Article
Chemistry, Physical
Zhaoru Zha, Prashant Deshlahra
Summary: This study investigates the mechanistic insights of vinyl acetate synthesis on Pd-based catalysts through experiments and DFT calculations, revealing that coverage effects play a significant role in the formation of acetate species, leading to complex trends in reaction rates and steady-state operation. The balance between acetate formation and consumption is crucial for achieving steady-state operation over a narrow coverage range where the barriers are nearly equal, shifting the rate-limiting step from VA formation to acetate formation. Additionally, high coverage promotes coupling and inhibits O-2 dissociation, providing a comprehensive framework for understanding high-coverage catalysis.
Article
Polymer Science
Bartosz Kopka, Bartlomiej Kost, Julia Wrzesniewska, Katarzyna Rajkowska, Slawomir Kadlubowski, Alina Kunicka-Styczynska, Andrzej Baryga, Weronika Gonciarz, Malgorzata Basko, Marek Brzezinski
Summary: Supramolecular hydrogels were prepared by cross-linking PVA with quercetin, which possesses antimicrobial and antifungal properties and can form hydrogen bonds with PVA. These hydrogels not only exhibit desired physicochemical properties but also have the ability to eliminate bacterial and fungal strains, including fluconazole-resistant yeast strains. Furthermore, the color change of the hydrogels depending on the bacteria strains indicates their potential as sensors for different bacteria strains. These advantageous features make supramolecular hydrogels highly effective antimicrobial and antifungal materials for food preservation or wound healing applications.
EUROPEAN POLYMER JOURNAL
(2023)
Article
Chemistry, Physical
Jere K. Mannisto, Ljiljana Pavlovic, Johannes Heikkinen, Tony Tiainen, Aleksi Sahari, Norbert M. Maier, Kari Rissanen, Martin Nieger, Kathrin H. Hopmann, Timo Repo
Summary: We developed a mildsuperbase-catalyzed carboxylation method for the synthesis of drug-like O-alkyl carbamates. Our mechanistic study reveals that when superbases interact with indoles and azoles, uncharged hydrogen-bonded complexes are formed instead of ionic salts. These complexes can be converted into carbamate salts upon exposure to CO2. The carbamate salts can be further classified into stable and fluxional types, with the latter being poor substrates for alkylation. We also identified the substrate-specific factors responsible for the fluxional behavior and proposed strategies to stabilize the carbamate salts for efficient alkylation.
Article
Chemistry, Physical
Fariba Golpayegani, Zohreh Mirjafary, Javad Mokhtari Aliabad, Hamid Saeidian
Summary: The study revealed that the basicity of phosphaallenes in the gas phase can be enhanced by introducing electron-donating substituents on the ring, making them potential candidates for strong neutral organic superbases and hyperbases.
COMPUTATIONAL AND THEORETICAL CHEMISTRY
(2021)
Article
Multidisciplinary Sciences
Blazej Gierczyk, Michal F. Rode, Gotard Burdzinski
Summary: In this study, the photochromic reaction of 3-(2-methoxyphenyl)-3-phenyl-3H-benzo[f]chromene (2) was investigated using both experimental and theoretical approaches. Experimental results demonstrated that irradiation at 365 nm can generate colored transoid-cis isomers with varying lifetimes. The theoretical interpretation can potentially guide the design of new photochromic systems with optimized photofunctionality.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Ricardo Meyrelles, Manuel Schupp, Boris Maryasin
Summary: A computational study reveals the mechanism of hydroxamic acid isomerization into para-aminophenols catalyzed by phenylselenyl bromide, providing insights into the reaction mechanism and explaining experimental observations. Joint theoretical and experimental studies also demonstrate the effectiveness of phenylsulfenyl bromide in mediating the reaction under the same conditions.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Ravindra S. Phatake, Arthur Averdunk, Christian Wurtele, Urs Gellrich
Summary: This study reports a Piers' borane-catalyzed dimerization of arylallenes, achieving catalytic turnover through transborylation with pinacolborane to access bench-stable pinacolborane-substituted 1,5-dienes, demonstrating their synthetic utility, and investigating the mechanism of the reaction.
Article
Chemistry, Applied
Sudip Gorai, Ayan Ghosh, Saikat Chakraborty, Pascal Retailleau, Tapan K. Ghanty, Birija Sankar Patro, Soumyaditya Mula
Summary: In this study, a specific Cu2+ sensor was developed for the detection of labile Cu2+ ions in vivo, overcoming the challenge of interference from other biologically important metal ions. The new ligand exhibited highly selective detection of Cu2+ ions via a fluorescent turn off mechanism, without any interference from other metal ions. The sensing mechanism was investigated, confirming the formation of a 1:1 complex between the BODIPY-phenanthroline conjugate and Cu2+ ions. The ligand was also found to be cell-permeable and non-toxic, and showed potential for monitoring cellular accumulation of Cu2+ ions and detecting Cu2+ ions in serum samples.
Article
Chemistry, Physical
Weikang Dai, Maoshuai Li, Jie Wei, Qi Yang, Yi Feng, Cheng Yang, Wanxin Yang, Mei-Yan Wang, Xinbin Ma
Summary: The paper investigates the dissociation and anion mechanism for formaldehyde hydroformylation using DFT calculation and experimental study. It finds that HCHO insertion into the Rh-H bond is the rate-controlling step in the dissociation mechanism, while the nucleophilic addition of HCHO to the HOCH2-Rh species is more energetically favorable in the anion mechanism. The research also suggests that the strong electron-donating ligand could lead to higher reactivity in the anion mechanism, providing insights for improving selectivity in the reaction.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Physical
Yoshihiko Yamamoto
Summary: Using density functional theory (DFT) calculations, the study investigated the reaction mechanisms of tungsten and ruthenium carbyne complexes with 1,6-heptadiyne, discussing the formation pathways of different intermediates and the process of product formation.
Article
Chemistry, Physical
Yaxuan Shang, Xiangzhou Li, Zhaoshuang Li, Liqun Shen, Jun Zhou, Runfeng Hu, Kai Chen
Summary: This study investigates the antioxidant activity of viniferin molecules against radicals, comparing their radical scavenging mechanisms and kinetically and thermodynamically. The results show that epsilon-viniferin is a more potent radical scavenger than delta-viniferin. This research provides insights into the antioxidant activity of viniferins and the different radical scavenging mechanisms of antioxidants.
JOURNAL OF MOLECULAR STRUCTURE
(2022)
Article
Chemistry, Physical
Tyler G. Saint-Denis, Nelson Y. S. Lam, Nikita Chekshin, Paul F. Richardson, Jason S. Chen, Jeff Elleraas, Kevin D. Hesp, Daniel C. Schmitt, Yajing Lian, Chan Woo Huh, Jin-Quan Yu
Summary: Enantioselective C(sp(3))-H activation has attracted significant interest, but the mechanisms responsible for enantioselection remain unclear. This study found extreme sensitivity differences in two substrate classes, leading to high enantiomeric ratios for thioether-directed-C(sp(3))-H arylation. The exploitation of transient chirality at sulfur was key to achieving stereochemical information transfer from ligand backbone to substrate carbons.
Article
Chemistry, Physical
Minhua Zhang, Hongpu Guo, Xinyue Guan, Fuchao Li, Yingzhe Yu
Summary: With the rapid development of the photovoltaic industry, the study of the synthetic monomer vinyl acetate, which is in high demand due to the growth of the industry, is crucial. This research focuses on the production mechanism of ethylene glycol diacetate, a byproduct in the ethylene vapor phase process. Molecular simulation techniques, including DFT and kMC simulations, were used to investigate the reaction mechanism on the PdAu(100) surface. The results provide insights into the production pathway and rate-determining step of ethylene glycol diacetate, offering theoretical foundations for reducing its production in industrial processes.
MOLECULAR CATALYSIS
(2023)
Article
Polymer Science
Seong Baek Yang, Mohammad Rezaul Karim, Jungeon Lee, Jeong Hyun Yeum, Sabina Yeasmin
Summary: Novel poly(vinyl alcohol)/poly(vinyl butyral-vinyl alcohol) films with improved hydrophobicity were prepared by saponification of poly(vinyl acetate)/poly(vinyl butyral) blend films. The saponification process was confirmed by various analysis techniques. The hydrophobicity of the films increased with increasing poly(vinyl butyral) content. The saponified films exhibited improved mechanical properties and unique surface characteristics. These films have potential applications in biomaterials, filters, and medical devices.
Article
Chemistry, Multidisciplinary
Maria Assunta Chiacchio, Daniela Iannazzo, Salvatore Giofre, Roberto Romeo, Laura Legnani
Summary: In this paper, a mechanistic study of RuO4-catalyzed oxidation on 2-methylisoxazolidine was conducted using computational methods. The investigation revealed that the oxidation reaction occurs in two steps involving double H-transfer. The study also found that all carbon atoms near the heteroatoms in the isoxazolidine system can undergo oxidation, with the formation of an ion pair leading to the preferred product N-methylisoxazolidin-3-one.
ARABIAN JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Anton Kuzmin, Bagrat A. Shainyan
Summary: In this study, the mechanism of oxygen reduction reaction on transition metal-doped nitrogen codoped single-walled nanotubes was investigated using density functional theory. The analysis revealed two active sites on the catalyst, with the C-2 site being more important than the MN4 site. Additionally, it was found that the 4e(-) mechanism of ORR was thermodynamically preferable for all studied catalysts.
Article
Chemistry, Organic
Dmitrii A. Shabalin, Evgeniya E. Ivanova, Igor A. Ushakov, Elena Yu Schmidt, Boris A. Trofimov
Summary: Convenient protocols have been developed for the synthesis of three highly functionalized azaheterocyclic scaffolds using readily available hydroxypyrrolines and hydrazides. The transformation of a common initial intermediate, a Bronsted acid-activated hydroxypyrroline, depends on reaction conditions and hydrazide structure.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Anton Kuzmin, Bagrat A. Shainyan
Summary: This study analyzed the efficiency of Ti- and Zr-doped nitrogen-codoped carbon nanomaterials based on carbon nanotubes at the DFT theory level, revealing two active sites on the catalyst surface and the distinct characteristics of Ti and Zr metals. Free energy diagrams of the ORR in acidic and alkaline media were plotted, determining intermediates depending on electrode potential and metal nature. The slightly lower exothermicity and lower-lying intermediates of oxygen adsorption for Ti metal suggest an advantage of Ti-doped over Zr-doped MN4-CNT catalysts.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2021)
Article
Chemistry, Organic
Dmitrii A. Shabalin, Maxim K. Kazak, Igor' A. Ushakov, Alexander V. Vashchenko, Elena Yu. Schmidt
Summary: A convenient synthesis of pyrrolo[2,1-a]isoquino-linium salts from 1-pyrrolines and alkynes through rhodium-catalyzed C-H functionalization/N-annulation tandem reaction is described. The protocol shows good substrate tolerance, mild reaction conditions, and high yields of target products. Exploration of the alkyne scope unexpectedly revealed a novel labile functional group-promoted rhodium-catalyzed C-H functionalization/C-annulation/elimination cascade reaction of 1-pyrrolines with electron-deficient alkynes.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Marina A. Borisova, Dmitry S. Ryabukhin, Alexander Yu Ivanov, Irina A. Boyarskaya, Dmitrii A. Shabalin, Lev E. Zelenkov, Elena Yu Schmidt, Boris A. Trofimov, Aleksander V. Vasilyev
Summary: 5-Hydroxy-1-pyrrolines react with arenes in TfOH or H2SO4 to afford 5-aryl-1-pyrrolines, and undergo dehydration in TfOH or H2SO4 to form N-protonated forms of 3H-pyrroles.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Anton Kuzmin, Bagrat A. Shainyan
Summary: The oxygen electroreduction mechanism on the V- and Nb-doped nitrogen-codoped (6,6)armchair carbon nanotube with incorporated MN4 fragment has been studied. The metal center in MN4 fragment and the adjacent NC(sic)CN double bond of the support have been revealed as active centers in the ORR process.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2023)
Article
Chemistry, Organic
Marina Yu. Dvorko, Dmitrii A. Shabalin, Igor A. Ushakov, Elena Yu. Schmidt, Boris A. Trofimov
Summary: The cascade dimerization of alkynones with sterically hindered secondary alkyl groups at the carbonyl function unexpectedly produced highly functionalized furans. This reaction efficiently takes place at room temperature in the presence of a potassium tert-butoxide/dimethylsulfoxide superbase catalytic system. Alkynones with an additional C-H active site at the carbon-carbon triple bond followed a different dimerization pathway to form 3-alkenylpyran-4-ones. The discovery of these reactions expands the traditional understanding of alkynone reactivity in strong basic conditions.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Evgeniya E. E. Ivanova, Dmitrii A. A. Shabalin, Igor' A. Ushakov, Alexander V. V. Vashchenko, Elena Yu. Schmidt, Boris A. A. Trofimov
Summary: Tetrahydropyrrolo[1,2-d]oxadiazoles were synthesized in good-to-excellent yields through the cycloaddition of nitrile oxides to readily accessible functionalized Delta(1)-pyrrolines in a two-phase system with sodium hypochloride as an oxidant. The reaction produced diastereoselective 1,2,4-oxadiazolines fused with a five-membered ring, which have pharmaceutical potential. The reaction demonstrated a broad substrate tolerance, including those with oxidant-sensitive functional groups and competitive reaction sites.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Review
Chemistry, Multidisciplinary
Anton V. Kuzmin, Bagrat A. Shainyan
Summary: The review discusses the electrochemical reactions of oxygen reduction (ORR) and carbon dioxide reduction (CO2RR), focusing on mechanisms, structure of intermediates, and thermodynamics. Metal, heteroatom-codoped nanocarbon substrates show promise as catalysts for ORR, providing a source of pure electrical energy. CO2RR, as a synthetic analogue of photosynthesis, has potential for generating partial or complete reduction products. Theoretical insights into CO2RR mechanisms and kinetics are still in early stages of development, making systematic organization of advances and emerging issues necessary for further progress. The bibliography includes 242 references.
RUSSIAN CHEMICAL REVIEWS
(2023)
Article
Food Science & Technology
Olga I. Belykh, Ekaterina G. Sorokovikova, Irina V. Tomberg, Galina A. Fedorova, Anton V. Kuzmin, Andrey Yu. Krasnopeev, Maria Yu. Suslova, Sergey A. Potapov, Tatiana I. Belykh, Jadambaa Norovsuren, Agnia D. Galachyants, Irina V. Tikhonova
Summary: For the first time, microcystin-producing cyanobacteria have been found in Lake Khubsugul, which is ancient and pristine. The taxonomic composition of cyanobacterial communities and the water quality of the lake were analyzed, showing that the water was clean and there were no signs of cyanobacterial blooms.
Article
Chemistry, Multidisciplinary
Dmitrii A. Shabalin, Lev E. Zelenkov
Summary: An expedient synthesis of previously unknown pyrrolo[2,1-a]isoquinolinium salts has been developed by utilizing non-aromatic aryl-substituted 2H- and 3H-pyrroles and internal alkynes. This reaction represents a rare example of N-nucleophilic reaction of 2H- and 3H-pyrroles and relies on the ortho-C-H bond activation of non-aromatic arylpyrroles in the presence of rhodium catalyst followed by alkyne annulation reaction. Diverse substituted salts were obtained in high yields under mild reaction conditions. Moreover, the photophysical properties of selected pyrrolo[2,1-a]isoquinolinium salts have been evaluated, demonstrating their potential applications as fluorescent materials for light-emitting devices and bioimaging.
Article
Chemistry, Organic
Anton V. V. Kuzmin, Dmitrii A. A. Shabalin
Summary: This study focuses on the density functional theory (DFT) investigation of substrate-controlled dimerizations of aliphatic alkynones using base catalysts. Theoretical analysis was conducted to understand the selectivity of cascade reactions and the thermodynamic and kinetic characteristics of deprotonation reactions. The computational results provide valuable insights for predicting the outcomes of related base-catalyzed reactions.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Environmental Sciences
Alexander Gorshkov, Tatyana Grigoryeva, Yurij Bukin, Anton Kuzmin
Summary: In this study, Lake Baikal was used as a model to investigate the distribution pattern of o-phthalic acid diester (PAE) in surface waters with background pollution levels. The results showed that dimethyl phthalate (DMP), diethyl phthalates (DEP), di-n-butyl phthalate (DnBP), and di-(2-ethylhexyl)phthalate (DEHP) were the priority PAEs in Baikal waters. The main source of PAEs was found to be the atmospheric transfer of polluted air masses. The study also assessed the ecological risk of PAE concentration levels for Lake Baikal biota, and found that the risk was low for crustaceans and fishes, but relatively high for algae.
Article
Environmental Sciences
Anton Kuzmin, Tatyana Grigoryeva, Alexander Gorshkov
Summary: A method is proposed for estimating the ratio of stable carbon isotopes C-13/(12) in phthalates from surface water at a trace concentration level. This method calculates the ratio based on the concentration of hydrophobic components of water using an analytical reversed phase HPLC column and the detection of eluted phthalates using a high-resolution time-of-flight mass spectrometer. The technique has been validated during the monitoring of priority phthalates in the waters of Lake Baikal.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Chemistry, Organic
Sofia O. Samultceva, Marina Yu Dvorko, Dmitrii A. Shabalin, Igor' A. Ushakov, Alexander V. Vashchenko, Elena Yu Schmidt, Boris A. Trofimov
Summary: 6-Methylene-5-oxaspiro[2.4]heptanones have been successfully synthesized via base-catalyzed dimerization of available alkynyl cyclopropyl ketones. The reaction proceeds at room temperature in the presence of the t-BuOK/t-BuOH/THF catalytic system, providing the desired spirocycles in a regio- and stereoselective manner. The study also demonstrates the wide synthetic utility of alkynyl cyclopropyl ketones as novel building blocks.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
