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 1
作者:Kazuko Ogasahara、Keiji Hirose、Yoshito Tobe、Koichiro Naemura
DOI:10.1039/a703452k
日期:——
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.
采用(2S,4S)-2,4-二甲基-3-氧戊烷-1,5-二醇和(S)-或(R)-1-苯乙烷-1,2-二醇作为手性子单元,合成了具有两个苯基和两个甲基取代基以及p-(2,4-二硝基苯基偶氮)酚基团的光学活性偶氮酚类冠醚(S,S,S,S)-1、(R,S,S,R)-2、(S,S,S,S)-3和(R,S,S,R)-4,并且这些化合物以对映体纯形式制备。通过在氯仿中采用紫外-可见光光谱法研究了这些冠醚与手性胺的复合过程中温度依赖的对映选择性,并根据观察到的结合常数计算了复合的热力学参数。