一种新的具有双螺旋结构特征的光学活性分子方的设计、合成及其光学性质

分别从手性构型高度稳定的(R)和(S)-2,2'-二乙炔基-1,1'-联萘模板出发, 通过保护基的控制导入、偶联反应、保护基脱去以及分子间偶合成环4个步骤成功地合成了一种具有螺旋结构特征的新的光学活性分子方(Molecular square)(R,R,R,R)-1和(S,S,S,S)-1. 用MS, IR, UV-Vis, 1H和13C NMR以及元素分析等方法对目标化合物进行了结构表征. 测定并分析比较了2个目标化合物的比旋光度α]D和圆二色性(CD)等光学性质. 在CH2Cl2溶液中, 异构体(R,R,R,R)-1和(S,S,S,S)-1的α]25D值分别为+887.3°和-889.7°, 并且其CD谱表现出对称的镜像特征.

Design, Synthesis and Optical Properties of a New Type of Chiral Molecular Square with Double Helical Structure

(R)- and (S)-2,2'-diethynyl-1,1'-binaphthyl with highly stable chiral configurations were used as the structural templates and linking bridges, and a new type of chiral molecular square with helical structure (R,R,R,R)-1 and (S,S,S,S)-1 were synthesized in enantiopure form via four steps including the introduction of protecting-group, intermolecular coupling reaction, removal of protecting group, and intermolecular cross-coupling cyclyzation. Compound 1 was characterized by MS, IR, 1H and 13C NMR as well as elemental analysis. The specific rotations(α]25D) of the two isomers in CH2Cl2 are +887.3° and -889.7°, respectively, and their circular dichroism(CD) spectra represented exactly the mirror images of each other. These results reflected unambiguously enantiomeric relationship between the two isomers.