Synthesis and evaluation of N-3,5-dinitrobenzoyl-beta-amino acid derived chiral stationary phases

The use of chiral stationary phases (CSPs) for the direct analytical and preparative separation of enantiomers has enjoyed increasing popularity in the past decade. The inherent advantages of chromatography; rapid analysis time, the ability to separate complex mixtures, reproducibility, flexibility and economy are extended to the problem of enantiomeric resolution when CSPs are employed.Considerable progress has been made in the development of synthetic CSPs for the direct chromatographic separation of enantiomers. An innate advantage of synthetic CSPs is the ability to prepare either optical antipode of the CSP as well as the racemic analogs. CSPs derived from the 3,5-dinitrobenzamides of $\alpha$-amino acids have been prepared and extensively evaluated for the separation of enantiomers. We became interested in the effect on enantiomer separations of a second stereogenic center in the CSP as a result of our studies of CSPs which have a single stereogenic center. To this end, a new $N$-(3,5-dinitrobenzoyl)-$\beta$-amino acid derived CSP was synthesized and evaluated for the separation of enantiomers.The $N$-(3,5-dinitrobenzoyl)-$\beta$-amino acid derived CSP affords superior performance for the separation of the enantiomers of many chiral compounds, including $\alpha$-naphthyl carbamate derivatives of chiral alcohols and 3,5-dimethylanilide derivatives of chiral carboxylic acids. In contrast to the 3,5-dimethylanilides of chiral carboxylic acids, the enantiomers of 3,5-dimethylanilide derivatives of $N$-protected $\alpha$-amino acids give higher separation factors on the $N$-(3,5-dinitrobenzoyl)-$\alpha$-amino acid derived CSPs.U of I OnlyETDs are only available to UIUC Users without author permissio