title: Enantiomeric separations of α-aryl ketones with cyclofructan chiral stationary phases via high performance liquid chromatography and supercritical fluid chromatography.
abstract: Normal phase chiral HPLC and SFC methods are presented for the enantiomeric separation of 21 α-aryl ketones with a unique class of chiral stationary phases (CSPs) based on cyclofructans (CFs). Separations were achieved for all but 2 analytes, with 17 compounds attaining baseline separation having resolution values up to 4.0. Most separations obtained in HPLC could be transferred to SFC, but the HPLC resolutions were generally better due to greater enantiomeric selectivity values. A structure-separation relationship (SSR) was developed to identify important structural features for separation of this class of compounds using CF-based CSPs. Preliminary studies are also presented that demonstrate the utility of the CF CSPs to investigate the base-induced enantiomerization of α-aryl ketones. It was demonstrated that even small amounts of base (0.01%v/v) in the mobile phase results in rapid, on-column, enantiomerization. Lastly, CSPs composed of superficially porous particles were used to achieve comparable separations of this class of chiral compounds, but at a fraction of the analysis time compared to CSPs composed of fully porous particles.
authors.affiliation: AZYP LLC, 700 Planetarium Place, Arlington, TX 76019, USA.
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Breitbach
authors.affiliation: The University of Texas at Arlington, 700 Planetarium Place, Arlington, TX 76019, USA.
authors.forename: Yeeun
authors.initials: Y
authors.lastname: Lim
authors.affiliation: Division of Chemistry, Department of Biochemistry, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
authors.forename: Qing-Long
authors.initials: QL
authors.lastname: Xu
authors.affiliation: Division of Chemistry, Department of Biochemistry, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
authors.forename: László
authors.initials: L
authors.lastname: Kürti
authors.affiliation: AZYP LLC, 700 Planetarium Place, Arlington, TX 76019, USA; The University of Texas at Arlington, 700 Planetarium Place, Arlington, TX 76019, USA.
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Armstrong
authors.affiliation: The University of Texas at Arlington, 700 Planetarium Place, Arlington, TX 76019, USA. Electronic address: zachary.breitbach@mavs.uta.edu.
authors.forename: Zachary S
authors.initials: ZS
authors.lastname: Breitbach
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D025924:Chromatography, Supercritical Fluid / Q000379:methods; D005630:Fructans / Q000737:chemistry*; D007659:Ketones / Q000302:isolation & purification*; D013237:Stereoisomerism
chemical_list: D005630:Fructans; D007659:Ketones
keywords: Cyclofructan chiral stationary phase; Enantiomerization; HPLC and SFC enantiomeric separation; Structure–separation relationship (SSR); Superficially porous particle; α-Aryl ketone