Highly enantioselective fluorescent recognition of mandelic acid derivatives by chiral salen macrocycles

Calixarene-like chiral salen macrocycles can be used for the enantioselective fluorescent recognition of mandelic acid derivatives. It was observed that one enantiomer of mandelic acid causes a 28-fold increase in the fluorescence intensity of a chiral salen macrocycle, whereas the other enantiomer causes only a 14-fold fluorescence enhancement. This highly enantioselective fluorescent response makes chiral salen macrocycles useful for the enantioselective fluorescent recognition of some mandelic acid derivatives.

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(4aS,5E,12E,13aS,17aS,18E,25E,26aS,30aS,31E,39aS)-1,2,3,4,4a,13a,14,15,16,17,17a,26a,27,28,29,30,30a,39a-Octadecahydro-9,22,35-tri-i-Propyl-, 11,7:20,24:33,37-Trimetheno-7H-tribenzo[b,m,x][1,4,12,15,23,26]hexaazacyclotritriacontine-40,41,42-triolC51H66N6O3[α]D25[α]D = +225 (c 0.1, CH2Cl2)Source of chirality: (1S,2S)-diaminocyclohexaneAbsolute configuration: (S,S,S,S,S,S)

(4aS,5E,12E,13aS,17aS,18E,25E,26aS,30aS,31E,39aS)-1,2,3,4,4a,13a,14,15,16,17,17a,26a,27,28,29,30,30a,39a-Octadecahydro-9,22,35-tri-t-Butyl-11,7:20,24:33,37-Trimetheno-7H-tribenzo[b,m,x][1,4,12,15,23,26]hexaazacyclotritriacontine-40,41,42-triolC54H72N6O3[α]D25 = +193 (c 0.1, CH2Cl2)Source of chirality: (1S,2S)-diaminocyclohexaneAbsolute configuration: (S,S,S,S,S,S)

(4aS,5E,12E,13aS,17aS,18E,25E,26aS,30aS,31E,39aS)-1,2,3,4,4a,13a,14,15,16,17,17a,26a,27,28,29,30,30a,39a-octadecahydro-9,22,35-trimethoxy-11,7:20,24:33,37-Trimetheno-7H-tribenzo[b,m,x][1,4,12,15,23,26]hexaazacyclotritriacontine-40,41,42-triolC45H54N6O6[α]D25 = +250 (c 0.1, CH2Cl2)Source of chirality: (1S,2S)-diaminocyclohexaneAbsolute configuration: (S,S,S,S,S,S)

(4aS,5E,12E,13aS,17aS,18E,25E,26aS,30aS,31E,39aS)-1,2,3,4,4a,13a,14,15,16,17,17a,26a,27,28,29,30,30a,39a-octadecahydro-9,22,35-tribromo-11,7:20,24:33,37-Trimetheno-7H-tribenzo[b,m,x][1,4,12,15,23,26]hexaazacyclotritriacontine-40,41,42-triolC42H45Br3N6O3[α]D25 = +192 (c 0.1, CH2Cl2)Source of chirality: (1S,2S)-diaminocyclohexaneAbsolute configuration: (S,S,S,S,S,S)