基于联萘衍生物手性构型高度稳定以及联萘结构中2个萘平面的两面角可以在一定范围内张合的特点。分别以光学活性的(R)和(S)-2,2’-二乙炔基-1,1'-联萘为模板,设计了一种含有8个“铰链”结构单元的新的环芳分子——(R,R,R,R,R,R,R,R)-3和(S,S,S,S,S,S,S,S)-3.其合成路线涉及间苯基连接桥的链接,保护基的脱去和控制导入以及分子间偶合等步骤.用MS,IR,UV-Vis,^1H和^13C NMR以及元素分析等技术对中间体和目标化合物进行了结构表征.测定并比较了2个目标化合物的比旋光度[α]D和圆二色(CD)性质.在CH2Cl2溶液中,两个异构体(R,R,R,R,R,R,R,R)-3和(S,S,S,S,S,S,S)-3的【α】d^25占值分别为-911.8和+908.6,并且它们的CD谱表现出对称的镜像特征.这些实验结果清楚地反映了它们之间的对映异构关系.
Based on highly stable chiral configuration of binaphthyls and behavior of extension/contraction of the dihedral angle between the two naphthalene rings in binaphthyl, we have designed two cyclophane enantiomers (R,R,R,R,R,R,R,R)-3 and (S,S,S,S,S,S,S,S)-3 containing eight chiral binaphthyl units by utilizing (R) and (S)-2,2'-diethyny1-1,1'-binaphthyl as hinges template, respectively. The synthetic procedure involved the multi steps reactions including the linking of meta-substituted benzene-bridge, removal and control introduction of protecting group, as well as intermolecular cross-coupling, etc. MS, IR, ^1H and ^13C NMR as well as elemental analysis characterized intermediates and target compound 3. The specific rotations ([α]D) of two isomers in CH2Cl2 are -911.8 and +908.6, and their circular dichroism (CD) spectra represented exactly mirror images of each other. These results reflected unambiguously enantiomeric relation between two optically pure isomers.