Tautomerism and conformational analysis in 3-fluoropiperidin-2-one inform on F···HO intramolecular hydrogen bond

2019 ◽  
Vol 217 ◽  
pp. 8-12 ◽  
Author(s):  
Josué M. Silla ◽  
Matheus P. Freitas
Keyword(s):  
Hydrogen Bond ◽  
Conformational Analysis ◽  
Intramolecular Hydrogen Bond ◽  
Intramolecular Hydrogen

scholarly journals Conformational analysis, stereoelectronic interactions and NMR properties of 2-fluorobicyclo[2.2.1]heptan-7-ols

2012 ◽  
Vol 8 ◽  
pp. 1227-1232 ◽  
Author(s):  
Fátima M P de Rezende ◽  
Marilua A Moreira ◽  
Rodrigo A Cormanich ◽  
Matheus P Freitas
Keyword(s):  
Hydrogen Bond ◽  
Conformational Analysis ◽  
Quantum Chemical Calculations ◽  
Intramolecular Hydrogen Bond ◽  
Quantum Chemical ◽  
Coupling Constant ◽  
Structural Stabilization ◽  
Intramolecular Hydrogen ◽  
Nmr Properties ◽  
Stereoelectronic Interactions

Four diastereoisomers of 2-fluorobicyclo[2.2.1]heptan-7-ols were computationally investigated by using quantum-chemical calculations, and their relative energies were analyzed on the basis of stereoelectronic interactions, particularly the presence or otherwise of the F∙∙∙HO intramolecular hydrogen bond in the syn-exo isomer. It was found through NBO and AIM analyses that such an interaction contributes to structural stabilization and that the 1h J F,H(O) coupling constant in the syn-exo isomer is modulated by the n F→σ*OH interaction, i.e., the quantum nature of the F∙∙∙HO hydrogen bond.

Quantification of Intramolecular Hydrogen Bond in Neurotransmitter Dopamine

2009 ◽  
Vol 2 (3) ◽  
pp. 671-674
Author(s):  
Nagaraju Garipelli ◽  
RB Sunoj ◽  
Madhava Reddy B ◽  
Jithan AV ◽  
Chinnalaliah Runja
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Conformational Analysis ◽  
Intramolecular Hydrogen Bond ◽  
Isodesmic Reaction ◽  
Hydroxyl Groups ◽  
Reaction Method ◽  
Aromatic Systems ◽  
Intramolecular Hydrogen ◽  
Different Levels

Dopamine is a catecholamine chemically, 3, 4-dihydroxyphenyethylamine. It has intramolecular H-bond (IHB) between the two hydroxyl groups. The energy of intramolecular H-bond might contribute energy in binding of the neurotransmitter with the receptors. Here the IHB in Dopamine is calculated in different levels of theories. The energetics of intramolecular hydrogen bonds is of fundamental importance in biochemistry. In contrast with intermolecular H-bonds, whose enthalpy can be determined by a supermolecular approach, there is no general accepted procedure to determine the enthalpy of an intramolecular H-bond. In this work, different ways for assessing the energetics of intramolecular H-bonds of selected aromatic systems were applied and compared. They include the widely used conformational analysis approach (cis-trans method), a recently proposed isodesmic reaction method, and a new procedure that is designated as the ortho-para method.

scholarly journals The conjugates of ferrocene-1,1′-diamine and amino acids. A novel synthetic approach and conformational analysis

2015 ◽  
Vol 44 (37) ◽  
pp. 16405-16420 ◽  
Author(s):  
Monika Kovačević ◽  
Ivan Kodrin ◽  
Mario Cetina ◽  
Ivana Kmetič ◽  
Teuta Murati ◽  
...  
Keyword(s):  
Amino Acids ◽  
Hydrogen Bond ◽  
Conformational Analysis ◽  
Intramolecular Hydrogen Bond ◽  
Synthetic Approach ◽  
Hydrogen Bond Pattern ◽  
Intramolecular Hydrogen

The first example of an orthogonally protected ferrocene-1,1′-diamine based peptidomimetic with a stable intramolecular hydrogen bond pattern comprised of two β-turns is reported.

Effect of the intramolecular hydrogen bond in the active metabolite analogs of leflunomide for blocking the Plasmodium falciparum dihydroorotate dehydrogenase enzyme: QTAIM, NBO, and docking study

2020 ◽  
Vol 16 ◽  
Author(s):  
Reihaneh Heidarian ◽  
Mansoureh Zahedi-Tabrizi
Keyword(s):  
Hydrogen Bond ◽  
Plasmodium Falciparum ◽  
Molecular Orbital ◽  
Intramolecular Hydrogen Bond ◽  
Active Metabolite ◽  
Chemical Hardness ◽  
Dihydroorotate Dehydrogenase ◽  
Molecular Orbital Analysis ◽  
Intramolecular Hydrogen ◽  
Orbital Analysis

: Leflunomide (LFM) and its active metabolite, teriflunomide (TFM), have drawn a lot of attention for their anticancer activities, treatment of rheumatoid arthritis and malaria due to their capability to inhibit dihydroorotate dehydrogenase (DHODH) and Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) enzyme. In this investigation, the strength of intramolecular hydrogen bond (IHB) in five analogs of TFM (ATFM) has been analyzed employing density functional theory (DFT) using B3LYP/6-311++G (d, p) level and molecular orbital analysis in the gas phase and water solution. A detailed electronic structure study has been performed using the quantum theory of atoms in molecules (QTAIM) and the hydrogen bond energies (EHB) of stable conformer obtained in the range of 76-97 kJ/mol, as a medium hydrogen bond. The effect of substitution on the IHB nature has been studied by natural bond orbital analysis (NBO). 1H NMR calculations show an upward trend in the proton chemical shift of the enolic proton in the chelated ring (14.5 to 15.7ppm) by increasing the IHB strength. All the calculations confirmed the strongest IHB in 5-F-ATFM and the weakest IHB in 2-F-ATFM. Molecular orbital analysis, including the HOMO-LUMO gap and chemical hardness, was performed to compare the reactivity of inhibitors. Finally, molecular docking analysis was carried out to identify the potency of inhibition of these compounds against PfDHODH enzyme.

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