An easy approach to dihydrochalcones via chalcone in situ hydrogenation

2016 ◽  
Vol 88 (4) ◽  
pp. 349-361 ◽  
Author(s):  
Ana R. Jesus ◽  
Ana P. Marques ◽  
Amélia P. Rauter
Keyword(s):  
Room Temperature ◽  
Aromatic Aldehydes ◽  
Iron Chloride ◽  
High Yield ◽  
Microwave Assisted ◽  
Olefinic Double Bond ◽  
Single Reaction Product ◽  
Very High ◽  
Single Reaction

AbstractDihydrochalcones are polyphenols that exhibit a diversity of bioactivities, namely anti-inflammatory, antimicrobial and antiviral. We have explored the synthetic access to such molecular entities, and describe now an easy and scalable approach based on reduction of the olefinic double bond of chalcone precursors via in situ hydrogenation with the system Et3SiH-Pd/C in very high yield. The intermediate chalcones were synthesized also by a simple and efficient microwave-assisted Claisen–Schmidt condensation of aromatic aldehydes with acetophenones, conveniently protected with ethoxymethyl ether, if required. Chalcones were obtained as single reaction product in high yield in 2–3 h, while under conventional conditions at room temperature the reaction was carried out with completion only after 24 h. In addition, microwave irradiation has proven very efficient for deprotection of ethoxymethyl ether with iron chloride in only 10 min and very high yield.

Reductions with sulfurated borohydrides. V. Reductions of ketones

1970 ◽  
Vol 48 (15) ◽  
pp. 2366-2371 ◽  
Author(s):  
J. M. Lalancette ◽  
A. Freche
Keyword(s):  
High Temperature ◽  
Carbonyl Group ◽  
Sodium Borohydride ◽  
Room Temperature ◽  
High Yield ◽  
High Yields ◽  
Very High

Ketones can be reduced with sulfurated sodium borohydride. Very high yield (≈90%) of the corresponding alcohol is obtained with the appropriate ratio of ketone and hydride at room temperature. The reaction is much influenced by the steric environment around the carbonyl group. At high temperature (65°) disulfides and tetrasulfides are produced. In some cases the structure of those sulfides have been established. Conjugated ketones can be reduced to the corresponding alcohols with very high yields.

Controllable Synthesis of Functional Polyaniline Nanotubes via a Complex Template

2015 ◽  
Vol 1120-1121 ◽  
pp. 220-224
Author(s):  
Ying Wang ◽  
Dong Hao Sun ◽  
Yan Feng Guo
Keyword(s):  
Electric Conductivity ◽  
Room Temperature ◽  
In Situ Polymerization ◽  
High Yield ◽  
Controllable Synthesis ◽  
Order Of Magnitude ◽  
Uv Visible ◽  
Acid Orange Ii ◽  
High Electric Conductivity

Functional Polyaniline (PANI) nanotubes are easily synthesized in high yield by an in situ polymerization using a fibrillar complex of acid orange II (AO II) and FeCl3as a template. During the process, the complex templates help direct the growth of fibrillar PANI on their surfaces, resulting in the formation of composite micro/nanofibers of PANI. After polymerization, by the post-treatment of removing templates in 1.0 M hydrochloric acid solution, PANI nanotubes with azo function and high electric conductivity of PANI are readily fabricated. The PANI nanotubes have about 150nm-300nm in diameter and several microns in length. At room temperature, the electric conductivity of PANI nanotubes is up to 10-1S/cm order of magnitude. The characterizations, including FTIR, UV-visible, XRD and TG, are presented.

scholarly journals One-Pot Synthesis of (Z)-β-Halovinyl Ketones via the Cascade of Sonogashira Coupling and Hydrohalogenation

2021 ◽  
Vol 8 ◽  
Author(s):  
Fa-Jie Chen ◽  
Zhenguo Hua ◽  
Jianhui Chen ◽  
Jiajia Chen ◽  
Daesung Lee ◽  
...  
Keyword(s):  
Efficient Method ◽  
Room Temperature ◽  
Copper Catalyst ◽  
High Yield ◽  
Sonogashira Coupling ◽  
Terminal Alkynes ◽  
Acid Chlorides ◽  
Triflic Acid ◽  
One Pot

Herein, we report an efficient method for the synthesis of (Z)-β-halovinyl ketones through a one-pot Sonogashira coupling and hydrohalogenation reaction promoted by palladium-copper catalyst and Brønsted acid. The ynone intermediates are generated in situ from readily available acid chlorides and terminal alkynes at room temperature, which are directly converted to (Z)-β-halovinyl ketones by treating with triflic acid. This method avoids the use of an external halogen source and features broad substrate scope, high yield, and good to excellent stereoselectivity.

TEM Studies of Shear Bands in a Bulk Metallic Glass Based Composite

2001 ◽  
Vol 7 (S2) ◽  
pp. 1120-1121
Author(s):  
E. Pekarskaya ◽  
C.P. Kim ◽  
W.L. Johnson
Keyword(s):  
Metallic Glasses ◽  
Shear Bands ◽  
High Yield ◽  
In Situ Tem ◽  
Two Phase ◽  
University Of Illinois ◽  
Glass Forming ◽  
The University ◽  
Very High

In 1980’s the discovery of multicomponent systems with exceptional glass forming ability enabled the synthesis of metallic glasses at relatively low cooling rates, 10−1 — 102 K/s and at a larger thicknesses. Bulk metallic glasses normally have very high yield stress, σy = 0.02 · Y (Y is Young’s modulus), high elastic limit of about 2%, but fail with very little global plasticity, typically along a localized shear band at a 45 degree angle with respect to the applied stress.The material studied in the present work is a two-phase Zr56.3Ti13.8Cu6.9Ni5.6Nb5.0Be12.5 alloy,prepared by in-situ processing. The alloy consists of amorphous and crystalline phases. In-situ TEM straining (tensile) experiments were performed at room temperature in JEOL 4000EX operating at 300kV. The experiments were carried out in the Center for Microanalysis of Materials in the University of Illinois at Urbana-Champaign. The goal of the study was to understand the deformation mechanisms of such composite material.

scholarly journals (C7H6NS)2[Nb6Cl18]·2C4H8O: first niobium cluster with an N,S-heterocyclic cation

IUCrData ◽  
2018 ◽  
Vol 3 (12) ◽  
Author(s):  
Eric Sperlich ◽  
Martin Köckerling
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Room Temperature ◽  
High Yield ◽  
Cluster Compound ◽  
One Pot ◽  
Cluster Precursor ◽  
Acidic Proton ◽  
Very High

The title compound bis(benzothiazolium) dodeca-μ-chlorido-hexachlorido-octahedro-hexaniobium(12 Nb—Nb) tetrahydrofuran disolvate, (C7H6NS)2[Nb6Cl18]·2C4H8O or (HBTh)2[Nb6Cl18]·2THF, is the first known niobium cluster compound to contain an N,S-heterocyclic cation. The synthesis takes place within a few hours as an one-pot reaction at room temperature of the cluster precursor compound [Nb6Cl14(H2O)4]·4H2O with SOCl2 in the presence of BTh (benzothiazole) in very high yield. The stabilization of the acidic proton of the cation is achieved by the use of tetrahydrofuran as a co-solvent and by the formation of hydrogen bonds.

Morpholinium hydrogen sulfate (MHS) ionic liquid as an efficient catalyst for the synthesis of bio-active multi-substituted imidazoles (MSI) under solvent-free conditions

2017 ◽  
Vol 72 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Adel A. Marzouk ◽  
Antar A. Abdelhamid ◽  
Shaaban K. Mohamed ◽  
Jim Simpson
Keyword(s):  
Ionic Liquid ◽  
Reaction Times ◽  
Aromatic Aldehydes ◽  
Solvent Free ◽  
Biologically Active ◽  
High Yield ◽  
Hydrogen Sulfate ◽  
Efficient Catalyst ◽  
Solvent Free Conditions ◽  
Very High

AbstractMorpholinium hydrogen sulfate as an ionic liquid was employed as a catalyst for the synthesis of a biologically active series of multi-substituted imidazoles by a four-component reaction involving the combination of benzil with different aromatic aldehydes, ammonium acetate, and 1-amino-2-propanol under solvent-free conditions. The key advantages of this method are shorter reaction times, very high yield, and ease of processing. Furthermore, the resulting products can be purified by a non-chromatographic method and the ionic liquid catalyst is reusable. All of these novel compounds have been fully characterized from spectral data. The X-ray crystal structures of two representative molecules are also detailed.

scholarly journals Nanostructuring of Nb-Si-Cr Alloys by Electron Beam Melting to Improve the Mechanical Properties and the Oxidation Behavior

2021 ◽  
Author(s):  
A. Förner ◽  
J. Vollhüter ◽  
D. Hausmann ◽  
C. Arnold ◽  
P. Felfer ◽  
...  
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Electron Beam Melting ◽  
Room Temperature ◽  
Single Layer ◽  
Atom Probe ◽  
Cooling Rates ◽  
High Cooling Rates ◽  
Very High

AbstractMaterials processed by additive manufacturing often exhibit a very fine-scaled microstructures due to high cooling rates in the process. In this study, single-layer surface electron beam melting is used to create very high cooling rates similar to additive manufacturing processes to investigate the resulting microstructure. In the case of Nb-Si-Cr in-situ composites, a nano-scaled eutectic microstructure is beneficial for improving the mechanical and oxidational properties. Fast solidification results in the formation of supersaturated phases of Nbss and Cr2Nb with phase diameters down to 10 nm as well as in the stabilization of the metastable Nb9(Cr,Si)5 phase at room temperature. After processing with different solidification rates, the decomposition of the Nb9(Cr,Si)5 phase has been studied in detail with atom probe microscopy. The stabilization of mixed silicide phases by electron beam melting shows a new pathway for improving hardness and enhancing oxidation resistance of nanostructured eutectic in-situ composites, by which the inherent weaknesses of Nb-Si-Cr can be overcome without further alloying elements. Graphical Abstract

scholarly journals Microwave-Assisted Synthesis of Some New Mixed Ligand Ni(II) Complexes Its Characterization and Its Antimicrobial Study

2021 ◽  
pp. 143-152
Author(s):  
Jitendra M. Pawara ◽  
Sunil S. Patil
Keyword(s):  
Thermal Analysis ◽  
Conventional Method ◽  
Mixed Ligand ◽  
High Yield ◽  
Microwave Assisted Synthesis ◽  
Microwave Method ◽  
Preparation Time ◽  
Microwave Assisted ◽  
Microwave Assisted Method ◽  
Very High

Nickel(II) complexes of the type [Ni(P)(L).2H2O] has been synthesized by using 2-amino-6-methyl pyrimidine-4-ol (HP) and amino acids (HL). Complexes synthesized by conventional as well as microwave methods. Results indicate that complexes synthesized by the microwave method are more efficient than the conventional method. In the microwave method preparation time is short (4-7 min.) compared to the conventional method (45 min.). Moreover, the microwave Assisted method gives a very high yield (90%) of the complexes. The microwave method used for the synthesis of the complexes has been found easier, convenient and eco-friendly. Complexes have been characterized by FTIR, Elemental analysis, Gouy experiment, Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA). Complexes have shown significant antimicrobial activity.

Asymmetric Direct Aldol Reaction Catalyzed by (1R, 2R)-(+)-1, 2- Diammonium Cyclohexane-L-tartrate in Water

2019 ◽  
Vol 6 (2) ◽  
pp. 165-170
Author(s):  
Anirban Mondal ◽  
Kartick Chandra Bhowmick
Keyword(s):  
Large Volume ◽  
Room Temperature ◽  
Aldol Reaction ◽  
Aromatic Aldehydes ◽  
High Yield ◽  
Direct Aldol Reaction ◽  
Reaction In Water

Background: A cheap and commercially available organocatalyst, (1R, 2R)-(+)-1, 2- diammonium cyclohexane-L-tartrate 1 was applied in direct aldol reaction in water. The organocatalyst 1 afforded aldol products from cyclohexanone and substituted aromatic aldehydes with high yield (up to 90%) and good stereoselectivity (up to 99% ee and up to 11.5:1 dr) in large volume of water (10 ml). Methods: The same aldol reaction when carried out in the presence of more expensive organocatalyst e.g. (1R, 2R)-(+)-1,2-diaminocyclohexane and 1,6-hexanediaoic acid as acid additive furnished the aldol products with only 20% yield, 2:1 anti/syn ratio and 92% ee. Results and Conclusion: In summary, we have applied a reasonably cheap and commercially available organocatalyst 1 for highly enantioselective direct aldol reaction in water at room temperature.

scholarly journals Synthesis of New 1,3,5-Triazine-Based 2-Pyrazolines as Potential Anticancer Agents

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1956 ◽  
Author(s):  
Leydi Moreno ◽  
Jairo Quiroga ◽  
Rodrigo Abonia ◽  
Jonathan Ramírez-Prada ◽  
Braulio Insuasty
Keyword(s):  
Anticancer Agents ◽  
Human Tumor ◽  
Aromatic Aldehydes ◽  
High Yield ◽  
Tumor Cell Lines ◽  
Human Tumor Cell ◽  
Human Tumor Cell Lines ◽  
Microwave Assisted ◽  
The Us ◽  
Cyclocondensation Reactions

A new series of 1,3,5-triazine-containing 2-pyrazoline derivatives (8–11)a–g was synthesized by cyclocondensation reactions of [(4,6-bis((2-hydroxyethyl)amino)-1,3,5-triazin-2-yl)amine]chalcones 7a–g with hydrazine hydrate and derivatives. Chalcones 7a–g were obtained by Claisen-Schmidt condensation between aromatic aldehydes and triazinic derivative 5, which was synthesized in high yield by a microwave-assisted reaction. Seventeen of the synthesized compounds were selected and tested by the US National Cancer Institute (NCI) for their anticancer activity against 58 different human tumor cell lines. Compounds 7g and 10d,e,g showed important GI50 values ranging from 0.569 to 16.6 µM and LC50 values ranging from 5.15 to >100 µM.

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