title: Separation of atropisomeric 1,4,5,6-tetrahydropyrimidinium salts by chiral HPLC and determination of their enantiomerization barriers.
abstract: Chiral HPLC separation of a series of novel atropisomeric quaternary (1) and ternary (2) 1,2-disubstituted 1,4,5,6-tetrahydropyrimidinium salts bearing disymmetric aryl groups in positions 1 and/or 2 is described. A screening of different polysaccharide stationary phases (OD-R, OJ-R and AD-RH) and chromatographic conditions allowed for partial or baseline resolution of 16 over 26 compounds. When a semi-preparative separation was achieved, the corresponding enantiomerization barriers were determined employing the off-column method. The experimental data were compared inter se in order to establish the factors influencing the magnitude of the barriers and with those corresponding to the parent amidines.
authors.affiliation: Umr 6180 Chirotechnologies: Catalyse et Biocatalyse, University Paul Cézanne, Aix-Marseille III, 13397 Marseille CEDEX 20, France.
authors.forename: María L
authors.initials: ML
authors.lastname: Magri
authors.forename: Nicolas
authors.initials: N
authors.lastname: Vanthuyne
authors.forename: Christian
authors.initials: C
authors.lastname: Roussel
authors.forename: María B
authors.initials: MB
authors.lastname: García
authors.forename: Liliana R
authors.initials: LR
authors.lastname: Orelli
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007536:Isomerism; D011743:Pyrimidines / Q000302:isolation & purification*; D013237:Stereoisomerism
chemical_list: D011743:Pyrimidines