Direct resolution of racemic compounds on chiral microbore columns by Sub- and Supercritical Fluid Chromatography

Fast resolutions of racemic compounds (sulfoxides, amino alcohols, and α-methylarylacetic acids derivatives) were achieved on a chiral microbore column using carbon dioxide and a polar methanol/dioxane modifier. The stationary phase used in this study contains the 3,5-dinitrobenzoyl derivative of R,R(−)-1,2-diaminocyclohexane (DACH-DNB) as the chiral moiety, anchored to a silica gel surface by covalent bonds. Both thermodynamic and kinetic separation performances were improved by using a super- or subcritical carbon dioxide mobile phase (SFC, SubFC).