Synthesis, Structures, and Isomerization of 9,10-Di-tert-butyl-9,10-dihydro-9,10-disilaanthracenes
Synthesis, Structures, and Isomerization of 9,10-Di-tert-butyl-9,10-dihydro-9,10-disilaanthracenes
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9,10-二叔丁基-9,10-二氢-9,10-二硅蒽的合成、结构和异构化
DOI：
10.1021/om961080b
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发表时间：
1997
期刊：
影响因子：
2.8
通讯作者：
H. Matsumoto
中科院分区：
文献类型：
--
作者：
S. Kyushin;T. Shinnai;Tomoyoshi Kubota;H. Matsumoto
合成了9，10-二叔丁基-9，10-二氢-9，10-二硅杂蒽（反式-3和顺式-3），并通过X射线单晶衍射确定了其结构。反式和顺式异构体具有不同的二硅杂环己二烯环构象：反式-3具有椅子状结构，而顺式-3具有船状结构。在过氧化二叔丁基存在下，照射反式-3或顺式-3的溶液，反式-3和顺式-3彼此异构化并达到平衡，得到顺式-3（81%）和反式-3（19%）的混合物。异构化过程中，中间体硅自由基中心发生了反转，这在硅自由基反应中是很少见的。考虑到反应机理，来自反式-3和顺式-3的甲硅烷基自由基被发现是相对稳定的，可能是由于庞大的叔丁基取代基。
9,10-Di-tert-butyl-9,10-dihydro-9,10-disilaanthracenes (trans-3 and cis-3) were synthesized, and their structures were determined by X-ray crystallography. The trans and cis isomers have a different conformation of the disilacyclohexadiene rings: trans-3 has a chair-like structure, while cis-3 has a boat-like structure. On irradiation of a solution of trans-3 or cis-3 in the presence of di-tert-butyl peroxide, trans-3 and cis-3 isomerized to each other and reached an equilibrium to give a mixture of cis-3 (81%) and trans-3 (19%). The isomerization shows the inversion of the radical center of the intermediate silyl radicals, which is rare in reactions of silyl radicals. Considering the reaction mechanism, the silyl radicals derived from trans-3 and cis-3 are found to be relatively stable, probably due to bulky tert-butyl substituents.