From Local Adsorption Stresses to Chiral Surfaces:  (R,R)-Tartaric Acid on Ni(110)

2002 ◽  
Vol 124 (3) ◽  
pp. 503-510 ◽  
Author(s):  
Vincent Humblot ◽  
Sam Haq ◽  
Chris Muryn ◽  
Werner A. Hofer ◽  
Rasmita Raval
Keyword(s):  
Tartaric Acid ◽  
Chiral Surfaces

Creating Chiral Surfaces for Enantioselective Heterogeneous Catalysis: R,R-Tartaric Acid on Cu(110)

1999 ◽  
Vol 103 (48) ◽  
pp. 10661-10669 ◽  
Author(s):  
M. Ortega Lorenzo ◽  
S. Haq ◽  
T. Bertrams ◽  
P. Murray ◽  
R. Raval ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
Tartaric Acid ◽  
Chiral Surfaces

ANTIPHYTOPATHOGENIC EFFECT OF TARTARIC ACID SYNTHETIC DERIVATIVES

2020 ◽  
pp. 3-6
Author(s):  
B. G. Babayan ◽  
S. A. Bagdasaryan ◽  
M. A. Melkumyan ◽  
A. R. Mikaelyan
Keyword(s):  
Tartaric Acid ◽  
Synthetic Derivatives

Enzymatic Iodination of Maleic and Fumaric Acids Diethyl Esters

2009 ◽  
Vol 59 (12) ◽  
pp. 1400-1404
Author(s):  
Marius Tudorascu ◽  
Spiridon Oprea ◽  
Afrodita Doina Marculescu ◽  
Stefania Tudorascu
Keyword(s):  
Hydrogen Peroxide ◽  
Tartaric Acid ◽  
Disperse System ◽  
Hydrogen Peroxide Solution ◽  
Ultrasonic Pretreatment ◽  
Tartaric Acids ◽  
Inactive Form ◽  
Generating System ◽  
Sole Product

The mechanism of the enzymatic iodination process of diethylmaleate and diethylfumarate (which present no miscibility with water) in the presence of lactoperoxidase, both in diluted hydrogen peroxide solution and in a generating system of hydrogen peroxide using ammonium and calcium iodides as halide sources in disperse system (after an ultrasonic pretreatment) was studied. The obtained sole product (diethyl-2, 3-diiodosuccinate) after the enzymatic iodination process was directly hydrolyzed to a tartaric acid present in an optically inactive form. The mechanism of obtaining the intermediate and final products and respectively, the existence of both D, L-tartaric acid and meso-tartaric acids (as lithium bitartrates) were also investigated.

Synthesis and Kinetics of Highly Substituted Piperidines in the Presence of Tartaric Acid as a Catalyst

2018 ◽  
Vol 21 (4) ◽  
pp. 302-311
Author(s):  
Younes Ghalandarzehi ◽  
Mehdi Shahraki ◽  
Sayyed M. Habibi-Khorassani
Keyword(s):  
Ambient Temperature ◽  
Tartaric Acid ◽  
Aromatic Aldehydes ◽  
One Pot ◽  
Rate Determining Step ◽  
State Approximation ◽  
Solvent Free Conditions ◽  
Steady State Approximation ◽  
Absorbance Changes ◽  
The One

Aim & Scope: The synthesis of highly substituted piperidine from the one-pot reaction between aromatic aldehydes, anilines and β-ketoesters in the presence of tartaric acid as a catalyst has been investigated in both methanol and ethanol media at ambient temperature. Different conditions of temperature and solvent were employed for calculating the thermodynamic parameters and obtaining an experimental approach to the kinetics and mechanism. Experiments were carried out under different temperature and solvent conditions. Material and Methods: Products were characterized by comparison of physical data with authentic samples and spectroscopic data (IR and NMR). Rate constants are presented as an average of several kinetic runs (at least 6-10) and are reproducible within ± 3%. The overall rate of reaction is followed by monitoring the absorbance changes of the products versus time on a Varian (Model Cary Bio- 300) UV-vis spectrophotometer with a 10 mm light-path cell. Results: The best result was achieved in the presence of 0.075 g (0.1 M) of catalyst and 5 mL methanol at ambient temperature. When the reaction was carried out under solvent-free conditions, the product was obtained in a moderate yield (25%). Methanol was optimized as a desirable solvent in the synthesis of piperidine, nevertheless, ethanol in a kinetic investigation had none effect on the enhancement of the reaction rate than methanol. Based on the spectral data, the overall order of the reaction followed the second order kinetics. The results showed that the first step of the reaction mechanism is a rate determining step. Conclusion: The use of tartaric acid has many advantages such as mild reaction conditions, simple and readily available precursors and inexpensive catalyst. The proposed mechanism was confirmed by experimental results and a steady state approximation.

Influence of substrate on modified oscillation reactions of the Belousov-Zhabotinskii type

1983 ◽  
Vol 48 (11) ◽  
pp. 3223-3228 ◽  
Author(s):  
Peter Ševčík ◽  
Ľubica Adamčíková
Keyword(s):  
Oxalic Acid ◽  
Kinetic Parameters ◽  
Tartaric Acid ◽  
Bz Reaction ◽  
Oscillation Cycle ◽  
Influence Of Substrate

The kinetic parameters of the reaction steps of the oscillation cycle and the parameters of modified oscillation reactions of the Belousov-Zhabotinskii (BZ) type with oxalic acid, tartaric acid, and hypophosphite ions were compared with predictions of Edelson's analysis based on the mechanism of the classical BZ reaction.

A Short Enantioselective Synthesis of (S)-Levetiracetam Through Direct Pd-Catalyzed Asymmetric N-Allylation of Methyl 4-Aminobutyrate

Synlett ◽  
2021 ◽  
Author(s):  
Dominik Albat ◽  
Jörg-Martin Neudörfl ◽  
Hans-Günther Schmalz
Keyword(s):  
Antiepileptic Drug ◽  
Tartaric Acid ◽  
Enantioselective Synthesis

An exceedingly short and enantioselective synthesis of the antiepileptic drug (S)-levetiracetam was elaborated. As the chirogenic key step a Pd-catalyzed asymmetric N-allylation of methyl 4-aminobutyrate was achieved in the presence of only 1 mol% of a catalyst prepared in situ from [Pd(allyl)Cl]2 and the tartaric acid-derived C2-symmetric diphosphane ligand (S,S)-iPr-MediPhos).

Rare Earth and Tetra Hydroxymethyl Phosphonium Sulfate Combination Tanning

2012 ◽  
Vol 479-481 ◽  
pp. 430-433
Author(s):  
Ya Li ◽  
Shuang Xi Shao ◽  
Lan Jiang ◽  
Kai Qi Shi
Keyword(s):  
Rare Earth ◽  
Tartaric Acid ◽  
Alkaline Ph ◽  
Uv Spectrum ◽  
Shrinkage Temperature

A new chrome free tanning system of rare earth (RE)-THPS has been developed in this study. It has been proved by UV spectrum that THPS and RE (CeCl3) can coordinate under certain conditions. The influence of CeCl3and THPS’s ratio, pH and ligands on the shrinkage temperature (Ts) was studied. Higher Ts was obtained while the tannage was processed in the sequence of THPS followed by CeCl3. The alkaline pH should be controlled between 5.5 and 6.0 to give ideal tanning effect. It was also found that employing of 0.5% tartaric acid in this combination tanning system can give high Ts of 89°C.

Development of Tartaric Acid Derived Chiral Guanidines and Their Application to Catalytic Enantioselective α-Hydroxylation of β-Dicarbonyl Compounds

2013 ◽  
Vol 15 (12) ◽  
pp. 3106-3109 ◽  
Author(s):  
Liwei Zou ◽  
Baomin Wang ◽  
Hongfang Mu ◽  
Huanrui Zhang ◽  
Yuming Song ◽  
...  
Keyword(s):  
Tartaric Acid ◽  
Dicarbonyl Compounds
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