Enantiomer composition determination chiral solvating agent

S )-Ar- -Butyl-2-(phenylcarbamoyloxy)propionamide (193) was used as chiral solvating agent in the NMR determination of the enantiomer composition of the N-(3,4-dinitrobenzoyl) derivative of amino acid ethyl esters400. 

The second approach, the so-called direct method, consists of the direct determination of enantiomers immersed in a chiral environment. A diversity of techniques has been used to determine enantiomeric composition in samples. Polarimetry, NMR using chiral solvating agents (CSAs), or the different chromatographic and related techniques are the most popular. Polarimetry is still broadly applied in organic chemistry laboratories at least as a semiquantitative method. The general, easy-to-perform, and nondestructive characteristics of polarimetry are properties that justify its use. However, limitations such as the need to know the specific optical rotation for the compound of interest, the inherent low sensitivity, and the possible inaccuracies related to the presence of impurities or to the low specific rotation of certain compounds cannot be overlooked. 

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