Novel sucrose-based macrocyclic receptors for enantioselective recognition of chiral ammonium cations

A new synthetic route to macrocyclic sucrose-based receptors with different substituents at the ring nitrogen atom is described. Very good enantioselectivity toward phenylethylammonium chloride was observed [a much stronger complex with the cation of the (S)-amine was formed] although the Ka values were low. Much higher Ka (1.4 × 104 M−1 in CDCl3/CD3OD) values of the complexes with aminoacid derivatives (especially valine) were found although this time the enantioselectivities were moderate.

The efficient synthesis of the macrocyclic derivative with sucrose scaffold containing ‘free’ nitrogen functionality is presented. This intermediate has been converted into a number of analogs from which those with methoxy-ethylene unit showed best complexing properties.Figure optionsDownload as PowerPoint slide

1′,2,3,3′,4,4′-Hexa-O-benzyl-6′-O-(2-tert-butoxy-2-oxoethyl)-6-O- cyanomethylsucroseC62H69NO13[α]D21=+40.4 (c 1, CHCl3)Source of chirality: sucroseAbsolute configuration: (1R,2R,3S,4R,5R,2′S,3′S,4′S,5′R)

6-O-(2-Aminoethyl)-1′,2,3,3′,4,4′-hexa-O-benzyl-6′-O-(2-hydroxyethyl)- sucroseC58H67NO12[α]D23=+54.0 (c 1, CHCl3)Source of chirality: sucroseAbsolute configuration: (1R,2R,3S,4R,5R,2′S,3′S,4′S,5′R)

6,6′-(3-Azapenta-1,5-di-yl)-1′,2,3,3′,4,4′-hexa-O-benzylsucroseC58H65NO11[α]D23=+38.9 (c 1, CHCl3)Source of chirality: sucroseAbsolute configuration: (1R,2R,3S,4R,5R,2′S,3′S,4′S,5′R)

6,6′-(3-Azabenzylpenta-1,5-di-yl)-1′,2,3,3′,4,4′-hexa-O-benzylsucroseC65H71NO11[α]D22=+28.1 (c 1, CHCl3)Source of chirality: sucroseAbsolute configuration: (1R,2R,3S,4R,5R,2′S,3′S,4′S,5′R)

6,6′-[3-Aza(4-methoxybenzyl)penta-1,5-di-yl]-1′,2,3,3′,4,4′-hexa-O-benzylsucroseC66H73NO12[α]D19=+17.3 (c 1, CHCl3)Source of chirality: sucroseAbsolute configuration: (1R,2R,3S,4R,5R,2′S,3′S,4′S,5′R)

6,6′-[3-Aza(pyridine-2-ylmethyl)penta-1,5-di-yl]-1′,2,3,3′,4,4′-hexa-O-benzylsucroseC64H70N2O11[α]D24=+21.9 (c 1, CH2Cl2)Source of chirality: sucroseAbsolute configuration: (1R,2R,3S,4R,5R,2′S,3′S,4′S,5′R)

6,6′-[3-Aza(prop-2-en-1-yl)penta-1,5-di-yl]-1′,2,3,3′,4,4′-hexa-O-benzylsucroseC61H69NO11[α]D23=+29.1 (c 1, CHCl3)Source of chirality: sucroseAbsolute configuration: (1R,2R,3S,4R,5R,2′S,3′S,4′S,5′R)

6,6′-[3-Aza(2-methoxy-2-oxoethyl)penta-1,5-di-yl]-1′,2,3,3′,4,4′-hexa-O-benzylsucroseC61H69NO11[α]D23=+24.6 (c 1, CH2Cl2)Source of chirality: sucroseAbsolute configuration: (1R,2R,3S,4R,5R,2′S,3′S,4′S,5′R)

6,6′-[3-Aza(2-methoxyethyl)penta-1,5-di-yl]-1′,2,3,3′,4,4′-hexa-O-benzylsucroseC61H71NO12[α]D22=+31.7 (c 1, CHCl3)Source of chirality: sucroseAbsolute configuration: (1R,2R,3S,4R,5R,2′S,3′S,4′S,5′R)