HPLC-BASED METHOD FOR DETERMINATION OF ABSOLUTE-CONFIGURATION OF ALPHA-CHIRAL AMINES

We introduce a novel, HPLC-based method for facile determination of th e absolute configuration of alpha-chiral amines. Our method is easily applied to a variety of compounds, including amino acid derivatives. T he method involves initial derivatization of the chiral amine analyte with the chiral derivatizing reagent, N-succinimidyl alpha-methoxyphen ylacetate (SMPA), to produce the corresponding diastereomeric adducts. Inspection of a particular rotomer of the SMPA adduct and application of simple rules correlates absolute configuration and HPLC elution or der. A key aspect of our method is that it can be used to determine ab solute configuration without using enantiomeric standards of the amine analytes. Furthermore, it is of utmost significance that our method c an also be used to determine absolute configuration even when only one analyte enantiomer of unknown absolute configuration is present, as i s often the case for enzymatic products, naturally derived compounds, or enantiomerically enriched compounds prepared via chiral syntheses. We have observed strict adherence between predicted and observed absol ute configuration for a wide variety of alpha-chiral amines. The chrom atographic method we present in this paper is very practical and has s everal important advantages over NMR-based approaches which have been previously developed. For example, microgram quantities of an analyte in a complex enzymatic mixture can be directly analyzed by our HPLC-ba sed method while the impurities often preclude definitive proton assig nments in the NMR approach.