scholarly journals Air and Moisture Tolerant Synthesis of a Chelated bis(NHC) Methylpalladium(II) Complex Relevant to Alkyl Migration Processes in Catalysis

2020 ◽  
Vol 73 (12) ◽  
pp. 1158
Author(s):  
Michael G. Gardiner ◽  
Curtis C. Ho ◽  
David S. McGuinness ◽  
Yi Ling Liu
Keyword(s):  
Room Temperature ◽  
Catalyst Deactivation ◽  
New Method ◽  
High Yield ◽  
Synthetic Pathway ◽  
Rapid Decomposition ◽  
Carbene Transfer ◽  
Unstable Intermediate ◽  
Catalyst Lifetime

An air- and moisture-tolerant alternate synthetic pathway to the preparation of a cationic chelated bis(NHC) methylpalladium(ii) complex, [{(MesIm)2CH2}Pd(Me)(NCMe)][PF6], is described. The pathway involves the isolation of a bis(NHC) AgI complex, [{(MesIm)2CH2}2Ag2][PF6]2, via metallation of the corresponding diimidazolium salt with Ag2O followed by carbene transfer to [(COD)PdBrMe]. This new method avoids a previously reported unstable intermediate that displayed rapid decomposition at room temperature, attaining the targeted cationic methylpalladium(ii) complex in high yield. CO/ethylene copolymerisation catalysis trials are reported showing solvent dependent catalyst lifetime and copolymer yields. Preliminary ethylene insertion studies are also outlined revealing possible pathways leading towards catalyst deactivation.

Phosphomolybdic Acid (PMA)-catalyzed One-pot Synthesis of 2,3- Dihydroquinazolines

2019 ◽  
Vol 16 (8) ◽  
pp. 683-687
Author(s):  
Chuanhuan Chen ◽  
A. Xuejiao ◽  
Xia Li ◽  
Guoli Huang ◽  
Bo Liu
Keyword(s):  
Reaction Time ◽  
Present Method ◽  
Room Temperature ◽  
Phosphomolybdic Acid ◽  
New Method ◽  
High Yield ◽  
One Pot ◽  
Short Reaction Time ◽  
One Pot Synthesis

We have developed a new method for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones in good to excellent yields via phosphomolybdic acid (PMA)-catalyzed cyclocondensation of 2- aminobenzamides with aldehydes or ketones in N,N-dimethylformamide (DMF) at room temperature. The present method proves to be efficient in terms of short reaction time, high yield, simple workup and easy purification.

scholarly journals ZnO/RGO Heterojunction Based near Room Temperature Alcohol SENSOR with Improved Efficiency

2021 ◽  
Vol 6 (1) ◽  
pp. 25
Author(s):  
Sanghamitra Ghosal ◽  
Partha Bhattacharyya
Keyword(s):  
Active Sites ◽  
Room Temperature ◽  
Surface Engineering ◽  
Gas Sensing ◽  
Energy Band Diagram ◽  
Future Generation ◽  
High Yield ◽  
Synthesis Process ◽  
Ethanol Sensor ◽  
Vapor Sensing

The systematic optimization of surface engineering (dimensionality) indeed plays a crucial role in achieving efficient vapor-sensing performance. Among various semiconducting metal oxides, owing to some of its unique features and advantages, ZnO has attracted researchers on a global scale due to its application in various fields, including chemical sensors. The concomitant optimization of the surface attributes (varying different dimensions) of ZnO have become a sensation for the entire research community. Moreover, the small thickness and extremely large surface of exfoliated 2D nanosheets render the gas sensing material an ideal candidate for achieving strong coupling with different gas molecules. However, temperature is a crucial factor in the field of chemical sensing. Recently, graphene-based gas sensors have attracted attention due to their variety of structures, unique sensing performances and room temperature working conditions. In this work, a highly sensitive and fast responsive low temperature (60 °C)-based ethanol sensor, based on RGO/2D ZnO nanosheets hybrid structure, is reported. After detailed characterizations, the vapor sensing potentiality of this sensor was tested for the detection of ethanol. The ethanol sensor offered the response magnitude of 89% (100 ppm concentration) with response and recovery time of 12 s/29 s, respectively. Due to excessively high number of active sites for VOC interaction, with high yield synthesis process and appreciably high carrier mobility, this has paved the way for developing future generation, miniaturized and flexible (wearable) vapor sensor devices, meeting the multidimensional requirements for traditional and upcoming (health/medical sector) applications. The underlying mechanistic framework for vapor sensing, using this hybrid junction, is explained with the Energy Band Diagram.

Cholinium-amino acid based ionic liquids: a new method of synthesis and physico-chemical characterization

2015 ◽  
Vol 17 (32) ◽  
pp. 20687-20698 ◽  
Author(s):  
Serena De Santis ◽  
Giancarlo Masci ◽  
Francesco Casciotta ◽  
Ruggero Caminiti ◽  
Eleonora Scarpellini ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Amino Acid ◽  
Room Temperature ◽  
Chemical Characterization ◽  
New Method ◽  
Room Temperature Ionic Liquids ◽  
Synthetic Method ◽  
Chemical Structures ◽  
Physico Chemical ◽  
Wide Range

Fourteen cholinium-amino acid based room temperature ionic liquids were prepared using a cleaner synthetic method. Chemicophysical properties were well correlated with the wide range of amino acid chemical structures.

Solvent effect on simple and high yield synthesis of polydichlorophosphazene precursor Cl3PNSiMe3

2021 ◽  
Author(s):  
Elif Büşra Çelebi ◽  
Ferda Hacıvelioğlu
Keyword(s):  
Solvent Effect ◽  
Room Temperature ◽  
Solvent Polarity ◽  
High Yield ◽  
Effect Of Solvent ◽  
Nonpolar Solvents

The effect of solvent polarity on the reaction of PCl5 with (Me3Si)2NH has been investigated and it is found that nonpolar solvents promote the formation of Cl3PNSiMe3, whereas the more polar chloroform gives unusual phosphazenes at room temperature.

A Novel and Efficient Alkoxylselenenylation of Alkenes

2019 ◽  
Vol 41 (6) ◽  
pp. 1039-1039
Author(s):  
Yingguo Fang and Jie Yan Yingguo Fang and Jie Yan
Keyword(s):  
Room Temperature ◽  
Electrophilic Addition ◽  
New Method ◽  
Reaction Conditions ◽  
Selenium Species

A novel and efficient alkoxylselenenylation from alkenes, diselenides, and alcohols mediated by iodine is developed, with which a series of β-alkoxy selenides are synthesized. In this procedure, firstly, I2 reacts with diselenide to form in situ the active electrophilic selenium species RSeI, then following an electrophilic addition of it to alkenes provides β-alkoxy selenides with high regioselectivity and in good yields. This new method for achieving β-alkoxy selenides has some advantages over other methods such as using available and cheap iodine as the oxidizing species at room temperature, which makes this reaction has milder reaction conditions and simpler procedure.

scholarly journals New Method for Nucleophilic Substitution on Hexachlorocyclotriphosphazene by Allylamine Using an Algerian Proton Exchanged Montmorillonite Clay (Maghnite-H+) as a Green Solid Catalyst

2016 ◽  
Vol 11 (2) ◽  
pp. 151 ◽  
Author(s):  
Lahouaria Medjdoub ◽  
Belbachir Mohammed
Keyword(s):  
Nucleophilic Substitution ◽  
Room Temperature ◽  
Montmorillonite Clay ◽  
New Method ◽  
Solid Catalyst ◽  
H Nmr ◽  
Flight Mass Spectrometry ◽  
Crystalline Product ◽  
First Time ◽  
C Nmr

<p>Nucleophilic substitution on hexachlorocyclotriphosphazene (HCCTP) with allylamine in order to give hexa(allylamino)cyclotriphosphazene (HACTP)  is performed for the first time under mild conditions by using diethylether as solvent to replace benzene which is very toxic. The reaction time is reduced to half and also performed at room temperature but especially in the presence of an eco-catalyst called Maghnite-H<sup>+</sup>. This catalyst has a significant role in the industrial scale. In fact, the use of Maghnite is preferred for its many advantages: a very low purchase price compared to other catalysts, the easy removal of the reaction mixture. Then, Maghnite-H<sup>+</sup> is became an excellent catalyst for many chemical reactions. The structure of HACTP synthesized in the presence of Maghnite-H<sup>+</sup> to 5% by weight is confirmed by <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, <sup>31</sup>P-NMR (Nuclear magnetic resonance) and FTIR (Fourier Transform Infrared spectroscopy). MALDI-TOF (Matrix-Assisted Laser Desorption/Ionisation-time-of-flight mass spectrometry) is used to establish the molecular weight of HACTP which is 471 g/mol. DSC (Differential Scanning Calorimetery) and TGA (Thermogravimetric Analysis) show that HACTP is a crystalline product with a melting point of 88 °C. It is reactive after melting but is degraded from 230 °C. Copyright © 2016 BCREC GROUP. All rights reserved</p><p><em>Received: 28<sup>th</sup> September 2015; Revised: 5<sup>th</sup> December 2015; Accepted: 4<sup>th</sup> January 2016</em></p><p><strong>How to Cite</strong>: Medjdoub, L., Mohammed, B. (2016). New Method for Nucleophilic Substitution on Hexachlorocyclotriphosphazene by Allylamine Using an Algerian Proton Exchanged Montmorillonite Clay (Maghnite-H+) as a Green Solid Catalyst. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 11 (2): 151-160 (doi:10.9767/bcrec.11.2.541.151-160)</p><p><strong>Permalink/DOI:</strong> http://dx.doi.org/10.9767/bcrec.11.2.541.151-160</p>

An efficient multicomponent, one-pot synthesis of Betti bases catalyzed by cerium (IV) ammonium nitrate (CAN) at ambient temperature

2016 ◽  
Vol 5 (4) ◽  
Author(s):  
Ramadan Ahmed Mekheimer ◽  
Abdullah Mohamed Asiri ◽  
Afaf Mohamed Abdel Hameed ◽  
Reham R. Awed ◽  
Kamal Usef Sadek
Keyword(s):  
Ambient Temperature ◽  
Environmental Pollution ◽  
Ammonium Nitrate ◽  
Room Temperature ◽  
Catalytic Amount ◽  
High Yield ◽  
Reaction Conditions ◽  
One Pot ◽  
Work Up ◽  
Cerium Iv Ammonium Nitrate

AbstractStarting from readily available 2-naphthol, aldehydes, aryl and alkylamines, a variety of Betti bases were efficiently synthesized utilizing a catalytic amount of cerium (IV) ammonium nitrate (CAN) at room temperature. This protocol has advantages of high yield, mild reaction conditions, no environmental pollution, diversity of reactants and simple work up procedure.

One-pot synthesis of chitosan–dehydropregnenolone acetate ketimine nanoparticles and their antifungal bioevaluation

RSC Advances ◽  
2015 ◽  
Vol 5 (13) ◽  
pp. 10065-10071 ◽  
Author(s):  
Archana M. Das ◽  
Raju Khan ◽  
Manash P. Hazarika ◽  
Debjani Baruah ◽  
Purnajyoti D. Bhuyan
Keyword(s):  
Room Temperature ◽  
Polymeric Nanoparticles ◽  
Communicable Diseases ◽  
New Method ◽  
One Pot ◽  
One Pot Synthesis ◽  
Dehydropregnenolone Acetate

This paper presents a new method for fabricating biodegradable bio-polymeric nanoparticles via a convenient one-pot strategy at room temperature under stirring conditions for application to communicable diseases.

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