Synthesis and properties of p-benzoquinone-fused hexadehydro[18]annulenes
Synthesis and properties of p-benzoquinone-fused hexadehydro[18]annulenes
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DOI：
10.1016/j.tet.2004.02.041
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发表时间：
2004-04-05
期刊：
影响因子：
2.1
通讯作者：
Komatsu, K
中科院分区：
文献类型：
--
作者：
Nishinaga, T;Miyata, Y;Komatsu, K
将脱氢轮烯3的对二甲氧基苯部分与3，6-二甲氧基-4，5-二甲苯在1，2-位的三个基团在硝酸铈铵作用下逐步转化为对苯二酚，合成了一系列含有不同对苯二酚基团的六氢[18]轮烯。化合物4和5的紫外-可见光谱显示，与只有对二甲氧基苯单元的化合物3和只有对苯二酚单元的化合物6相比，化合物4和5的最大吸收峰发生了红移。然而，4和5的溶致变色性被发现是相当弱的，可能是因为HOMO和LUMO(B3LYP/6-31G(D))在整个pi-体系中不是定域的，而是离域的。(C)2004爱思唯尔有限公司。保留所有权利。
A series of hexadehydro[18]annulenes fused with different numbers of p-benzoquinone, 4-6, were synthesized by stepwise transformation of the p-dimethoxybenzene moiety of the precursor dehydroannulene 3 fused with three 3,6-dimethoxy-4,5-dimethylbenzene units at 1,2-positions into p-benzoquinone using ceric ammonium nitrate. The UV-vis spectra of compounds 4 and 5, which have both electron-donating p-dimethoxybenzene unit(s) and electron-accepting p-benzoquinone unit(s) in the pi-systems, showed the maximum absorption bands bathochromically shifted in comparison with 3 having only p-dimethoxybenzene units and 6 having only p-benzoquinone units. However, the solvatochromism expected for 4 and 5 was found to be quite weak possibly because the HOMO and LUMO (B3LYP/ 6-31G(d)) are not localized but rather delocalized over the whole pi-systems. (C) 2004 Elsevier Ltd. All rights reserved.