Preparation of Silica Supported Tin Chloride: As a Recyclable Catalyst for the Silylation of Hydroxyl Groups with HMDS
作者:Khodabakhsh Niknam、Mohammad Ali Zolfigol、Dariush Saberi、Hajar Molaee
DOI:10.1002/jccs.200900181
日期:2009.12
Silica‐supportedtinchloride [SiO2‐Sn(Cl)4‐n] has been prepared by mixing tinchloride with activated silica gel in toluene under refluxing conditions for one day. A range of primary, secondary, and tertiary alcohols as well as phenolic hydroxylgroups were converted into their corresponding trimethylsilyl ethers with hexamethyldisilazane in the presence of catalytic amounts of silica‐supported tin
Polystyrene-Gallium Trichloride Complex: A Mild, Highly Efficient, and Recyclable Polymeric Lewis Acid Catalyst for Chemoselective Silylation of Alcohols and Phenols with Hexamethyldisilazane
作者:Ali Rahmatpour、Ali Vakili、Setare Azizian
DOI:10.1002/hc.21109
日期:2013.11
(HMDS) for the efficientsilylation of alcohols and phenols at room temperature. In this heterogeneous catalytic system, primary, secondary, and tertiaryalcohols as well as phenols were converted to their corresponding trimethylsilyl ethers with short reaction times and high yields under mild reaction conditions. The heterogenized catalyst is of high reusability and stability in the silylation reactions
Nanomagnetic zirconia-based sulfonic acid (Fe<sub>3</sub>O<sub>4</sub>@ZrO<sub>2</sub>-Pr-SO<sub>3</sub>H): a new, efficient and recyclable solid acid catalyst for the protection of alcohols via HMDS under solvent free conditions
alcohols using hexamethyldisilazane (HMDS) under solvent-free conditions at room temperature. The solid nanocatalyst can easily be separated and reused several times without significant loss of its catalytic activity. Also, in addition to its being inexpensive and the simplicity of the separation process, this heterogeneouscatalyst has shown a good chemoselectivity in the reactions.
在本工作中,通过(3-巯基丙基)三甲氧基硅烷与纳米磁性氧化锆的反应来制备磺酸官能化的纳米磁性氧化锆。然后,通过过氧化氢和H 2 SO 4直接氧化硫醇基,合成了纳米氧化锆基磺酸(Fe 3 O 4 @ZrO 2 -Pr -SO 3 H)。随后。通过傅里叶变换红外光谱(FT-IR),场发射扫描电子显微镜(FE-SEM)成像,能量色散X射线光谱(EDX),X射线衍射(XRD)测量和振动样品磁力分析法对催化剂进行了表征( VSM)。六甲基二硅氮烷(HMDS)在无溶剂条件下于室温下用作具有高催化活性的有效纳米催化剂,用于保护醇。固体纳米催化剂可以容易地分离并重复使用数次,而不会显着降低其催化活性。而且,除了其廉价和分离过程的简便性之外,这种非均相催化剂在反应中还显示出良好的化学选择性。
Tributyltin grafted onto the surface of 3-aminopropyl functionalized γ-Fe<sub>2</sub>O<sub>3</sub>nanoparticles: a magnetically-recoverable catalyst for trimethylsilylation of alcohols and phenols
Bonding of a homogenous tributyltin chloride catalyst on the surface of functionalized magnetic nanoparticles provides a new stable, efficient and magnetically recyclable catalyst for trimethylsilylation of alcohols and phenols with hexamethyldisilazan under mild reaction conditions. The catalyst showed good stability and could be reused at least 10 times. The catalyst was characterized using spectroscopic, magnetic, and thermal techniques (FT-IR, SEM, TEM, XRD, ICP, VSM, and TGA).
ethers and the [4+2] cycloadducts between the silene and diene, which confirms the presence of 2 and that it is unreactive towards alcohols. The observed silylethers are substitution adducts where the amide group of the silylamide is replaced by an alkoxy group, and the reaction time is reflected in the steric bulk of the alcohol. Indeed, the formation of silylethers from the reaction of alcohols with