Preparation of a novel cyclodextrin derivative of benzimido-β-cyclodextrin and its enantioseparation performance in HPLC

Abstract

A novel cyclodextrin (CD) derivative, mono-6-deoxy-benzimide-β-CD (MB-β-CD), in which a rigid substituent was linked to the narrow edge of the CD with a flexible H(2)C-N group, was successfully synthesized through the condensation of mono-6-deoxy-6-amino-β-cyclodextrin and benzaldehyde. To evaluate its enantioseparation abilities and investigate the role of the CD substituents and linkage in chiral recognition, MB-β-CD and mono-6-deoxyphenylimine-β-CD (MP-β-CD) with a rigid linkage were compared in the separation of 36 chiral compounds in a methanol/water mobile phase. The separation results showed that most of the analytes with rigid structures afforded better enantioresolutions on the MP-β-CD (with a rigid linkage) chiral stationary phase (CSP), while better enantioseparations for analytes with flexible structures and big steric hindrance were obtained on the MB-β-CD (with a flexible linkage) CSP. The former exhibited a specificity for the analyte structures, while the latter was more adaptable. Molecular dynamics simulations were performed to further understand the discrimination process and the function of the CD side arm.

Engineering Cyclodextrin Clicked Chiral Stationary Phase for High-Efficiency Enantiomer Separation

“…Comparison with CCN-CSP and CCP-CSP 20 21 12 , CCC3M4-CSP afforded much higher resolution for aryl alcohols. Impressively, the R s of ( E )-1,3-diphenylprop-2-en-1-ol was as high as 13.7, which was over 3 and 11 times higher than that obtained with mono-6-deoxyphenylimine-β-CD and mono-6-deoxybenzimide-β-CD, respectively 31 . These behavious can be explained with the enhanced π-π conjugation between C=C bond and phenyl group via forming stronger π–π interactions, dipole-dipole and steric repulsion interactions with the existence of 3-chloro and 4-methyl in phenylcarbamate moieties.…”

Preparation of chiral oxazolinyl-functionalized β-cyclodextrin-bonded stationary phases and their enantioseparation performance in high-performance liquid chromatography

“…In our previous work, we confirmed that the rigid C=N bonds attached to CDs are essential for obtaining good enantioselectivity in asymmetric catalysis [12][13][14]. This configuration may have a tendency toward hydrolysis, which could affect the stability of chiral stationary phases.…”

“…Three ferrocene derivatives were examined in this paper (Table 1, entries [14][15][16]. The corresponding graph is given in Fig.…”

Recent development of cationic cyclodextrins for chiral separation

“…Most of selected analytes could be well resolved (R s > 1.5) under reversed-phase mode for both CSPs. Also, mono-6-deoxy-benzimide-β-CD was synthesized via the condensation of mono-6-deoxy-6-amino-β-CD and benzaldehyde [47]. The chiral recognition ability of CD substituents and linkage was further investigated in HPLC towards 36 chiral compounds.…”