Conformational analysis of intramolecular hydrogen-bonded amino alcohols. Determination of the NH/N-electron pair equilibrium and assignment of conformational free energies for interactions in decahydroquinoline and piperidine compounds in a dilute nonpolar medium

1976 ◽  
Vol 98 (22) ◽  
pp. 7013-7017 ◽  
Author(s):  
Herbert S. Aaron ◽  
C. Parker Ferguson
Keyword(s):  
Conformational Analysis ◽  
Electron Pair ◽  
Amino Alcohols ◽  
Free Energies ◽  
Nonpolar Medium ◽  
Intramolecular Hydrogen ◽  
Hydrogen Bonded

Hydrogen bonding in some t-amino-alcohols related to methadone

1969 ◽  
Vol 47 (9) ◽  
pp. 1587-1592 ◽  
Author(s):  
A. F. Casy ◽  
M. M. A. Hassan
Keyword(s):  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bonding ◽  
Amino Alcohols ◽  
Frequency Data ◽  
Intramolecular Hydrogen ◽  
Hydrogen Bonded

Hydroxyl stretching frequency data upon 1-dimethylamino-3,3-diphenylhexan-4-ol and related amino-alcohols are reported which give evidence of unusually strong intramolecular hydrogen bonding between the hydroxy and t-amino functions of these compounds. In corresponding salts, concentration independent vOH bands, typical of hydrogen bonded species, also occur and a bonded system comprising anion, OH, and N+H functions is proposed together with probable methadol base and salt conformations.

scholarly journals Crystal structure and conformational analysis of doxorubicin nitrate

2018 ◽  
Vol 74 (3) ◽  
pp. 400-405 ◽  
Author(s):  
Logesh Mathivathanan ◽  
Guang Yang ◽  
Fenfei Leng ◽  
Raphael G. Raptis
Keyword(s):  
Crystal Structure ◽  
Conformational Analysis ◽  
Crystal Lattice ◽  
Structure Determination ◽  
Crystal Structure Determination ◽  
Asymmetric Unit ◽  
Two Component ◽  
Hydrogen Bonded

Crystal structure determination of doxorubicin nitrate, (DoxH)NO3, systematic name (7S,9S)-7-{[(2R,4S,5S,6S)-4-azaniumyl-5-hydroxy-6-methyloxan-2-yl]oxy}-6,9,11-trihydroxy-9-(2-hydroxyacetyl)-4-methoxy-8,10-dihydro-7H-tetracen-5,12-dione nitrate, shows two formula units present in the asymmetric unit. In the crystal lattice, hydrogen-bonded pairs of (DoxH+) cations and segregation of the aglycone and sugar moieties are observed. Inspection of molecular overlays reveals that the conformation of (DoxH)NO3resembles that of DNA-intercalated, but not of protein-docked (DoxH)+. The structure was refined as a two-component twin.

2-Deoxyribose Radicals in the Gas Phase and Aqueous Solution. Transient Intermediates of Hydrogen Atom Abstraction from 2-Deoxyribofuranose

2005 ◽  
Vol 70 (11) ◽  
pp. 1769-1786 ◽  
Author(s):  
Luc A. Vannier ◽  
Chunxiang Yao ◽  
František Tureček
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Atom ◽  
Gas Phase ◽  
Computational Study ◽  
Hydrogen Atom Abstraction ◽  
Oh Radical ◽  
Free Energies ◽  
Intramolecular Hydrogen ◽  
Solvation Free Energies ◽  
Transient Intermediates

A computational study at correlated levels of theory is reported to address the structures and energetics of transient radicals produced by hydrogen atom abstraction from C-1, C-2, C-3, C-4, C-5, O-1, O-3, and O-5 positions in 2-deoxyribofuranose in the gas phase and in aqueous solution. In general, the carbon-centered radicals are found to be thermodynamically and kinetically more stable than the oxygen-centered ones. The most stable gas-phase radical, 2-deoxyribofuranos-5-yl (5), is produced by H-atom abstraction from C-5 and stabilized by an intramolecular hydrogen bond between the O-5 hydroxy group and O-1. The order of radical stabilities is altered in aqueous solution due to different solvation free energies. These prefer conformers that lack intramolecular hydrogen bonds and expose O-H bonds to the solvent. Carbon-centered deoxyribose radicals can undergo competitive dissociations by loss of H atoms, OH radical, or by ring cleavages that all require threshold dissociation or transition state energies >100 kJ mol-1. This points to largely non-specific dissociations of 2-deoxyribose radicals when produced by exothermic hydrogen atom abstraction from the saccharide molecule. Oxygen-centered 2-deoxyribose radicals show only marginal thermodynamic and kinetic stability and are expected to readily fragment upon formation.

scholarly journals Rapid Organocatalytic Chirality Analysis of Amines, Amino Acids, Alcohols, Amino Alcohols and Diols with Achiral Iso(thio)cyanate Probes

2021 ◽  
Author(s):  
Eryn Nelson ◽  
Jeffrey S. S. K. Formen ◽  
Christian Wolf
Keyword(s):  
Amino Acids ◽  
Absolute Configuration ◽  
Rapid Determination ◽  
Amino Alcohols ◽  
Enantioselective Synthesis ◽  
Widespread Occurrence ◽  
Chiral Compounds ◽  
New Methods ◽  
The Absolute

The widespread occurrence and significance of chiral compounds does not only require new methods for their enantioselective synthesis but also efficient tools that allow rapid determination of the absolute configuration,...

Asymmetric Total Synthesis and Determination of the Absolute Configuration of (+)-Srilankenyne via Sequence-Sensitive Halogenations Guided by Conformational Analysis

2021 ◽  
Vol 23 (4) ◽  
pp. 1321-1326
Author(s):  
Hongjun Jang ◽  
Soo Yeon Kwak ◽  
Dongjoo Lee ◽  
Juan V. Alegre-Requena ◽  
Hyoungsu Kim ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Conformational Analysis ◽  
Absolute Configuration ◽  
Asymmetric Total Synthesis ◽  
The Absolute
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