Synthesis of (Z)-1-thio- and (Z)-2-thio-1-alkenyl boronates via copper-catalyzed regiodivergent hydroboration of thioacetylenes: an experimental and theoretical study.
Synthesis of (Z)-1-thio- and (Z)-2-thio-1-alkenyl boronates via copper-catalyzed regiodivergent hydroboration of thioacetylenes: an experimental and theoretical study.
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DOI：
10.1021/jo4028402
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发表时间：
2014-02
期刊：
影响因子：
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通讯作者：
Gangguo Zhu;Wei-Guang Kong;Hui Feng;Zhaosheng Qian
中科院分区：
文献类型：
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作者：
Gangguo Zhu;Wei-Guang Kong;Hui Feng;Zhaosheng Qian
分别以频哪醇硼烷或双频哪醇合二硼为硼氢化试剂，实现了铜催化的硫代炔类的发散硼氢化反应，以中到高产率和优异的区域和立体选择性提供了（Z）-1-硫代-或（Z）-2-硫代-1-烯基硼酸酯。密度泛函理论计算表明，硫原子通过极化C-C三键和参与HOMO轨道，在决定区域选择性方面起着关键作用。此外，SR基团可以作为一个很好的离去基团，导致通过C-B和C-S键的迭代交叉偶联的三取代烯烃5的六个区域和立体异构体的简洁合成。显然，它对于在有机合成中组装立体化学不同的三取代烯烃将是有价值的。
A Cu-catalyzed divergent hydroboration of thioacetylenes has been achieved, providing (Z)-1-thio- or (Z)-2-thio-1-alkenyl boronates in moderate to high yields with excellent regio- and stereoselectivity, by using pinacolborane or bis(pinacolato)diboron as the hydroborating reagents, respectively. DFT calculations indicate that the sulfur atom plays a key role in determining the regioselectivity through polarizing the C-C triple bonds and participating in the HOMO orbitals. Moreover, the SR group can serve as a good leaving group, resulting in the concise synthesis of six regio- and stereoisomers of trisubstituted alkenes 5 via the iterative cross-coupling of C-B and C-S bonds. Clearly, it will be valuable for assembling stereochemically diverse trisubstituted olefins in organic synthesis.