One-pot synthesis of polysaccharide 3,5-dimethylphenylcarbamates having a random vinyl group for immobilization on silica gel as chiral stationary phases

Different kinds of vinyl groups were randomly introduced onto the glucose units of cellulose 3,5-dimethylphenylcarbamates by a one-pot method using the bifunctional reagents dec-1-ene-10-isocyanate, 2-isocyanatoethyl methacrylate, and methacryloyl chloride. The chiral recognition properties of the prepared derivatives were then evaluated by coating and immobilizing them on silica gel as HPLC packing material. Immobilization was carried out by radical copolymerization with a vinyl comonomer, 1,5-hexadiene, in toluene at 80 degrees C. The effects of the structures and content of the vinyl groups on the immobilization and on enantioseparations were investigated. This one-pot method was also extended to the synthesis of amylose 3,5-dimethylphenylcarbamates having a random vinyl group. Comparisons of the chiral resolution powers of our laboratory-made packing materials and the newly commercialized Chiralpak IA with immobilized amylose 3,5-dimethylphenylcarbamate and Chiralpak IB with immobilized cellulose 3,5-dimethylphenylcarbamate are discussed.