Synthesis of Biaryls and Oligoarenes Using Aryl[2-(hydroxymethyl)phenyl]dimethylsilanes
Synthesis of Biaryls and Oligoarenes Using Aryl[2-(hydroxymethyl)phenyl]dimethylsilanes
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DOI：
10.1246/bcsj.20090325
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发表时间：
2010-05-15
影响因子：
4
通讯作者：
Hiyama, Tamejiro
中科院分区：
文献类型：
--
作者：
Chen, Jinshui;Tanaka, Masaaki;Hiyama, Tamejiro
通过分子内活化，高度稳定的芳基[2-（羟甲基）苯基]二甲基硅烷可以选择性地转移它们的芳基，以在弱非氟化物碱和钯/铜催化剂存在下实现与各种芳基溴化物和氯化物的交叉偶联反应。该反应容许宽范围的官能团，以高产率和优异的化学选择性产生相应的官能化联芳基。新公开的反应条件允许以中等至良好的产率回收环状甲硅烷基醚并重新用于芳基硅烷的合成。在硅中心引入两个异丙基而不是甲基提高了稳定性并允许定量回收硅残留物。最后，具有O-保护的[2-（羟甲基）苯基]二甲基甲硅烷基的芳基卤化物与芳基硅烷试剂交叉偶联，得到甲硅烷基官能化的联芳基。在脱保护后，联芳基进一步与甲硅烷基化的亲电试剂反应。迭代交叉偶联脱保护序列允许甲硅烷基化的低聚芳烃的快速组装。二-和三甲硅烷基低聚芳烃的合成也通过使用正交的O-保护基团来实现。
Through intramolecular activation, highly stable aryl[2-(hydroxymethyl)phenyl]dimethylsilanes can selectively transfer their aryl groups to effect a cross-coupling reaction with various aryl bromides and chlorides in the presence of a weak non-fluoride base and a palladium/copper catalyst. This reaction tolerates a wide range of functional groups, producing the corresponding functionalized biaryls in high yields with excellent chemoselectivity. Newly disclosed reaction conditions allow the recovery of a cyclic silyl ether in modest-to-good yields and reuse for the synthesis of the arylsilanes. The introduction of two isopropyl groups on the silicon center instead of methyl groups improves the stability and allows quantitative recovery of the silicon residue. Finally, aryl halides having an O-protected [2-(hydroxymethyl)phenyl]dimethylsilyl group cross-couple with the arylsilane reagents to give silyl-functionalized biaryls. Upon deprotection, the biaryls further react with the silylated electrophiles. The iterative cross-coupling deprotection sequences allow rapid assembly of silylated oligoarenes. Syntheses of di- and trisilyloligoarenes are also achieved by use of orthogonal O-protecting groups.