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The activation of alkynes toward nucleophilic attack upon coordination to gold-based catalysts (neutral and positively charged gold clusters and gold complexes commonly used in homogeneous catalysis) is investigated to elucidate the role of the σ donation and π back-donation components of the Au-C bond (where we consider ethyne as prototype substrate). Charge displacement (CD) analysis is used to obtain a well-defined measure of σ donation and π back-donation and to find out how the corresponding charge flows affect the electron density at the electrophilic carbon undergoing the nucleophilic attack. This information is used to rationalize the activity of a series of catalysts in the nucleophilic attack step of a model hydroamination reaction. For the first time, the components of the Dewar-Chatt-Duncanson model, donation and back-donation, are put in quantitative correlation with the kinetic parameters of a chemical reaction.
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http://dx.doi.org/10.1021/acs.jpca.6b01037 | DOI Listing |
Chemistry
September 2025
Department of Molecular Theory and Spectroscopy, Max-Planck-Institut für Kohlenforschung, 45470, Mülheim an der Ruhr, Germany.
In this study, we seek to deepen the understanding of the Fe effect in Ni-oxyhydroxide-mediated oxygen evolution reaction (OER) electrocatalysis in alkaline conditions, where extremely small amounts of Fe can have a dramatic impact on catalytic performance. For this purpose, Density Functional Theory (DFT) electronic structure calculations with implicit solvation description is employed in a constant pH/potential simulation framework. Nanoparticle models are considered for the nickel-based oxyhydroxide material with different degrees of Fe incorporation, and the pH/U-dependent interface structure is studied.
View Article and Find Full Text PDFJ Am Chem Soc
September 2025
Riken, Center for Sustainable Resource Sciences, Saitama 351-0198, Japan.
-Adenosyl-l-methionine (SAM) is well-known as a methyl donor for methyltransferases but also functions as a 3-amino-3-carboxypropyl (3-ACP) donor for 3-ACP transferases. NAT is a 3-ACP transferase which accepts β-lactam antibiotic nocardicin G () and SAM to produce isonocardicin C. Due to the lack of structural information about this enzyme, its reaction mechanism has not been fully identified.
View Article and Find Full Text PDFJ Org Chem
September 2025
Ural Federal University Named After the First President of Russia B. N. Yeltsin, Mira Str. 19, Ekaterinburg 620062, Russia.
Azolo[1,5-]pyrimidines (APs) are widely recognized as challenging scaffolds for diverse applications in both medicinal chemistry and materials science. Owing to their high potential, active research is focused on developing new derivatives through the derivatization and functionalization of their molecular structure. Herein, we report an unusual transformation in the AP series initiated by a hydroperoxide anion.
View Article and Find Full Text PDFJ Org Chem
September 2025
Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati 781039, India.
The synthesis of α-ketoamides through oxidative ring opening of 1-acetylindoline-3-one under electrochemical conditions is reported. In an undivided cell, the reaction proceeds via the formation of an iminium ion intermediate, nucleophilic attack by a hydroxide ion, and subsequent ring opening through pre-existing C-N bond cleavage. The reaction in the presence of HO confirms that the amidic oxygen originated from the moisture present in the medium.
View Article and Find Full Text PDFJ Phys Chem A
September 2025
College of Chemistry, Liaoning University, Shenyang 110036, China.
This work investigated the ring-opening reaction mechanism between F and oxirane by combining electronic structure calculations with chemical dynamics simulations. Electronic structure calculations revealed two primary reaction pathways: nucleophilic substitution (S2) and elimination (E2). The S2 pathway was further classified into oxygen-side attack (ret-S2) and backside attack (inv-S2) based on the nucleophilic approach direction.
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