title: High-performance liquid chromatographic enantioseparation of naphthol-substituted tetrahydroisoquinolines on polysaccharide-based chiral stationary phases.
abstract: The stereoisomers of 15 naphthol-substituted tetrahydroisoquinoline analogs were separated on chiral stationary phases containing the chiral selectors cellulose tris-(3,5-dimethylphenyl carbamate) (Cellulose 1), cellulose tris-(3-chloro-4-methylphenyl carbamate) (Cellulose 2), cellulose tris-(4-methylbenzoate) (Cellulose 3) and cellulose tris-(4-chloro-3-methylphenyl carbamate) (Cellulose 4). Experiments were performed in normal-phase mode with n-heptane(n-hexane)-alcohol-diethylamine mobile phases in the temperature range 5-40 °C. Thermodynamic parameters were calculated from plots of lnk or lnα vs 1/T. On the Cellulose 1 column, Δ(ΔH°) ranged from -6.8 to 5.9 kJ/mol, Δ(ΔS°) from -16.7 to 21.0 J/mol/K and the Gibbs energy, -Δ(ΔG°) from 0.2 to 1.5 kJ/mol; on the Cellulose 2 column, Δ(ΔH°) ranged from -7.8 to 2.5 kJ/mol, Δ(ΔS°) from -16.1 to 13.2 J/mol/K and - Δ(ΔG°) from 0.7 to 3.0 kJ/mol. Both enthalpy- and entropy-controlled enantioseparations were observed. The latter was advantageous with regard to the shorter retention and greater selectivity at high temperature.
authors.affiliation: Department of Inorganic and Analytical Chemistry, University of Szeged, H-6720, Szeged, Dóm tér 7, Hungary.
authors.forename: István
authors.initials: I
authors.lastname: Ilisz
authors.forename: Zsanett
authors.initials: Z
authors.lastname: Gecse
authors.forename: István
authors.initials: I
authors.lastname: Szatmári
authors.forename: Ferenc
authors.initials: F
authors.lastname: Fülöp
authors.forename: Antal
authors.initials: A
authors.lastname: Péter
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D006358:Hot Temperature; D009284:Naphthols / Q000737:chemistry* / Q000302:isolation & purification; D011134:Polysaccharides / Q000737:chemistry; D013237:Stereoisomerism; D044005:Tetrahydroisoquinolines / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D009284:Naphthols; D011134:Polysaccharides; D044005:Tetrahydroisoquinolines
keywords: direct enantiomer separation of naphthol-substituted tetrahydroisoquinoline analogs; high-performance liquid chromatography (HPLC); temperature dependence of chiral separation