一种含有手性联萘“铰链”单元的环芳分子的设计、合成及表征

Design, Synthesis and Characterization of a New Type of Cyclo-phane Containing Chiral Binaphthyls as Hinges Units

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13CNMR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,S)-3的[α]2D5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.