199991-74-7Relevant articles and documents
Preparation of optically active azophenolic crown ethers containing 1-phenylethane-1,2-diol and 2,4-dimethyl-3-oxapentane-1,5-diol as a chiral subunit: Temperature-dependent enantiomer selectivity in the complexation with chiral amines
Ogasahara, Kazuko,Hirose, Keiji,Tobe, Yoshito,Naemura, Koichiro
, p. 3227 - 3236 (2007/10/03)
With (2S,4S)-2,4-dimethyl-3-oxapentane-1,5-diol and (S)- or (R)-1-phenylethane-1,2-diol as chiral subunits, optically active azophenolic crown ethers (S,S,S,S)-1, (R,S,S,R)-2, (S,S,S,S)-3 and (R,S,S,R)-4 possessing two phenyl and two methyl substituents together with the p-(2,4-dinitrophenylazo)phenol moiety have been prepared in enantiomerically pure forms. Temperature-dependent enantiomer selectivity in the complexation of these crown ethers with chiral amines has been studied by the UV-visible spectroscopic method in chloroform and from the observed association constants, thermodynamic parameters for the complexation have been calculated.