Synthesis of a novel tweezers-type host aiming at chiral discrimination by circular dichroism spectroscopy †
作者:Shigeyuki Yagi、Hirokazu Kitayama、Toru Takagishi
DOI:10.1039/a909468g
日期:——
In order to develop a methodology for chiral discrimination by utilizing complexation-induced circular dichroism (ICD) in host–guest systems, the novel tweezers-type host 1 was synthesized. From UV-VIS and fluorescence emission studies, it was confirmed that the host 1 formed a 1∶1 complex with optically active N,N′-dimethyl-trans-1,2-diaminocyclohexane 16, and the CD spectrum was induced as the concentration of the complex increased. The sign of the Cotton effect induced by (S,S)-16 was opposite to that induced by (R,R)-16, indicating that enantioselective formation of the atropisomer of 1 upon complexation leads to determination of the chirality of the guest by CD. On the other hand, the ICD of 1 upon complexation with the chiral monoamine 17 implied that the axial chirality of 1 was not induced until the host complexed two molecules of 17.
为了在主-客体系统中利用络合诱导的圆二色性(ICD)开发一种手性鉴别方法,合成了新型镊子型主体 1。紫外-可见光谱和荧光发射研究证实,宿主 1 与具有光学活性的 N,N′-二甲基-反式-1,2-二氨基环己烷 16 形成了 1∶1 的络合物,并且随着络合物浓度的增加,CD 光谱被诱导。(S,S)-16诱导的科顿效应的符号与(R,R)-16诱导的科顿效应的符号相反,这表明络合时 1 的对映选择性异构体的形成可导致通过 CD 确定客体的手性。另一方面,1 与手性单胺 17 复配后的 ICD 表明,直到宿主与两个分子的 17 复配,才会诱导出 1 的轴向手性。