- Magnetic nanoparticle-supported DABCO tribromide: A versatile nanocatalyst for the synthesis of quinazolinones and benzimidazoles and protection/deprotection of hydroxyl groups
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1,4-Diazabicyclo[2.2.2]octane tribromide supported on magnetic Fe3O4 nanoparticles (MNPs-DABCO tribromide) as a novel heterogeneous tribromide type compound was found to be an efficient and reusable nanocatalyst for the one-pot synthesis of 2-arylquinazolin-4(3H)-ones and 2-aryl-1H-benzo[d]imidazoles through oxidative cyclization of aldehydes with 2-aminobenzamides and 1,2-phenylenediamine, respectively. Also, MNPs-DABCO tribromide catalyzed trimethylsilylation/tetrahydropyranylation and desilylation/depyranylation of a wide variety of alcohols and phenols through changing the solvent medium at room temperature.
- Rostami, Amin,Pourshiani, Omid,Navasi, Yahya,Darvishi, Neda,Saadati, Shaghayegh
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p. 9033 - 9040
(2017/08/29)
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- Selective silylation of alcohols, phenols and oximes using N-chlorosaccharin as an efficient catalyst under mild and solvent-free conditions
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Efficient silylation of OH group in alcohols, phenols and oximes is described using a catalytic amount of N-chlorosaccharin and hexamethyldisilazane (HMDS) under mild and solvent-free conditions. This silylation reaction can be carried out with excellent and interesting various selectivities.
- Aghapour, Ghasem,Moghaddam, Ali Kazemi,Nadali, Samaneh
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p. 197 - 203
(2015/05/12)
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- {[[K.18-Crown-6]Br3}n: A tribromide catalyst for the catalytic protection of amines and alcohols
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{[K.18-Crown-6]Br3}n, a unique tribromide-type catalyst, was utilized for the N-boc protection of amines and trimethylsilylation (TMS) and tetrahydropyranylation (THP) of alcohols. The method is general for the preparation of N-boc derivatives of aliphatic (acyclic and cyclic) and aromatic, and primary and secondary amines and also various TMS-ethers and THP-ethers. The simple separation of the catalyst from the product is one of the many advantages of this method.
- Chehardoli, Gholamabbas,Zolfigol, Mohammad Ali,Derakhshanpanah, Fateme
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p. 1730 - 1733
(2013/10/21)
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- Protection of hydroxyl groups as a trimethylsilyl ether by 1,1,1,3,3,3-hexamethyldisilazane promoted by aspartic acid as an efficient organocatalyst
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A wide variety of alcohols and phenols were protected as trimethylsilyl ethers using 1,1,1,3,3,3-hexamethyl disilazane catalyzed by aspartic acid as a non-toxic, metal-free, and green organocatalyst at room temperature in acetonitrile under mild and heterogeneous conditions. The procedure is operationally simple and the silylated product was obtained in high yield and purity.
- Ghorbani-Choghamarani, Arash,Norouzi, Masoomeh
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scheme or table
p. 595 - 598
(2012/01/06)
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- [H2-Cryptand 222]2+(Br3-) 2 as a tribromide-type catalyst for the trimethylsilylation/ tetrahydropyranylation of alcohols
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A stable organic tribromide, [H2-cryptand 222] 2+(Br3-)2 was utilized as an active catalyst for the trimethylsilylation/ tetrahydropyranylation of alcohols. The method is general for the preparation of OH-protected aliphatic (acyclic and cyclic), aromatic, primary, secondary and tertiary alcohols.
- Chehardoli, Gholamabbas,Zolfigol, Mohammad Ali,Khakyzadeh, Vahid,Gholami, Hadi,Niknam, Khodabakhsh
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experimental part
p. 127 - 131
(2012/06/18)
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- A new crystal engineering approach for the synthesis of {[K.18-Crown-6]I3}n as a nanotube-like and recyclable catalyst for the chemoselective silylation of alcohols
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Reaction of 18-crown-6 with KI in ethanol solution followed by addition of iodine (I2) afforded a unique triiodide salt with a nanotube-like structure ({[K.18-Crown-6]I3}n). It is shown that this reagent may be used for the chemoselective trimethylsilylation of alcohols. The synthesis of the crystalline reagent is a good example of crystal engineering. Reagent was recycled and reused.
- Zolfigol,Kolvari,Koukabi,Salehzadeh,Chehardoli,Tidmarsh,Niknam
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experimental part
p. 484 - 494
(2012/06/18)
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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
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supporting information; experimental part
p. 94 - 98
(2010/05/18)
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- Protection of hydroxy groups as trimethylsilyl ethers using 1,1,1,3,3,3-hexamethyldisilazane (HMDS) catalyzed BY poly(4-VINYLPYRIDINIUM TRIBROMIDE)
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A very efficient procedure for the protection of alcohols and phenols is presented. The mixture of 1,1,1,3,3,3-hexamethyldisilazane (HMDS) and catalytic amounts of poly(4-vinylpyridinium tribromide) was found to be effective for the trimethylsilylation of
- Ghorbani-Choghamarani, Arash,Zolfigol, Mohammad Ali,Hajjami, Maryam,Darvishi, Khorshid,Gholamnia, Laleh
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experimental part
p. 607 - 615
(2011/08/05)
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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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- P-toluenesulfonyl chloride (p-TsCl)-catalyzed trimethylsilylation of hydroxyl groups using hexamethyldisilazane and their regeneration under mild conditions: The first example for catalytic application of p-toluenesulfonyl chloride
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The first catalytic application of p-toluenesulfonyl chloride (p-TsCl) for the efficient and selective trimethylsilylation of various types of hydroxyl groups with hexamethyldisilazane (HMDS) in dichloromethane and desilylation of these compounds in water is reported. The reactions were carried out at room temperature and were found to proceed in good to excellent yields.
- Khazaei, Ardeshir,Rostami, Amin,Mantashlo, Fatemeh
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experimental part
p. 2288 - 2296
(2010/04/06)
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- Preparation of silica supported tin chloride: As a recyclable catalyst for the silylation of hydroxyl groups with HMDS
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Silica-supported tin chloride [SiO2-Sn(Cl)4-n] has been prepared by mixing tin chloride with activated silica gel in toluene under refluxing conditions for one day. Arange of primary, secondary, and tertiary alcohols as well as phenolic hydroxyl groups were converted into their corresponding trimethylsilyl ethers with hexamethyldisilazane in the presence of catalytic amounts of silica-supported tin chloride at room temperature. An excellent chemoselective silylation of hydroxyl groups in the presence of other functional groups was also observed. This catalyst could be recycled and reused fifteen times without loss of efficiency.
- Niknam, Khodabakhsh,Zolfigol, Mohammad Ali,Saberi, Dariush,Molaee, Hajar
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experimental part
p. 1257 - 1264
(2010/08/19)
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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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- 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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- 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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- Co2( CO)8-Catalyzed reaction of aromatic aldehydes with hydrosilanes under carbon monoxide as 1 atm: Incorporation of CO into the carbonyl carbon atom of aldehydes
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Co2(CO)8-catalyzed reaction of aromatic aldehydes with hydrosilanes under CO as 1 atm results in incorporation of CO into the carbonyl carbon atom of aldehydes to give arylethane-1,2-diol disilyl ethers as the main product.The reaction of aliphatic aldehydes gives similar products, only with low yields.Keywords: Cobalt; Silicon; Hydrosilane; Aldehyde; Carbon monoxide; Oxymethylation
- Chatani, Naoto,Tokuhisa, Hideo,Kokubu, Ichiro,Fujii, Satoru,Murai, Shinji
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p. 193 - 198
(2007/10/02)
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