Synthesis of new chiral calix[4]arene diamide derivatives for liquid phase extraction of α-amino acid methylesters

The synthesis of chiral diamide derivatives of calix[4]arene from the reaction of p-tert-butylcalix[4]arene diester 1a and calix[4]arene diester 1b with various amino alcohols were reported. The 1H and 13C NMR, data showed that the compounds synthesized exist in the cone conformation. The extraction study properties of these new compounds 3a,b–4a,b towards some selected α-amino acid methylesters are also reported.

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5,11,17,23-Tetra-tert-butyl-25,27-bis[(R,R)-phenylglycinolyl-carbonylmethoxy]-26,28-dihydroxy-calix[4]areneC64H78N2O8[α]D20=-8.7 (c 0.3, CHCl3)Source of chirality: (R)-(−)-phenylglycinolAbsolute configuration: (R,R)

25,27-bis[(R,R)-phenylglycinolyl-carbonylmethoxy]-26,28-dihydroxy-calix[4]areneC48H46N2O8[α]D20=-30 (c 0.5, CHCl3)Source of chirality: (R)-(−)-phenylglycinolAbsolute configuration: (R,R)

5,11,17,23-Tetra-tert-butyl-25,27-bis[(R,R)-2-amino-1-butanolyl-carbonylmethoxy]-26,28-dihydroxy-calix[4]areneC56H78N2O8[α]D20=-9.3 (c 0.4, CHCl3)Source of chirality: (R)-(−)-2-amino-1-butanolAbsolute configuration: (R,R)

25,27-bis[(R,R)-2-amino-1-butanolyl-carbonylmethoxy]-26,28-dihydroxy-calix[4]areneC40H46N2O8[α]D20=-24 (c 0.5, CHCl3)Source of chirality: (R)-(−)-2-amino-1-butanolAbsolute configuration: (R,R)

5,11,17,23-Tetra-tert-butyl-25,27-bis[(S,S)-2-amino-3-phenyl-propanolyl-carbonylmethoxy]-26,28-dihydroxy-calix[4]areneC66H82N2O8[α]D20=-14.3 (c 0.4, CHCl3)Source of chirality: (S)-(−)-2-amino-3-phenyl-propanolAbsolute configuration: (S,S)

25,27-bis[(S,S)-2-amino-3-phenyl-propanolyl-carbonylmethoxy]-26,28-dihydroxy-calix[4]areneC50H50N2O8[α]D22=-26.9 (c 0.2, CHCl3)Source of chirality: (S)-(−)-2-amino-3-phenyl-propanolAbsolute configuration: (S,S)