36309-42-9Relevant academic research and scientific papers
Activation of hexamethyldisilazane (HMDS) by TiO2 nanoparticles for protection of alcohols and phenols: the effect of the catalyst phase on catalytic activity
Azad, Alireza,Dekamin, Mohammad G.,Afshar, Shahrara,Tadjarodi, Azadeh,Mollahosseini, Afsaneh
, p. 2951 - 2963 (2018/04/11)
Anatase TiO2 nanoparticles (TiO2 NPs) were synthesized by the sol–gel method using titanium tetra-isopropoxide (TTIP), isopropyl alcohol, and distilled water and then calcined at 400?°C for 3?h. X-ray diffraction and scanning electron microscopy methods, and Fourier transform infrared spectroscopy were used for characterization of the obtained TiO2 NPs. The obtained anatase TiO2 NPs were used as heterogeneous catalyst for trimethylsilation of various alcohols or phenols with hexamethyldisilazane (HMDS) in CH3CN at room temperature. High to quantitative yields of the products were obtained within short reaction times at room temperature using a very low loading of pure TiO2 NPs without any post-modification with Bronsted or Lewis acid species such as ClSO3H or HClO4. The catalyst can be recycled at least three times without significant loss of its activity. The results of this study provide evidence that the pure anatase phase of TiO2 exhibits higher catalytic activity in terms of catalyst loading and required reaction time compared to a mixture of anatase and rutile phases found in the commercial samples for trimethylsilation of various alcohols or phenols with HMDS.
Fast and efficient method for Silylation of alcohols and phenols with HMDS in the presence of bis-thiourea complexes of cobalt, nickel, copper and zinc chlorides
Zeynizadeh, Behzad,Sorkhabi, Serve
, p. 127 - 135 (2018/02/06)
Bis-thiourea complexes of cobalt, nickel, copper and zinc chlorides were used efficiently for rapid and efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) in CH3CN. All reactions were carried out at room temperature within immediate-120?min timeframe to afford trimethylsilyl ether derivatives in high to excellent yields. Investigation of the results exhibited that the prepared bis-thiourea metal complexes show the activity as Co(tu)2Cl2> Ni(tu)2Cl2> Cu(tu)2Cl2> Zn(tu)2Cl2 in their silylation reactions.
Nano Fe3O4@ZrO2/SO42?: A highly efficient catalyst for the protection and deprotection of hydroxyl groups using HMDS under solvent-free condition
Ghafuri, Hossein,Paravand, Fatemeh,Rashidizadeh, Afsaneh
supporting information, p. 129 - 135 (2016/12/24)
In this work, we introduce a new procedure for the protection and deprotection process of various types of alcohols and phenols by HMDS in the presence of nano magnetic sulfated zirconia (Fe3O4@ZrO2/SO42?) as a solid acid catalyst under very mild and solvent-free condition. This method has interesting advantages like short reaction times and a simple workup process. With regard to some outstanding benefits of this new heterogeneous catalyst such as excellent yield, reusability of the catalyst and easy thermal stability, high acidity, strong and excellent magnetic properties, this method can be very interesting in aspect of green chemistry Principles.
P4VPy–CuO nanoparticles as a novel and reusable catalyst: application at the protection of alcohols, phenols and amines
Shirini, Farhad,Fallah-Shojaei, Abdollah,Abedini, Masoumeh,Samavi, Laleh
, p. 1699 - 1712 (2016/07/27)
P4VPy–CuO nanoparticles were synthesized using ultrasound irradiations. Relevant properties of the synthesized nanoparticles were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. After identification, the prepared reagent was used for the promotion of different types of protection reactions of alcohols, phenols and amines. Easy workup, short reaction times, excellent yields, relatively low cost and reusability of the catalyst are the striking features of the reported methods.
Tributyltin grafted onto the surface of 3-aminopropyl functionalized γ-Fe2O3 nanoparticles: A magnetically-recoverable catalyst for trimethylsilylation of alcohols and phenols
Nikbakht, Fatemeh,Ghonchepour, Ehsan,Ziyadi, Hakimeh,Heydari, Akbar
, p. 34428 - 34434 (2014/10/15)
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 un
Preparation of nano silica supported sodium hydrogen sulfate: As an efficient catalyst for the trimethyl, triethyl and t-butyldimethyl silylations of aliphatic and aromatic alcohols in solution and under solvent-free conditions
Abri, Abdolreza,Ranjdar, Somayeh
, p. 929 - 934 (2014/10/16)
Nano silica supported sodium hydrogen sulfate has been prepared by mixing NaHSO4 with activated Nano silicagel. We wish to report a new method for the synthesis of trimethyl (TMS), triethyl (TES) and t-butyldimethyl silyl (TBS) ethers from benzylic, allylic, propargylic alcohols, phenols, naphtholes and some of phenolic drugs in the solution and under solvent-free conditions.
DIHYDROPYRROLONES AND THEIR USE AS ANTIMICROBIAL AGENTS
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Page/Page column 29, (2014/12/12)
The present invention relates generally to antimicrobial dihydropyrrolone compounds, methods for their use and methods for preparing surfaces to which the dihydropyrrolone compounds are attached.
Preparation, characterization and use of 1,3-disulfonic acid imidazolium hydrogen sulfate as an efficient, halogen-free and reusable ionic liquid catalyst for the trimethylsilyl protection of hydroxyl groups and deprotection of the obtained trimethylsilanes
Shirini, Farhad,Khaligh, Nader Ghaffari,Akbari-Dadamahaleh, Somayeh
, p. 15 - 23 (2013/01/14)
Novel 1,3-disulfonic acid imidazolium hydrogen sulfate, a halogen-free ionic liquid, is a recyclable and eco-benign catalyst for the trimethylsilyl protection of hydroxyl groups at room temperature under solvent free conditions to afford trimethylsilanes in excellent yields (92-100%) and in very short reaction times (1-5 min). Deprotection of the resulting trimethylsilanes can also be achieved using the same catalyst in methanol. The catalyst was characterized by IR, 1H NMR, 13C NMR and MS studies. All the products were extensively characterized by IR, 1H NMR, MS, and elemental and melting point analyses. This new method consistently has the advantages of excellent yields and short reaction times. Further, the catalyst can be recovered and reused for several times without loss of activity. The work-up of the reaction consists of a simple separation, followed by concentration of the crude product and purification.
A mild and highly efficient method for the preparation of silyl ethers using Fe(HSO4)3/Et3N by chlorosilanes
Abri, Abdolreza,Assadi, Mohammad Galeh,Pourreza, Samira
, p. 1449 - 1454 (2013/03/13)
Avery efficient and mild procedure for preparation of silyl ethers from benzylic, allylic, propargilic alcohols, phenols, naphtoles and some of phenolic drugs with trimethylsilylchloride (TMSCl), triethylsilylchloride (TESCl) and t-buthyldimethylsilyl chloride (TDSCl) ethers in the presence of Fe(HSO 4)3/Et3N in roomtemperature in excellent yields is reported. This procedure also allows the excellent selectivity for silylation of alcohols and phenols.
Preparation, characterization and use of 3-methyl-1-sulfonic acid imidazolium hydrogen sulfate as an eco-benign, efficient and reusable ionic liquid catalyst for the chemoselective trimethylsilyl protection of hydroxyl groups
Khaligh, Nader Ghaffari
experimental part, p. 63 - 70 (2011/12/02)
New and novel ionic liquid (3-methyl-1-sulfonic acid imidazolium hydrogen sulfate) is a recyclable and eco-benign catalyst for the chemoselective trimethylsilyl protection of hydroxyl groups under solvent-free conditions to afford trimethylsilanes in excellent yields (92-100%) and in very short reaction times (1-8 min). The catalyst was characterized by FT-IR, 1H NMR and 13C NMR studies. All the products were extensively characterized by 1H NMR, IR, GC-MS and melting point analyses. A mechanism for the catalytic activity is proposed. The catalyst can be recovered and reused without loss of activity. The work-up of the reaction consists of a simple separation, followed by concentration of the crude product and purification.
