1403601-13-7Relevant articles and documents
Isocyanurates with planar chirality: Design, optical resolution, and isomerization
Goto, Hidetoshi,Sudoh, Masanao,Kawamoto, Keiko,Sugimoto, Hiroshi,Inoue, Shohei
, p. 867 - 878,12 (2020/07/30)
Designs and syntheses of isocyanurates (1-3) are described on the basis of a novel concept that two enantiotopic faces of Cs-symmetric, prochiral planar molecules are differentiated with a location of groups at the top or bottom of the planar skeleton using a rigid linker. Such isocyanurates are atropisomeric. The planar-chiral structures of and anti (anti-conformer of) were confirmed by single-crystal X-ray analyses, and the space groups were P1 (for) and P21/c (for anti), resulting that the crystals were racemates. Optical resolutions of 1-3 were successfully accomplished by using chiral high-performance liquid chromatography technique in combination with circular dichroism, absorption, and nuclear magnetic resonance spectroscopies and mass spectrometry. Furthermore, the rotational barriers (ΔGs) related to isomerizations of 1-3 were estimated to be 27.2 (for at 50 °C), 27.6 (for anti at 50 °C), and 40.6 (for syn at 150 °C) kcal/mol. The ΔGs of and were higher than that of and, in particular, that of was highest among them. This result indicates that an introduction of bulky substituents and an intramolecular bridging are effective for inhibitions of the isomerizations. Copyright
