A novel method which effects ring extension of the ladder oligosilsesquioxanes was developed. By applying this method, we synthesized the first functionalized tricyclic laddersiloxanes and pentacyclic laddersiloxane. The reaction of (i-PrSi(OH)O)4 with (i-PrPhClSiO)2 in pyridine gave the tetraphenyl tricyclic laddersiloxane. Following dephenylchlorination with AlCl3/HCl, and hydrolysis enabled us to isolate the tetrahydroxyl tricyclic laddersiloxane in good yield. We repeated the similar reaction from this tetrahydroxyl laddersiloxane, and the first pentacyclic laddersiloxane was obtained. The structures of the tetraphenyl and tetrahydroxyl tricyclic laddersiloxanes, and pentacyclic laddersiloxane were determined by X-ray crystallography.
A novel method which effects ring extension of the ladder oligosilsesquioxanes was developed. By applying this method, we synthesized the first functionalized tricyclic laddersiloxanes and pentacyclic laddersiloxane. The reaction of (i-PrSi(OH)O)4 with (i-PrPhClSiO)2 in pyridine gave the tetraphenyl tricyclic laddersiloxane. Following dephenylchlorination with AlCl3/HCl, and hydrolysis enabled us to isolate the tetrahydroxyl tricyclic laddersiloxane in good yield. We repeated the similar reaction from this tetrahydroxyl laddersiloxane, and the first pentacyclic laddersiloxane was obtained. The structures of the tetraphenyl and tetrahydroxyl tricyclic laddersiloxanes, and pentacyclic laddersiloxane were determined by X-ray crystallography.
studies on thermostable materials, heptacyclicladdersiloxanes and ladderpolysilsesquioxane were synthesized. The first heptacyclicladdersiloxanes were obtained by chlorination of pentacyclic laddersiloxanes prepared using our stereocontrolled synthesis procedure; thereafter, the heptacyclicladdersiloxanes were made to react with disiloxanediol. Ladderpolysilsesquioxane was obtained from cis–trans–c
Three new pentacyclic laddersiloxanes were prepared by a new method utilizing single stereoisomer of disiloxanediol as a growing unit. Thus, one diastereomer of disiloxanediol, (RS)–[i-PrPhSi(OH)]2O was isolated and treated with tetrachlorocyclotetrasiloxane, resulting in the formation of tricyclic laddersiloxanes with cis-Ph groups at terminals. All of the obtained isomers could be transformed into
利用二硅氧烷二醇的单一立体异构体作为生长单元的新方法,制备了三种新的五环梯形硅氧烷。因此,分离出二硅氧烷二醇的一种非对映异构体(RS)– [ i -PrPhSi(OH)] 2 O并用四氯环四硅氧烷处理,从而形成了末端带有顺式-Ph基团的三环梯形硅氧烷。所有获得的异构体都可以通过脱苯氯化,然后与(RS)– [ i -PrPhSiSi(OH)] 2反应,转化为五环梯形硅氧烷。O.通过X射线晶体学测定新的三环和五环梯形硅氧烷的结构。总结了取决于分子量和结构的梯形硅氧烷的热引力性质。
Pentacyclic Laddersiloxane
作者:Masafumi Unno、Akiko Suto、Hideyuki Matsumoto
DOI:10.1021/ja0173876
日期:2002.2.1
A novel method which effects ring extension of the ladder oligosilsesquioxanes was developed. By applying this method, we synthesized the first functionalized tricyclic laddersiloxanes and pentacyclic laddersiloxane. The reaction of (i-PrSi(OH)O)4 with (i-PrPhClSiO)2 in pyridine gave the tetraphenyl tricyclic laddersiloxane. Following dephenylchlorination with AlCl3/HCl, and hydrolysis enabled us to isolate the tetrahydroxyl tricyclic laddersiloxane in good yield. We repeated the similar reaction from this tetrahydroxyl laddersiloxane, and the first pentacyclic laddersiloxane was obtained. The structures of the tetraphenyl and tetrahydroxyl tricyclic laddersiloxanes, and pentacyclic laddersiloxane were determined by X-ray crystallography.