Article
Chemistry, Multidisciplinary
Subhrashis Banerjee, Kumar Vanka
Summary: The great success of asymmetric organocatalysis has made it one of the most important advancements in chemistry in the past two decades. A significant achievement in this field is the asymmetric organocatalysis of the thiocyanation reaction. Computational studies with density functional theory have been conducted to understand the reversal of enantioselectivity in this reaction, which is caused by the presence of the C-H···S noncovalent interaction.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Physical
Meena Rittiruam, Siriwimol Somdee, Puwit Buapin, Nuttanon Aumnongpho, Nuttapat Kerdprasit, Tinnakorn Saelee, Soorathep Kheawhom, Nutchapon Chotigkrai, Supareak Praserthdam, Piyasan Praserthdam
Summary: The study investigates the deactivation mechanisms of alpha-manganese dioxide electrocatalyst during charge-discharge cycling using density functional theory-based analysis, attributing the deactivation to phase transformation from alpha-MnO2 to beta-MnO2 and the formation of the limiting *OOH species during oxygen reduction reaction. It suggests that preventing phase transformation is crucial for high-performance MnO2-based electrocatalysts for ORR/OER.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Multidisciplinary
Ridge Michael P. Ylagan, Eric Jaewon Lee, Daniela E. Negru, Paolo Ricci, Bohyun Park, Haram Ryu, Mu-Hyun Baik, P. Andrew Evans
Summary: We report an enantioselective rhodium(I)-catalyzed Pauson-Khand reaction using 1,6-chloroenynes that contain challenging 1,1-disubstituted olefins. Unlike previous studies, this new approach allows for a wider range of substrates, including both carbon and heteroatom tethers with polar and non-polar substituents on the alkene. DFT calculations reveal the critical role of the halide, which pre-polarizes the alkyne and provides the appropriate steric profile for a favorable interaction with the chiral diphosphine ligand.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yong Wu, Shanshan Cao, Iskander Douair, Laurent Maron, Xihe Bi
Summary: The [2+1] cycloaddition reaction of a metal carbene with an alkene often suffers from side reactions, leading to lower yields of cyclopropanation products. By adding a low concentration of diazo compound to alkenes, it was found that AgOTf catalysis can efficiently produce cyclopropane products from hindered alkenes.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Marin Puget, Viacheslav Shcherbakov, Sergey Denisov, Philippe Moreau, Jean-Pierre Dognon, Mehran Mostafavi, Sophie Le Caer
Summary: The nature of the primary species formed in FEC depends on the amount of FEC in the solution, which will affect its performance in the electrolyte.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Zhiyao Duan, Graeme Henkelman
Summary: This study uses global optimization and constant-potential density functional theory to simulate the complete process of Pt dissolution, revealing the formation and dissolution mechanism of a two-dimensional Pt surface oxide. The findings provide a fundamental understanding of Pt dissolution under potential cycling, which is essential for the rational design of durable Pt-based cathodes for fuel cells.
Article
Chemistry, Multidisciplinary
Raphael Robidas, Claude Y. Legault
Summary: A mechanism is proposed to explain the formation of benzobicyclo[3.2.0]heptane derivatives from 1,7-enyne derivatives bearing a terminal cyclopropane, which has been previously reported.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Manussada Ratanasak, Takumi Murata, Taishin Adachi, Jun-ya Hasegawa, Tadashi Ema
Summary: BPh3 catalyzes the N-methylation of secondary amines and the C-methylenation of N,N-dimethylanilines or 1-methylindoles in the presence of CO2 and PhSiH3. The mechanism involves the activation of PhSiH3 by BPh3 to generate key CO2-derived species for the N-methylation reaction. DFT calculations also suggest other mechanisms involving water for the activation of PhSiH3.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Engineering, Environmental
Nannan Wu, Mingzhu Liu, Bingru Tian, Zunyao Wang, Virender K. Sharma, Ruijuan Qu
Summary: In this study, the oxidation of five phenolic contaminants using ferrate(VI) was investigated to understand the reaction mechanisms. Experimental and theoretical calculations revealed that the reaction rate constants were correlated with the energy of the highest occupied molecular orbital. Electron-donating groups (-R) were found to be more easily oxidized by ferrate(VI) compared to weak electron withdrawing groups (-X) and strong electron-withdrawing groups (-(C=O)-). The dominance of Fe(VI) in the reaction process was determined, and four main reaction mechanisms, including single-oxygen transfer, double-oxygen transfer, ·OH attack, and electron-transfer-mediated coupling reaction, were proposed. Density functional theory calculations suggested that the presence of -(C=O)- facilitated the occurrence of double-oxygen transfer and ·OH attack reactions, while the tendency of single-oxygen transfer and electron-transfer reaction varied with different substituents. Furthermore, the double-oxygen transfer pathway was found to be a common reaction mechanism during the ferrate(VI) oxidation of phenolic compounds.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Organic
Miglena K. Georgieva, A. Gil Santos
Summary: The Diels-Alder reaction is a fascinating chemical process that has been extensively studied, both in its achiral and chiral versions. In this study, the authors investigate the Diels-Alder reaction of 2'-hydroxychalcones with two dienes, catalyzed by chiral organo-boron Lewis acid complexes. The authors use theoretical methods to evaluate the proposed reaction mechanism and provide insights into the enantioselectivity and endo/exo selectivity of the reaction.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
B. B. Xiao, L. Yang, H. Y. Liu, X. B. Jiang, B. Aleksandr, E. H. Song, Q. Jiang
Summary: The study systematically investigates the oxygen reduction reaction and oxygen evolution reaction of graphene materials embedded with TMN4 clusters (TM = Fe, Co, Ni) using density functional theory calculations. It demonstrates that the functionalization of graphene can dramatically alter the activity and stability of TMN4 clusters, offering new insights into the design of bifunctional oxygen electrodes.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Yang'en You, Shaozhong Ge
Summary: An enantioselective cobalt-catalyzed hydrosilylation/cyclization reaction of 1,6-enynes with secondary and tertiary hydrosilanes produced chiral organosilane products in high yields and excellent enantioselectivity, which could be further converted into a variety of chiral five-membered heterocyclic compounds without loss of enantiopurity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Guangtong Hai, Haihui Wang
Summary: Accurate prediction of catalytic performance based on DFT calculation is crucial for nitrogen fixation. However, current computational methods ignore the effects of electrode potential and solvation, resulting in large deviations between predicted and measured potentials. This study proposes an external iteration method and a hybrid solvent model to account for these effects, achieving good agreement between theoretical and experimental potentials. These findings have important implications for prediction of other electrocatalytic systems.
Article
Multidisciplinary Sciences
Babak Karimi, Ehsan Jafari, Fariborz Mansouri, Mina Tavakolian
Summary: The chiral chloro-indeno pybox ligand serves as a new catalyst for the Yb(OTf)(3)-catalyzed asymmetric Friedel-Crafts alkylation reaction. The tunability of pybox ligands allows for the rational design of catalysts with optimal performance in terms of both activity and stereoselectivity. Under optimized conditions, good to excellent yields and enantioselectivities were achieved for a wide range of substrates, including sterically hindered compounds.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Multidisciplinary
Lia Sotorrios, Fedor M. Miloserdov, Anne-Frederique Pecharman, John P. Lowe, Stuart A. Macgregor, Mary F. Mahon, Michael K. Whittlesey
Summary: The syntheses, reactivity, and electronic structure analyses of [Ru(PPh3)(2)(ZnMe)(4)H-2] and [Ru(PPh3)(2)(ZnPh)(4)H-2] are reported. [Ru(PPh3)(2)(ZnMe)(4)H-2] exhibits an 8-coordinate Ru center with axial phosphines and a symmetrical (2 : 2) arrangement of ZnMe ligands in the equatorial plane. The ZnMe ligands in [Ru(PPh3)(2)(ZnMe)(4)H-2] undergo facile, sequential exchange with ZnPh2 to give [Ru(PPh3)(2)(ZnPh)(4)H-2], which shows a 3 : 1 arrangement of ZnPh ligands. Mechanisms for ZnMe/ZnPh exchange and isomerization are proposed using DFT calculations, and the relationships of these {Ru(ZnR)(4)H-2} species to isoelectronic Group 8 transition metal polyhydrides and related Schlenk equilibria in the Negishi reaction are discussed.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Tomasz Madry, Agnieszka Czapik, Marcin Kwit
JOURNAL OF ORGANIC CHEMISTRY
(2020)
Article
Chemistry, Organic
Bartosz Stasiak, Agnieszka Czapik, Marcin Kwit
Summary: A series of artificial triarylmethanols have been synthesized and studied for their induced optical activity. The chiroptical response observed in these compounds is attributed to the chiral conformation of the triarylmethyl core. The formation of carbocations, reversible in nature, and their chiroptical effects in different environments have been analyzed.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Multidisciplinary Sciences
Tomasz Madry, Agnieszka Czapik, Marcin Kwit
Summary: The compound serves as a sensor for primary amine chirality, with interactions forcing a change in chromophore conformation. The induction of optical activity in the chromophore is attributed to a cascade chirality transmission mechanism. The sensitivity of the reporter system to subtle differences in inductor structure is highlighted.
Article
Chemistry, Organic
Natalia Prusinowska, Agnieszka Czapik, Marcin Kwit
Summary: The research has demonstrated the effectiveness and versatility of chiral triphenyl-acetic acid esters as chirality-sensing probes and molecular components in crystal engineering. The study revealed that the packing arrangement of molecules in the crystal lattice is influenced by various factors, including hydrogen bonding, van der Waals interactions, and London dispersion forces, as well as the type of substituents and the optical purity of the sample.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Daniel Lowicki, Justyna Watral, Maciej Jelecki, Wiktor Bohusz, Marcin Kwit
Summary: An efficient enantioselective protonation of 2-methyl-1-tetralone lithium enolate catalyzed by salan-type diamines is reported in this study. A broad series of salan-type catalysts were synthesized and tested in the reaction, with a chiral amine organocatalyst showing better results than a stoichiometric protonating agent for the first time. The use of only 10 mol% of salan allows for high yield and enantiomeric excess up to 75% in obtaining the title ketone.
News Item
Chemistry, Multidisciplinary
Jadwiga Gajewy, Marcin Kwit
Summary: The development of a zinc-catalysed desymmetrization method enables the synthesis of chiral alcohols with all-carbon quaternary centres by the selective reduction of symmetrical alpha,alpha-disubstituted malonates.
Article
Chemistry, Organic
Agnieszka Janiak, Jadwiga Gajewy, Joanna Szymkowiak, Blazej Gierczyk, Marcin Kwit
Summary: Chiral isotrianglimines were synthesized through [3 + 3] cyclocondensation, and the structure and supramolecular arrangement of the molecules were influenced by the substituent's properties and the presence of solvent molecules. Polar substituents led to self-association of the molecules into dimers, which further formed higher-order structures held together by solvent molecules. Non-associating molecules formed a container accommodating other molecules.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Agnieszka Czapik, Marcin Kwit
Summary: The crystal structures of solvates of N-triphenylacetyl-L-tyrosine with chloroform and dichloromethane were analyzed, revealing the presence of hydrogen bonds and structural voids in the crystals which can accommodate guest molecules. Upon loss of solvent, the solvates transform into the solvent-free form. Additionally, the racemic amide N-triphenylacetyl-DL-tyrosine was also studied, showing similar interactions between molecules and formation of structural voids in the crystals.
ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Anna M. Czombik, Jadwiga Gajewy, Agnieszka Czapik, Marcin Kwit
Summary: Magnesium, as one of the most abundant metal elements in the Earth's crust, has played a significant role in organic chemistry since the beginning of the 20th century. The discovery of organomagnesium compounds by Philippe A. Barbier and Victor Grignard marked a milestone in the development of organic chemistry, particularly in the realm of enantioselective reactions. While the use of magnesium as a catalyst in asymmetric reactions is relatively limited compared to transition metal-catalyzed or organocatalyzed transformations, there is a growing trend towards utilizing Earth-abundant metals for more environmentally friendly catalysis.
Article
Chemistry, Organic
Natalia Prusinowska, Joanna Szymkowiak, Marcin Kwit
Summary: Introducing urea or thiourea functionality allows for control of conformational dynamics in chiral, polyamines with a figure-shaped periodic structure. The nature of the amide linker and substitution pattern in the aromatic units determine the diverse conformations these macrocycles can adapt. The type of heteroatom X in each vertex of the macrocycle core determines the chiroptical properties. Thioureas exhibit chiroptical properties controlled by the chiral neighborhood closest to the chromophore. The presence of biphenyl chromophores in the macrocycle core leads to the observation of a dynamically induced exciton couplet. In the solid state, seemingly disordered molecules can form ordered networks stabilized by intermolecular interactions.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Sylwia Ostrowska, Lorenzo Palio, Agnieszka Czapik, Subhrajyoti Bhandary, Marcin Kwit, Kristof Van Hecke, Steven P. Nolan
Summary: In this study, a synthetic protocol was developed to prepare palladacycle complexes using a mild base and environmentally friendly solvent, with a focus on complexes with backbone-substituted N-heterocyclic carbene ligands. The accessible complexes exhibited high catalytic activity in the Buchwald-Hartwig amination, with low catalyst loading and mild reaction conditions achieved in a green solvent.
Article
Chemistry, Inorganic & Nuclear
Ekaterina A. Martynova, Marco Zuccarello, Domenic Kronenberg, Marek Belis, Agnieszka Czapik, Ziyun Zhang, Kristof Van Hecke, Marcin Kwit, Olivier Baudoin, Luigi Cavallo, Steven P. Nolan
Summary: Green and sustainable access to chiral and achiral gold-IBiox complexes is achieved through a simple and air-tolerant synthesis method using a green solvent. The catalytic activity of these complexes in the hydroamination of alkynes is examined, and their steric protection of the gold center is compared with commonly encountered NHCs using the %V-bur model.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Organic
Natalia Prusinowska, Joanna Szymkowiak, Marcin Kwit
Summary: The introduction of urea or thiourea functionality to the macrocycle skeleton allows for control of the conformational dynamics of chiral, polyamines with a figure-shaped periodic structure. The chiroptical properties are determined by the type of heteroatom X in the N-C(= X)-N units in the macrocycle core. Thiourea-containing derivatives exhibit chiral control closest to the chromophore, while urea-containing derivatives have their electronic circular dichroism influenced by the substitution pattern in the aromatic units. The self-sorting phenomenon is observed in the crystal structures of thiourea-derived trianglamine with two bromine substituents in each aromatic unit.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
