Article
Chemistry, Multidisciplinary
Tobias Biberger, Stephan N. Hess, Markus Leutzsch, Alois Fuerstner
Summary: In this study, a new hydrogenation reaction transformation was reported, where propargyl alcohol derivatives were converted to cyclopentene products using [(CpRu)-Ru-X(MeCN)(3)]PF6 as catalyst. It was also discovered that rearrangements leading to other organic compounds could occur when the transient carbene carried appropriate substituents.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Tobias Biberger, Nils Noethling, Markus Leutzsch, Christopher P. Gordon, Christophe Coperet, Alois Fuerstner
Summary: In the investigation of ruthenium precatalysts used for light-driven alkyne gem-hydrogenation reactions, a thermally robust anionic dinuclear sigma-dihydrogen complex was found. This complex, formed by the reaction of [(IPr)(eta(6)-cymene)RuCl2] with H-2 under UV-irradiation, is a rare example of anionic sigma-complexes lacking any structural attributes to counterbalance the negative charge and prevent metal center insertion into ligated H-2.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Alexander Mutschke, Guy M. Bernard, Marko Bertmer, Antti J. Karttunen, Clemens Ritter, Vladimir K. Michaelis, Nathalie Kunkel
Summary: A novel mixed-anionic compound, the sulfate hydride Na3SO4H, was successfully synthesized by precise reaction control to prevent the reduction of sulfate to sulfide. X-ray and neutron diffraction studies revealed its crystalline structure and properties.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Edina Sic, Jochen Rohrer, Emmanuel Ricohermoso, Karsten Albe, Emmanuel Ionescu, Ralf Riedel, Hergen Breitzke, Torsten Gutmann, Gerd Buntkowsky
Summary: Polymer-derived silicon oxycarbide ceramics (SiCO) have been investigated as potential anode materials for lithium- and sodium-ion batteries. This study focuses on understanding the local structures of SiCO ceramics with different amounts of carbon. Through various spectroscopic and computational techniques, significant changes in the local structures of SiCO ceramics have been observed, even with small changes in the material composition. These findings will provide valuable insights into the electrochemical storage processes of alkali metal/ions inside polymer-derived ceramics, particularly in the context of future research.
Article
Chemistry, Multidisciplinary
Matthieu Hedouin, Anne-Laure Barthelemy, Nicolas Vanthuyne, Hend Besrour, Jacques Maddaluno, Emmanuel Magnier, Hassan Oulyadi
Summary: This work explains the importance of using an excess of butyllithium in the directed ortho-lithiation of a trifluoromethyl sulfoximine. The study shows that the presence of excess n-BuLi leads to deprotonation on the ortho-position of the aromatic, resulting in the formation of six different aggregates. DFT calculations provide optimized solvated structures for these aggregates that are consistent with the experimental NMR data.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Raphael J. Zachmann, Alois Fuerstner
Summary: The newly discovered light-driven gem hydrogenation of alkynes provides a safe and versatile approach to synthesizing Grubbs-type ruthenium carbene complexes, using a triple bond as the carbene source without needing sacrificial phosphines.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
En-He Huang, Ying-Qi Zhang, Da-Qiu Cui, Xin-Qi Zhu, Xiao Li, Long-Wu Ye
Summary: A new copper-catalyzed Si-H bond insertion reaction involving N-propargyl ynamides and hydrosilanes has been discovered, providing an efficient method for the practical and atom-economic synthesis of valuable organosilanes in generally moderate to excellent yields under mild reaction conditions. This reaction also introduces a new pathway for Si-H bond insertion involving vinyl cations as key intermediates.
Article
Chemistry, Physical
Kailai Lin, Patrick TomHon, Soren Lehmkuhl, Raul Laasner, Thomas Theis, Volker Blum
Summary: This study provides an in-depth theoretical analysis of key chemical equilibria in Signal Amplification by Reversible Exchange (SABRE) using density functional theory calculations and harmonic transition state theory. The research shows that under typical experimental conditions, the Gibbs free energies of the two key states involved in pyridine-hydrogen exchange are essentially the same, indicating optimality for SABRE. Additionally, a methanol-containing intermediate is proposed as a plausible transient species in the process.
Article
Chemistry, Multidisciplinary
Weiqing Mao, Dominik Fehn, Frank W. Heinemann, Andreas Scheurer, Dominik Munz, Karsten Meyer
Summary: The synthesis of high-valent cobalt(IV) imido complex [(TIMMNmes)Co-IV(NAd)](OTf)(2) (4) via reaction with 1-adamantylazide is discussed. Despite a short half-life at room temperature, compound 4 can be isolated at low temperatures in pure form. Experimental and computational analysis confirm the molecular and electronic structure of 4, suggesting high covalency and substantial triplet nitrene character.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Biochemistry & Molecular Biology
Svetlana A. Kondrashova, Shamil K. Latypov
Summary: The study examines the scopes and limitations of theoretical methods for estimating various NMR metrics of NHCs using computational approximations on a range of model NHCs and their derivatives. It concludes that the most reliable methods are the 31P/13C NMR shifts of NHC-phosphinidene adducts and 13C CSs of carbenes, while the method based on the analysis of 77Se CS NHC-selenoureas has some limitations due to exchange effects. The accuracy of estimating the HEP metric may also be limited due to the nonlinear effect of electron distribution. 13C CSs of NHC-azolium salts are deemed unreliable due to the influence of counterion exchange.
Article
Chemistry, Inorganic & Nuclear
Margarita Ruiz-Castaneda, Lucia Santos, Blanca R. Manzano, Gustavo Espino, Felix A. Jalon
Summary: Deuterium labeling is a process that leads to compounds useful in various fields, with the transfer hydrogenation of aldehydes and selective deuteration of alcohols described in this study. The use of a biphasic water/toluene system was found to enable higher yields and selective D incorporation. Additionally, efficient M-H/D+ exchange from D2O was found to play a key role in the deuteration process.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Adam Mames, Mariusz Pietrzak, Piotr Bernatowicz, Adam Kubas, Roman Luboradzki, Tomasz Ratajczyk
Summary: N-heterocyclic carbene ligands (NHC) are known for their steric and electronic properties, which are quantified through X-ray diffraction for steric properties and liquid state Se-77 NMR for electronic properties. Se-77 NMR crystallography provides valuable information about the structural and electronic properties of NHC ligands.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Vladimir Ya. Lee, Ryo Sakai, Kazunori Takanashi, Olga A. Gapurenko, Ruslan M. Minyaev, Heinz Gornitzka, Akira Sekiguchi
Summary: Two novel 18-electron titanium germylene complexes with distinct structural characteristics were synthesized and classified as different types of complexes, providing important insights into the chemical bonding between germanium and titanium.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Tomas J. Saiegh, Tobias Biberger, Raphael J. Zachmann, Alois Fuerstner
Summary: The light-driven gem-hydrogenation of internal alkynes in the presence of [(NHC)(eta(6)-cymene)RuCl2] generates discrete ruthenium carbene complexes. These complexes can be used to efficiently perform metathetic ring closure reactions with tethered olefins, while simultaneously producing Hoveyda-Grubbs-type complexes as secondary carbenes. This unconventional approach offers a safe, short, phosphine-free, and easily accessible alternative to existing catalysts for olefin metathesis.
HELVETICA CHIMICA ACTA
(2022)
Article
Chemistry, Physical
Wenlong Jiang, Qiwei Peng, Huijun Sun, Qi Zhang, Chengda Huang, Shuohui Cao, Xinchang Wang, Zhong Chen
Summary: The use of PHIP NMR in determining the enantioselectivity of asymmetric hydrogenation and the absolute chirality of products has been demonstrated in this study. Through simulating the PHIP patterns of all possible temporary hyperpolarized diastereoisomers and assigning NMR peaks using density functional theory calculations, the chirality of products and the enantioselectivity of asymmetric hydrogenation were unambiguously determined. This work showcases the potential of PHIP in revealing the mechanism of asymmetric hydrogenation.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Clement Ghiazza, Lucas Wagner, Sergio Fernandez, Markus Leutzsch, Josep Cornella
Summary: Among the tools available to chemists for drug design of bioactive compounds, the bioisosteric replacement of atoms or groups of atoms is the cornerstone of modern strategies. The enzymatic deaminative hydroxylation remains unmatched despite the interest in amino-to-hydroxyl interchange. The study reports a safe and user-friendly procedure using a pyrylium tetrafluoroborate salt to selectively convert aminoheterocycles to hydroxylated analogues. Mechanistic experiments revealed an unusual mechanism for this aromatic substitution.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Anson Thomas, Tuhin S. S. Khan, Puneet Gupta
Summary: Coating metal surfaces with ceramic oxides is an established technique to prevent corrosion. In this study, periodic spin-polarized density functional theory (DFT) was used to analyze the corrosion-inhibition potentials of Al2O3, TiO2, HfO2, and ZrO2 under different corrosive conditions. Adsorption of corrosive atoms on ceramic oxide surfaces was studied using DFT-computed indicators, and the energetically most favorable sites were identified. The DFT calculations predicted the experimentally observed trends of the ceramic oxides in a chlorine-rich medium, and the computational model was also tested in sulfur-rich and oxidizing environments.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Parveen Rawal, Puneet Gupta
Summary: This work examines the reactivity of boron oxide (B2O3) towards dioxygen for methane activation. Multiple pathways were screened on the triplet spin state, and the best route via the triplet spin state was identified. In the singlet spin state, a different intermediate was found, and the singlet pathway was found to be energetically preferred over the triplet one. Orbitals further capture that at singlet and triplet states, methane activation follows a hydride and a hydrogen-atom-transfer mechanism, respectively.
Article
Chemistry, Multidisciplinary
Xiuxiu Yang, Edward J. Reijerse, Nils Noethling, Daniel J. SantaLucia, Markus Leutzsch, Alexander Schnegg, Josep Cornella
Summary: In this study, we synthesized, isolated, and characterized two cationic organobismuth(II) compounds with N,C,N pincer frameworks, which mimic crucial intermediates in bismuth radical processes. X-ray crystallography revealed a monomeric Bi(II) structure, and SQUID magnetometry combined with NMR and EPR spectroscopy provided evidence for a paramagnetic S = 1/2 state. High-resolution multifrequency EPR at the X-, Q-, and W-band allowed for precise assignment of the full g- and 209Bi A-tensors. Experimental data and DFT calculations showed that both complexes are metal-centered radicals with minimal delocalization onto the ligands.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Rajat Maji, Santanu Ghosh, Oleg Grossmann, Pinglu Zhang, Markus Leutzsch, Nobuya Tsuji, Benjamin List
Summary: In this study, a catalytic asymmetric hydrolactonization using a confined imidodiphosphorimidate (IDPi) Bronsted acid catalyst is reported. The method is simple, scalable, and compatible with a wide variety of substrates. The mechanism and enantioselectivity of this reaction are elucidated through in-depth physicochemical and DFT analyses.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Hui Zhou, Roberta Properzi, Markus Leutzsch, Paola Belanzoni, Giovanni Bistoni, Nobuya Tsuji, Jung Tae Han, Chendan Zhu, Benjamin List
Summary: Chiral organosilanes are not naturally occurring and are therefore rare. However, a new synthetic approach using racemic silanes as starting materials has been developed, which expands the range of accessible Si-stereogenic compounds. This approach involves the use of strong and confined imidodiphosphorimidate (IDPi) catalysts to enable the dynamic kinetic asymmetric transformation (DYKAT) of racemic allyl silanes, leading to the formation of Si-stereogenic silyl ethers. The products can be easily converted into enantiopure monohydrosilanes. A proposed mechanism involves the epimerization of a catalyst-bound intermediate.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Joyce A. A. Grimm, Hui Zhou, Roberta Properzi, Markus Leutzsch, Giovanni Bistoni, Johanna Nienhaus, Benjamin List
Summary: The discovery of a highly efficient and selective catalyst enables the conversion of natural or synthetic neral to (1R,6S)-trans-isopiperitenol, providing sustainable routes to menthol and cannabinoids.
Article
Multidisciplinary Sciences
Yue Pang, Nils Noethling, Markus Leutzsch, Liqun Kang, Eckhard Bill, Maurice van Gastel, Edward Reijerse, Richard Goddard, Lucas Wagner, Daniel SantaLucia, Serena DeBeer, Frank Neese, Josep Cornella
Summary: In this work, the synthesis and characterization of a monocoordinate bismuthinidene compound with a rigid and bulky ligand were reported. Despite showing diamagnetic properties in all magnetic measurements, multiconfigurational quantum chemical calculations revealed that the compound's ground state is dominated by a spin triplet. The apparent diamagnetism is explained by an extremely large spin-orbit coupling-induced positive zero-field splitting.
Article
Electrochemistry
Abhiruchi Sharma, Anson Thomas, Puneet Gupta
Summary: Calcium-ion batteries (CIBs) have great potential, but the lack of suitable electrolytes has hindered their development. In this study, silaborane clusters were investigated using density functional theory (DFT), and SiB11 H12- ${{{\rm H}}_{12}<^>{-}}$ cluster was found to be the most promising candidate. Ab initio molecular dynamics (AIMD) simulations revealed the interaction between the silaborane-based electrolytes and the Ca anode, and -CH3 substituted silaborane-based Ca-salt (Ca(SiB11H11CH3)(2)) was identified as a promising electrolyte for CIBs.
BATTERIES & SUPERCAPS
(2023)
Article
Chemistry, Multidisciplinary
Hye Won Moon, Feng Wang, Kalishankar Bhattacharyya, Oriol Planas, Markus Leutzsch, Nils Noethling, Alexander A. Auer, Josep Cornella
Summary: This research investigates the transfer hydrogenation of azoarenes catalyzed by bismuth through experimental and computational studies. The role of protic and hydridic hydrogens in the reaction is identified through kinetic analysis and reactivity studies using p-trifluoromethylphenol and pinacolborane. The possibility of bismuth-ligand cooperativity is also assessed.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Chinky Binnani, Sumangla Arora, Bhanu Priya, Puneet Gupta, Sanjay K. Singh
Summary: A class of 2-hydroxypyridine based ligands have been explored to enhance the catalytic activity of [(eta(6)-p-cymene)RuCl2](2) catalyst for ortho-C-H bond activation/arylation reaction in water. Among the studied ligands, 5-trifluoromethyl-2-hydroxypyridine (L6) showed significant enhancement in the catalytic activity of Ru(II) catalyst for ortho C-H bond arylation of 2-phenylpyridine. NMR and mass investigations suggested the involvement of ligand coordinated Ru(II) species in the C-H bond activation reaction. DFT calculations confirmed the important role of 2-hydroxypyridine based ligands in Ru(II) catalyzed C-H bond arylation of 2-phenylpyridine with lower energy barrier.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Organic
Davide Spinnato, Markus Leutzsch, Feng Wang, Josep Cornella
Summary: In this article, a method to transform isoxazoles and oxadiazoles into pyrazoles and 1,2,4-triazoles in one step using a copper catalyst is provided. The method allows for rapid evaluation of different five-membered azole scaffolds, avoiding de novo synthesis of the molecule of interest.
Article
Chemistry, Physical
Nupur Goswami, Nikunj Kumar, Sukdev Bag, Puneet Gupta, Debabrata Maiti
Summary: This study investigates the palladium-catalyzed C(sp(2))-Holefination reaction of 2-arylbenzaldehyde with the aid of a temporary directing group. Computational and experimental methods are used to understand the reaction mechanism and selectivity. The results show that the reaction proceeds in three major steps and the selectivity is determined by the C-H activation step.
Article
Chemistry, Multidisciplinary
Mannar R. Maurya, Devesh Singh, Fernando Avecilla, Akhilesh Sharma, Puneet Gupta
Summary: Five new tricompartmental ligands with three tridentate dibasic ONO sites were synthesized from the condensation of benzene-1,3,5-tricarbohydrazide and 4-formyl-5-pyrazolone derivatives. These ligands formed tris{cis-[MoO2]} complexes with good catalytic potential for oxidation reactions and bromination reactions. The complexes exhibited high selectivity and yield for specific reactions, making them useful functional models of vanadium-dependent haloperoxidases.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Takuya Tsuruta, Davide Spinnato, Hye Won Moon, Markus Leutzsch, Josep Cornella
Summary: We present a dual-catalyzed C-H trifluoromethylation of (hetero)-arenes using CF3SO2Cl under light irradiation. The reaction enables direct modification of various heterocycles with different functional groups. Structural and computational studies reveal that the reaction proceeds through an open-shell redox reaction at bismuth, involving three unusual elementary steps.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)