Regio- and Stereoselective Hydrosilylation of Alkynes Catalyzed by Three-Coordinate Cobalt(I) Alkyl and Silyl Complexes
Regio- and Stereoselective Hydrosilylation of Alkynes Catalyzed by Three-Coordinate Cobalt(I) Alkyl and Silyl Complexes
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DOI：
10.1021/ja510924v
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发表时间：
2014-12-17
影响因子：
15
通讯作者：
Deng, Liang
中科院分区：
文献类型：
--
作者：
Mo, Zhenbo;Mao, Jie;Deng, Liang
三配位钴（I）配合物在炔硅氢加成反应中表现出高的催化效率和选择性以及良好的官能团相容性。[Co（IAd）（PPh 3）（CH 2 TMS）]（1）（IAd = 1，3-二金刚烷基咪唑-2-亚基）促进末端、对称内炔和三甲基甲硅烷基取代的不对称内炔的区域和立体选择性氢化硅烷化，以高产率分别产生β-（E）-甲硅烷基烯烃、（E）-甲硅烷基烯烃和（Z）-α，α-二甲硅烷基烯烃形式的单一氢化硅烷化产物。由1与H_2SiPh_2反应制备的Co（I）甲硅烷基络合物[Co（IAd）（PPh_3）（SiHPh_2）]的催化效率和选择性与由1与乙炔反应分离的炔Co（I）络合物[Co（IAd）（eta（2）-PhC=CPh）（CH_2TMS）]的催化效率和选择性相当，指出了这些氢化硅烷化反应的改进的Chalk-Harrod催化循环。高选择性被认为是由空间因素决定的。
A three-coordinate cobalt(I) complex exhibits high catalytic efficiency and selectivity as well as good functional group compatibility in alkyne hydrosilylation. [Co(IAd)(PPh3)(CH2TMS)] (1) (IAd = 1,3-diadamantylimidazol-2-ylidene) facilitates regio- and stereoselective hydrosilylation of terminal, symmetrical internal, and trimethylsilyl-substituted unsymmetrical internal alkynes to produce single hydrosilylation products in the forms of beta-(E)-silylalkenes, (E)-silylalkenes, and (Z)-alpha,alpha-disilylalkenes, respectively, in high yields. The comparable catalytic efficiency and selectivity of the Co(I) silyl complex [Co(IAd)(PPh3)(SiHPh2)] that was prepared from the reaction of 1 with H2SiPh2, and the isolation of an alkyne Co(I) complex [Co(IAd)(eta(2)-PhC=CPh)(CH2TMS)] from the reaction of 1 with the acetylene, point out a modified Chalk-Harrod catalytic cycle for these hydrosilylation reactions. The high selectivity is thought to be governed by steric factors.