Synthesis and characteristics of composite chiral stationary phases based on cellulose derivatives

Abstract

Synthesis and characteristics of composite chiral stationary phases based on cellulose derivativesComposite chiral stationary phases (CSPs) were prepared on the basis of cellulose derivatives coated or bonded onto silica. "Molecular exterior" type CSPs were prepared by mixing together two different cellulose tris-derivatives before or after being coated or bonded onto silica, and the "molecular interior" type was obtained by synthesizing non-regioselectively heterosubstituted cellulose derivatives coated or bonded onto silica. For the sake of comparison, the individual phases were also prepared with corresponding cellulose derivatives by coating or bonding approaches, respectively. All of the prepared CSPs were characterized and their chiral recognition properties were evaluated by HPLC with several test racemates. The experimental results demonstrated that the "molecular exterior" CSPs generally exhibit chiral recognition capacities intermediate between those of the two individual phases. However, in the separation of some racemates higher enantioselectivity may be achieved on the "molecular interior" phases than on individual phases, thus broadening the application range of a single cellulose-based CSP.

Capillary electrochromatographic separation of enantiomers on chemically bonded type of cellulose derivative chiral stationary phases with a positively charged spacer

“…All of the prepared phases were characterized by FT-IR spectrum. The peaks due to the carbonyl group at around 1710 cm 21 and phenyl group at around 1550, 1615 cm 21 were observed. Elemental analyses of the base materials and the prepared CSPs were carried out and the results are listed in Table 1.…”

“…The details for preparation of cellulose 2,3-bi(phenylcarbamate) (CPC) and cellulose 2,3-bi(3,5-dimethylphenylcarbamate) (CDMPC) were reported previously [21].…”

Synthesis of covalently bonded cellulose derivative chiral stationary phases with a bifunctional reagent of 3-(triethoxysilyl)propyl isocyanate

“…Although a been successfully developed to prepare the bondedvery large range of enantiomers have been separated type phases reported by Okamoto and co-workerś on these coated CSPs, the main drawback of these [9][10][11], Minguillon et al [12][13][14], and others [8]. phases is related to the solubility of chiral selectors Recently, we have successfully synthesized a compoin a number of solvents, thus the solvents used as the site type of CSP by chemically bonding two different cellulose derivatives onto a silica matrix [15]. In this study, the main objective is to develop a bifunctional reagent of 3-(triethoxysilyl)propyl isowas allowed to react at 90 8C for 10 h. Then the cyanate (TEPI), on which the isocyanate groups are cooled solution was poured into a large flask and expected to react with the hydroxyl groups of isolated as the fraction insoluble in methanol.…”

Preparation and Enantioseparation of Biselector Chiral Stationary Phases Based on Amylose and Chitin Derivatives

“…This tendency was consistent with the reported conclusion. 30,31 However, some racemates, such as 18 and 30, could be baseline separated. For example, analyte 18 was separated by biselector CSPs 3 -5 with the resolutions of 2.95, 3.48, 4.38, respectively, but it was not recognized by single selector CSPs 1 and 2 in the same mobile phase (Fig.…”