Synthesis of ladder-type π-conjugated heteroacenes via palladium-catalyzed double N-arylation and intramolecular O-arylation
Synthesis of ladder-type π-conjugated heteroacenes via palladium-catalyzed double N-arylation and intramolecular O-arylation
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DOI：
10.1021/jo070427p
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发表时间：
2007-07-06
影响因子：
3.6
通讯作者：
Nozaki, Kyoko
中科院分区：
文献类型：
--
作者：
Kawaguchi, Keiko;Nakano, Koji;Nozaki, Kyoko
以常见的中间体2,5-双（邻氯芳基）对苯二酚为原料，有效地合成了含吡咯或呋喃环的阶梯型杂环化合物吲哚[3,2-b]咔唑和二苯并[d，d']苯并[1,2-b:4,5-b']二呋喃。关键的反应是钯催化苯胺的双n -芳基化和分子内o -芳基化，从而实现区域选择性的环闭合。除了母体吲哚[3,2-b]咔唑和二苯并[d，d']苯并[1,2-b:4,5-b']二呋喃外，还首次合成了它们带有烷基或氰基的衍生物。光物理和电化学研究表明，得到的杂苯类化合物比相应的碳氢化合物苊和并苯具有更低的HOMO能级和更大的带隙。对二苯并[d，d']和二苯并[1,2-b:4,5-b']二呋喃的x射线分析显示它呈人字形排列。
Ladder-type heteroacenes containing pyrrole or furan rings, indolo[3,2-b]carbazoles and dibenzo[d,d']benzo[1,2-b:4,5-b']difurans, were effectively synthesized from the common intermediates, 2,5-bis(o-chloroaryl)hydroquinones. The key reactions are palladium-catalyzed double N-arylation of aniline and intramolecular O-arylation, which enable regioselective ring closure. In addition to the parent indolo[3,2-b]carbazole and dibenzo[d,d']benzo[1,2-b:4,5-b']difuran, their derivatives with an alkyl or cyano group were first synthesized. Photophysical and electrochemical studies showed that the obtained heteroacenes have lower HOMO energy levels and larger band gaps than the corresponding hydrocarbon acene, pentacene. An X-ray analysis of dibenzo[d,d']benzo[1,2-b:4,5-b']difuran revealed that it was packed in herringbone fashion.