Chromatography

Biography

Biography: Sheng Tang

Abstract

Due to the fact that cellulose and amylose derivatives tend to dissolve in some organic solvents, the related polysaccharide derivatives-based CSPs prepared by coating manner can only work in a limited range of mobile phases, thus, restricting their widespread application in enantioseparation. Chitin, as one of the most abundant optically active biopolymers, is similar to cellulose in primary structure. Much lower solubility of chitosan derivatives was observed compared with the derivatives of cellulose and amylose, enabling the corresponding chitosan derived CSPs to be possibly worked in a wider range of mobile phases. Herein, in order to develop new types of chitosan derivatives-based CSPs, which not only are capable of excellent enantioseparation performance, but also bear a desirable tolerability, we introduce a class of coated-type CSPs, which are based on chitosan bis(arylcarbamate)-(amide) (CACA). The N-acylated chitosan derivatives were synthesized by the reaction of chitosan with carboxylic acid anhydrides in water/methanol in the presence of the corresponding carboxylic acids. CACAs were prepared by further derivatizing N-acylated chitosan with aryl isocyanates. Fig. 1 shows the structures of the prepared CACAs, which were then coated onto 3-aminopropyl silica gel, affording the corresponding CACAs-based CSPs. When the substituents introduced on acyl group at 2-position and on aryl group of phenylcarbamates at 3- and 6-positions were perfectly coordinated, the prepared N-acylated chitosan bis(arylcarbamate) would possess powerful chiral recognition and enatioseparation abilities, and meanwhile exhibited a desirable tolerability towards a wider range of mobile phases, consequently resulting in a new class of promising chiral separation materials.