| Research Abstract |
New axially chirai aromatic compounds were designed based on the structure of 9,9'-bianthryl, and their chiroptical properties, features of chiral spaces in crystals, and dynamic stereochemistry were studied.
1.Chiral 9,9'-bianthryldicarboxylic acid derivatives, Enantiomers of 2,2'-or 3,3'-dicarboxylic acid derivatives were resolved via diastereomeric salts. The absolute stereochemistry about the chiral axis was determined by the X-ray structural analysis. The observed circular dichroism(CD) spectra were reasonably reproduced by the TDDFT method. The inclusion experiments were carried out for the 2,2'-dicarbocxylie esters. The enantiopure methyl ester includes a wide range of smalt organic molecules, while the racemic compound includes only benzene, The corresponding phenyl ester showed no inclusion ability. These differences are discussed on the basis of X-ray structures.
2.Optically active 9,9'-bitriptycyl rotamers. Optically inactive and active rotamers of substituted 9,9'-bitriptycyls were isolated as a stereochemical model of meso-tartaric acid. We revisited the term of "absolute conformation" through this study.
3.Restricted rotation about acetylenic axis, To restrict the rotation about acetylenic axis, sterically hindered alkynes with 9-anthryl, 9-triptycyl, or 1-naphthyl groups at the both termini were prepared, When bulky substituents Were introduced, the dynamic processes could be observed by the NMR. The highest rotational barrier was 77 kJ/mol observed in a di(9-triptycyl)ethyne derivative. The substituent effects on the rotational barriers are examined by the X-ray structure and the kinetic data.
|
