Back
Synthesis, resolution, and VCD analysis of an enantiopure diazaoxatricornan derivative.
Journal article

Synthesis, resolution, and VCD analysis of an enantiopure diazaoxatricornan derivative.

  • 2008-04-17
Published in:
  • Journal of the American Chemical Society. - 2008
Agrostemma
Aza Compounds
Benzopyrenes
Circular Dichroism
Models, Molecular
Molecular Conformation
Spectrophotometry, Infrared
Stereoisomerism
Thermodynamics
English Using simple organic synthetic transformations, a novel diazaoxatricornan derivative, the 12 c-methyl-12-phenyl-8-propyl-12,12 c-dihydro-8 H-4-oxa-8,12-diazadibenzo[ cd, mn]pyrene ( 6a), was prepared. This novel chiral cup-shaped molecule was isolated in racemic form and in excellent yield after the addition of methyl lithium to the BF 4 salt of a novel unsymmetrical diazaoxatriangulenium cation. Compound 6a was found to be stable under classical laboratory conditions-something not obvious considering the extreme stability of the carbenium ion precursor, the electron-rich nature of the core, and the strain induced by the pyramidalization of the central carbon. The enantiomers were readily separated by chiral stationary phase chromatography, and the absolute configuration of (-)-( S)- 6a was determined by a comparison of the experimental and theoretical vibrational circular dichroism (VCD) spectra. This isolation of (-)-( S)- 6a and (+)-( R)- 6a constitutes thus the first report of a nonracemic closed-capped chiral bowl molecule for which the chirality is due to the intrinsic dissymmetry of the central core of the structure only.
Language
  • English
Open access status
closed
Identifiers
Persistent URL
https://sonar.ch/global/documents/117887
Statistics
Document views: 26 File downloads: