Preparation and characterization of a RHA/TiO<sub>2</sub>nanocomposite: introduction of an efficient and reusable catalyst for chemoselective trimethylsilyl protection and deprotection of alcohols and phenols
nanoparticles leading to the RHA/TiO2 nanocomposite. This nanocomposite was used as an efficientcatalyst for the chemoselective trimethylsilylation of various alcohols and phenols and deprotection of the obtained trimethylsilyl ethers. The procedure gave the products in excellent yields in very short reaction times. Also this catalyst can be reused at least six times without loss of its catalytic activity.
在这项工作中,稻壳灰(RHA)作为无定形二氧化硅的天然来源,被用作合成RHA / TiO 2纳米复合材料的锐钛矿相二氧化钛纳米粒子的载体。该纳米复合材料用作各种醇和酚的化学选择性三甲基甲硅烷基化和所得三甲基甲硅烷基醚的脱保护的有效催化剂。该程序在非常短的反应时间内以优异的产率获得了产物。同样,该催化剂可以重复使用至少六次,而不会损失其催化活性。
Highly efficient and selective trimethylsilylation of alcohols and phenols with hexamethyldisilazane catalyzed by polystyrene-bound tin(IV) porphyrin
[Sn IV (TNH 2 PP)(OTf) 2 ], supported on chloromethylated polystyrene in the trimethylsilylation of alcohols and phenols with hexamethyldisilazane is reported. The prepared catalyst was characterized by elemental analysis, FT-IR and diffuses reflectance UV–Vis spectroscopic methods. This catalyst was used for selective trimethylsilylation of different alcohols and phenols with HMDS, with short reaction
of carbonyl compounds has been developed. When carbonyl compounds were allowed to react with trimethylsilyl phenylselenide and tributylstannyl hydride in the presence of a catalytic amount of AIBN as the radical initiator, hydrosilylation of the carbonyl compounds efficiently proceeded to give the corresponding silyl ethers in moderate to good yields. In the absence of carbonyl compounds, the triethylsilyl
Direct Oxidative Deprotection using Montmorillonite Supported Bis(trimethylsilyl)chromate
作者:M. M. Heravi、D. Ajami、K. Tabar-Heydar、M. M. Mojtahedi
DOI:10.1039/a803237h
日期:——
Direct oxidative deprotection of different trimethylsilyl ethers to their corresponding carbonyl compounds has been achieved using montmorillonite K-10 supported bis(trimethylsilyl)chromate in dichloromethane.
Silica chloride in the presence of NaI is a useful system for the efficient and selective conversion of TMS, TBDMS and THP ethers into their corresponding iodides
Direct and highly selective conversion of benzylic, allylic and propargylic TMS, TBDMS and THP ethers into their corresponding iodides with the SiO2–Cl/NaI system is described. Reactions were conducted in CH3CN at room temperature. Aliphatic silyl and tetrahydropyranyl ethers remained almost intact under similar reaction conditions.