Soghra Farahi - Academia.edu (original) (raw)
Papers by Soghra Farahi
Nashrieh Shimi va Mohandesi Shimi Iran, Oct 22, 2020
TiCl<sub>2</sub>(OTf)-SiO<sub>2</sub> is simply prepared by immobilizatio... more TiCl<sub>2</sub>(OTf)-SiO<sub>2</sub> is simply prepared by immobilization of TiCl<sub>3</sub>(OTf) on silica gel surface and introduced as a non-hygroscopic Lewis acid catalyst for C-N and C-C bond formation <i>via</i> Michael addition reaction. A variety of structurally diverse nitrogen nucleophiles including α-aminophosphonates, aliphatic and aromatic amines and imidazole were evaluated as Michael donors. Friedel–Crafts alkylation of indoles and pyrrole was also investigated through Michael addition reaction in the presence of TiCl<sub>2</sub>(OTf)-SiO<sub>2</sub> as a catalyst. The reactions were conducted at room temperature or 60 °C under solvent-free conditions and the desired Michael adducts were obtained in high to excellent yields.
Some protic ionic liquids (PILs) were synthesized by direct neutralization reaction of Some proti... more Some protic ionic liquids (PILs) were synthesized by direct neutralization reaction of Some protic ionic liquids (PILs) were synthesized by direct neutralization reaction of N-methylimidazole and 4-N,N-dimethylaminopyridine as nitrogen containing heterocyclic organic bases with acetic acid and trifluoroacetic acid. The relative acidity of the prepared ionic liquids was evaluated by Hammet acidity function using UV-Vis spectroscopy. The catalytic effects of the obtained ionic liquids were investigated in the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones and thione derivatives through Biginelli reaction. Among N-methylimidazolium acetate [MImH][OAc], N-methylimidazolium trifluoroacetate [MImH][CF3CO2], 4-N,N-dimethylaminopyridinium acetate [DMAPH][OAc] and 4-N,N-dimethylaminopyridinium trifluoroacetate [DMAPH][CF3CO2], [MImH][OAc] provided the best results. Using 5 mol% of [MImH][OAc] as a catalyst, 3,4-dihydropyrimidin-2-(1H)-ones and thione derivatives were obtained in high to excel...
Phosphorus, Sulfur, and Silicon and the Related Elements
Iranian Journal of Science and Technology, Transactions A: Science
Journal of Organometallic Chemistry, Nov 1, 2009
TiCl 2 (OTf)-SiO 2 as an easy handling recyclable catalyst was applied for trimethylsilylation of... more TiCl 2 (OTf)-SiO 2 as an easy handling recyclable catalyst was applied for trimethylsilylation of diethyl a-hydroxyphosphonates, alcohols and phenols with high selectivity using HMDS as a silylating agent.
Journal of Molecular Catalysis a Chemical, Jun 17, 2008
Solid TiCl 3 (OTf) catalyzed acetylation of alcohols, phenols and thiols with acetic anhydride in... more Solid TiCl 3 (OTf) catalyzed acetylation of alcohols, phenols and thiols with acetic anhydride in the absence of organic solvents at room temperature in a short reaction time. Benzoylation of alcohols, phenols and thiols also proceeded at higher temperature (∼80 • C) under solvent-free conditions. Transesterification of alcohols with ethyl acetate and ethyl formate was also carried out efficiently in the presence of this catalyst. Direct esterification of different alcohols with different carboxylic acids also occurred readily in the presence of this catalyst and in the absence of any organic solvents.
Letters in Organic Chemistry, 2015
Journal of Sulfur Chemistry
Sulfonated charcoal was found to be an efficient heterogeneous catalyst for the acetylation of al... more Sulfonated charcoal was found to be an efficient heterogeneous catalyst for the acetylation of alcohols in acetic acid. Esterification of different carboxylic acids with different alcohols was also achieved with this catalyst. Acetylation and formylation of alcohols can also be catalysed efficiently in ethyl acetate and ethyl formate in high yields.
Scientia Iranica, 2012
Various aqueous solutions of silver and silver/cobalt nanoparticles (Ag and Ag/Co NPs) were obtai... more Various aqueous solutions of silver and silver/cobalt nanoparticles (Ag and Ag/Co NPs) were obtained, and their fluorescence emission spectra have been studied. First, colloidal Ag NPs were prepared by an electrochemical method under different time intervals and at different rotation speeds of rotating electrode. Next, in a reduction method, Ag/Co core-shell NPs were prepared, using Ag NPs as a core. The core-shell structure of Ag/Co NPs has been demonstrated by the Transmission Electron Micrograph (TEM) and X-Ray Diffraction (XRD) pattern. The fluorescence emission spectra of Ag and Ag/Co NPs, at different ranges of excitation wavelength, were investigated, which revealed two kinds of fluorescence emission peak. The shorter emission peak was fixed at about 485 (for Ag NPs) and 538 nm (for Ag/Co NPs). For both NPs, with an increase in excitation wavelength, the latter emission peak becomes red-shifted. The effect of duration time and rotation speed of the rotating electrode, in the electrochemical preparation of Ag NPs, on its fluorescence emission spectra, has also been investigated.
Highly regio-and chemoselective silylation of diethyl a-hydroxyphosphonates, alcohols and phenols... more Highly regio-and chemoselective silylation of diethyl a-hydroxyphosphonates, alcohols and phenols in the presence of solid TiCl 3 (OTf) as a catalyst with hexamethyldisilazane (HMDS) at room temperature in the absence of solvent
Scientia Iranica, 2012
Various aqueous solutions of silver and silver/cobalt nanoparticles (Ag and Ag/Co NPs) were obtai... more Various aqueous solutions of silver and silver/cobalt nanoparticles (Ag and Ag/Co NPs) were obtained, and their fluorescence emission spectra have been studied. First, colloidal Ag NPs were prepared by an electrochemical method under different time intervals and at different rotation speeds of rotating electrode. Next, in a reduction method, Ag/Co core-shell NPs were prepared, using Ag NPs as a core. The core-shell structure of Ag/Co NPs has been demonstrated by the Transmission Electron Micrograph (TEM) and X-Ray Diffraction (XRD) pattern. The fluorescence emission spectra of Ag and Ag/Co NPs, at different ranges of excitation wavelength, were investigated, which revealed two kinds of fluorescence emission peak. The shorter emission peak was fixed at about 485 (for Ag NPs) and 538 nm (for Ag/Co NPs). For both NPs, with an increase in excitation wavelength, the latter emission peak becomes red-shifted. The effect of duration time and rotation speed of the rotating electrode, in the electrochemical preparation of Ag NPs, on its fluorescence emission spectra, has also been investigated.
Journal of Sulfur Chemistry, 2007
ABSTRACT Sulfonated charcoal was found to be an efficient heterogeneous catalyst for the acetylat... more ABSTRACT Sulfonated charcoal was found to be an efficient heterogeneous catalyst for the acetylation of alcohols in acetic acid. Esterification of different carboxylic acids with different alcohols was also achieved with this catalyst. Acetylation and formylation of alcohols can also be catalysed efficiently in ethyl acetate and ethyl formate in high yields.
Journal of Organometallic Chemistry, 2009
TiCl 2 (OTf)-SiO 2 as an easy handling recyclable catalyst was applied for trimethylsilylation of... more TiCl 2 (OTf)-SiO 2 as an easy handling recyclable catalyst was applied for trimethylsilylation of diethyl a-hydroxyphosphonates, alcohols and phenols with high selectivity using HMDS as a silylating agent.
Journal of Molecular Catalysis A: Chemical, 2008
Solid TiCl 3 (OTf) catalyzed acetylation of alcohols, phenols and thiols with acetic anhydride in... more Solid TiCl 3 (OTf) catalyzed acetylation of alcohols, phenols and thiols with acetic anhydride in the absence of organic solvents at room temperature in a short reaction time. Benzoylation of alcohols, phenols and thiols also proceeded at higher temperature (∼80 • C) under solvent-free conditions. Transesterification of alcohols with ethyl acetate and ethyl formate was also carried out efficiently in the presence of this catalyst. Direct esterification of different alcohols with different carboxylic acids also occurred readily in the presence of this catalyst and in the absence of any organic solvents.
Catalysis Communications, 2009
Highly regio-and chemoselective silylation of diethyl a-hydroxyphosphonates, alcohols and phenols... more Highly regio-and chemoselective silylation of diethyl a-hydroxyphosphonates, alcohols and phenols in the presence of solid TiCl 3 (OTf) as a catalyst with hexamethyldisilazane (HMDS) at room temperature in the absence of solvent
Tetrahedron Letters, 2015
ABSTRACT An efficient method for the synthesis of 5-substituted-1H-tetrazoles through the reactio... more ABSTRACT An efficient method for the synthesis of 5-substituted-1H-tetrazoles through the reaction of nitriles with sodium azide using 4-(N,N-dimethylamino)pyridinium acetate as a recyclable catalyst with ionic liquid character is described. The reactions proceed well at 100 °C and provide the corresponding tetrazoles in good to excellent yields. This method has the advantage of easy work-up of the product without the requirement of HCl. Mono [3+2] cycloaddition products were obtained from dicyanides via this method.
Nashrieh Shimi va Mohandesi Shimi Iran, Oct 22, 2020
TiCl<sub>2</sub>(OTf)-SiO<sub>2</sub> is simply prepared by immobilizatio... more TiCl<sub>2</sub>(OTf)-SiO<sub>2</sub> is simply prepared by immobilization of TiCl<sub>3</sub>(OTf) on silica gel surface and introduced as a non-hygroscopic Lewis acid catalyst for C-N and C-C bond formation <i>via</i> Michael addition reaction. A variety of structurally diverse nitrogen nucleophiles including α-aminophosphonates, aliphatic and aromatic amines and imidazole were evaluated as Michael donors. Friedel–Crafts alkylation of indoles and pyrrole was also investigated through Michael addition reaction in the presence of TiCl<sub>2</sub>(OTf)-SiO<sub>2</sub> as a catalyst. The reactions were conducted at room temperature or 60 °C under solvent-free conditions and the desired Michael adducts were obtained in high to excellent yields.
Some protic ionic liquids (PILs) were synthesized by direct neutralization reaction of Some proti... more Some protic ionic liquids (PILs) were synthesized by direct neutralization reaction of Some protic ionic liquids (PILs) were synthesized by direct neutralization reaction of N-methylimidazole and 4-N,N-dimethylaminopyridine as nitrogen containing heterocyclic organic bases with acetic acid and trifluoroacetic acid. The relative acidity of the prepared ionic liquids was evaluated by Hammet acidity function using UV-Vis spectroscopy. The catalytic effects of the obtained ionic liquids were investigated in the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones and thione derivatives through Biginelli reaction. Among N-methylimidazolium acetate [MImH][OAc], N-methylimidazolium trifluoroacetate [MImH][CF3CO2], 4-N,N-dimethylaminopyridinium acetate [DMAPH][OAc] and 4-N,N-dimethylaminopyridinium trifluoroacetate [DMAPH][CF3CO2], [MImH][OAc] provided the best results. Using 5 mol% of [MImH][OAc] as a catalyst, 3,4-dihydropyrimidin-2-(1H)-ones and thione derivatives were obtained in high to excel...
Phosphorus, Sulfur, and Silicon and the Related Elements
Iranian Journal of Science and Technology, Transactions A: Science
Journal of Organometallic Chemistry, Nov 1, 2009
TiCl 2 (OTf)-SiO 2 as an easy handling recyclable catalyst was applied for trimethylsilylation of... more TiCl 2 (OTf)-SiO 2 as an easy handling recyclable catalyst was applied for trimethylsilylation of diethyl a-hydroxyphosphonates, alcohols and phenols with high selectivity using HMDS as a silylating agent.
Journal of Molecular Catalysis a Chemical, Jun 17, 2008
Solid TiCl 3 (OTf) catalyzed acetylation of alcohols, phenols and thiols with acetic anhydride in... more Solid TiCl 3 (OTf) catalyzed acetylation of alcohols, phenols and thiols with acetic anhydride in the absence of organic solvents at room temperature in a short reaction time. Benzoylation of alcohols, phenols and thiols also proceeded at higher temperature (∼80 • C) under solvent-free conditions. Transesterification of alcohols with ethyl acetate and ethyl formate was also carried out efficiently in the presence of this catalyst. Direct esterification of different alcohols with different carboxylic acids also occurred readily in the presence of this catalyst and in the absence of any organic solvents.
Letters in Organic Chemistry, 2015
Journal of Sulfur Chemistry
Sulfonated charcoal was found to be an efficient heterogeneous catalyst for the acetylation of al... more Sulfonated charcoal was found to be an efficient heterogeneous catalyst for the acetylation of alcohols in acetic acid. Esterification of different carboxylic acids with different alcohols was also achieved with this catalyst. Acetylation and formylation of alcohols can also be catalysed efficiently in ethyl acetate and ethyl formate in high yields.
Scientia Iranica, 2012
Various aqueous solutions of silver and silver/cobalt nanoparticles (Ag and Ag/Co NPs) were obtai... more Various aqueous solutions of silver and silver/cobalt nanoparticles (Ag and Ag/Co NPs) were obtained, and their fluorescence emission spectra have been studied. First, colloidal Ag NPs were prepared by an electrochemical method under different time intervals and at different rotation speeds of rotating electrode. Next, in a reduction method, Ag/Co core-shell NPs were prepared, using Ag NPs as a core. The core-shell structure of Ag/Co NPs has been demonstrated by the Transmission Electron Micrograph (TEM) and X-Ray Diffraction (XRD) pattern. The fluorescence emission spectra of Ag and Ag/Co NPs, at different ranges of excitation wavelength, were investigated, which revealed two kinds of fluorescence emission peak. The shorter emission peak was fixed at about 485 (for Ag NPs) and 538 nm (for Ag/Co NPs). For both NPs, with an increase in excitation wavelength, the latter emission peak becomes red-shifted. The effect of duration time and rotation speed of the rotating electrode, in the electrochemical preparation of Ag NPs, on its fluorescence emission spectra, has also been investigated.
Highly regio-and chemoselective silylation of diethyl a-hydroxyphosphonates, alcohols and phenols... more Highly regio-and chemoselective silylation of diethyl a-hydroxyphosphonates, alcohols and phenols in the presence of solid TiCl 3 (OTf) as a catalyst with hexamethyldisilazane (HMDS) at room temperature in the absence of solvent
Scientia Iranica, 2012
Various aqueous solutions of silver and silver/cobalt nanoparticles (Ag and Ag/Co NPs) were obtai... more Various aqueous solutions of silver and silver/cobalt nanoparticles (Ag and Ag/Co NPs) were obtained, and their fluorescence emission spectra have been studied. First, colloidal Ag NPs were prepared by an electrochemical method under different time intervals and at different rotation speeds of rotating electrode. Next, in a reduction method, Ag/Co core-shell NPs were prepared, using Ag NPs as a core. The core-shell structure of Ag/Co NPs has been demonstrated by the Transmission Electron Micrograph (TEM) and X-Ray Diffraction (XRD) pattern. The fluorescence emission spectra of Ag and Ag/Co NPs, at different ranges of excitation wavelength, were investigated, which revealed two kinds of fluorescence emission peak. The shorter emission peak was fixed at about 485 (for Ag NPs) and 538 nm (for Ag/Co NPs). For both NPs, with an increase in excitation wavelength, the latter emission peak becomes red-shifted. The effect of duration time and rotation speed of the rotating electrode, in the electrochemical preparation of Ag NPs, on its fluorescence emission spectra, has also been investigated.
Journal of Sulfur Chemistry, 2007
ABSTRACT Sulfonated charcoal was found to be an efficient heterogeneous catalyst for the acetylat... more ABSTRACT Sulfonated charcoal was found to be an efficient heterogeneous catalyst for the acetylation of alcohols in acetic acid. Esterification of different carboxylic acids with different alcohols was also achieved with this catalyst. Acetylation and formylation of alcohols can also be catalysed efficiently in ethyl acetate and ethyl formate in high yields.
Journal of Organometallic Chemistry, 2009
TiCl 2 (OTf)-SiO 2 as an easy handling recyclable catalyst was applied for trimethylsilylation of... more TiCl 2 (OTf)-SiO 2 as an easy handling recyclable catalyst was applied for trimethylsilylation of diethyl a-hydroxyphosphonates, alcohols and phenols with high selectivity using HMDS as a silylating agent.
Journal of Molecular Catalysis A: Chemical, 2008
Solid TiCl 3 (OTf) catalyzed acetylation of alcohols, phenols and thiols with acetic anhydride in... more Solid TiCl 3 (OTf) catalyzed acetylation of alcohols, phenols and thiols with acetic anhydride in the absence of organic solvents at room temperature in a short reaction time. Benzoylation of alcohols, phenols and thiols also proceeded at higher temperature (∼80 • C) under solvent-free conditions. Transesterification of alcohols with ethyl acetate and ethyl formate was also carried out efficiently in the presence of this catalyst. Direct esterification of different alcohols with different carboxylic acids also occurred readily in the presence of this catalyst and in the absence of any organic solvents.
Catalysis Communications, 2009
Highly regio-and chemoselective silylation of diethyl a-hydroxyphosphonates, alcohols and phenols... more Highly regio-and chemoselective silylation of diethyl a-hydroxyphosphonates, alcohols and phenols in the presence of solid TiCl 3 (OTf) as a catalyst with hexamethyldisilazane (HMDS) at room temperature in the absence of solvent
Tetrahedron Letters, 2015
ABSTRACT An efficient method for the synthesis of 5-substituted-1H-tetrazoles through the reactio... more ABSTRACT An efficient method for the synthesis of 5-substituted-1H-tetrazoles through the reaction of nitriles with sodium azide using 4-(N,N-dimethylamino)pyridinium acetate as a recyclable catalyst with ionic liquid character is described. The reactions proceed well at 100 °C and provide the corresponding tetrazoles in good to excellent yields. This method has the advantage of easy work-up of the product without the requirement of HCl. Mono [3+2] cycloaddition products were obtained from dicyanides via this method.