Absolute configuration assignment of (3-phenyloxirane-2,2-diyl)bis(phenylmethanone) via density functional calculations of optical rotation and vibrational circular dichroism

Chirality ◽  
2010 ◽  
Vol 22 (1E) ◽  
pp. E130-E135 ◽  
Author(s):  
Alessandra Lattanzi ◽  
Alessio Russo ◽  
Paola Rizzo ◽  
Guglielmo Monaco ◽  
Riccardo Zanasi
Keyword(s):  
Circular Dichroism ◽  
Absolute Configuration ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Optical Rotation ◽  
Vibrational Circular Dichroism ◽  
Configuration Assignment ◽  
Circular Dichroïsm

scholarly journals Absolute Configuration Assignment of 3′,4′-di-O-acylkhellactones Using Vibrational Circular Dichroism Exciton Chirality

2015 ◽  
Vol 10 (6) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Abigail I. Buendía-Trujillo ◽  
J. Martín Torrres-Valencia ◽  
Pedro Joseph-Nathan ◽  
Eleuterio Burgueño-Tapia
Keyword(s):  
Circular Dichroism ◽  
Diffraction Analysis ◽  
Absolute Configuration ◽  
Optical Rotation ◽  
Vibrational Circular Dichroism ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aerial Parts ◽  
Configuration Assignment ◽  
Circular Dichroïsm

The 3′R,4 ‘R absolute configuration (AC) of the angular-type pyranocoumarins (-)-3′,4′-di- O-acetylkhellactone (2), (-)-4′- O-acetyl-3′- O-angeloylkhellactone (3), (+)-3′- O-acetyl-4- O-isobutyroylkhellactone (4), and (-)-3′- O-angeloyl-4′- O-senecioylkhellactone (5), isolated from the aerial parts of Prionosciadum thapsoides, was assigned by vibrational circular dichroism exciton chirality (VCDEC), and confirmed by comparison of their VCD frequencies with those calculated using DFT at the B3LYP/DGDZVP level. This again reveals that AC assignments based on optical rotation data are not very confident. Evaluation of Flack and Hooft parameters obtained after single-crystal X-ray diffraction analysis of 3, independently confirmed this AC.

scholarly journals Absolute Configuration Sensing of Chiral Aryl- and Aryloxy-Propionic Acids by Biphenyl Chiroptical Probes

Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 154
Author(s):  
Stefania Vergura ◽  
Stefano Orlando ◽  
Patrizia Scafato ◽  
Sandra Belviso ◽  
Stefano Superchi
Keyword(s):  
Circular Dichroism ◽  
Absolute Configuration ◽  
Optical Rotation ◽  
Environmental Pollutants ◽  
Red Shift ◽  
Electronic Circular Dichroism ◽  
Configuration Assignment ◽  
Clear Sign ◽  
The Absolute ◽  
Circular Dichroïsm

The absolute configuration of chiral 2-aryl and 2-aryloxy propionic acids, which are among the most common chiral environmental pollutants, has been readily and reliably established by either electronic circular dichroism spectroscopy or optical rotation measurements employing suitably designed 4,4′-disubstituted biphenyl probes. In fact, the 4,4′-biphenyl substitution gives rise to a red shift of the diagnostic electronic circular dichroism signal of the biphenyl A band employed for the configuration assignment, removing its overlap with other interfering dichroic bands and allowing its clear sign identification. The largest A band red shift, and thus the most reliable results, are obtained by employing as a probe the 4,4′-dinitro substituted biphenylazepine 3c. The method was applied to the absolute configuration assignment of 2-arylpropionic acids ibuprofen (1a), naproxen (1b), ketoprofen (1c) and flurbiprofen (1d), as well as to the 2-aryloxypropionic acids 2-phenoxypropionic acid (2a) and 2-naphthoxypropionic acid (2b). This approach, allowing us to reveal the sample’s absolute configuration by simple optical rotation measurements, is potentially applicable to online analyses of both the enantiomeric composition and absolute configuration of these chiral pollutants.

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