Synthesis, Optical Resolution and Enantiomeric Recognition Ability of Novel, Inherently Chiral Calix[4]arenes: Trial Application to Asymmetric Reactions as Organocatalysts
Newly designed, inherentlychiralcalix[4]arenes containing amino phenol structures have been synthesized and resolved to optically pure forms. The enantiomeric recognition ability of one chiralcalix[4]arene was examined with mandelic acid by 1H NMR spectroscopy, and we found that the inherentlychiralcalix[4]arene could be used as a chiral NMR solvating agent to determine the enantiopurity of mandelic