State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, P. R. China.
Chemistry. 2010 Nov 2;16(41):12412-24. doi: 10.1002/chem.201001620.
Enantiomerically pure tribenzotriquinacenes (TBTQs) bearing two monofunctionalized aromatic nuclei were synthesized for the first time and their optical properties and absolute configuration determined. A remarkably regioselective bis-formylation of the fully bridgehead methylated parent TBTQ hydrocarbon with MeOCHCl(2)/TiCl(4) afforded a mixture of two C(s)-symmetrical (achiral) difunctionalized derivatives together with one C(1)-symmetrical (chiral) isomer. Reduction and subsequent column chromatography furnished the three respective benzylic TBTQ dialcohols. Optical resolution of the racemic 2,6-bis(hydroxymethyl) derivative was achieved via the diastereomeric (R)-1,1'-bi-2-naphthol ethers and the absolute configuration of the enantiomers was determined by CD exciton model analysis. The electronic circular dichroism (ECD) spectra and the specific rotation of the enantiomers were found to agree with the results of DFT calculations. Among the C(s)-symmetrical isomers, the "proximal" 2,11-dialdehyde and the corresponding benzylic dialcohol were identified by 2D NMR spectroscopy and X-ray crystallographic analysis, respectively, and used as the starting point for the synthesis of several novel dithiametacyclophanes. These include the first "dimeric" tribenzotriquinacene-based cyclophanes bearing the bowls of the two TBTQ units attached to each other in a syn (concave-concave) or anti (convex-concave) configuration. The usefulness of such thiacyclophanes as fluorescent chemosensors for different metal ions is also demonstrated.
首次合成了具有两个单官能化芳核的对映体纯三苯并三嗪（TBTQ），并测定了它们的光学性质和绝对构型。用 MeOCHCl(2)/TiCl(4) 对完全桥甲基化的母体 TBTQ 烃进行了非常区域选择性的双甲酰化，得到了两种 C(s)-对称（非手性）的双官能化衍生物和一种 C(1)-对称（手性）异构体的混合物。还原和随后的柱层析得到了三个相应的苄基 TBTQ 二醇。通过非对映体（R）-1,1'-双-2-萘酚醚实现了外消旋 2,6-双（羟甲基）衍生物的光学拆分，并通过 CD 激子模型分析确定了对映体的绝对构型。电子圆二色性（ECD）光谱和对映体的比旋光度与 DFT 计算的结果一致。在 C(s)-对称异构体中，通过 2D NMR 光谱和 X 射线晶体学分析分别鉴定了“近端”2,11-二醛和相应的苄基二醇，并将其用作合成几种新型二硫杂环戊烷的起点。其中包括第一个基于“二聚体”三苯并三嗪的环戊烷，其两个 TBTQ 单元的碗彼此相连，呈顺式（凹-凹）或反式（凸-凹）构型。还证明了此类硫杂环戊烷作为不同金属离子荧光化学传感器的有用性。
