Directed ortho-C-H Silylation Coupled with trans-Selective Hydrogenation of Arylalkynes Catalyzed by Ruthenium Complexes of a Xanthene-Based Si,O,Si-Chelate Ligand, “Xantsil”
Directed ortho-C-H Silylation Coupled with trans-Selective Hydrogenation of Arylalkynes Catalyzed by Ruthenium Complexes of a Xanthene-Based Si,O,Si-Chelate Ligand, “Xantsil”
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呫吨基 Si,O,Si 螯合物配体“Xantsil”的钌配合物催化芳基炔的定向邻 C-H 硅烷化与反式选择性氢化
DOI：
10.1021/acs.organomet.5b01013
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发表时间：
2016
期刊：
影响因子：
2.8
通讯作者：
Hiromi Tobita
中科院分区：
文献类型：
--
作者：
Takashi Komuro;Takeo Kitano;Nobukazu Yamahira;Keisuke Ohta;Satoshi Okawara;Nathalie Mager;Masaaki Okazaki;Hiromi Tobita
带有呫吨基双（甲硅烷基）螯合配体“xantsil”（（9,9-二甲基呫吨-4,5-二基）双（二甲基甲硅烷基））、Ru{κ3(Si,O,Si)-xantsil}(CO)(PR3)（1-Cy：R = Cy（环己基），1-Cyp：R = Cyp（环戊基））的钌络合物被发现在中等温度（室温至70℃）下催化内芳基炔与叔硅烷（1-1.3当量）反应，得到具有邻位甲硅烷基化芳基的（E）-烯烃，即（E）-R1C（H）C（H）（C6H3-o-SiR33-p-R2）。这些催化反应涉及芳基炔中芳基的独特邻位选择性C-H甲硅烷基化，并伴随着其C-C三键的氢化（邻位-C-H甲硅烷基化/氢化）。重要的是，在这些反应中，芳基炔的炔基部分既充当导向基团又充当氢受体。通过使用芳基炔和叔硅烷的八种组合探索了邻位 C-H 甲硅烷基化/氢化的底物范围。在使用大体积底物的情况下，具有相对较小体积的膦配体（PCyp3）的1-Cyp的催化性能被证明优于PCy3类似物1-Cy。
Ruthenium complexes bearing a xanthene-based bis(silyl) chelate ligand, “xantsil” ((9,9-dimethylxanthene-4,5-diyl)bis(dimethylsilyl)), Ru{κ3(Si,O,Si)-xantsil}(CO)(PR3) (1-Cy: R = Cy (cyclohexyl),1-Cyp: R = Cyp (cyclopentyl)), were found to catalyze the reactions of internal arylalkynes with tertiary silanes (1–1.3 equiv) at a moderate temperature (room temperature to 70 °C) to give (E)-alkenes having anortho-silylated aryl group, i.e., (E)-R1C(H)C(H)(C6H3-o-SiR33-p-R2). These catalytic reactions involve a uniqueortho-selective C–H silylation of an aryl group in arylalkynes accompanied by hydrogenation of their C–C triple bonds (ortho-C–H silylation/hydrogenation). Importantly, in these reactions, the alkynyl moiety of arylalkynes serves as both a directing group and a hydrogen acceptor. The substrate scope of thisortho-C–H silylation/hydrogenation was explored by use of eight combinations of arylalkynes and tertiary silanes. In cases using bulky substrates, the catalytic performance of1-Cypwith a relatively less bulky phosphine ligand (PCyp3) was shown to be superior to that of the PCy3analogue1-Cy.