Facile Microwave-Assisted Synthetic Approach to Palladium Nanoparticles Supported on Copper Oxide as an Efficient Catalyst for Heck and Sonogashira Cross-Coupling Reactions

2019

Can J Chem Eng

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In this research, a facile and reproducible approach was implemented for the synthesis of palladium nanoparticles supported on Fe 3 O 4 with remarkable activity as an ideal catalyst for Suzuki-Miyaura cross-coupling. Magnetite supported Pd nanoparticles reveal high activity in Suzuki-Miyaura coupling reactions since they could be recycled up to seven times with the same high catalytic activity. This adopted method of catalyst synthesis has many advantages, including reproducibility and the reliability of the adopted synthetic method. The produced catalyst has unique magnetic properties to facilitate catalyst recovery from the reaction mixture by using a strong magnet as an external magnetic field. The synthetic approach adopted in this research is based on the microwave-assisted irradiation (MWI). The distinctive advantage of adopting this approach rather than conventional heating is the simplicity of adding reactants at mild reaction conditions. Moreover, this method offers a high rate of recyclability as the catalyst itself has a high recyclability rate up to seven times under mild reaction conditions, in addition to reproducibility with an excellent turnover number (8500) and a turnover frequency of 95 000 h À1 . The magnetic properties of the prepared catalyst increase the possibility to separate and purify the products from the catalyst and other byproducts, leading to an increase in the economic value of the catalyst. The prepared catalyst was characterized by various spectroscopic techniques including x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), vibrating sample magnetometer (VSM), and transmission electron microscopy (TEM).

Section: Resultsmentioning

confidence: 99%

“…The solid product was extracted from the filtrate by removing the solvent, and then the solid product was purified using flash chromatography over a mixture of hexane and ethyl acetate as eluent. This general procedure has been adopted in several reported research studies …”

Section: Introductionmentioning

confidence: 99%

Investigation of microwave‐assisted synthesis of palladium nanoparticles supported on Fe₃O₄ as efficient recyclable magnetic catalysts for Suzuki‐Miyaura cross‐coupling

2019

Can J Chem Eng

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“…were added, and finally the resulting mixture is introduced to flow continuously over the palladiummagnetite supported on graphene nanoparticles catalyst (Pd-Fe3O4/G) with different tested catalyst loading. The following catalyst amounts (10,25,35,50, and 100 mg) were previously loaded into CatCart cartridge TM , and then heating took place at the assigned temperature and time. The progress of the reaction was monitored using GC-MS analysis to an aliquot of the reaction mixture.…”

Section: General Procedures For Suzuki Cross-coupling Under Flow Reactmentioning

confidence: 99%

“…Generally, a scalable flow technique by optimizing the reaction parameters under hightemperature and continuous reaction conditions could be successfully developed.to solve several critical issues in many aspects including organic chemistry and applied catalysis [1][2][3][4][5][6][7][8]. This new technology has created new promising horizons for chemical synthesis and industry via performing chemistry under continuous flow reaction conditions instead of the conventional batch chemistry [9][10][11][12][13][14][15][16]. This…”

mentioning

confidence: 99%

Pd-Fe3O4/RGO: a Highly Active and Magnetically Recyclable Catalyst for Suzuki Cross Coupling Reaction using a Microfluidic Flow Reactor

Bull. Chem. React. Eng. Catal.

Siamaki

Gupton

et al. 2019

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There are several crucial issues that need to be addressed in the field of applied catalysis. These issues are not only related to harmful environmental impact but also include process safety concerns, mass and heat transfer limitations, selectivity, high pressure, optimizing reaction conditions, scale-up issues, reproducibility, process reliability, and catalyst deactivation and recovery. Many of these issues could be solved by adopting the concept of micro-reaction technology and flow chemistry in the applied catalysis field. A microwave assisted reduction technique has been used to prepare well dispersed, highly active Pd/Fe3O4 nanoparticles supported on reduced graphene oxide nanosheets (Pd-Fe3O4/RGO), which act as a unique catalyst for Suzuki cross coupling reactions due to the uniform dispersion of palladium nanoparticles throughout the surface of the magnetite -RGO support. The Pd-Fe3O4/RGO nanoparticles have been shown to exhibit extremely high catalytic activity for Suzuki cross coupling reactions under both batch and continuous reaction conditions. This paper reported a reliable method for Suzuki cross-coupling reaction of 4-bromobenzaldehyde using magnetically recyclable Pd/Fe3O4 nanoparticles supported on RGO nanosheets in a microfluidic-based high throughput flow reactor. Organic synthesis can be performed under high pressure and temperature by using a stainless steel micro tubular flow reactor under continuous flow reaction conditions. Optimizing the reaction conditions was performed via changing several parameters including temperature, pressure, and flow rate. Generally, a scalable flow technique by optimizing the reaction parameters under hightemperature and continuous reaction conditions could be successfully developed.to solve several critical issues in many aspects including organic chemistry and applied catalysis [1][2][3][4][5][6][7][8]. This new technology has created new promising horizons for chemical synthesis and industry via performing chemistry under continuous flow reaction conditions instead of the conventional batch chemistry [9][10][11][12][13][14][15][16]. This

“…It is widely known that one of the most important processes in the field of organic synthesis is the carbon-carbon bond formation through crosscoupling reactions that are catalyzed by transition metals. Those types of reactions are widely used in many areas like agricultural, medicinal, and pharmaceutical applications [11][12][13]23,[38][39][40][41][42]. The new synthetic trends are mainly focused recently on using catalysis at the nano scale for green chemistry using microwave assisted synthesis [11][12][13]15,16,18,20,22,23,[40][41][42][43][44][45][46].…”

Section: Introductionmentioning

confidence: 99%

Polyvinylpyrrolidone - Reduced Graphene Oxide - Pd Nanoparticles as an Efficient Nanocomposite for Catalysis Applications in Cross-Coupling Reactions

Bull. Chem. React. Eng. Catal.

El-Idreesy

2019

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This paper reported a scientific approach adopting microwave-assisted synthesis as a synthetic route for preparing highly active palladium nanoparticles stabilized by polyvinylpyrrolidone (Pd/PVP) and supported on reduced Graphene oxide (rGO) as a highly active catalyst used for Suzuki, Heck, and Sonogashira cross coupling reactions with remarkable turnover number (6500) and turnover frequency of 78000 h -1 . Pd/PVP nanoparticles supported on reduced Graphene oxide nanosheets (Pd-PVP/rGO) showed an outstanding performance through high catalytic activity towards cross coupling reactions. A simple, reproducible, and reliable method was used to prepare this efficient catalyst using microwave irradiation synthetic conditions. The synthesis approach requires simultaneous reduction of palladium and in the presence of Gaphene oxide (GO) nanosheets using ethylene glycol as a solvent and also as a strong reducing agent. The highly active and recyclable catalyst has so many advantages including the use of mild reaction conditions, short reaction times in an environmentally benign solvent system. Moreover, the prepared catalyst could be recycled for up to five times with nearly the same high catalytic activity. Furthermore, the high catalytic activity and recyclability of the prepared catalyst are due to the strong catalyst-support interaction. The defect sites in the reduced Graphene oxide (rGO) act as nucleation centers that enable anchoring of both Pd/PVP nanoparticles and hence, minimize the possibility of agglomeration which leads to a severe decrease in the catalytic activity.one of the main interests that attracted researchers' attention is transition metals based materials, especially when using palladium nanoparticles [5][6][7][8][9][10]. It is well established that palladium-based catalysts have been widely used in homogeneous and heterogeneous catalysis due to their several outstanding properties that combine between those of single metal atoms and other bulk metals [11][12][13][14][15][16]. In order to design new compounds with tailored chemical and