High-performance liquid chromatographic enantioseparation of amino alcohol analogues possessing 1,2,3,4-tetrahydroisoquinoline skeleton on polysaccharide-based chiral stationary phases.

The stereoisomers of 1,2,3,4-tetrahydroisoquinoline amino alcohol analogues and derivatives thereof were separated in normal-phase mode on chiral stationary phases based on preprepared silica coated with cellulose tris-(3,5-dimethylphenyl carbamate), cellulose tris-(3-chloro-4-methylphenyl carbamate), cellulose tris-(4-methylbenzoate) or cellulose tris-(4-chloro-3-methylphenyl carbamate). On all the investigated chiral columns, the retention and the enantioseparation were influenced by the nature and the concentrations of the mobile phase components and additives, and also the temperature. Experiments were performed in the temperature range 10-50°C. Thermodynamic parameters were calculated from plots of lnα vs 1/T. On these polysaccharide-based chiral columns, both enthalpy-driven separations and entropy-controlled enantioseparations were observed. The latter was advantageous with regard to the shorter retention and greater selectivity at high temperature. The sequence of elution of the stereoisomers was determined in all cases.