Synthesis of Polycyclic and Cage Siloxanes by Hydrolysis and Intramolecular Condensation of Alkoxysilylated Cyclosiloxanes
Synthesis of Polycyclic and Cage Siloxanes by Hydrolysis and Intramolecular Condensation of Alkoxysilylated Cyclosiloxanes
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DOI：
10.1002/chem.201805942
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发表时间：
2019-02-21
影响因子：
4.3
通讯作者：
Kuroda, Kazuyuki
中科院分区：
文献类型：
--
作者：
Sugiyama, Tomoaki;Shiba, Hiroya;Kuroda, Kazuyuki
具有明确结构的低聚硅氧烷的可控合成对于基于正庚烷的纳米材料的自下而上设计是重要的。本工作报告的各种多环和笼硅氧烷的水解和分子内缩合的单环四，六硅氧烷官能化与各种烷氧基甲硅烷基。单烷氧基硅烷化环硅氧烷的研究表明，分子内缩合优先发生在相邻的烷氧基甲硅烷基之间，形成新的四硅氧烷环。二烷氧基和三烷氧基甲硅烷基化环四硅氧烷的研究表明，多步分子内缩合反应，形成立方八硅氧烷在相对较高的产率。与从有机硅烷单体开始的常规方法不同，分子内缩合使得能够以受控排列引入不同的有机取代基。已经成功地获得了所谓的Janus立方体，即Ph4R4Si8O12，其中R=Me，OSiMe 3和OSiMe（2）Vi（Vi=乙烯基）。这些发现将使具有不同功能的基于双氢呋喃的材料的创建成为可能。
The controlled synthesis of oligosiloxanes with well-defined structures is important for the bottom-up design of siloxane-based nanomaterials. This work reports the synthesis of various polycyclic and cage siloxanes by the hydrolysis and intramolecular condensation of monocyclic tetra- and hexasiloxanes functionalized with various alkoxysilyl groups. An investigation of monoalkoxysilylated cyclosiloxanes revealed that intramolecular condensation occurred preferentially between adjacent alkoxysilyl groups to form new tetrasiloxane rings. The study of dialkoxy- and trialkoxysilylated cyclotetrasiloxanes revealed multistep intramolecular condensation reactions to form cubic octasiloxanes in relatively high yields. Unlike conventional methods starting from organosilane monomers, intramolecular condensation enables the introduction of different organic substituents in controlled arrangements. So-called Janus cubes have been successfully obtained, that is, Ph4R4Si8O12, in which R=Me, OSiMe3, and OSiMe(2)Vi (Vi=vinyl). These findings will enable the creation of siloxane-based materials with diverse functions.