نتایج جستجو برای: electrophilicity iindex

تعداد نتایج: 392  

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2012
Drew J Adams Mingji Dai Giovanni Pellegrino Bridget K Wagner Andrew M Stern Alykhan F Shamji Stuart L Schreiber

Piperlongumine is a naturally occurring small molecule recently identified to be toxic selectively to cancer cells in vitro and in vivo. This compound was found to elevate cellular levels of reactive oxygen species (ROS) selectively in cancer cell lines. The synthesis of 80 piperlongumine analogs has revealed structural modifications that retain, enhance, and ablate key piperlongumine-associate...

1999
Christopher J. Cramer Susan E. Barrows

Hydroxyallyl cation and lithium and sodium oxyallyl cations are predicted to react with 1,3-butadiene both in a stepwise fashion and via concerted [4‡ 3] cycloaddition with so-called extended stereochemistry. With hydroxyallyl cation, the stepwise process is preferred and subsequent second bond closures generate products equivalent to those that would arise from concerted [4‡ 3] or [3‡ 2] cyclo...

Journal: :Food frontiers 2023

Browning is a severe problem in the juice industry, which tremendously affected by quinone (Q) reactivity. Here, formation rate, electrophilicity, and oxidizing ability of different quinones were investigated. LC/MS was applied to monitor loss polyphenols model systems during storage. Mathematical modeling collected data conducted derive rate constants various reactions. Polyphenols containing ...

Journal: :Dalton transactions 2012
Mehmed Z Ertem Christopher J Cramer

Quantum chemical modeling is employed to elucidate the catalytic cycle of a recently described supported cobalt compound that catalyzes water oxidation. Key features of the catalytic cycle include a supporting corrole that is rendered non-innocent early in the oxidation process and a pendant carboxylate moiety that functions as a general base to further activate a water molecule that nucleophil...

Journal: :Foundations of Chemistry 2022

Abstract We review the early works which were precursors of Conceptual Density Functional Theory. Starting from Thomas–Fermi approximation and exact formulation Theory by Hohenberg Kohn’s theorem, we will introduce electronegativity theory hard soft acids bases. also present a general introduction to Fukui functions, their relation with nucleophilicity electrophilicity, an emphasis towards impo...

1998
Jianbo Wang Fengting Liang Bei Chen

The electronic effects of Rh(II)-mediated carbenoid intramolecular C-H insertion have been intensively investigated. The chemo-, regio-, and stereoselectivity of the reaction have been observed to be affected by the electrophilicity of the carbene-Rh intermediate, the substituents on the carbon at which the C-H insertion occurs, and steric and conformational factors.1 It has been well documente...

In this research, IR and frontier molecular orbital computations were employed for investigating the influence of B12N12 on the energetic and thermodynamic parameters of TATB. The Computed enthalpy changes and Gibbs free energy variations showed TATB interaction with this nanostructure is exothermic, spontaneous and experimentally possible. The specific ...

2014
Shaozhong Ge Sophie I. Arlow Michael G. Mormino John F. Hartwig

We report the arylation and heteroarylation of α,α-difluoro-α-(trimethylsilyl)acetamides with aryl and heteroaryl bromides catalyzed by an air- and moisture-stable palladacyclic complex containing P(t-Bu)2Cy as ligand. A broad range of electronically varied aryl and heteroaryl bromides underwent this transformation to afford α-aryl-α,α-difluoroacetamides in high yields. Due to the electrophilic...

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