Cesium Carbonate-Catalyzed Oxidation of Substituted Phenylsilanes for the Efficient Synthesis of Polyhedral Oligomeric Silsesquioxanes.
Cesium Carbonate-Catalyzed Oxidation of Substituted Phenylsilanes for the Efficient Synthesis of Polyhedral Oligomeric Silsesquioxanes.
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DOI：
10.1021/acs.inorgchem.8b02107
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发表时间：
2018-10
影响因子：
4.6
通讯作者：
Yuefeng Li;C. Cui
中科院分区：
文献类型：
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作者：
Yuefeng Li;C. Cui
以N，N-二甲基甲酰胺（DMF）为溶剂，碳酸铯为催化剂，室温下氧化取代苯基硅烷（ArSiH 3）合成了多面体低聚倍半硅氧烷（POSS）。该方案允许在非水条件下以适度至良好的产率快速和选择性地获得几种类型的新POSS笼。根据苯环上取代基的体积，可以选择性地获得六-（T6）、八-（T8）和十二苯基倍半硅氧烷（T12）。在较大体积的2-（2 '，4'，6 '-三甲基苯基）苯基的情况下，分离出带有四个羟基的环状四硅氧烷（D4）。机理研究表明，初始步骤涉及Cs2 CO 3催化的DMF与氢硅烷的氢化硅烷化反应，以生成二甲胺中间体，然后由脱氢碳酸化的交叉偶联的氢硅烷与二甲胺。
Cesium carbonate-catalyzed oxidation of substituted phenylsilanes (ArSiH3) in N, N-dimethylformamide (DMF) at room temperature for the efficient synthesis of polyhedral oligomeric silsesquioxanes (POSS) was described. This protocol allowed the rapid and selective access to several types of new POSS cages in modest to good yields under nonaqueous conditions. Depending on the bulkiness of the substituents on the phenyl rings, hexa- (T6), octa- (T8), and dodecaphenylsilsesquioxanes (T12) can be selectively obtained. With the more bulky 2-(2',4',6'-trimethylphenyl)phenyl group, the cyclic tetrasiloxane (D4) bearing four hydroxyl groups was isolated. Mechanism studies disclosed that the initial step involved the Cs2CO3-catalyzed hydrosilylation of DMF with a hydrosilane to generate a siloxymethylamine intermediate followed by the dehydrocarbonative cross-coupling of the hydrosilane with the siloxymethylamine.