Active pyridinium based ionic liquid anchored quinuclidine organocatalyst for Morita-Baylis-Hillman reaction

2021 ◽  
Vol 18 ◽  
Author(s):  
Vivek Srivastava
Keyword(s):  
Ionic Liquid ◽  
Analytical Techniques ◽  
Chemical Yield ◽  
Biologically Active ◽  
Catalyst Loading ◽  
Catalyst Recycling ◽  
Ether Extraction ◽  
Different Types ◽  
Low Catalyst Loading

: In the present manuscript, we easily synthesized three different types of ionic liquid supported 3-quinuclidinone organocatalysts such as [PyAmEQ][BF4] (Py-CATALYST-1), [PyAmEQ][PF6] (Py-CATALYST-2), and [PyAmEQ][NTf2] (Py-CATALYST-3). After performing the careful characterization of the above catalysts with sophisticated analytical techniques, we utilized them as a catalyst to study the passive Morita-Baylis-Hillman reaction. The corresponding Morita-Baylis-Hillman adducts were easily isolated, followed by the simple ether extraction method. Moreover, the above protocol also promoted low catalyst loading, short reaction time, wide substrate scope, easy product, and catalyst recycling. We easily recycled the catalytic system for 5 runs with no noticeable loss in the chemical yield. Additionally, Py-CATALYST-3 was also used to prepare biologically active materials, i.e., N-((E,3S,4R)-5-benzylidene-tetrahydro-4-hydroxy-6-oxo-2H-pyran-3-yl) palmitamide derivatives.

scholarly journals Synthesis and Characterization of Pd exchanged MMT Clay for Mizoroki-Heck Reaction

2018 ◽  
Vol 16 (1) ◽  
pp. 605-613 ◽  
Author(s):  
Vivek Srivastava
Keyword(s):  
Heck Reaction ◽  
Exchange Process ◽  
Reaction Medium ◽  
Analytical Techniques ◽  
Catalyst Loading ◽  
Catalyst Recycling ◽  
Mmt Clay ◽  
Vinyl Phosphonates ◽  
Low Catalyst Loading

AbstractWe successfully synthesized Pd@MMT clay using a cation exchange process. We characterized all the synthesized Pd@MMT clays using sophisticated analytical techniques before testing them as a heterogeneous catalyst for the Mizoroki - Heck reaction (mono and double). The highest yield of the Mizoroki-Heck reaction product was recovered using thermally stable and highly reactive Pd@ MMT-1 clay catalyst in the functionalized ionic liquid reaction medium. We successfully isolated 2-aryl-vinyl phosphonates (mono-Mizoroki-Heck reaction product) and 2,2-diaryl-vinylphosphonates (double-Mizoroki-Heck reaction product) using aryl halides and dialkyl vinyl phosphonates in higher yields. The low catalyst loading, easy recovery of reaction product and 8 times catalyst recycling are the major highlights of this proposed protocol.

Acceleration of Baylis-Hillman reaction using ionic liquid supported organocatalyst

2021 ◽  
Vol 08 ◽  
Author(s):  
Vivek Srivastava
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Reaction Rate ◽  
Reaction Medium ◽  
Catalyst Loading ◽  
Catalyst Recycling ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Highly Active ◽  
Low Catalyst Loading

Background: Baylis-Hillman reaction suffers from the requirement of cheap starting materials, easy reaction protocol, possibility to create the chiral center in the reaction product has increased the synthetic efficacy of this reaction, and high catalyst loading, low reaction rate, and poor yield. Objective: The extensive use of various functional or non-functional ionic liquids (ILs) with organocatalyst increases the reaction rate of various organic transformations as a reaction medium and as a support to anchor the catalysts. Methods: In this manuscript, we have demonstrated the synthesis of quinuclidine-supported trimethylamine-based functionalized ionic liquid as a catalyst for the Baylis-Hillman reaction. Results: We obtained the Baylis-Hillman adducts in good, isolated yield, low catalyst loading, short reaction time, broad substrate scope, accessible product, and catalyst recycling. N-((E,3S,4R)-5-benzylidene-tetrahydro-4-hydroxy-6-oxo-2H-pyran-3-yl) palmitamide was also successfully synthesized using CATALYST-3 promoted Baylis-Hillman reaction. Conclusion: We successfully isolated the 25 types of Baylis-Hillman adducts using three different quinuclidine-supported ammonium-based ionic liquids such as Et3AmQ][BF4] (CATALYST-1), [Et3AmQ][PF6] (CATALYST-2), and [TMAAmEQ][NTf2](CATALYST-3) as new and efficient catalysts. Tedious and highly active N-((E,3S,4R)-5-benzylidene-tetrahydro-4-hydroxy-6-oxo-2H-pyran-3-yl) palmitamide derivative was also synthesized using CATALYST-3 followed by Baylis-Hillman reaction. Generally, all the responses demonstrated higher activity and yielded high competition with various previously reported homogenous and heterogeneous Catalytic systems. Easy catalyst and product recovery followed by six catalysts recycling were the added advantages of the prosed catalytic system.

scholarly journals Functional characterization of three flavonoid glycosyltransferases from Andrographis paniculata

2019 ◽  
Vol 6 (6) ◽  
pp. 190150 ◽  
Author(s):  
Yuan Li ◽  
Xin-Lin Li ◽  
Chang-Jiang-Sheng Lai ◽  
Rui-Shan Wang ◽  
Li-Ping Kang ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Biochemical Properties ◽  
Flavonoid Glycoside ◽  
Andrographis Paniculata ◽  
Biologically Active ◽  
Flavonoid Glycosides ◽  
Asian Countries ◽  
Pharmacological Activities ◽  
Different Types

Andrographis paniculata is an important traditional medicinal herb in South and Southeast Asian countries with diverse pharmacological activities that contains various flavonoids and flavonoid glycosides. Glycosylation can transform aglycones into more stable, biologically active and structurally diverse glycosides. Here, we report three glycosyltransferases from the leaves of A. paniculata (ApUFGTs) that presented wide substrate spectra for flavonoid glycosylation and exhibited multi-site glycosylation on the substrate molecules. They acted on the 7-OH position of the A ring and were able to glycosylate several other different types of compounds. The biochemical properties and phylogenetic analysis of these glycosyltransferases were also investigated. This study provides a basis for further research on the cloning of genes involved in glycosylation from A. paniculata and offers opportunities for enhancing flavonoid glycoside production in heterologous hosts. These enzymes are expected to become effective tools for drug discovery and for the biosynthesis of derivatives via flavonoid glycosylation.

Ionic Liquid – Assisted Synthesis and Characterization of Cerium Oxide Nanocubes for Degradation of Methylene Blue

2014 ◽  
Vol 625 ◽  
pp. 164-167
Author(s):  
Mohd Aliff Irham Md. Azhar ◽  
Sujan Chowdhury ◽  
Pradip Chandra Mandal ◽  
Muhd Fahmi Daman ◽  
Sekhar Bhattacharjee ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Ionic Liquid ◽  
Cerium Oxide ◽  
Treatment Method ◽  
Acetate Anion ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Different Types ◽  
Average Size

Cerium Oxide (CeO2) nanocubes are synthesized by using hydrothermal treatment method in the presence of four different types of ionic liquid such as acetate anion, phosphate anion, and dicyanamide anion. Ceria nanocubes has been consisted with average size of 16 to 31 nm in diameter and characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), and surface analyzer and porosimetry analysis (ASAP). Ceria nanocubes have higher photocatalytical ability in the degradation of methylene blue as compared to commercial ceria nanoparticles which are confirmed through ultraviolet-visible spectroscopy (UV/Vis).

scholarly journals Ru@hyperbranched Polymer for Hydrogenation of Levulinic Acid to Gamma-Valerolactone: The Role of the Catalyst Support

2022 ◽  
Vol 23 (2) ◽  
pp. 799
Author(s):  
Svetlana A. Sorokina ◽  
Stepan P. Mikhailov ◽  
Nina V. Kuchkina ◽  
Alexey V. Bykov ◽  
Alexander L. Vasiliev ◽  
...  
Keyword(s):  
Levulinic Acid ◽  
Catalyst Support ◽  
Physicochemical Characterization ◽  
Significant Loss ◽  
Catalyst Loading ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Low Catalyst Loading

Hydrogenation of levulinic acid (LA) obtained from cellulose biomass is a promising path for production of γ-valerolactone (GVL)—a component of biofuel. In this work, we developed Ru nanoparticle containing nanocomposites based on hyperbranched pyridylphenylene polymer, serving as multiligand and stabilizing matrix. The functionalization of the nanocomposite with sulfuric acid significantly enhances the activity of the catalyst in the selective hydrogenation of LA to GVL and allows the reaction to proceed under mild reaction conditions (100 °C, 2 MPa of H2) in water and low catalyst loading (0.016 mol.%) with a quantitative yield of GVL and selectivity up to 100%. The catalysts were successfully reused four times without a significant loss of activity. A comprehensive physicochemical characterization of the catalysts allowed us to assess structure-property relationships and to uncover an important role of the polymeric support in the efficient GVL synthesis.

scholarly journals Preparation and Characterization of Sulfonated Carbon Cryogel Doped Zinc as a Catalyst for Glucose Ethanolysis to Ethyl Levulinate

2021 ◽  
Vol 21 (1) ◽  
pp. 1
Author(s):  
Muzakkir Mohammad Zainol ◽  
Mohamad Nor Fitri Roslan ◽  
Mohd Asmadi ◽  
Nor Aishah Saidina Amin
Keyword(s):  
Chemical Properties ◽  
Catalyst Loading ◽  
Solid Catalyst ◽  
Ethyl Levulinate ◽  
Different Types ◽  
Carbon Cryogel ◽  
Physical And Chemical ◽  
Catalytic Effects ◽  
And Chemical Properties

In this study, sulfonated carbon cryogel (CC) doped with zinc was prepared and used as a solid catalyst. Carbon cryogel was prepared by mixing urea and furfural, freeze-drying, and calcination. The CC was then sulfonated and impregnated with zinc (II) nitrate for ethyl levulinate production from ethanolysis of glucose. Experiment results showed that different types of catalyst prepared from CC precursor had different catalytic effects on the ethanolysis of glucose. Sulfonated carbon cryogel doped with zinc (SCC-Zn) which prepared at a calcination temperature of 300 °C showed better performance as a catalyst for the ethanolysis reaction of glucose. In addition, the 10 wt.% of Zn was recommended as optimum loading for the impregnation on the catalyst. The ethyl levulinate yield of 19.6 mol% was obtained at 180 °C for 6 h with 0.15 g catalyst loading and 0.4 g of glucose feed. The selected SCC-Zn catalyst was further characterized by using FTIR, TGA XRD, and SEM-EDX to evaluate its physical and chemical properties as a catalyst.

Cu(II) ionic liquid promoted Simple and Economical Synthesis of 1,4-disubstituted-1,2,3-triazoles with Low Catalyst Loading

2021 ◽  
Vol 133 (4) ◽  
Author(s):  
Parmita Phukan ◽  
Akshay Kulshrestha ◽  
Arvind Kumar ◽  
Srijita chakraborti ◽  
Pronobesh Chattopadhyay ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Catalyst Loading ◽  
Low Catalyst Loading

Recent Trends in the Development of Novel Catalysts for Asymmetric Michael Reaction

2020 ◽  
Vol 24 (13) ◽  
pp. 1397-1458
Author(s):  
Shagufta Kamal ◽  
Ameer Fawad Zahoor ◽  
Sajjad Ahmad ◽  
Rabia Akhtar ◽  
Iqra Khaliq ◽  
...  
Keyword(s):  
Michael Reaction ◽  
Phase Transfer ◽  
Cinchona Alkaloids ◽  
Biologically Active ◽  
Catalyst Loading ◽  
Reaction Yield ◽  
Phase Transfer Catalysts ◽  
Potential Applications ◽  
Asymmetric Michael Reaction ◽  
Low Catalyst Loading

: Michael reaction is the nucleophilic addition of active methylene compounds to conjugated olefins, resultantly affording a variety of biologically active scaffolds with high enantiopurity. To improve the reaction yield, as well as enantioselectivity of the product, a variety of catalysts (amine-based catalysts, bifunctional L-proline amides, bifunctional squaramides, chiral ionic liquids, cinchona alkaloids, enzymes, indolinols, metal catalysts, peptide derived catalytic system, phase transfer catalysts, pyrrolidine based organocatalysts) have been investigated by a different era of chemists. Besides this, different methodologies have been developed to improve reaction yield and enantioselectivity of the targeted products with low catalyst loading. : This review article provides a concise overview of the catalysts applied recently by different scientists in the Michael addition reaction. Moreover, current strategies and potential applications of this reaction have also been illustrated in this review.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Some applications of electron beam microanalysis techniques in VLSI process evaluation

1983 ◽  
Vol 41 ◽  
pp. 160-161
Author(s):  
Simon Thomas
Keyword(s):  
Integrated Circuits ◽  
Process Evaluation ◽  
Large Scale ◽  
Technology Development ◽  
Analytical Techniques ◽  
Successful Implementation ◽  
Analysis Of Failures ◽  
Characterization Of Materials ◽  
Circuits Vlsi

Trends in the technology development of very large scale integrated circuits (VLSI) have been in the direction of higher density of components with smaller dimensions. The scaling down of device dimensions has been not only laterally but also in depth. Such efforts in miniaturization bring with them new developments in materials and processing. Successful implementation of these efforts is, to a large extent, dependent on the proper understanding of the material properties, process technologies and reliability issues, through adequate analytical studies. The analytical instrumentation technology has, fortunately, kept pace with the basic requirements of devices with lateral dimensions in the micron/ submicron range and depths of the order of nonometers. Often, newer analytical techniques have emerged or the more conventional techniques have been adapted to meet the more stringent requirements. As such, a variety of analytical techniques are available today to aid an analyst in the efforts of VLSI process evaluation. Generally such analytical efforts are divided into the characterization of materials, evaluation of processing steps and the analysis of failures.

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