Li+-induced selective gelation of discrete homochiral structural isomers derived from l-tartaric acid

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.

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

Combinatorial Chemistry & High Throughput Screening ◽

10.2174/1386207321666180228115130 ◽

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.

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

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19833223 ◽

1983 ◽

Vol 48 (11) ◽

pp. 3223-3228 ◽

Cited By ~ 2

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.

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

Synlett ◽

10.1055/a-1493-9078 ◽

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).

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Rare Earth and Tetra Hydroxymethyl Phosphonium Sulfate Combination Tanning

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.479-481.430 ◽

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.

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Multitasking tartaric-acid-enabled, highly conductive, and stable MXene/conducting polymer composite for ultrafast supercapacitor

Cell Reports Physical Science ◽

10.1016/j.xcrp.2021.100449 ◽

2021 ◽

pp. 100449

Author(s):

Miao Zhang ◽

Frédéric Héraly ◽

Ming Yi ◽

Jiayin Yuan

Keyword(s):

Tartaric Acid ◽

Conducting Polymer ◽

Polymer Composite

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Data-Independent Acquisition for the Quantification and Identification of Metabolites in Plasma

Metabolites ◽

10.3390/metabo10120514 ◽

2020 ◽

Vol 10 (12) ◽

pp. 514

Author(s):

Tom van der Laan ◽

Isabelle Boom ◽

Joshua Maliepaard ◽

Anne-Charlotte Dubbelman ◽

Amy C. Harms ◽

...

Keyword(s):

Mass Spectra ◽

Mass Range ◽

Correct Identification ◽

Hydrophilic Interaction ◽

Specific Mass ◽

Structural Isomers ◽

Data Independent Acquisition ◽

Targeted Analysis ◽

Theoretical Mass ◽

Accurate Quantification

A popular fragmentation technique for non-targeted analysis is called data-independent acquisition (DIA), because it provides fragmentation data for all analytes in a specific mass range. In this work, we demonstrated the strengths and weaknesses of DIA. Two types of chromatography (fractionation/3 min and hydrophilic interaction liquid chromatography (HILIC)/18 min) and three DIA protocols (variable sequential window acquisition of all theoretical mass spectra (SWATH), fixed SWATH and MSALL) were used to evaluate the performance of DIA. Our results show that fast chromatography and MSALL often results in product ion overlap and complex MS/MS spectra, which reduces the quantitative and qualitative power of these DIA protocols. The combination of SWATH and HILIC allowed for the correct identification of 20 metabolites using the NIST library. After SWATH window customization (i.e., variable SWATH), we were able to quantify ten structural isomers with a mean accuracy of 103% (91–113%). The robustness of the variable SWATH and HILIC method was demonstrated by the accurate quantification of these structural isomers in 10 highly diverse blood samples. Since the combination of variable SWATH and HILIC results in good quantitative and qualitative fragmentation data, it is promising for both targeted and untargeted platforms. This should decrease the number of platforms needed in metabolomics and increase the value of a single analysis.

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Discrimination of structural isomers of amphetamine using carbon dioxide negative-ion chemical ionization mass spectrometry

Spectroscopy An International Journal ◽

10.1155/1997/521216 ◽

1997 ◽

Vol 13 (2) ◽

pp. 151-161 ◽

Cited By ~ 1

Author(s):

Kevin B. Thurbide ◽

C. M. Elson ◽

P. G. Sim

Keyword(s):

Carbon Dioxide ◽

Mass Spectra ◽

Chemical Ionization ◽

Negative Ion ◽

Ionization Mass ◽

Structural Isomers ◽

Mass Spectral ◽

Negative Ion Chemical Ionization ◽

Spectral Behaviour ◽

Carbon Dioxide Plasma

The negative‒ion chemical ionization mass spectra of a group of structural isomers of amphetamine have been studied using carbon dioxide as the reagent gas. Characteristic and reproducible differences are observed for each member of the set implying that this technique offers a means of distinguishing among groups of amphetamine isomers. Characteristic adducts to the molecular ion are observed in the form (M–[H]+[O]) and (M–[H]+[CO2]). Descriptions of some fragments are given based on the mass spectral behaviour of a set of analogue compounds and the results of oxygen-18 labelled carbon dioxide reagent gas experiments. Contents of the carbon dioxide plasma and their impact on various analytes is also discussed.

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