scholarly journals Palladium Nanoparticles Supported on Smopex-234® as Valuable Catalysts for the Synthesis of Heterocycles

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 706
Author(s):  
Gianluigi Albano ◽  
Claudio Evangelisti ◽  
Laura Antonella Aronica
Keyword(s):  
Catalytic Activity ◽  
Palladium Nanoparticles ◽  
Supported Catalysts ◽  
Fiber Surface ◽  
Preliminary Test ◽  
Green Economy ◽  
Homogeneous Catalyst ◽  
Active Metal ◽  
Almost All ◽  
Sonogashira Reactions

Supported catalysts are important tools for developing green-economy-based processes. Palladium nanoparticles (NPs) that are immobilized on two fibers developed as metal scavengers (i.e., Smopex®-234 and Smopex®-111, 1% w/w) have been prepared and tested in copper-free cyclocarbonylative Sonogashira reactions. Their catalytic activity has been compared with that of a homogeneous catalyst (i.e., PdCl2(PPh3)2). Pd/Smopex®-234 showed high activity and selectivity in the synthesis of functionalized heterocycles, such as phthalans and isochromans, even when working with a very low amount of palladium (0.2–0.5 mol%). The extension of Pd/Smopex®-234 promoted cyclocarbonylative reactions to propargyl and homopropargyl amides afforded the corresponding isoindoline and dihydrobenzazepine derivatives. A preliminary test on Pd NPs leaching into the solution (1.7 × 10−3 mg) seems to indicate that, at the end of the reaction, almost all of the active metal is present on the fiber surface.

scholarly journals Chiral MnIII (Salen) Immobilized on Organic Polymer/Inorganic Zirconium Hydrogen Phosphate Functionalized with 3-Aminopropyltrimethoxysilane as an Efficient and Recyclable Catalyst for Enantioselective Epoxidation of Styrene

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 212 ◽  
Author(s):  
Xiaochuan Zou ◽  
Yue Wang ◽  
Cun Wang ◽  
Kaiyun Shi ◽  
Yanrong Ren ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Supported Catalysts ◽  
Organic Polymer ◽  
Solid Catalyst ◽  
Homogeneous Catalyst ◽  
Hydrogen Phosphate ◽  
Characterization Methods ◽  
Salen Complexes ◽  
Enantioselective Epoxidation ◽  
Better Than

Organic polymers/inorganic zirconium hydrogen phosphate (ZSPP, ZPS-IPPA, and ZPS-PVPA) functionalized with 3-aminopropyltrimethoxysilane were prepared and used to support chiral MnIII (salen) complexes (Jacobsen’s catalyst). Different characterization methods demonstrated that the chiral MnIII (salen) complexes was successfully supported on the surface of the carrier (ZSPP, ZPS-IPPA, or ZPS-PVPA) through a 3-aminopropyltrimethoxysilane group spacer. The supported catalysts effectively catalyzed epoxidation of styrene with m-chloroperbenzoic acid (m-CPBA) as an oxidant in the presence of N-methylmorpholine N-oxide (NMO) as an axial base. These results (ee%, 53.3–63.9) were significantly better than those achieved under a homogeneous counterpart (ee%, 46.2). Moreover, it is obvious that there was no significant decrease in catalytic activity after the catalyst 3 was recycled four times (cons%: from 95.0 to 92.6; ee%: from 64.7 to 60.1). Further recycles of catalyst 3 resulted in poor conversions, although the enantioselectivity obtained was still higher than that of corresponding homogeneous catalyst even after eight times. After the end of the eighth reaction, the solid catalyst was allowed to stand in 2 mol/L of dilute hydrochloric acid overnight, prompting an unexpected discovery that the catalytic activity of the catalyst was recovered again at the 9th and 10th cycles of the catalyst.

PHYTOTOXICITY OF WASTEWATER CONTAINING CADMIUM (Cd) USING OLEANDER

2020 ◽  
Vol 51 (4) ◽  
pp. 1231-1238
Author(s):  
Zeki & Ridha
Keyword(s):  
Translocation Factor ◽  
Preliminary Test ◽  
Dry Weight ◽  
Exposure Dose ◽  
Test Duration ◽  
Plant Analysis ◽  
Wet Weight ◽  
Simulated Wastewater ◽  
Almost All ◽  
Plant Shoots

This study was aimed to investigate the ability of N.oleander to remove Cadmium (Cd) from wastewater. A prolonged toxicity test was performed in a single exposure and run for 65 days with various concentrations of Cd. Plants were grown in sand medium and irrigated with simulated wastewater contaminated with Cd, using different concentrations (0, 10, 25, 50, 75 mg/L), which were chosen based on previous preliminary test. The results of physical observation of the plants didn’t show any withering symptoms. The Cd concentration in plants increased, while in water decreased. The results of plant analysis showed that Cd concentration in plant shoots (stems and leaves) was higher than that in roots for almost all exposure doses along the test duration. The concentration of Cd in water decreased significantly from the first week of the test and become (0 mg/l) on day-35 for 10 and 25 mg/l exposure doses, while exceeded the permissible limits for 50 and 75 mg/l exposure doses and were 0.14 and 0.91 mg/l, respectively. Wet weight and dry weight of Oleander decreased with increasing Cd concentration level except for 10 mg/l exposure dose where the plant wet weight and dry weight increased at the end of the test. Bioaccumulation factor (BAF) and Translocation Factor (TF) was found to be greater than 1, indicating that Oleander is a successful hyperaccumulator for Cd.

scholarly journals Recyclable Catalysts for Alkyne Functionalization

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3525
Author(s):  
Leslie Trigoura ◽  
Yalan Xing ◽  
Bhanu P. S. Chauhan
Keyword(s):  
Supported Catalysts ◽  
Metal Organic Framework ◽  
Metal Nanoparticle ◽  
Homogeneous Catalyst ◽  
Catalyst Recycling ◽  
Catalytic Systems ◽  
Recyclable Catalysts ◽  
Metal Organic ◽  
Porous Organic Framework ◽  
Organic Framework

In this review, we present an assessment of recent advances in alkyne functionalization reactions, classified according to different classes of recyclable catalysts. In this work, we have incorporated and reviewed the activity and selectivity of recyclable catalytic systems such as polysiloxane-encapsulated novel metal nanoparticle-based catalysts, silica–copper-supported nanocatalysts, graphitic carbon-supported nanocatalysts, metal organic framework (MOF) catalysts, porous organic framework (POP) catalysts, bio-material-supported catalysts, and metal/solvent free recyclable catalysts. In addition, several alkyne functionalization reactions have been elucidated to demonstrate the success and efficiency of recyclable catalysts. In addition, this review also provides the fundamental knowledge required for utilization of green catalysts, which can combine the advantageous features of both homogeneous (catalyst modulation) and heterogeneous (catalyst recycling) catalysis.

In situimmobilization of palladium nanoparticles in microfluidic reactors and assessment of their catalytic activity

2010 ◽  
Vol 21 (32) ◽  
pp. 325605 ◽  
Author(s):  
Rui Lin ◽  
Ruel G Freemantle ◽  
Nicholas M Kelly ◽  
Thomas R Fielitz ◽  
Sherine O Obare ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Palladium Nanoparticles ◽  
Microfluidic Reactors

Characterization and Catalytic Activity of Poly(4-Vinylpyridine-Co-Divinylbenzene)-Co2+ Complex

2005 ◽  
Vol 494 ◽  
pp. 363-368 ◽  
Author(s):  
D. Lončarević ◽  
Ž. Čupić
Keyword(s):  
Catalytic Activity ◽  
Molecular Level ◽  
Supported Catalysts ◽  
Lone Pair ◽  
Polymer Support ◽  
Polymeric Complex ◽  
Reaction Conditions ◽  
Pyridine Nitrogen ◽  
Nitrogen Lone Pair ◽  
Thermal Stability Of

Poly(4-vinylpyridine-co-divinylbenzene)-Co2+ was characterized using infrared spectroscopy (IR), thermogravimetric analysis (TG-DTA), N2-physisorption and polarography. Thermal analysis suggests sufficient thermal stability of the polymer support, under reaction conditions. From polarography measurements, the Co2+ content on polymer-supported catalysts is estimated and it was proved that no significant leaching occurred during the activity tests. At the molecular level, FTIR of P4VP-DVB-Co2+ reveals that the pyridine nitrogen lone pair coordinates to the metal center in the polymeric complex. The obtained P4VP-DVB-Co2+ catalysts performed interesting catalytic activity in reaction of the cyclohexane oxidation with air, indicating that increasing Co2+ content lowers the initiation temperature and raises the decomposition of cyclohexylhydroperoxide.

Palladium nanoparticles supported on polyvinylpyridine: Catalytic activity in Heck-type reactions and XPS structural studies

2009 ◽  
Vol 262 (2) ◽  
pp. 287-293 ◽  
Author(s):  
Claudio Evangelisti ◽  
Nicoletta Panziera ◽  
Paolo Pertici ◽  
Giovanni Vitulli ◽  
Piero Salvadori ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Palladium Nanoparticles ◽  
Structural Studies

Structure and supramolecular organization of tri-n-butyl(octadecyl)phosphonium tetrafluoroborate and its influence on catalytic activity of stabilized palladium nanoparticles

2015 ◽  
Vol 64 (10) ◽  
pp. 2486-2492 ◽  
Author(s):  
D. M. Arkhipova ◽  
V. V. Ermolaev ◽  
V. A. Miluykov ◽  
G. A. Gaynanova ◽  
F. G. Valeeva ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Palladium Nanoparticles ◽  
Supramolecular Organization

scholarly journals Rozwój zielonej gospodarki w sektorze rolnictwa w krajach Unii Europejskiej i w Polsce w kontekście koncepcji zrównoważonego rozwoju

2017 ◽  
Vol 17(32) (3) ◽  
pp. 195-206
Author(s):  
Łukasz Kozar
Keyword(s):  
Great Britain ◽  
Rural Areas ◽  
Agricultural Sector ◽  
Agricultural Land ◽  
Statistical Data ◽  
Green Economy ◽  
Pilot Studies ◽  
Level Of Knowledge ◽  
The Subject ◽  
Almost All

The paper presents the issues related to the green economy in the agricultural sector. In order to discuss it, an analysis of the subject literature was carried out and some selected statistical data describing the process of greening of agriculture were presented. The timeframe of the analysis covered the years 2010-2015. The GUS and Eurostat were the source of the used values. Studies have shown that almost all EU countries have increased the area of organic agricultural land in the surveyed period (except for Great Britain). In addition, the article presents the results of pilot studies conducted in the Lodz Region, aimed at diagnosing key barriers to the development of the green economy in rural areas. According to the research, the insufficient level of knowledge of farmers in this area is an important obstacle to building a green economy in rural areas.

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