| Research Abstract |
We have prepared chiral stationary phases 1 having anisole type pseudo-18-crown-6 ether as selector, and found high separation ability of chiral amino compound. This CSP was succeeded to put to practical use. In order to investigate the effect of structure of chiral moiety and functional group placed in the crown cavity on enantioselectivity, chiral column (2,3) having phenolic psoudo-18-crown-6 ethers as selectors were synthesized. The enantioselectivity of the selectors having 1-phenyl-1,2-cydohexanediol (4,5),3,5-dimethylphenyl derivative (6),4-tryfluoromethylphenyl derivative (7), and 1-naphtyl derivative (8) were investigated. Corresponding chiral selectors (9,10,11,12) were derived to CSPs (1,13,14,15) and chiral column for chromatography were prepared. In addition, chiral selectors for secondary amines were designed and synthesized. Chiral crown ether 11 was applied for chiral sift reagent with lanthanide compound.
Chromatographic performance of chemically bonded type CSP 13 having a relatively bulky chiral 1-phenyl-1,2-cydohexanediol unit was tested. Using normal phase chromatographic conditions, CSP 13 exhibited short retention times and good resolution of the enantiomers of various amino compounds including amino acids, amino alcohols, and hydrophobic amino compounds. The separation of relatively bulky amino compounds was better on CSP 1, whereas small amino compounds were separated better on CSP 13 Overall, considerable improvements in the enantiomer separation was achieved for many amino compounds on CSP 13 compared to CSP 1. CSP 13 is not always superior to CSP 1. The two CSPs are complementary with each other in terms of chiral recognition. CSP 13 and CSP 1 have little restriction in mobile phases, additives, and analytes because of chemically bonded nature, so that both phases have wide applicability for enantiomer separation.
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