Chiral trans-1,2-diaminocyclohexane derivatives as chiral solvating agents for carboxylic acids

Abstract

Efficient use of the readily accessible chiral C 2-symmetric acyclic diamines (1-2) as well as macrocyclic amines (3-5) containing trans-1,2-diaminocyclohexyl moiety as chiral solvating agents (CSA) for the determination of enantiomeric excess of representative carboxylic acids (6-7) and an amino acid derivative (8) is illustrated. The enantiomeric composition of different carboxylic acids estimated here by the 1H NMR method, based on the integration of the corresponding methine proton signals are in good correlation with that determined using HPLC method. The data are in accordance with the formation of multimolecular diastereomeric complexes in solution, which render good splitting of NMR signals for the enantiomers of representative carboxylic acids as well as for N-Ts-phenylglycine (up to ΔΔ§ = 0.295 ppm, 118 Hz). © Indian Academy of Sciences.