structural features extracted from the fructo-oligosaccharide derivatives, having a large chiral discrimination ability, and were then synthesized. These hosts showed chiral discrimination toward chiral organic ammonium salts. For example, the chiral discrimination ability (the ratio of association constants: K(R)/K(S)) of host 1, which has the highest value among them, was K(R)/K(S) = 3 for Trp-O-(i)Pr(+)
基于从低聚
果糖衍
生物中提取的结构特征,设计了具有手性来源的
吡喃半
乳糖骨架和氧
乙烯骨架作为结合位点的新型线性主体(1)和环状主体(2和3) ,然后合成。这些宿主显示出对手性有机
铵盐的手性歧视。例如,对于其中的Trp,具有最高价值的宿主1的手性鉴别能力(缔合常数的比率:K(R)/ K(S))为K(R)/ K(S)= 3 -O-(i)Pr(+)和K(R)/ K(S)= 0.7,在HCl中于298 K的1-(1-
萘基)乙基
铵(NEA(+))(3)。明确了,主体1通过与碱
金属离子和手性有机
铵离子等阳离子络合而从线性结构变为假环结构。(1)H NMR通过添加NEA(+)客体诱导了宿主1的转变,表明宿主-客体的复杂结构明显不同,这取决于客体的手性。在与(R)-NEA(+)的配合物中,客体的
萘基位于主体的氧化
乙烯骨架上方,在与(S)-NEA(+)的配合物中,客体的
萘基位于主机伪环的边缘。动态分子识别可能是