Optically Active Macrocycliccis-3 Bis-Adducts of C60: Regio- and Stereoselective Synthesis, Exciton Chirality Coupling, and Determination of the Absolute Configuration, and First Observation of Exciton Coupling between Fullerene Chromophores in a Chiral Environment
作者:Roland Kessinger、Carlo Thilgen、Tiziana Mordasini、François Diederich
DOI:10.1002/1522-2675(20001220)83:12<3069::aid-hlca3069>3.0.co;2-w
日期:2000.12.20
agreement with the ap conformation, and, in combination with the calculations, this allowed assignment of the fC-configuration to the inherently chiral addition pattern. This conformational analysis was further supported by the regio- and diastereoselective synthesis of cis-3 bis-adducts from bis-malonates, including tethers derived from cyclic glycol units with a fixed gauche conformation of the alkyl residues
一系列光学活性 cis-3 双加合物,例如 (R,R,fC)-16(方案 6),通过 C60 与双丙二酸酯的 Bingel 大环化反应区域选择性和非对映选择性获得,其中含有衍生的光学活性系链来自 1,2-二醇。cis-3 双加合物中固有手性加成模式的绝对构型先前已通过计算和实验圆二色谱 (CD) 光谱的比较来确定。现在通过基于半经验 AM1(“奥斯汀模型 1”)和 OM2(“正交化方法 2”)计算并结合 1H-NMR 光谱的独立方法获得了对这些早期分配的完全确认。通过计算发现双丙二酸酯 [CHR(OCOCH2COOEt)]2 含有 (R,R)- 或 (S,S)-butane-2,3-diol 衍生物作为光学活性系链,优先形成 C60 的 cis-3 双加合物作为单一的非对映异构体,其中烷基 R 采用左旋构象,而两个乙醇酸 H 原子在反平面 (ap) 中,与富勒烯的酯键在左右关系(图 2 和图