Bis-silicon-bridged stilbene homologues synthesized by new intramolecular reductive double cyclization.
Bis-silicon-bridged stilbene homologues synthesized by new intramolecular reductive double cyclization.
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DOI：
10.1021/ja038487
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发表时间：
2003-10
影响因子：
15
通讯作者：
S. Yamaguchi;Caihong Xu;K. Tamao
中科院分区：
文献类型：
--
作者：
S. Yamaguchi;Caihong Xu;K. Tamao
基于双（邻硅基）二苯基乙炔的一种新的分子内还原环化反应，合成了一系列同系的双硅桥芪。因此，双（邻甲硅烷基）-二苯基乙炔与过量萘锂的反应在乙炔部分经历两电子还原以产生二价阴离子中间体，其进一步经历以5-exo模式的双环化以产生双-硅桥连的二苯乙烯。该方法也可应用于四硅桥连双苯乙烯基苯的合成。由此制备的硅桥π共轭体系在可见光区显示出强烈的荧光。一个双硅桥芪与其碳类似物的比较表明，硅桥上的电子结构，从而对荧光性能的实质性影响。
A homologous series of bis-silicon-bridged stilbenes has been synthesized on the basis of a new intramolecular reductive cyclization of bis(o-silyl)-diphenylacetylene. Thus, the reaction of bis(o-silyl)-diphenylacetylenes with excess lithium naphthalenide undergoes the two-electron reduction at the acetylene moiety to produce a dianion intermediate, which further undergoes a double cyclization in a 5-exo mode to produce the bis-silicon-bridged stilbenes. This methodology can also be applied to the synthesis of tetrakis-silicon-bridged bis(styryl)benzenes. The silicon-bridged pi-conjugated systems thus prepared show intense fluorescence in the visible region. Comparison of a bis-silicon-bridged stilbene with its carbon analogue demonstrates the substantial effects of the silicon-bridges on the electronic structures and thus on the fluorescence properties.