2,3,6,7,10,11-Hexamethoxytribenzotriquinacene: Synthesis, Solid-State Structure, and Functionalization of a Rigid Analogue of Cyclotriveratrylene
作者:Marco Harig、Beate Neumann、Hans-Georg Stammler、Dietmar Kuck
DOI:10.1002/ejoc.200300782
日期:2004.6
The syntheses of several tribenzotriquinacenes bearing six methoxy groups at the outer peripheral positions of the aromatic rings are reported. The centro-methyl derivative is accessible in surprisingly good yield through two-fold cyclodehydration in the final step of a synthesis route which requires special care in the preparation of some electron-rich key intermediates, such as 5,6-dimethoxy-2-methylindane-1
报道了几种在芳环外周位置带有六个甲氧基的三苯并三喹并苯的合成。在合成路线的最后一步中,通过两次环化脱水,可以以惊人的高收率获得中心甲基衍生物,这在制备一些富含电子的关键中间体(例如 5,6-二甲氧基-2-甲基茚满)时需要特别小心-1,3-二酮和双(3,4-二甲氧基苯基)甲醇。中心甲基衍生物的 X 射线单晶结构分析证实了其 C-3v 对称分子结构,但与母体中心甲基三苯并三喹苯和类似形状的环三戊四烯不同,六甲氧基三苯并三喹苯类似物不会在固体中形成柱状堆积状态。三个二苯甲基桥头位置的官能化以良好的产率得到四甲基类似物和桥头三醇。相比之下,通过硝化或溴化使邻位官能化的尝试主要通过亲电子 ipso 攻击引起环裂解,这与环三苯和环三戊四烯的行为相似。(C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004。