- KF/clinoptilolite NPs: An efficient and heterogeneous catalyst for chemoselective silylation of alcohols and phenols
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Potassium fluoride incorporated on clinoptilolite nanoparticles (KF/CP NPs) by ion exchanging is found to be an effective and inexpensive heterogeneous nanocatalyst for chemoselective silylation of alcohols and phenols with 1,1,1,3,3,3-hexamethyldisilazane (HMDS) at room temperature. Nano-powder of clinoptilolite (CP) was prepared using a planetary ball mill mechanically method and characterized by dynamic light scattering (DLS), X-ray powder diffraction (XRD) and scanning electron microscope (SEM) analyses. Almost all of products were obtained in high yields as well as short reaction times and the catalyst was also reused eight times without loss of its catalytic activity.
- Oladee, Razieh,Zareyee, Daryoush,Khalilzadeh, Mohammad A.
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p. 731 - 737
(2021/03/31)
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- Synthesis and characterization of a bifunctional nanomagnetic solid acid catalyst (Fe3O4@CeO2/SO42?) and investigation of its efficiency in the protection process of alcohols and phenols via hexamethyldisilazane under solvent-free conditions
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In this research, Fe3O4@CeO2 (FC) was synthesized using the coprecipitation method and functionalized by an ammonium sulfate solution to achieve a heterogeneous solid acid Fe3O4@CeO2/SO42? (FCA) catalyst. The synthesized bifunctional catalyst was used in the protection process of alcohols and phenols using hexamethyldisilazane (HMDS) at ambient temperature under solvent-free conditions. Due to its excellent magnetic properties, FCA can easily be separated from the reaction mixture and reused several times without significant loss in its catalytic activity. Excellent yield and selectivity, simple separation, low cost, and high recyclability of the nanocatalyst are outstanding advantages of this procedure. The characterization was carried out using different techniques such as Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM).
- Mohammadiyan, Esmaeel,Ghafuri, Hossein,Kakanejadifard, Ali
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p. 171 - 178
(2018/09/12)
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- A simple and efficient room temperature silylation of diverse functional groups with hexamethyldisilazane using CeO2 nanoparticles as solid catalysts
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In this study, a mild and efficient method is developed for the silylation of diverse functional groups using CeO2 nanoparticles (n-CeO2) as solid catalysts with hexamethyldisilazane (HMDS) as silylating agent at room temperature. Alcohols, phenols and acids are silylated to their respective silyl derivatives with faster reaction rate while amines and thiols required relatively longer reaction time. Moreover, the solid catalyst is easily be separated from the reaction mixture and recycled more than five times without any obvious decay in its activity. Powder X-ray diffraction (XRD), transmission electron microscope (TEM), UV–vis diffuse reflectance spectra (UV-DRS) and Raman analyses revealed identical structural integrity, particle size, absorption edge and valence state for the reused solid compared to the fresh solid catalyst.
- Anbu, Nagaraj,Vijayan, Chellappa,Dhakshinamoorthy, Amarajothi
-
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- Activation of hexamethyldisilazane (HMDS) by TiO2 nanoparticles for protection of alcohols and phenols: the effect of the catalyst phase on catalytic activity
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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.
- Azad, Alireza,Dekamin, Mohammad G.,Afshar, Shahrara,Tadjarodi, Azadeh,Mollahosseini, Afsaneh
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p. 2951 - 2963
(2018/04/11)
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- 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
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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.
- Zeynizadeh, Behzad,Sorkhabi, Serve
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p. 127 - 135
(2018/02/06)
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- Nano Fe3O4@ZrO2/SO42?: A highly efficient catalyst for the protection and deprotection of hydroxyl groups using HMDS under solvent-free condition
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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.
- Ghafuri, Hossein,Paravand, Fatemeh,Rashidizadeh, Afsaneh
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supporting information
p. 129 - 135
(2016/12/24)
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- Room temperature silylation of alcohols catalyzed by metal organic frameworks
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The commercial Al(OH)(BDC) (BDC: 1,4-benzenedicarboxylic acid) metal organic framework (Basolite A100) is a suitable heterogeneous catalyst for the silylation of benzylic and aliphatic alcohols by hexamethyldisilazane in toluene at room temperature. Al(OH
- Dhakshinamoorthy, Amarajothi,Santiago-Portillo, Andrea,Concepción, Patricia,Herance, José R.,Navalón, Sergio,Alvaro, Mercedes,Garcia, Hermenegildo
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p. 2445 - 2449
(2017/07/24)
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- Nanomagnetic zirconia-based sulfonic acid (Fe3O4@ZrO2-Pr-SO3H): A new, efficient and recyclable solid acid catalyst for the protection of alcohols: Via HMDS under solvent free conditions
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In the present work, sulfonic acid functionalized nanomagnetic zirconia is prepared by the reaction of (3-mercaptopropyl)trimethoxysilane and nanomagnetic zirconia. Then, nanomagnetic zirconia-based sulfonic acid (Fe3O4@ZrO2/su
- Tadjarodi, Azadeh,Khodikar, Rahim,Ghafuri, Hosssein
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p. 63480 - 63487
(2016/07/19)
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- Polystyrene-gallium trichloride complex: A mild, highly efficient, and recyclable polymeric lewis acid catalyst for chemoselective silylation of alcohols and phenols with hexamethyldisilazane
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Polystyrene-supported gallium trichloride (PS/GaCl3) as a highly active and reusable heterogeneous Lewis acid effectively activates hexamethyldisilazane (HMDS) for the efficient silylation of alcohols and phenols at room temperature. In this he
- Rahmatpour, Ali,Vakili, Ali,Azizian, Setare
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p. 443 - 451
(2013/12/04)
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- Alum: An efficient catalyst for trimethylsilylation of alcohols and phenols with hexamethyldisilazane
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A highly convenient method for the trimethylsilylation of alcohols and phenols via treatment by hexamethyldisilazane in the presence of alum as a catalyst has been developed. A wide variety of hydroxyl groups were selectively protected in CH3CN under mild conditions.
- Yang, Xiaojuan,Liang, Jinying
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experimental part
p. 228 - 230
(2012/08/07)
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- Highly efficient and selective trimethylsilylation of alcohols and phenols with hexamethyldisilazane catalyzed by polystyrene-bound tin(IV) porphyrin
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In the present work, investigation of the catalytic activity of tetrakis(p-aminophenyl)porphyrinatotin(IV) trifluoromethanesulfonate, [Sn IV(TNH2PP)(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 times and high yields. Also the catalyst is of high reusability and stability, in that it was recovered several times without loss of its initial activity.
- Gharaati, Shadab,Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj
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experimental part
p. 87 - 95
(2012/05/05)
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- Tetrabutylammonium phthalimide-N-oxyl: An efficient organocatalyst for trimethylsilylation of alcohols and phenols with hexamethyldisilazane
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Tetrabutylammonium phthalimide-N-oxyl (TBAPINO) was found to be an effective organocatalyst for rapid, simple and chemoselective protection of the hydroxyl group of alcohols and phenols using hexamethyldisilazane (HMDS) under mild conditions. The low catalyst loading, high to quantitative yields and simple removal of the catalyst from the reaction mixture illustrate the other attractive features of this protocol.
- Dekamin,Yazdaninia,Mokhtari,Naimi-Jamal
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experimental part
p. 537 - 544
(2012/06/18)
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- Rapid and efficient trimethylsilyl protection of hydroxyl groups catalyzed by niobium(V) chloride
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An efficient and convenient procedure for the trimethylsilylation of a wide variety of alcohols, including primary, benzylic, secondary, and phenols with hexamethyldisilazane, has been developed. The reactions were carried out at room temperature in the presence of a catalytic amount of niobium(V) chloride and afforded the corresponding trimethylsilyl ethers in high to excellent yields in short time. Copyright Taylor & Francis Group, LLC.
- Hou, Jun-Tao,Chen, Hong-Li,Zhang, Zhan-Hui
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experimental part
p. 88 - 93
(2011/04/22)
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- InCl3/Me3SiBr-catalyzed direct coupling between silyl ethers and enol acetates
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A combined Lewis acid catalyst of InCl3 and Me3SiBr promoted the direct use of enol acetates in the coupling with low-reactive silyl ethers, in which functional groups including ketones and aldehydes survived. Sterically hindered silyl ethers such as ROSiEt3, ROSiPh3, ROSit-BuMe2, and ROSii-Pr3 were also applicable.
- Onishi, Yoshiharu,Nishimoto, Yoshihiro,Yasuda, Makoto,Baba, Akio
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supporting information; experimental part
p. 2762 - 2765
(2011/08/02)
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- Melamine-trisulfonic-acid-catalyzed trimethylsilylation of alcohols and phenols
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A highly convenient method for the trimethylsilylation of alcohols and phenols via treatment by hexamethyldisilazane in the presence ofmelamine trisulfonic acid as a catalyst has been developed. A wide variety of hydroxyl groups were selectively protected under solvent-free conditions. Copyright Taylor & Francis Group, LLC.
- Wu, Liqiang,Sun, Pengli,Yan, Fulin
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experimental part
p. 2055 - 2060
(2011/11/30)
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- Silylation of alcohols and phenols with hexamethyldisilazane over highly reusable propyl sulfonic acid functionalized nanostructured SBA-15
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Various alcohols and phenols were trimethylsilylated in excellent yields using hexamethyldisilazane in the presence of catalytic amounts of environmentally friendly, hydrophobic, highly thermal stable, and completely heterogeneous sulfonic acid functionalized mesostructured SBA-15 in dichloromethane at ambient temperature. Primary, bulky secondary, tertiary, and phenolic hydroxyl functional groups were transformed to the corresponding trimethylsilyl ethers in excellent yields. The simple experimental procedure was accompanied by easy recovery and the catalyst was reusable (at least 18 reaction cycles); these are attractive features of this protocol.
- Zareyee, Daryoush,Asghari, Rezvaneh,Khalilzadeh, Mohammad A.
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experimental part
p. 1864 - 1868
(2012/02/16)
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- Sulfonated ordered nanoporous carbon (CMK-5-SO3H) as an efficient and highly recyclable catalyst for the silylation of alcohols and phenols with hexamethyldisilazane (HMDS)
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An environmentally friendly catalytic system for trimethylsilylation of alcohols and phenols with hexamethyldisilazane can be successfully carried out for the first time over sulfonated mesoporous carbon catalyst (CMK-5-SO 3H) in dichloromethane at ambient temperature and excellent conversions were obtained. Furthermore, the catalyst displays high activity and thermal stability (to 200 °C) and it can be reused repeatedly for at least 25 cycles without any evidence of loss of activity, confirming the stability of covalent bonding of acidic centers.
- Zareyee, Daryoush,Ghandali, Mohammad S.,Khalilzadeh, Mohammad A.
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experimental part
p. 1521 - 1525
(2012/06/18)
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- Metal-free relay oxidation: Valuable synthesis of acylsilane and ketones under aerobic oxidation
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In this letter, an example of interesting metal-free relay air oxidation of -hydroxysilanes, promoted by the hydroperoxidated carbonyl compounds derived from the Michael reaction of 5,5-dimethylcyclohexane-1,3-dione and chalcone, is reported. A series of aromatic acylsilanes with TBDPS were obtained in promising isolated yields. In addition, as an extension of the relay oxidation under aerobic conditions, this catalyst-free relay oxidation induced by diketone can be applied to the oxidation of general aromatic alcohols (up to 75% yield). Georg Thieme Verlag Stuttgart · New York.
- Bai, Xing-Feng,Gao, Guang,Zheng, Zhan-Jiang,Li, Fei,Lai, Guo-Qiao,Jiang, Kezhi,Li, Fuwei,Xu, Li-Wen
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supporting information; scheme or table
p. 3031 - 3035
(2012/01/05)
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- Catalyst-free silylation of alcohols and phenols by promoting HMDS in CH3NO2 as solvent
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An uncatalyzed method for the silylation of alcohols and phenols with HMDS in CH3NO2 at rt is developed. A diverse range of aromatic and aliphatic alcohols as well as phenols undergo the silylation in very short reaction time with ex
- Kadam, Santosh T.,Kim, Sung Soo
-
supporting information; experimental part
p. 94 - 98
(2010/05/18)
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- An expeditious, efficient green methodology for the Boc protection of amines and silyl protection of alcohols over tungstophosphoric acid-doped mesoporous silica
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An efficient, chemoselective and eco-friendly protocol for the protection of amines as N-tert-butylcarbamate using (Boc)2O and protection of alcohols as silyl ether using HMDS over tungstophosphoric acid/SBA15 has been developed. Solventless condition, easy work-up, short reaction time, excellent yields and reusability of the catalyst are the striking features of this methodology which can be considered to be one of the better methods for the protection of amines and alcohols.
- Karmakar, Bikash,Banerji, Julie
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experimental part
p. 3855 - 3858
(2010/08/20)
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- Nafion SAC-13: heterogeneous and reusable catalyst for the activation of HMDS for efficient and selective O-silylation reactions under solvent-free condition
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Nafion SAC-13 effectively activates hexamethyldisilazane (HMDS) for the efficient and selective silylation of alcohols. Primary, secondary, and tertiary alcohols and phenols are efficiently converted to their corresponding silylethers in short reaction ti
- Rajagopal, Gurusamy,Lee, Hanbin,Kim, Sung Soo
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experimental part
p. 4735 - 4741
(2009/10/09)
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- Mild and efficient silylation of alcohols and phenols with HMDS using Bi(OTf)3 under solvent-free condition
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A very efficient and mild silylation of alcohols and phenols with hexamethyldisilazane (HMDS) at rt is developed using Bi(OTf)3 as the catalyst. Primary, secondary and tertiary alcohols as well as phenols are excellently converted into correspo
- Kadam, Santosh T.,Kim, Sung Soo
-
experimental part
p. 2562 - 2566
(2009/12/24)
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- Efficient trimethylsilylation of alcohols and phenols with HMDS in the presence of a catalytic amount of 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) as a safe and cheap industrial chemical
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1,3-Dibromo-5,5-dimethylhydantoin (DBDMH) is found to be an effective catalyst for trimethylsilylation various alcohols and phenols with hexamethyldisilazane (HMDS) in dichloromethane at room temperature.
- Khazaei, Ardeshir,Rostami, Amin,Mahboubifar, Marjan
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p. 483 - 487
(2008/02/11)
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- N-Bromosuccinimide (NBS) - Selective and effective catalyst for trimethylsilylation of alcohols and phenols using hexamethyldisilazane and their regeneration under mild and neutral reaction conditions
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Structurally diverse alcohols and phenols were trimethylsilylated in a clean and efficient reaction with hexamethyldisilazane (HMDS) based on the use of a catalytic amount of N-bromosuccinimide under both dichloromethane and solvent-free conditions at roo
- Khazaei, Ardeshir,Rostami, Amin,Raiatzadeh, Ayeh,Mahboubifar, Marjan
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p. 336 - 340
(2008/03/14)
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- A novel and highly efficient method for the silylation of alcohols with hexamethyldisilazane (HMDS) catalyzed by recyclable sulfonic acid-functionalized ordered nanoporous silica
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Silylation of alcohols with hexamethyldisilazane (HMDS) in dichloromethane provides the corresponding silyl ethers in almost quantitative yields at room temperature using 1-3 mol % of sulfonic acid-functionalized silica. Additionally, the catalyst display
- Zareyee, Daryoush,Karimi, Babak
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p. 1277 - 1280
(2007/10/03)
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- Efficient and convenient procedure for protection of hydroxyl groups to the THP, THF and TMS ethers and oxidation of these ethers to their aldehydes or ketones in [BPy]FeCl4 as a low cost room temperature ionic liquid
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Alcohols were converted to the corresponding THP, THF or TMS ethers in high to excellent yields in 1-n-butylpyridinium chloroferrate media as a stable and low cost room temperature ionic liquid. In addition, oxidation of these ethers to their aldehydes or ketones without any overoxidation reactions in this ionic liquid was also performed.
- Khosropour, Ahmad R.,Khodaei, Mohammad M.,Ghaderi, Sattar
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p. 326 - 330
(2007/10/03)
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- A novel and highly efficient method for the direct conversion of aryl aldehyde bisulfite adducts to their aryl trimethylsilyl ethers in a one-pot manner catalyzed by montmorillonite K-10
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A new, convenient, and chemoselective method has been developed for the one-pot conversion of aryl aldehyde bisulfite adducts to the corresponding trimethylsilyl ethers. Copyright Taylor & Francis LLC.
- Khodaei, Mohammad M.,Khosropour, Ahmad R.,Abbasi, Jamshide
-
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- Aluminium triflate [Al(OTf)3] as a recyclable catalyst for the conversion of α-hydroxyphosphonates, alcohols and phenols to their corresponding O-silylated products with hexamethyldisilazane (HMDS)
-
Al(OTf)3 as a recyclable catalyst conducts the efficient conversion of various types of α-hydroxyphosphonates to their corresponding α-trimethysilyloxyphosphonates with HMDS in the absence of solvent at room temperature. The general applicabili
- Firouzabadi, Habib,Iranpoor, Nasser,Sobhani, Sara,Ghassamipour, Soheila
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p. 595 - 599
(2007/10/03)
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- Magnesium triflate [Mg(OTf)2] a highly stable, non-hygroscopic and a recyclable catalyst for the high yielding preparation of diethyl α-trimethylsilyloxyphosphonates from diethyl α-hydroxyphosphonates by HMDS under solventless conditions
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A broad, adaptable, high yielding and convenient procedure for the easy conversion of various α-hydroxyphosphonates to α-trimethylsilyloxyphosphonates under mild conditions with HMDS in the presence of a catalytic amount of magnesium triflate as a highly stable and a non-hygroscopic recyclable catalyst in neat conditions is described. In order to show the general applicability of this method, we have also applied this procedure successfully for the silylation of ordinary alcohols and phenols.
- Firouzabadi, Habib,Iranpoor, Nasser,Sobhani, Sara,Ghassamipour, Soheila
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p. 3197 - 3202
(2007/10/03)
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- Copper triflate [Cu(OTf)2] is an efficient and mild catalyst for the silylation of α-hydroxyphosphonates to α-trimethylsilyloxyphosphonates with HMDS at room temperature
-
A broad, adaptable, high yielding and convenient procedure for the fast conversion of various α-hydroxyphosphonates to α-trimethylsilyloxyphosphonates under mild conditions with HMDS in the presence of a catalytic amount of copper triflate is described. T
- Firouzabadi, Habib,Iranpoor, Nasser,Sobhani, Sara,Ghassamipour, Soheila,Amoozgar, Zohreh
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p. 891 - 893
(2007/10/03)
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- Reaction of carbonyl compounds with trialkylsilyl phenylselenide and tributylstannyl hydride under radical conditions
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A novel method for the hydrosilylation 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 hydride was obtained by the reaction of PhSeSiEt3 with Bu3SnH. Although the tributylgermyl phenylselenide instead of PhSeSiMe3 was treated with tributylstannyl hydride in the presence of a benzaldehyde under radical conditions, hydrogermylated product was not obtained and tributylgermyl hydride was mainly formed.
- Nishiyama, Yutaka,Kajimoto, Hiroyuki,Kotani, Kazuya,Nishida, Takuma,Sonoda, Noboru
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p. 5696 - 5700
(2007/10/03)
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- Tungstophosphoric acid (H3PW12O40) as a heterogeneous inorganic catalyst. Activation of hexamethyldisilazane (HMDS) by tungstophosphoric acid for efficient and selective solvent-free O-silylation reactions
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The role of tungstophosphoric acid (H3PW12O40) as heterogeneous organic catalysts was discussed. Activation of hexamethyldisilazane by tungstophosphoric acid for efficient and selective solvent-free O-silylation reactions
- Firouzabadi, Habib,Iranpoor, Nasser,Amani, Kamal,Nowrouzi, Farhad
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p. 2601 - 2604
(2007/10/03)
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- Hydrosilylation of carbonyl compounds using a PhSeSiMe3/Bu3SnH/AIBN system
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(equation presented) When carbonyl compounds were allowed to react with phenyl trimethylsilyl selenide and tributylstannyl hydride in the presence of a catalytic amount of AIBN as a radical initiator, the hydrosilylation of the carbonyl compounds efficiently proceeded to give the corresponding silyl ethers in moderate to good yields.
- Nishiyama, Yutaka,Kajimoto, Hiroyuki,Kotani, Kazuya,Sonoda, Noboru
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p. 3087 - 3089
(2007/10/03)
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- A New Synthesis of Organodifluorophosphites and their Reaction with Platinum(II) Complexes
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Alkyldifluorophosphites, ROPF2 (R = p-substituted benzyl group, neopentyl, 1-adamantyl) have been obtained by a new method, involving reaction of the appropriate alkyl trimethylsilylether, ROSiMe3 with chlorodifluorophosphine, PF2Cl.Reactions of these dif
- Krueger, Wieland,Sell, Michael,Schmutzler, Reinhard
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p. 1074 - 1080
(2007/10/02)
-