Synthesis and Self-Aggregation of Enantiopure and Racemic Molecular Tweezers Based on the Bicyclo[3.3.1]nonane Framework
作者:Carl-Johan Wallentin、Torbjörn Wixe、Ola F. Wendt、Karl-Erik Bergquist、Kenneth Wärnmark
DOI:10.1002/chem.200902925
日期:2010.4.6
A pair of moleculartweezers (syn‐4) that consists of quinoline and pyrazine units fused to a bicyclic framework is presented. The tweezers were synthesised both as a racemic mixture (rac‐4) and an enantiomerically pure form ((R,R,R,R)‐4) starting from either racemic or enantiomerically pure bicyclo[3.3.1]nonane‐2,6‐dione (3). Homochiral dimers were observed in the solid state for rac‐4. The self‐association
提出了一对由镊子和吡嗪单元稠合到双环骨架上的分子镊子(syn - 4)。从外消旋或对映体纯的双环[3.3.1]壬烷-2,6开始,镊子既可以作为外消旋混合物(rac - 4)也可以作为对映体纯形式((R,R,R,R,R)-4)合成。 -dione(3)。在rac - 4的固态下观察到手性二聚体。两者的自缔合外消旋- 4和(- [R ,- [R,R,R)‐4在溶液中进行了研究。通过1 H NMR光谱稀释滴定实验,在几次质子共振之后,通过1 H NMR光谱稀释滴定实验估计出CDCl 3中的弱自缔合常数。为此目的,开发了用于从多个数据集中准确确定关联常数的通用归一化模型。与固态相反,在溶液中未观察到rac - 4的非对映异构性。