Optimized Dispersion and Stability of Hybrid Fe3O4/Pd Catalysts in Water for Suzuki Coupling Reactions: Impact of Organic Capping Agents

Excellent Pd-Loaded Magnetic Nanocatalyst on Multicarboxyl and Boronic Acid Biligands

An effective palladium nanocatalyst (Fe3O4@SiO2-FPBA-DTPA-Pd) was proposed and prepared, which was immobilized on magnetic silica with ethylenediamine pentaacetic acid and formylphenylboronic acid as biligands. A series of characterizations showed that Fe3O4@SiO2-FPBA-DTPA-Pd was 5-15 nm and contained 1.44 mmol/g Pd2+/Pd0. It was stable below 232.7 °C, and its saturation magnetization value was 21.17 emu/g which was easily recycled by a magnet. Its catalytic ability was evaluated through 7 Suzuki reactions and 15 Heck reactions. Results showed that the yields of 14 reactions catalyzed by Fe3O4@SiO2-FPBA-DTPA-Pd were more than 90%, while were better than those of the other two immobilized Pd catalysts on a single diethyltriamine pentaacetic acid (DTPA) group or boronic acid group. Moreover, Fe3O4@SiO2-FPBA-DTPA-Pd showed good reusability in both Suzuki and Heck reactions. In two model Suzuki and Heck reactions, after seven cycles, its yields were still above 95% without significant loss, which exceeded those of many reported catalysts; therefore, it has great potential in future large-scale industrial production.

Hollow-Shell-Structured Mesoporous Silica-Supported Palladium Catalyst for an Efficient Suzuki-Miyaura Cross-Coupling Reaction

The construction of a high stability heterogeneous catalyst for privileged common catalysis is a benefit in regard to reuse and separation. Herein, a palladium diphenylphosphine-based hollow-shell-structured mesoporous catalyst (HS@PdPPh2@MSN) was prepared by immobilizing bis((diphenylphosphino)ethyltriethoxysilane)palladium acetate onto the inner wall of a mesoporous organicsilicane hollow shell, whose surface was protected by a –Si(Me)3 group. Electron microscopies confirmed its hollow-shell-structure, and structural analyses and characterizations revealed its well-defined single-site active species within the silicate network. As presented in this study, the newly constructed HS@PdPPh2@MSN enabled an efficient Suzuki-Miyaura cross-coupling reaction for varieties of substrates with up to 95% yield in mild conditions. Meanwhile, it could be reused at least five times with good activity, indicating its excellent stability and recyclability. Furthermore, the cost-effective and easily synthesized HS@PdPPh2@MSN made it a good candidate for employment in fine chemical engineering.

Recent Novel Hybrid Pd–Fe3O4 Nanoparticles as Catalysts for Various C–C Coupling Reactions

The use of nanostructure materials as heterogeneous catalysts in the synthesis of organic compounds have been receiving more attention in the rapid developing area of nanotechnology. In this review, we mainly focused on our own work on the synthesis of hybrid palladium–iron oxide nanoparticles. We discuss the synthesis of Pd–Fe3O4—both morphology-controlled synthesis of Pd–Fe3O4 and transition metal-loaded Pd–Fe3O4—as well as its application in various C–C coupling reactions. In the case of rose-like Pd–Fe3O4 hybrid nanoparticles, thermal decomposition can be used instead of oxidants or reductants, and morphology can be easily controlled. We have developed a method for the synthesis of nanoparticles that is facile and eco-friendly. The catalyst was recyclable for up to five continual cycles without significant loss of catalytic activity and may provide a great platform as a catalyst for other organic reactions in the near future.

The Current Status of Heterogeneous Palladium Catalysed Heck and Suzuki Cross-Coupling Reactions

In the last 30 years, C–C cross coupling reactions have become a reliable technique in organic synthesis due their versatility and efficiency. While drawbacks have been experienced on an industrial scale with the use of homogenous systems, many attempts have been made to facilitate a heterogeneous renaissance. Thus, this review gives an overview of the current status of the use of heterogeneous catalysts particularly in Suzuki and Heck reactions. Most recent developments focus on palladium immobilised or supported on various classes of supports, thus this review highlights and discuss contributions of the last decade.

Nanostructured biogel templated synthesis of Fe3O4 nanoparticles and its application for catalytic degradation of xylenol orange

Using jellyfish mesoglea as a natural template, nanocomposite hydrogels with well-dispersed Fe₃O₄ nanoparticles are obtained.

Activated nanostructured bimetallic catalysts for C–C coupling reactions: recent progress

This minireview highlights the recent progress made in the last decade towards the development of activated bimetallic alloy nanoparticle catalysts for C–C coupling reactions, including asymmetric C–C bond coupling reactions.

Immobilized palladium nanoparticles within polymers as active catalysts for Suzuki–Miyaura reaction

A highly active and reusable catalyst Pd@PNP was developed for Suzuki–Miyaura reaction of aryl chlorides and bromides with aryl boronic acids, and the corresponding biphenyl compounds were obtained in good to excellent yields.

Rose-like Pd-Fe3O4 hybrid nanocomposite-supported Au nanocatalysts for tandem synthesis of 2-phenylindoles

A facile synthesis of rose-like Pd-Fe3O4 nanocomposites via controlled thermal decomposition of Fe(CO)5 and reduction of Pd(OAc)2, followed by the immobilization of Au nanoparticles (NPs) onto the Pd-Fe3O4 supports, is reported. The morphology of these hybrid nanostructures could be easily controlled by varying the amount of Fe(CO)5 and the reaction temperature. Moreover, the synthesized Au/Pd-Fe3O4 catalyst exhibited high catalytic activity for the tandem synthesis of 2-phenylindoles and demonstrated magnetic recyclability.

Surfactant-free Pd@pSiO2 yolk–shell nanocatalysts for selective oxidation of primary alcohols to aldehydes

The surfactant-free Pd@pSiO₂ yolk–shell nanoparticles proved to be an efficient catalyst for the oxidation of substituted benzyl alcohols.