Desulfonylation of poly(4‐hydroxystyrene sulfone) by vapor phase silylation

Vapor phase silylation of poly(4‐hydroxystyrene sulfone) (PHOSS) film was carried out with (trimethylsilyl)dimethylamine (TMSDMA) as a silylation reagent. Infrared spectroscopy was used to follow the silylation. Phenolic hydroxyl groups were trimethylsilylated, but desulfonylation of PHOSS was greatly enhanced simultaneously. The reaction rates were investigated at reaction temperatures of 50, 60, and 70°C. The rate of silylation increased with increasing reaction temperature. However, the rate of desulfonylation was very fast in the presence of TMSDMA and was virtually invariant with reaction temperature. It was confirmed that trimethylsilylation in the polymer side chain of PHOSS enhanced desulfonylation in the main chain. Trimethylsilylation might be expected to lower the ceiling temperature of the polymer. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1549–1554, 1999     

衍生化固相微萃取与气相色谱-质谱联用测定生活垃圾渗沥液中双酚A

建立了固相微萃取-顶空衍生化与色谱-质谱联用技术测定水中双酚A定量分析方法。对影响萃取和衍生化过程的参数进行了条件优化,实验选用聚丙烯酸酯(PA)萃取纤维,在搅拌速度为1200r/min、溶液离子强度100g/L、pH2和25℃的条件下萃取60min后,N,O双(三甲基硅烷基)三氟乙酰胺(BSTFA)顶空衍生化5min。方法的线性范围是0.09~200μg/L;检出限0.03μg/L;相对标准偏差为3·88%。应用本方法对广州大田山垃圾填埋场的垃圾渗沥液中的双酚A进行了测定。     

Regiospecific synthesis of 6-halouridine derivatives: An effective method for coupling sterically hindered pyrimidine bases to ribose

6-Halouridine derivatives were synthesized regiospecifically through the coupling of N3-protected 6-halouracil to a ribose derivative. The combination of the silylating reagent N,O-bis(trimethylsilyl)acetamide and Lewis acid catalyst trimethylsilyl trifluoromethanesulfonate is unique in their ability to facilitate the coupling of sterically hindered pyrimidine bases to ribose to form nucleoside derivatives.     

Silylation of Cellulose with Hexamethyldisilazane in Ammonia – Activation, Catalysis, Mechanism, Properties

Synthesis of trimethylsilylcellulose (TMSC) from cellulose and hexamethyldisilazane (HMDS) in liquid ammonia is reviewed, with emphasis on the scope of the reaction and mechanistic features. Conditions for complete and for controlled stoichiometric partial silylation have been established. Stoichiometric desilylation of TMSC is also possible in tetrahydrofuran containing ammonia as hydrogen bond donor. The activating effect of ammonia, solubility of reactants, catalysis and kinetics of the heterogeneous reaction are discussed. Silylation follows first order kinetics in the presence of saccharin as the catalyst, indicating that the accessibility of hydroxy groups is not the rate-determining factor. TMSCs have a solubility window in THF with a DS from 1.6 to 2.6. This window is narrower for higher molecular weight TMSC.     

A New Synthesis of 2-(6-Methoxycarbonylhexyl)-Cyclopent-2-EN-1-One Using α-Silylallyl Sulphide

Acylation of the α-trimethylsilylallyl phenyl sulphide (2). by reaction with the acid chloride (3), catalyzed by aluminium chloride in CH₂Cl₂ at ?78°C, gave methyl 9-oxo-12-phenylthio-11-dodecene (4). Hydrolysis of (4) followed by aldol condensation gave 2-(6-methoxycarbonylhexyl)-cyclopent-2-en-1-one (6).     

三甲基硅基化有机硅玻璃树脂的合成及性能

它进一步交联同化后便得到高度交联的固化体。由于其高透明性及高硬度,外观似玻璃,故该树脂有玻璃树脂之美称。它对紫外光有高度的透明性,因而是优良的耐紫外涂层。然而,这种玻璃树脂固化体质脆,作为涂层,其可涂厚度通常在20μm 以下。若将它配以高量填料,则该有色涂层极易开裂。为克服其脆性。Gilligan 等采用(CH_3)_3SiCl 作为硅基化试剂与玻璃树脂溶液在 DMF 中0℃下进行反应,成功地使三甲基硅氧基(CH_3)_3SiO 取代树脂中部分硅醇基,制得韧性硅基化玻璃树脂2作为     

Silylation of 1-alkynes with chlorosilanes promoted by Zn(OTf)2: an efficient way to the preparation of alkynylsilanes

Promoted by Zn(OTf)₂, a series of alkynylsilanes were prepared in high yields via direct silylation of terminal alkynes with chlorosilanes under mild conditions. It was supposed that the reaction was through the intermediate of Zn alkynilide.     

Synthesis and some properties of 2-acetylamido-4,5-benzo-1,3,2-dioxaphospholane

The reaction of pyrocatechol chlorophosphite with N-trimethylsilylacetamide gave 2-acetamido-4,5-benzo-1,3,2-dioxaphospholane. The reaction of this product with hexamethyldisilazane leads to 2-trimethylsiloxy-4,5-benzo-1,3,2-dioxaphospholane, while its reactions with diethylamine, trimethylsilyldiethylamine, and bis(dimethylamino)methane give 2-dialkylamino-4,5-benzo-1,3,2-dioxaphospholanes.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Branch, Russian Academy of Sciences, 420008 Kazan. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 220–222, January, 1992.     

氨基硅烷修饰的SBA-15用于CO2的吸附

以3-丙胺基三乙氧基硅烷(APTES)为硅烷化试剂,分别采用后修饰法和一步嫁接法将其嫁接到SBA-15的孔内,形成了功能化的介孔分子筛用于CO2吸附.利用X射线衍射和氮气物理吸附等方法考察了嫁接前后SBA-15的孔结构变化,用静态吸附天平考察了不同温度和不同分压下CO2的吸附行为.实验结果表明,一步嫁接法比后修饰法更有利于实现APTES在SBA-15上的嫁接.与传统的活性炭吸附剂相比,该种介孔分子筛更有利于较低分压下CO2的吸附脱除.