NMR enantiodiscrimination by cyclic tetraamidic chiral solvating agents

Cyclic tetraamidic chiral selectors are efficient chiral solvating agents (CSAs) for NMR spectroscopy, which enantiodiscriminate several classes of chiral substrates, mainly endowed with a π-acidic aromatic ring. The great potential of DOSY techniques in the investigation of enantiodiscrimination phenomena, also in complex mixtures, was clearly demonstrated.

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(4R,5R,15R,16R)-4,5,15,16-Tetraphenyl-10,21-bis(octyloxy)-3,6,14,17-tetraazatricyclo[17.3.1.18,12]tetracosa-1(23),8,10,12(24),19,21-hexaene-2,7,13,18-tetraoneC60H68N4O6Ee >99%[α]D25=-72.9 (c 0.2, CHCl3)Source of chirality: (1R,2R)-(+)-1,2-diphenylethylenediamine

(4aR,13aR,17aR,26aR)-1,2,3,4,4a,5,13,13a,14,15,16,17,17a,18,26,26a-Hexadecahydro-9,22-bis(methoxy)-7,11:20,24-dimethenodibenzo[b,m][1,4,12,15]tetraazacyclodocosine-6,12,19,25-tetraoneC30H36N4O6Ee >99%[α]D25=+65.3 (c 0.2, CHCl3)Source of chirality: (1R,2R)-(−)-1,2-diaminocyclohexane