In Situ Measurement of the Enantiomeric Excess of Alcohols and Amines under Asymmetric Reduction Reaction by1H NMR

2010 ◽  
Vol 12 (14) ◽  
pp. 3238-3241 ◽  
Author(s):  
Xiaoxia Ye ◽  
Xinxiang Lei ◽  
Zhenfei Chen ◽  
Lixue Zhang ◽  
Anjiang Zhang
Keyword(s):  
Asymmetric Reduction ◽  
Enantiomeric Excess ◽  
Reduction Reaction ◽  
In Situ Measurement

Syntheses of 1,2-Amino Alcohols and Their Applications for Oxazaborolidine Catalyzed Enantioselective Reduction of Aromatic Ketones

2007 ◽  
Vol 60 (3) ◽  
pp. 196 ◽  
Author(s):  
Namdev S. Vatmurge ◽  
Braja G. Hazra ◽  
Vandana S. Pore
Keyword(s):  
Amino Alcohol ◽  
Good Yield ◽  
Asymmetric Reduction ◽  
Enantiomeric Excess ◽  
Amino Alcohols ◽  
Secondary Alcohols ◽  
Aromatic Ketones ◽  
Enantioselective Reduction ◽  
Aryl Ketones

Six new chiral 1,2-amino alcohol derivatives have been synthesized starting from (1R,2R)-2-amino-1-phenylpropane-1,3-diol. Asymmetric reduction of aryl ketones with in-situ generated oxazaborolidine from these amino alcohol derivatives and BH3·Me2S afforded secondary alcohols with good yield and moderate to high enantiomeric excess.

In Situ Measurement of Soil Heat Flux with the Gradient Method

2003 ◽  
Vol 2 (4) ◽  
pp. 589
Author(s):  
Douglas R. Cobos ◽  
John M. Baker
Keyword(s):  
Heat Flux ◽  
Gradient Method ◽  
Soil Heat Flux ◽  
In Situ Measurement

In-Situ Measurement Technique of Stress and Structure Change

2015 ◽  
Vol 84 (8) ◽  
pp. 567-572
Author(s):  
Tadafumi HASHIMOTO ◽  
Masahito MOCHIZUKI
Keyword(s):  
Measurement Technique ◽  
Structure Change ◽  
In Situ Measurement

In-situ stabilization of silver nanoparticles in polymer hydrogels for enhanced catalytic reduction of macro and micro pollutants

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Luqman Ali Shah ◽  
Rida Javed ◽  
Mohammad Siddiq ◽  
Iram BiBi ◽  
Ishrat Jamil ◽  
...  
Keyword(s):  
Catalytic Reduction ◽  
Thermo Gravimetric Analysis ◽  
Activation Parameters ◽  
Reduction Reaction ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
In Situ Stabilization ◽  
Hybrid Hydrogels ◽  
Kinetics Of

AbstractThe in-situ stabilization of Ag nanoparticles is carried out by the use of reducing agent and synthesized three different types of hydrogen (anionic, cationic, and neutral) template. The morphology, constitution and thermal stability of the synthesized pure and Ag-entrapped hybrid hydrogels were efficiently confirmed using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermo gravimetric analysis (TGA). The prepared hybrid hydrogels were used in the decolorization of methylene blue (MB) and azo dyes congo red (CR), methyl Orange (MO), and reduction of 4-nitrophenol (4-NP) and nitrobenzene (NB) by an electron donor NaBH4. The kinetics of the reduction reaction was also assessed to determine the activation parameters. The hybrid hydrogen catalysts were recovered by filtration and used continuously up to six times with 98% conversion of pollutants without substantial loss in catalytic activity. It was observed that these types of hydrogel systems can be used for the conversion of pollutants from waste water into useful products.

scholarly journals Electrokinetic and in situ spectroscopic investigations of CO electrochemical reduction on copper

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jing Li ◽  
Xiaoxia Chang ◽  
Haochen Zhang ◽  
Arnav S. Malkani ◽  
Mu-jeng Cheng ◽  
...  
Keyword(s):  
Mass Transport ◽  
Active Sites ◽  
Gas Diffusion ◽  
Reduction Reaction ◽  
Adsorbed Hydrogen ◽  
Diffusion Type ◽  
Proton Coupled Electron Transfer ◽  
Alkaline Electrolytes ◽  
Reaction Orders

AbstractRigorous electrokinetic results are key to understanding the reaction mechanisms in the electrochemical CO reduction reaction (CORR), however, most reported results are compromised by the CO mass transport limitation. In this work, we determined mass transport-free CORR kinetics by employing a gas-diffusion type electrode and identified dependence of catalyst surface speciation on the electrolyte pH using in-situ surface enhanced vibrational spectroscopies. Based on the measured Tafel slopes and reaction orders, we demonstrate that the formation rates of C2+ products are most likely limited by the dimerization of CO adsorbate. CH4 production is limited by the CO hydrogenation step via a proton coupled electron transfer and a chemical hydrogenation step of CO by adsorbed hydrogen atom in weakly (7 < pH < 11) and strongly (pH > 11) alkaline electrolytes, respectively. Further, CH4 and C2+ products are likely formed on distinct types of active sites.

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