Synthesis of macrocycles and their application as chiral solvating agents in the enantiomeric recognition of carboxylic acids and α-amino acid derivatives

The chiral macrocycles 1 and 2 with multiple binding sites have been synthesized from D-phenylalanine as chiral solvating agents (CSAs) for the enantiomeric discrimination and determination of the enantiomeric excess of carboxylic acids and a-amino acids derivatives by the 1H NMR spectroscopy. The results show that chiral macrocycles 1 and 2 are effective CSAs towards the carboxylic acids and a-amino acids derivatives.

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C38H36N4O4[α]D20=-202.9 (c 0.05, CHC13)Source of chirality: the precursor and formationAbsolute configuration: (R,S,R,R)

1-(4-Methylphenyl)-3-(1R,2S,5R)-menthyloxycarbonyl)-5-(S)-ethoxycarbonyl-4,5-dihydropyrazoleC45H48N5O4[α]D20=-77.85 (c 0.06, CHCl3)Source of chirality: the precursor and formationAbsolute configuration: (R,S,R,R)