Cobalt Schiff base complexes: Synthesis characterization and catalytic application in Suzuki–Miyaura reaction

3-Methoxysalicylaldehyde was condensed with the amines 4-aminoacetophenone and 2-amino-5-bromopyridine to obtain Schiff base ligands, 1 and 2, which were coordinated to cobalt salts as complex 1 and complex 2, respectively. The synthesized ligands and complexes were characterized by spectroscopic (FT-IR, UV-Vis, ¹H-NMR and mass spectrometry), thermal (TGA) and elemental analysis. The structures of the complexes were verified by evaluating their magnetic susceptibility and spectroscopic evidences. Synthesized complexes were studied for their catalytic activity in the Suzuki-Miyaura cross-coupling of aryl halides with phenylboronic acid. Optimized reaction yields 90% of the cyanobiphenyl for complex 1 and 91% for complex 2 with 0.1 mmol of catalyst loading thereby substantiating the C-C coupling efficiency of the synthesized complexes, 1 and 2.     

Pd(II)/Pd(0) Anchored on Magnetic Organic–Inorganic Hybrid Mesoporous Silica Nanoparticles: A Nanocatalyst for Suzuki–Miyaura and Heck–Mizoroki Coupling Reactions

Journal of Inorganic and Organometallic Polymers and Materials - 3-Chloropropyltrimethoxysilane (CPTMS) was grafted on the surface of silica coated Fe3O4 core (Fe3O4@MCM-41) and then condensed with...     

Palladium Nanoparticles Supported on Poly(2-hydroxyethyl methacrylate)/KIT-6 Composite as an Efficient and Reusable Catalyst for Suzuki–Miyaura Reaction in Water

Pd nanoparticle-poly(2-hydroxyethyl methacrylate)/KIT-6 (Pd-PHEMA/KIT-6) composite was fabricated through in situ polymerization method and was evaluated as a novel heterogeneous catalyst in Suzuki–Miyaura cross coupling reactions of aryl halides and phenylboronic acid in an aqueous medium. The catalyst was characterized by XRD, FT-IR, UV–Vis, TG, BET, and TEM techniques. The results revealed that the supported catalyst Pd-PHEMA/KIT-6 exhibited excellent catalytic activity for the coupling of aryl iodides, aryl bromides, and aryl chlorides. This heterogeneous catalyst could be reused at least nine times without any decrease in activity.     

Palladium(II) thiosemicarbazone-catalyzed Suzuki–Miyaura cross-coupling reactions of aryl halides

A new air- and moisture-stable palladium(II) complex bearing pyridoxal thiosemicarbazone ligand has been synthesized. The synthesized complex was characterized by analytical and spectral methods. The molecular structure of the complex was confirmed by X-ray diffraction method. The palladium(II) complex was used as potential catalyst for Suzuki–Miyaura coupling reaction of several aryl halides under optimized conditions.     

Sol–gel Preparation of K–Co–Mo Catalyst and its Application in Mixed Alcohol Synthesis from CO Hydrogenation

A kind of K–Co–Mo catalyst with large surface area, small particle size and homogenous components distribution was prepared by sol–gel method using citric acid as complexant, and characterized by XRD, BET, HR-TEM, EXAFS and TPD techniques. The activity for mixed alcohol synthesis from syngas on the catalysts was investigated. During the preparation, a gelation process was adopted to prevent the components from precipitating during the solvent extraction and keep the homogeneity and small particle size of final products. Heat-treated the dried gel in argon, the decomposition of critic acid partly reduced the sample and decreases the particle sizes remarkably. The synthesized K–Co–Mo catalyst exhibited excellent performance for mixed alcohol synthesis from CO hydrogenation, which may be due to its large surface area and small particle size creating more active sites. Beside it, the homogeneity of various components was also helpful to enhance the synergistic effect of Co promoters. The high selectivity to the C₂₊OH was due to the large amount of SH species adsorbed on the catalyst surface.     

Synthesis,Characterization and Application of Co–MgO Mixed Oxides in Oxidation of Carbon Monoxide

The present work deals with the synthesis of nanostructured Co–MgO mixed oxides with different weight ratios of cobalt by a facile co-precipitation method as a catalyst for low-temperature CO oxidation. The prepared samples were characterized by X-ray diffraction (XRD), N₂ adsorption/desorption (BET), Fourier transform infrared spectroscopy (FTIR), and transmission and scanning electron microscopies (TEM and SEM) techniques. The results revealed that inexpensive cobalt–magnesium mixed metal oxide nanoparticles have a high potential as catalyst in low-temperature CO oxidation. The Co–MgO mixed oxide with 30 wt.% cobalt had the highest activity. The results showed that the catalysts pretreated under O₂-containing atmosphere possessed higher activity compared to the catalyst pretreated under H₂ atmosphere. Co–MgO catalyst showed a good repeatability in reaction condition. The stability test exhibited that the Co–MgO mixed oxides were highly stable for CO oxidation over a 30 h time on stream in the feed gas containing a high amount of moisture and CO₂.     

Synthesis and Digestibility Inhibition of Diarylheptanoids: Structure–Activity Relationship

(±)-5-Hydroxy-1,7-bis-(4-hydroxyphenyl)-3-heptanone (2a), (±)-5-hydroxyl-1-(4-hydroxyphenyl)-7-phenyl-3-heptanone (2b), (±)-5-hydroxy-7-(4-hydroxyphenyl)-1-phenyl-3-heptanone (2c), and (±)-5-hydroxy-1,7-bis-(phenyl)-3-heptanone (2d) have been synthesized to study the structure–activity relationship regarding digestibility inhibition in vitro in cow rumen fluid. The activities were compared with the activity of chiral (S)-2a and its glucoside platyphylloside (1), isolated from Betula pendula. Compound 2a was slightly less active, 2b and 2c were more active, and 2d was less active than (S)-2a and platyphylloside.     

Immobilization of palladium on benzimidazole functionalized mesoporous silica nanoparticles: catalytic efficacy in Suzuki–Miyaura reaction and nitroarenes reduction

Journal of Porous Materials - Benzimidazole functionalized mesoporous silica nanoparticles immobilized Pd(0)/Pd(II) has been proposed as an efficient catalyst for the one-pot preparation of biaryls...     

Novel polymer-supported phosphine palladium catalyst: one-pot synthesis from and application in Suzuki–Miyaura coupling reaction

A “one-pot” strategy has been developed for the synthesis of polymer-supported phosphine-Pd catalyst using Suzuki–Miyaura coupling reaction. The fine and uniform Pd nanoparticles were well dispersed on the skeleton of the phosphine-containing polymer. This Pd catalyst exhibited excellent catalytic activity and recycling performance in the Suzuki–Miyaura coupling reaction under the mild conditions and water–ethanol mixed media.