Conformational analysis. Part 34. An NMR investigation of the conformational equilibrium and intramolecular hydrogen bonding in nipecotic acid derivatives

2000 ◽  
pp. 2382-2392 ◽  
Author(s):  
Raymond J. Abraham ◽  
Nuria Aboitiz ◽  
John Merrett ◽  
Brad Sherborne ◽  
Ian Whitcombe
Keyword(s):  
Hydrogen Bonding ◽  
Conformational Analysis ◽  
Conformational Equilibrium ◽  
Intramolecular Hydrogen Bonding ◽  
Nipecotic Acid ◽  
Intramolecular Hydrogen

scholarly journals Conformational analysis and intramolecular interactions in monosubstituted phenylboranes and phenylboronic acids

2013 ◽  
Vol 9 ◽  
pp. 1127-1134 ◽  
Author(s):  
Josué M Silla ◽  
Rodrigo A Cormanich ◽  
Roberto Rittner ◽  
Matheus P Freitas
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Conformational Analysis ◽  
Conformational Equilibrium ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Interactions ◽  
Coupling Constant ◽  
Intramolecular Hydrogen ◽  
Phenylboronic Acids ◽  
Electron Donation

A 1 TS J F,H(O) coupling pathway, dictated by a hydrogen bond, in some 2-fluorobenzoic acids has been observed, while such an interaction does not occur in 2-fluorophenol. Thus, this work reports the conformational analysis of 2-fluorophenylboronic acid (1), in order to evaluate a possible intramolecular OH∙∙∙F hydrogen bond in comparison to an nF→pB interaction, which mimics the quantum nF→σ*OH hydrogen bond that would be expected in 2-fluorophenol. 2-Fluorophenylborane (3), which does not experience hydrogen bonding, was used to verify whether nF→pB interaction governs the conformational equilibrium in 1 due to a predominant OH∙∙∙F hydrogen bond or to other effects. A series of 2-X-phenylboranes (X = Cl, Br, NH2, PH2, OH and SH) were further computationally analyzed to search for electron donors to boron, capable of influencing the conformational equilibrium. Overall, the intramolecular OH∙∙∙F hydrogen bond in 1 is quite stabilizing and dictates the 1 h J F,H(O) coupling constant. Moreover, electron donation to the empty p orbital of boron (for noncoplanar BH2 moiety relative to the phenyl ring) is also significantly stabilizing for the NH2 and PH2 derivatives, but not enough to make the corresponding conformers appreciably populated, because of steric effects and the loss of πCC→pB resonance. Thus, the results found earlier for 2-fluorophenol about the lack of intramolecular hydrogen bonding are now corroborated.

Microwave Spectrum, Intramolecular Hydrogen Bonding and Conformational Equilibrium of trans-2-Methylcyclopropanemethanol.

1992 ◽  
Vol 46 ◽  
pp. 861-866 ◽  
Author(s):  
K.-M. Marstokk ◽  
Harald Møllendal ◽  
Sine Larsen ◽  
Carsten H. Petersen ◽  
Johan Springborg ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Conformational Equilibrium ◽  
Intramolecular Hydrogen Bonding ◽  
Microwave Spectrum ◽  
Intramolecular Hydrogen

Intramolecular Hydrogen Bonding in α-Epoxy Alcohols: A Conformational Analysis of 1,2-Dialkyl-2,3-epoxycyclopentanol Diastereomers

2018 ◽  
Vol 47 (2) ◽  
pp. 156-159 ◽  
Author(s):  
Yasmeen A. Abdo ◽  
Justin W. Weeks ◽  
William Layfield ◽  
William M. Tremlett ◽  
Joshua W. Graham ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Conformational Analysis ◽  
Intramolecular Hydrogen Bonding ◽  
Epoxy Alcohols ◽  
Intramolecular Hydrogen

Conformational analysis and intramolecular hydrogen bonding of cis-3-aminoindan-1-ol: a quantum chemical study

2013 ◽  
Vol 19 (11) ◽  
pp. 4837-4847 ◽  
Author(s):  
Djaffar Kheffache ◽  
Hind Guemmour ◽  
Azzedine Dekhira ◽  
Ahmed Benaboura ◽  
Ourida Ouamerali
Keyword(s):  
Hydrogen Bonding ◽  
Conformational Analysis ◽  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Hydrogen
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