Chiral mono and diamide derivatives of calix[4]arene for enantiomeric recognition of chiral amines.
Novel chiral mono and diamide derivatives of calix[4]arene have been prepared from the aminolysis reaction of 5,11,17,23-tetra-tert-butyl-25,27-diethoxycarbonyl-methoxy-26,28-dihydroxycalix[4]arene 1 and 25,27-diethoxycarbonyl-methoxy-26,28-dihydroxycalix[4]arene 2 with chiral (S)-(-)-1-phenylethylamine (PEA) and (1S,2S)-(+)-2-amino-1-(4-nitrophenyl)-1,3-propanediol, respectively. Spectrophotometric titrations have been performed in CHCl(3) at 20-30 degrees C in order to obtain the binding constants (K) and the thermodynamic quantities (DeltaH and DeltaS) for the stoichiometric 1:1 inclusion complexation of various chiral amines with these new host compounds. Preliminary experiments were undertaken to confirm the complexation properties of receptors 9 and 13 with PEA by (1)H NMR in CDCl(3) at room temperature. The molecular recognition abilities and enantioselectivities for guests (R and S)-alpha-PEA and (R and S)-cyclohexylethylamine (CHEA) are discussed from a thermodynamic point of view.
Kocabas
Erdal
E
Department of Chemistry, Selçuk University, Konya, Turkey.
Durmaz
Mustafa
M
Alpaydin
Sabri
S
Sirit
Abdulkadir
A
Yilmaz
Mustafa
M
D000588:Amines / Q000138:chemical synthesis*; D047250:Calixarenes / Q000138:chemical synthesis*; D003958:Diamide / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D010636:Phenols / Q000138:chemical synthesis*; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism
D000588:Amines; D010636:Phenols; C121325:calix(4)arene; D003958:Diamide; D047250:Calixarenes