorobenzene to benzene within 1 h. In addition, the catalyst exhibits remarkable catalytic stability for several cycles without any significant loss of products. The excellent catalytic activities can be attributed to synergistic effect of uniformly dispersed Pd NPs, favorable interaction between metal and support, and tubular interconnected mesoporous framework of N-functionalized CMK-9 that accelerate mass transportation. The present work signifies the versatility of Pd@N-CMK-9 nanocatalysts for various catalytic reactions.

N-heterocyclic carbene Pd(II) complex supported on Fe3O4@SiO2: Highly active, reusable and magnetically separable catalyst for Suzuki-Miyaura cross-coupling reactions in aqueous media

A new type magnetic nano Fe3O4@SiO2@NHC@Pd-MNPs heterogeneous catalyst was fabricated and characterized by Fourier Transform Infrared (FTIR) spectroscopy, Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Energy Disperse X-ray analysis (EDX), Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA), and Scanning Electron Microscopy (SEM). The loading amount of Palladium (Pd) to magnetic nano Fe3O4@SiO2@NHC@Pd-MNPs was measured by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) analysis. The catalytic activity of magnetic nano Fe3O4@SiO2@NHC@Pd-MNPs heterogeneous catalyst was examined on Suzuki-Miyaura cross-coupling reactions of aryl halides with different substituted arylboronic acid derivatives. All coupling reactions yielded excellent results and high TOF (up to 76528 h−1) in the presence of 2 mg of Fe3O4@SiO2@NHC@Pd-MNPs catalyst (0.0197 mmolg−1, 0.00394 mmol%Pd) at 80 °C in 2-propanol/H2O (1:2). In addition, the magnetic nano Fe3O4@SiO2@NHC@Pd-MNPs catalyst was easily recovered by using an external Nd-magnet and reused for the Suzuki cross-coupling reactions. The catalyst showed strong structural and chemical stability and was reused six times without losing its catalytic activity substantially.

N-Alkoxycarbonyl / carbamoylmethyl substituted 1H-imidazol-2-ylidenPd (II) complexes as highly efficient catalysts for Suzuki-Miyaura crosscoupling reaction

N-Alkoxycarbonyl / carbamoylmethyl substituted 1H-imidazol-2-yliden-Pd (II) complexes (Cat-1-5) were used for the first time as catalysts in the Suzuki-Miyaura reaction between aryl bromides and arylboronic acids. All complexes screened were found to be excellent catalysts in the selected coupling between 4-bromobenzaldehyde and phenylboronic acid at room temperature. Cat-3 was shown to be the most efficient one and used for the optimisation of the reaction conditions and determining the substrate scope. The application of the optimised method provided a series of biaryls (3a-l) in excellent isolated yields. With these promising results the catalysts could be applied succesfully to some other classic cross-coupling reactions such as Sonogashira, Stille and Buchwald-Hartwig.

Novel cigarette butts-derived porous carbon-based catalyst for highly efficient Suzuki-Miyaura cross-coupling reaction

Cigarette butts (CB), a major hazardous waste, are discarded improperly into the environment, which poses serious threats to environment and human health. To reduce the pollution and realize the transformation of dangerous waste into high value products, we reported a novel Pd@carbon composite derived from CB as a heterogeneous catalyst for Suzuki-Miyaura cross-coupling reaction. The cigarette butt-derived carbon was super porous and had high surface area, which effectively improved the dispersion of Pd nanoparticles and stabilized them in porous carbon during multiple catalytic cycles without obvious aggregating or leaching. The Pd@CCB catalyst showed good catalytic activity and selectivity for Suzuki-Miyaura cross-coupling reactions under mild reaction conditions, which provided high yields (up to 98%) and good stability even after seven cycles. Moreover, the catalytic activity of Pd@CCB is comparable to that of commercial Pd@C and is superior to that of activated-carbon (AC) supported Pd. This work not only solves a knotty environmental problem (discarded cigarette butts) but also provides new insights on valorization route to high-performance carbon nanomaterials for numerous applications, which is available at low cost and in large quantities.

The Synthesis of SBA-15-Pr-3AP@Pd and its Application as a Highly Dynamic, Eco-Friendly Heterogeneous Catalyst for Suzuki-Miyaura Cross-Coupling Reaction

The Synthesis of SBA-15-Pr-3AP@Pd and its Application as a Highly Dynamic, Eco-Friendly Heterogeneous Catalyst for Suzuki-Miyaura Cross-Coupling Reaction

Designing a bifunctional metal-organic framework by tandem post-synthetic modifications; an efficient and recyclable catalyst for Suzuki-Miyaura cross-coupling reaction

A new Cu/Pd bimetallic Cu-MOF-[Pd] was synthesized through covalent, dative and inorganic post-synthetic modifications. In order to achieve the Cu-MOF-[Pd], Zn-MOF (TMU-17-NH2) was initially selected and fabricated by grafting of salicylaldehyde via Schiff-base formation followed by complex formation with Pd(II). Then, the as-synthesis MOF, Zn-MOF-[Pd], was subjected as 3D-template to obtain Cu-MOF-[Pd] by transmetalation process. The Cu-MOF-[Pd] was characterized by FT-IR spectroscopy, atomic absorption spectroscopy (AAS), field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (PXRD), energy dispersive X-ray spectroscopy (EDS), and EDS mapping techniques. The feasibility of using Cu-MOF-[Pd] as a highly active recoverable catalyst was confirmed in the Suzuki–Miyaura cross-coupling reaction in a mixed water/ethanol solvent. The results show that this novel nano-composite could serve as an efficient bimetallic heterogeneous catalyst and reuse at least for 5 times without loss in activity.

Tailoring Graphene Oxide Framework with N- and S- Containing Organic Ligands for the Confinement of Pd Nanoparticles Towards Recyclable Catalyst Systems

Graphene oxide frameworks (GOFs) tailored with heteroatom-containing organic ligands were utilized for the efficient confinement of Pd nanoparticles (NPs) to achieve highly recyclable Pd catalysts for Suzuki-Miyaura cross-coupling reaction (SMC). The tailored GOFs were constructed using benzene-1,4-diboronic acid as a pillaring unit and N- and S- containing additional organic ligands to anchor Pd NPs. Highly dispersed Pd NPs with narrow size distribution were generated inside the gallery space of the GOFs. The presence of the anchoring ligands significantly enhanced the stability of Pd NPs via strong Pd−N and Pd−S bonds, leading to high activity and recyclability in the SMC reaction.

Designing a Bifunctional Metal-Organic Framework by Tandem Post-Synthetic Modifications; an Efficient and Recyclable Catalyst for Suzuki-Miyaura Cross-Coupling Reaction

A new Cu/Pd bimetallic Cu-MOF-[Pd] was synthesized through covalent, dative and inorganic post-synthetic modifications. In order to achieve the Cu-MOF-[Pd], Zn-MOF (TMU-17-NH2) was initially selected and fabricated by grafting of salicylaldehyde via Schiff-base formation followed by complex formation with Pd(II). Then, the as-synthesis MOF, Zn-MOF-[Pd], was subjected as 3D-template to obtain Cu-MOF-[Pd] by transmetalation process. The Cu-MOF-[Pd] was characterized by FT-IR spectroscopy, atomic absorption spectroscopy (AAS), field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (PXRD), energy dispersive X-ray spectroscopy (EDS), and EDS mapping techniques. The feasibility of using Cu-MOF-[Pd] as a highly active recoverable catalyst was confirmed in the Suzuki–Miyaura cross-coupling reaction in a mixed water/ethanol solvent. The results show that this novel nano-composite could serve as an efficient bimetallic heterogeneous catalyst and reuse at least for 5 times without loss in activity.

Palladium loaded on ZnO nanoparticles: Synthesis, characterization and application as heterogeneous catalyst for Suzuki–Miyaura cross-coupling reactions under ambient and ligand-free conditions

Pd loaded ZnO nanoparticles have been explored as an efficient catalyst for Suzuki-Miyaura cross-coupling reactions under ambient and ligand-free conditions. For this purpose, the low temperature synthesis of ZnO nanoparticle was accomplished by the solution based approach using stoichiometric amount of zinc acetate and urea. The Pd/ZnO nanocrystalline catalyst was prepared by loading 3% PdCl2 on ZnO nanoparticles by simple wet impregnation technique. This catalyst efficiently performed Suzuki-Miyaura reactions with various ring substituted aryl bromides and boronic acids. The resultant Pd/ZnO nanocrystalline material conferred 97% yield under optimized reaction conditions. The nanostructured Pd loaded ZnO catalyst was characterized by XRD, FESEM, EDS, FETEM, STEM-BF-DF, XPS and BET techniques. XRD pattern of Pd/ZnO sample hints the presence of Pd as minor phase loaded on ZnO nanocrystalline material, while overall XPS analysis discloses effective loading of Pd (0) on ZnO surface. FESEM/TEM–EDS also revealed reasonable Pd loading on ZnO nanoparticles. The FETEM examination of unloaded ZnO and Pd loaded ZnO disclosed particle size in the range 25–40 nm. The nanocrystalline Pd/ZnO catalyst was reused without significant loss of catalytic activity. The present methodology is cost effective, environmentally friendly, easy to scale up and can become an alternative to homogeneous catalysis.

Palladium nanoparticles supported on fluorine-doped tin oxide as an efficient heterogeneous catalyst for Suzuki coupling and 4-nitrophenol reduction

Immobilization of palladium nanoparticles onto the fluorine-doped tin oxide (FTO) as support Pd/FTO, resulted in a highly active heterogeneous catalyst for Suzuki-Miyaura cross-coupling reactions and 4-nitrophenol reduction. The Pd/FTO catalyst has been synthesized by immobilization of palladium nanoparticles onto FTO via a simple impregnation method. ICP-MS analysis confirmed that there is 0.11 mmol/g of palladium was loaded successfully on FTO support. The crystallinity, morphologies, compositions and surface properties of Pd/FTO were fully characterized by various techniques. It was further examined for its catalytic activity and robustness in Suzuki coupling reaction with different aryl halides and solvents. The yields obtained from Suzuki coupling reactions were basically over 80%. The prepared catalyst was also tested on mild reaction such as reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Pd/FTO catalyst exhibited high catalytic activity towards 4-NP reduction with a rate constant of 1.776 min−1 and turnover frequency (TOF) value of 29.1 hr−1. The findings revealed that Pd/FTO also maintained its high stability for five consecutive runs in Suzuki reactions and 4-NP reductions. The catalyst showed excellent catalytic activities by using a small amount of Pd/FTO for the Suzuki coupling reaction and 4-NP reduction. Novel Pd-supported FTO nano-powder catalyst exhibited high activity and selectivity towards C-C Suzuki coupling reaction and nitroarene reduction.

Asymmetric palladacycle complexes with N,O-bidentate barbiturate ligands: Preparation, characterization and catalytic application in Suzuki-Miyaura reaction

Three N,O-chelate ligands (1a-1c) were synthesized by the reaction of aniline derivatives with 1,3-dimethyl-2,4,6-trioxohexahydropyrimidine-5-carbaldehyde. The corresponding palladacycles complexes (2a-2c) were prepared from treatment of N,O-chelate ligands (1a-1c) with [Pd(μ-OAc)(ppy)]2. The structures of all synthesized compounds were characterized by elemental analyses, ATR-FTIR, 1H- and 13C NMR spectroscopy. Crystal structures of Pd(II) complexes 2a and 2c were determined by single crystal X-ray diffraction. X-ray diffraction studies revealed that the palladium atom in 2a and 2c has distortion of square-planar geometry. Synthesized complexes were tested as catalyst in Suzuki-Miyaura cross-coupling reaction of various aryl bromide with phenyl boronic acid. All complexes behaved as efficient catalyst to produce the biaryls with both high yields and short time under mild reaction conditions.

Room-Temperature Aqueous Suzuki-Miyaura Cross-Coupling Reactions Catalyzed via a Recyclable Palladium@Halloysite Nanocomposite.

A reliable method for encapsulation of palladium nanoparticles (6-8 nm particles) in halloysite (Pd@Hal) has been developed. The Pd@Hal was found to be a highly efficient room-temperature catalyst for Suzuki-Miyaura cross-coupling reactions that gave high yields of a diverse array of coupling products in 5:2 n-PrOH/H2O within 1 h. The catalytic system was remarkably effective with a broad substrate scope. In addition, the catalyst was easily recovered and recycled without a significant loss of catalytic activity.

Pd nanoparticles at N-heterocyclic carbene at ZIF-8 as an ultrafine, robust and sustainable heterogeneous system for Suzuki-Miyaura cross coupling processes

Producing nanoparticles with controlled size without any aggregation is an important challenge for enhancing the catalytic activities of the metal nanoparticles (MNPs) supported on metal–organic frameworks (MOFs). In this work, a new hybrid nanoporous material, Pd nanoparticles at N-heterocyclic carbene at zeolitic imidazolate framework (Pd NPs at NHC at ZIF-8), with a high internal surface area was successfully prepared by immobilizing anionic sulfonated N-heterocyclic carbene–palladium(II) precursor inside the cavities of ZIF-8 using “impregnation approach” followed by reduction with Sodium borohydride (NaBH4). The as-prepared new Pd NPs at NHC at ZIF-8 composite proved to be highly active and showed excellent stability as a heterogeneous catalyst for Suzuki-Miyaura cross-coupling reaction.