A facile and efficient method to fabricate high-resolution immobilized cellulose-based chiral stationary phases via thiol-ene click chemistry

Immobilized chiral stationary phases (CSPs) have attracted much attention because of strong solvent resistance and selection of wide range of eluents. In this work, a facile, efficient and engineering method is developed to fabricate high-resolution immobilized cellulose-based CSPs. A controllable amount of acrylate groups, the key to dominate the immobilization degree, is introduced into cellulose chains to obtain cellulose mixed esters with well-defined structure by homogeneous esterification reaction. Subsequently, via simple, efficient, and highly selective thiol-ene click reaction, cellulose mixed esters were chemically bonded onto thiol-modified silica gel to obtain immobilized cellulose-based CSPs, C-AC5-N95 and C-AC25-N75. Due to the stable "C-S-C" crosslinking bonds, the resultant immobilized CSPs exhibit strong solvent resistance, thus they can be used in a wide range of eluents, including normal-phase non-standard solvents and reversed-phase solvents. They withstand even strong solvents of cellulose derivatives, such as hot pyridine, chloroform, DMF and DMSO. More importantly, the immobilized CSPs C-AC5-N95 displays excellent chiral recognition capability, which is similar with, or even better than, that of coated CSPs.