Сan Plasmon Change Reaction Path? An Unprecedented Regioselective Decomposition of Unsymmetrical Iodonium Salts

2020 ◽  
Author(s):  
Elena Miliutina ◽  
Olga Guselnikova ◽  
Natalia Soldatova ◽  
Polina Bainova ◽  
Roman Elashnikov ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Room Temperature ◽  
Reaction Path ◽  
Comprehensive Investigation ◽  
Radical Species ◽  
Chemical Modeling ◽  
Iodonium Salts ◽  
Direct Excitation ◽  
Selective Surface Modification ◽  
Plasmon Interaction

<p>Plasmon-assisted transformations of organic compounds represent a novel opportunity for conversion of light to chemical energy at room temperature. Herein, we propose a comprehensive investigation of plasmon-triggered decomposition of iodonium salts containing various substituents (ISs). We found that plasmon interaction with unsymmetrical ISs led to the intramolecular excitation of electron followed by the regioselective cleavage of C–I bond with the formation of electron-rich radical species. Such unprecedented C–I cleavage brings the possibility of selective surface modification using ISs. The high regioselectivity is explained by the direct excitation of electron to LUMO with the formation of dissociative excited state ac-cording to quantum-chemical modeling.</p>

Сan Plasmon Change Reaction Path? An Unprecedented Regioselective Decomposition of Unsymmetrical Iodonium Salts

2020 ◽  
Author(s):  
Elena Miliutina ◽  
Olga Guselnikova ◽  
Natalia Soldatova ◽  
Polina Bainova ◽  
Roman Elashnikov ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Room Temperature ◽  
Reaction Path ◽  
Comprehensive Investigation ◽  
Radical Species ◽  
Chemical Modeling ◽  
Iodonium Salts ◽  
Direct Excitation ◽  
Selective Surface Modification ◽  
Plasmon Interaction

<p>Plasmon-assisted transformations of organic compounds represent a novel opportunity for conversion of light to chemical energy at room temperature. Herein, we propose a comprehensive investigation of plasmon-triggered decomposition of iodonium salts containing various substituents (ISs). We found that plasmon interaction with unsymmetrical ISs led to the intramolecular excitation of electron followed by the regioselective cleavage of C–I bond with the formation of electron-rich radical species. Such unprecedented C–I cleavage brings the possibility of selective surface modification using ISs. The high regioselectivity is explained by the direct excitation of electron to LUMO with the formation of dissociative excited state ac-cording to quantum-chemical modeling.</p>

scholarly journals Quantum chemical modeling of the reaction path of chorismate mutase based on the experimental substrate/product complex

FEBS Open Bio ◽  
2017 ◽  
Vol 7 (6) ◽  
pp. 789-797 ◽  
Author(s):  
Daniel Burschowsky ◽  
Ute Krengel ◽  
Einar Uggerud ◽  
David Balcells
Keyword(s):  
Quantum Chemical ◽  
Reaction Path ◽  
Chorismate Mutase ◽  
Quantum Chemical Modeling ◽  
Chemical Modeling

Kinetics of the Thermal Disappearance of Radicals Formed During the Radiolysis of Aspartic Acid

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Mihai Contineanu ◽  
iulia Contineanu ◽  
Ana Neacsu ◽  
Stefan Perisanu
Keyword(s):  
Thermal Resistance ◽  
Aspartic Acid ◽  
Room Temperature ◽  
Esr Spectra ◽  
Complex Mechanism ◽  
Radical Species ◽  
Mechanisms Of Formation ◽  
Kinetics Of

The radiolysis of the isomers L-, D- and DL- of the aspartic acid, in solid polycrystalline state, was investigated at room temperature. The analysis of their ESR spectra indicated the formation of at least two radicalic entities. The radical, identified as R3, resulting from the deamination of the acid, exhibits the highest concentration and thermal resistance. Possible mechanisms of formation of three radical species are suggested, based also on literature data. The kinetics of the disappearance of radical R3 indicated a complex mechanism. Three possible variants were suggested for this mechanism.

A Study on the Rearrangement of Dialkyl 1-Aryl-1-hydroxymethylphosphonates to Benzyl Phosphates

2020 ◽  
Vol 24 (4) ◽  
pp. 465-471 ◽  
Author(s):  
Zita Rádai ◽  
Réka Szabó ◽  
Áron Szigetvári ◽  
Nóra Zsuzsa Kiss ◽  
Zoltán Mucsi ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Room Temperature ◽  
Phase Transfer ◽  
One Pot ◽  
Substrate Dependence ◽  
Triethylbenzylammonium Chloride ◽  
One Step ◽  
The Pudovik Reaction ◽  
The One ◽  
Solid Liquid

The phospha-Brook rearrangement of dialkyl 1-aryl-1-hydroxymethylphosphonates (HPs) to the corresponding benzyl phosphates (BPs) has been elaborated under solid-liquid phase transfer catalytic conditions. The best procedure involved the use of triethylbenzylammonium chloride as the catalyst and Cs2CO3 as the base in acetonitrile as the solvent at room temperature. The substrate dependence of the rearrangement has been studied, and the mechanism of the transformation under discussion was explored by quantum chemical calculations. The key intermediate is an oxaphosphirane. The one-pot version starting with the Pudovik reaction has also been developed. The conditions of this tandem transformation were the same, as those for the one-step HP→BP conversion.

scholarly journals Prebiotic Route to Thymine from Formamide—A Combined Experimental–Theoretical Study

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2248
Author(s):  
Lukáš Petera ◽  
Klaudia Mrazikova ◽  
Lukas Nejdl ◽  
Kristyna Zemankova ◽  
Marketa Vaculovicova ◽  
...  
Keyword(s):  
Formic Acid ◽  
Quantum Chemical ◽  
Prebiotic Chemistry ◽  
Theoretical Study ◽  
Reaction Pathway ◽  
Hydrolysis Product ◽  
Current Paper ◽  
Reaction Conditions ◽  
Chemical Modeling ◽  
Chemistry Research

Synthesis of RNA nucleobases from formamide is one of the recurring topics of prebiotic chemistry research. Earlier reports suggest that thymine, the substitute for uracil in DNA, may also be synthesized from formamide in the presence of catalysts enabling conversion of formamide to formaldehyde. In the current paper, we show that to a lesser extent conversion of uracil to thymine may occur even in the absence of catalysts. This is enabled by the presence of formic acid in the reaction mixture that forms as the hydrolysis product of formamide. Under the reaction conditions of our study, the disproportionation of formic acid may produce formaldehyde that hydroxymethylates uracil in the first step of the conversion process. The experiments are supplemented by quantum chemical modeling of the reaction pathway, supporting the plausibility of the mechanism suggested by Saladino and coworkers.

scholarly journals Quantum Chemical Studies and Electrochemical Investigations of Polymerized Brilliant Blue-Modified Carbon Paste Electrode for In Vitro Sensing of Pharmaceutical Samples

Chemosensors ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 135
Author(s):  
Pattan-Siddappa Ganesh ◽  
Sang-Youn Kim ◽  
Savas Kaya ◽  
Rajae Salim ◽  
Ganesh Shimoga ◽  
...  
Keyword(s):  
Electrochemical Sensor ◽  
Carbon Paste Electrode ◽  
Quantum Chemical ◽  
Electrochemical Sensing ◽  
Quantum Chemical Modeling ◽  
Brilliant Blue ◽  
Carbon Paste ◽  
Chemical Modeling ◽  
The Real ◽  
Paste Electrode

To develop an electrochemical sensor for electroactive molecules, the choice and prediction of redox reactive sites of the modifier play a critical role in establishing the sensing mediating mechanism. Therefore, to understand the mediating mechanism of the modifier, we used advanced density functional theory (DFT)-based quantum chemical modeling. A carbon paste electrode (CPE) was modified with electropolymerization of brilliant blue, later employed for the detection of paracetamol (PA) and folic acid (FA). PA is an analgesic, anti-inflammatory and antipyretic prescription commonly used in medical fields, and overdose or prolonged use may harm the liver and kidney. The deficiency of FA associated with neural tube defects (NTDs) and therefore the quantification of FA are very essential to prevent the problems associated with congenital deformities of the spinal column, skull and brain of the fetus in pregnant women. Hence, an electrochemical sensor based on a polymerized brilliant blue-modified carbon paste working electrode (BRB/CPE) was fabricated for the quantification of PA and FA in physiological pH. The real analytical applicability of the proposed sensor was judged by employing it in analysis of a pharmaceutical sample, and good recovery results were obtained. The potential excipients do not have a significant contribution to the electro-oxidation of PA at BRB/CPE, which makes it a promising electrochemical sensing platform. The real analytical applicability of the proposed method is valid for pharmaceutical analysis in the presence of possible excipients. The prediction of redox reactive sites of the modifier by advanced quantum chemical modeling-based DFT may lay a new foundation for researchers to establish the modifier–analyte interaction mechanisms.

Elektrostatische Aktivierung der SNAr-Reaktivität durch Sulfonyloniosubstituenten/Electrostatic Activation of SNAr-Reactivity by Sulfonylonio Substituents

2001 ◽  
Vol 56 (12) ◽  
pp. 1360-1368 ◽  
Author(s):  
Robert Weiss ◽  
Frank Pühlhofer
Keyword(s):  
Room Temperature ◽  
Reaction Path ◽  
Mild Conditions ◽  
Electrostatic Effect

Abstract 4-Fluorobenzenesulfonyl chloride (1) and pentafluorobenzenesulfonyl chloride (2) are transformed into the corresponding N-sulfonylpyridinium triflates 4a-d by treatment with one equivalent of the reagent pair L/TMSOTf (L = 4-dimethylaminopyridine (DMAP), 4-ferf-butylpyridine (TBUPY), 1-methylimidazole (NMI); TMSOTf = trimethylsilyl triflate). Due to the electrostatic effect of the sulfonylonio function, SNAr reactions on these systems can be performed under mild conditions. So the reaction of 2 with excess DMAP/TMSOTf leads by way of peronio substitution to hexakis[(4-dimethylamino)-l-pyridinio]benzene hexa-kis(trifluoromethansulfonate) (7) [22] at room temperature. Additionally, a new reaction path to 4-(1-pyridinio)-substituted benzenesulfonamides, a class of pharmaceutically interesting substances, is shown.

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