scholarly journals SCREENING OF THE CATALYTIC ACTIVITY OF Pd0 AND Pd2+- SUPPORTED ON CHITOSAN BEADS AND CRYOGELS

2018 ◽  
Vol XXIII ◽  
pp. 149-158
Author(s):  
Aleksandr Pestov ◽  
Aleksandr Mekhaev ◽  
Yuliya Privar ◽  
Natalya Prokuda ◽  
Evgeniy Modin ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Pd Nanoparticles ◽  
High Catalytic Activity ◽  
Mesomeric Effect ◽  
Catalytic Systems ◽  
Chitosan Beads ◽  
Cross Coupling Reaction ◽  
Significant Difference

Here, we report the results of screening of the catalytic activity of Pd-containing chitosan beads and cryogels in the cross-coupling reaction, hydrogenation of alkenes, nitro-, and carbonyl compounds and the hydrodechlorination of chlorophenols. Pd0-containing chitosan beads and cryogels show moderate catalytic activity in the reduction of alkenes and nitroaromatics. The conversion of nitroaromatics decreases for substrates with electron-withdrawing substituents, while the conversion of alkenes increases with the activation of carbon-carbon double bonds. For several substrates, a significant difference in kinetics and conversion degrees was observed for Pd nanoparticles supported on chitosan beads and cryogels. It was found that conversion in the hydrodechlorination reaction depends on substrate structure, being higher for substrates containing substituents with a positive mesomeric effect. Pd2+-chitosan catalysts showed high catalytic activity in cross-coupling (Heck reaction) offering the following advantages over known catalytic systems: lower reaction temperature, the selective functionalisation of C-I bonds, and the possibility to perform reactions with iodobenzene without base addition.

scholarly journals Modified ultradispersed diamonds based catalytic systems in cross-coupling reactions

2021 ◽  
Vol 57 (1) ◽  
pp. 7-14
Author(s):  
A. A. Lugovski ◽  
G. A. Gusakov ◽  
M. P. Samtsov ◽  
V. A. Parhomenko ◽  
S. V. Adamchyk
Keyword(s):  
Catalytic Activity ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Model Systems ◽  
High Catalytic Activity ◽  
Coupling Reactions ◽  
Catalytic Systems ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Metallic Palladium

Methods for preparation of nanocomposites of modified detonation nanodiamonds (DND) with metallic palladium have been developed and their catalytic activity in the Suzuki-Miyaura cross-coupling reaction in various reaction media has been studied. Methods for the regeneration of palladium-containing nanocomposites from the reaction mixture have been developed. The high catalytic activity of nanocomposites is confirmed by kinetic analysis based on the results of chromatographic analysis of the reaction mixture and is comparable to the literature data about similar catalytic systems. Regenerated nanocomposites showed the retention of catalytic activity for 3 consecutive cross-coupling cycles on model systems.

scholarly journals N,N-Dimethylformamide-stabilized copper nanoparticles as a catalyst precursor for Sonogashira–Hagihara cross coupling

RSC Advances ◽  
2017 ◽  
Vol 7 (37) ◽  
pp. 22869-22874 ◽  
Author(s):  
Hideo Oka ◽  
Katsuya Kitai ◽  
Takeyuki Suzuki ◽  
Yasushi Obora
Keyword(s):  
Catalytic Activity ◽  
Copper Nanoparticles ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
High Catalytic Activity ◽  
Catalyst Precursor ◽  
Cross Coupling Reaction

We found that DMF-stabilized Cu NPs have high catalytic activity in the Sonogashira cross-coupling reaction at low catalyst loadings (0.2 mol%).

Palladium nanoparticles supported on a carbazole functionalized mesoporous organic polymer: synthesis and their application as efficient catalysts for the Suzuki–Miyaura cross coupling reaction

2017 ◽  
Vol 8 (9) ◽  
pp. 1488-1494 ◽  
Author(s):  
Hui Zhou ◽  
Chuanguang Wu ◽  
Qiaolin Wu ◽  
Bixuan Guo ◽  
Wanting Liu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Palladium Nanoparticles ◽  
High Performance ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Pd Nanoparticles ◽  
Polymer Synthesis ◽  
Organic Polymer ◽  
Cross Coupling Reaction ◽  
Good Catalytic Activity

Pd nanoparticles supported on a carbazole functionalized mesoporous organic polymer exhibit high performance in the Suzuki–Miyaura cross coupling reaction with good catalytic activity, substrate adaptability and recyclability.

Fabrication of a Fe3O4@SiO2@mSiO2-HPG-COOH-Pd(0) supported catalyst and its performance in catalyzing the Suzuki cross-coupling reaction

2015 ◽  
Vol 39 (4) ◽  
pp. 2767-2777 ◽  
Author(s):  
Wei Li ◽  
Yi Tian ◽  
Baoliang Zhang ◽  
Lei Tian ◽  
Xiangjie Li ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Supported Catalyst ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
High Catalytic Activity ◽  
Cross Coupling Reaction

A novel Fe3O4@SiO2@mSiO2-HPG-COOH-Pd(0) catalyst with high catalytic activity and stability was successfully synthesized.

scholarly journals Pd Nanoparticles Stabilized by Hypercrosslinked Polystyrene Catalyze Selective Triple C-C Bond Hydrogenation and Suzuki Cross-Coupling

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Linda Zh. Nikoshvili ◽  
Nadezhda A. Nemygina ◽  
Tatiana E. Khudyakova ◽  
Irina Yu. Tiamina ◽  
Alexey V. Bykov ◽  
...  
Keyword(s):  
Phase Transfer ◽  
Aryl Halide ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Pd Nanoparticles ◽  
Hypercrosslinked Polystyrene ◽  
Reductive Activation ◽  
Pd Nanoparticle ◽  
Cross Coupling Reaction ◽  
Precursor Decomposition

This paper describes the synthesis of Pd-containing catalysts based on nonfunctionalized hypercrosslinked polystyrene via impregnation with Pd acetate. Developed Pd nanoparticulate catalyst allowed achieving conversion of aryl halide up to 90% in Suzuki cross-coupling reaction under mild conditions and at the absence of phase-transfer agents. During the selective hydrogenation of triple C-C bond of 2-methyl-3-butyn-2-ol, up to 96% selectivity with respect to corresponding olefinic alcohol was found at 95% conversion. The influences of the procedure of catalyst synthesis like precursor decomposition and reductive activation method on Pd nanoparticle formation are discussed.

High Catalytic Activity of Pd Nanoparticles Synthesized from Green Alga Chlorella vulgaris in Buchwald-hartwig Synthesis of N-Aryl Piperazines

2019 ◽  
Vol 7 (1) ◽  
pp. 23-33
Author(s):  
Vaibhav Mishra ◽  
Anju Arya ◽  
Tejpal Singh Chundawat
Keyword(s):  
Catalytic Activity ◽  
Green Alga ◽  
Chlorella Vulgaris ◽  
Direct Synthesis ◽  
Coupling Reaction ◽  
Pd Nanoparticles ◽  
High Catalytic Activity ◽  
Pd Nanoparticle ◽  
Green Algal ◽  
Green Alga Chlorella

Background: The N-aryl piperazines are an important component of many drug products used for the treatment of malaria, depression, anxiety and Parkinson diseases. Buchwald-Hartwig amination is the latest and well-known reaction for Pd catalyzed direct synthesis of N-aryl piperazine from aryl halides. Although several Pd-ligand systems have already been discovered for this conversion, Pd nanoparticles are recently being used for this useful coupling reaction due to their recyclability and durability. Metal nanoparticles show enhanced catalytic activity compared to their bulk counterparts due to increased surface area at the edges and corners. The use of green algal extract in place of chemical ligands makes this process more environment-friendly and cost-effective. In this research, Pd nanoparticles synthesized using green alga C. Vulgaris were utilized as an alternative approach for the coupling reaction during the preparation of N-aryl piperazines. Methods: Synthesized Pd nanoparticles from C. Vulgaris were characterized by FTIR, SEM and XRD techniques. The catalytic activity of the synthesized nanoparticles was monitored for the synthesis of N-aryl piperazines by Buchwald-Hartwig reaction. The synthesized N-aryl piperazines were characterized by NMR, FTIR and mass analysis. Results: A very good catalytic activity of the synthesized Pd nanoparticles from green alga Chlorella vulgaris extract was observed. The green alga not only reduces the size of the Pd metal to nanoparticles but also acts as a green ligand for reduction of Pd(II) to Pd(0) during nanoparticle synthesis. Using this Pd nanoparticles-green ligand system, several N-aryl piperazines were synthesized in good to excellent yields. Reaction conditions for better conversion were optimized. The comparative advantage of the catalytic system with recently published works on Buchwald-Hartwig C-N coupling reaction is given. Recyclability and durability of the catalyst were explored and the results were found to be promising. A plausible mechanism of Pd nanoparticle catalyzed reaction is also proposed. Conclusion: Catalytic activity of the Pd nanoparticle synthesized from Chlorella vulagris in the synthesis of N-aryl piperazines by Buchwald-Hartwig reaction is reported first time to the best of our knowledge and understanding. The green approach of Pd catalyst to facilitate the reaction and its environmental impact is the main characteristic of the process.

Palladium-Schiff-base-silica framework as a robust and recyclable catalyst for Suzuki–Miyaura cross-coupling in aqueous media

RSC Advances ◽  
2015 ◽  
Vol 5 (48) ◽  
pp. 38085-38092 ◽  
Author(s):  
Tahshina Begum ◽  
Manoj Mondal ◽  
Pradip K. Gogoi ◽  
Utpal Bora
Keyword(s):  
Schiff Base ◽  
Catalytic Activity ◽  
Room Temperature ◽  
Aqueous Media ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Recyclable Catalyst ◽  
Cross Coupling Reaction

A novel Pd@imine-SiO2 catalyst was prepared and found to exhibit excellent catalytic activity in a Suzuki-Miyaura cross-coupling reaction under aqueous media at room temperature.

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