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Shū Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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well dispersed Trifluoromethanesulfonic Acid treated metal oxide nanoparticles immobilized on nitrogen doped carbon as catalysts for friedel crafts acylation
Chemistry-an Asian Journal, 2021Co-Authors: Xi Yang, Tomohiro Yasukawa, Tei Maki, Yasuhiro Yamashita, Shū KobayashiAbstract:Although strong Acid-treated metal oxides are useful heterogeneous superAcid catalysts for various organic transformations, they usually have a limited density of Acidic sites due to their low surface areas. Herein, heterogeneous Trifluoromethanesulfonic Acid immobilized nitrogen-doped carbon-incarcerated titanium nanoparticle (NP) catalysts have been developed that are composed of well-dispersed, small Ti NPs (ca 7 nm) that are otherwise difficult to achieve using Acid-treated metal oxides. The catalysts showed high activity for Friedel-Crafts acylation with low titanium loading (2 mol%, <1 mg of metal for 1 mmol of substrate). A range of microscopic, spectroscopic and physicochemical studies revealed that the nitrogen-doped carbon immobilized the Trifluoromethanesulfonic Acid and that the addition of metals further changed the nature of the Acidic species and enhanced catalytic activity.
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Well-Dispersed Trifluoromethanesulfonic Acid-Treated Metal Oxide Nanoparticles Immobilized on Nitrogen-Doped Carbon as Catalysts for Friedel-Crafts Acylation.
Chemistry an Asian journal, 2020Co-Authors: Xi Yang, Tomohiro Yasukawa, Tei Maki, Yasuhiro Yamashita, Shū KobayashiAbstract:Although strong Acid-treated metal oxides are useful heterogeneous superAcid catalysts for various organic transformations, they usually have a limited density of Acidic sites due to their low surface areas. Herein, heterogeneous Trifluoromethanesulfonic Acid immobilized nitrogen-doped carbon-incarcerated titanium nanoparticle (NP) catalysts have been developed that are composed of well-dispersed, small Ti NPs (ca 7 nm) that are otherwise difficult to achieve using Acid-treated metal oxides. The catalysts showed high activity for Friedel-Crafts acylation with low titanium loading (2 mol%,
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Catalytic Friedel-Crafts acylation of benzene, chlorobenzene, and fluorobenzene using a novel catalyst system, hafnium triflate and Trifluoromethanesulfonic Acid
Tetrahedron Letters, 1998Co-Authors: Shū Kobayashi, Shunsuke IwamotoAbstract:Abstract Catalytic Friedel-Crafts acylation of benzene and unactivated benzenes such as chlorobenzene and fluorobenzene has been successfully carried out using hafnium (IV) triflate and Trifluoromethanesulfonic Acid as catalysts. Both aromatic and aliphatic carboxylic Acid chlorides reacted smoothly under the conditions to afford the corresponding aromatic ketones in good yields.
Luis R. Pizzio - One of the best experts on this subject based on the ideXlab platform.
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Trifluoromethanesulfonic Acid immobilized on zirconium oxide obtained by the sol gel method as catalyst in paraben synthesis
Applied Catalysis A-general, 2011Co-Authors: Marina Gorsd, Luis R. Pizzio, Mirta N. BlancoAbstract:Abstract The parabens, alkylic esters of p-hydroxybenzoic Acid, were synthesized using Trifluoromethanesulfonic Acid immobilized on zirconium oxide (zirconia) as catalyst. The oxide was obtained by the sol–gel method, using urea as a pore-forming agent. After removing urea by extraction with water, the solid was dried and then calcined at 100, 205, 310 and 425 °C for 24 h. Afterward, it was impregnated with Trifluoromethanesulfonic Acid in toluene at reflux and leached to remove the weakly adsorbed Acid. Mesoporous materials were obtained, whose mean pore diameter increased with the temperature of the thermal treatment of the support, while the specific surface area and the amount of Acid bonded to the support decreased. The samples are crystalline from 400 °C and are thermally stable up to 250 °C. The catalysts have strong Acidity and the number of Acid sites decreased with the Acid content in the support. The catalytic activity in the synthesis of propyl paraben, expressed as moles of ester formed at 5 h/mol Acid in the catalyst, decreased when samples obtained from supports thermally treated at higher temperature were used. The activity also slightly diminished for the synthesis of different parabens in the order propyl > ethyl > methyl ester.
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Trifluoromethanesulfonic Acid immobilized on zirconium oxide obtained by the sol–gel method as catalyst in paraben synthesis
Applied Catalysis A-general, 2011Co-Authors: Marina Gorsd, Luis R. Pizzio, Mirta N. BlancoAbstract:Abstract The parabens, alkylic esters of p-hydroxybenzoic Acid, were synthesized using Trifluoromethanesulfonic Acid immobilized on zirconium oxide (zirconia) as catalyst. The oxide was obtained by the sol–gel method, using urea as a pore-forming agent. After removing urea by extraction with water, the solid was dried and then calcined at 100, 205, 310 and 425 °C for 24 h. Afterward, it was impregnated with Trifluoromethanesulfonic Acid in toluene at reflux and leached to remove the weakly adsorbed Acid. Mesoporous materials were obtained, whose mean pore diameter increased with the temperature of the thermal treatment of the support, while the specific surface area and the amount of Acid bonded to the support decreased. The samples are crystalline from 400 °C and are thermally stable up to 250 °C. The catalysts have strong Acidity and the number of Acid sites decreased with the Acid content in the support. The catalytic activity in the synthesis of propyl paraben, expressed as moles of ester formed at 5 h/mol Acid in the catalyst, decreased when samples obtained from supports thermally treated at higher temperature were used. The activity also slightly diminished for the synthesis of different parabens in the order propyl > ethyl > methyl ester.
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Synthesis and characterization of catalysts obtained by Trifluoromethanesulfonic Acid immobilization on zirconia
Scientific Bases for the Preparation of Heterogeneous Catalysts - Proceedings of the 10th International Symposium Louvain-la-Neuve Belgium July 11-15 , 2010Co-Authors: Marina Gorsd, Mirta N. Blanco, Luis R. PizzioAbstract:Abstract Mesoporous zirconia (zirconium oxide) materials containing mainly mesopores have been synthesized via sol-gel reactions from zirconium propoxide using urea as a template. The solid was dried, extracted with water to remove urea, calcined at different temperatures and impregnated with Trifluoromethanesulfonic Acid. The samples thus obtained were extracted with a mixture of dichloromethane and diethyl ether using a Soxhlet apparatus in order to remove the loosely adsorbed Acid. The solids were characterized by FT-IR, XRD, DTA-TGA, and N 2 adsorption-desorption measurements. The mean pore diameter of the support was higher than 3.7 nm, which increased with the increment of the thermal treatment temperature. At the same time, the specific surface area and the amount of triflic Acid attached on the support decreased. The potentiometric titration with n-butylamine indicated that the catalysts present very strong Acid sites. The catalytic activity of the prepared catalysts in the esterification of 4-hydroxybenzoic Acid with propyl alcohol was evaluated.
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Supported Trifluoromethanesulfonic Acid as catalyst in the synthesis of flavone and chromone derivatives
Applied Catalysis A: General, 2007Co-Authors: Daniel Oscar Bennardi, Gustavo Pablo Romanelli, Juan Carlos Autino, Luis R. PizzioAbstract:Abstract Solid Acid catalysts based on Trifluoromethanesulfonic Acid (triflic Acid, TFMS) were synthesized using titania with different textural properties as support, obtained by increasing the calcination temperature (Ti 100 , Ti 200 , Ti 300, and Ti 400 ). They were characterized by FT-IR, DTA-TGA, and BET. The Acidic characteristics of the catalysts were determined by potentiometric titration with n -butylamine. According to this technique, the catalysts present very strong Acid sites. Their Acid strength decreases slightly in the order Ti 100 > Ti 200 > Ti 300 > Ti 400 , as a result of the partial dehydroxylation that takes place during the thermal treatment of the supports. The amount of Trifluoromethanesulfonic Acid firmly adsorbed on the support depends on the number of –OH groups available on the titania to be protonated, which decreases with the increase in the calcination temperature. The new catalysts were tested in the cyclization of 1-(2-hydroxyphenyl)-3-phenyl-1,3-propanedione. The reaction experiments were performed using toluene as the solvent at reflux. In all cases, the product (flavone) was obtained with high selectivity. The activity of the catalysts is dependent on the textural properties of the support used to obtain the catalysts and the amount of triflic Acid firmly adsorbed on it. The same reaction conditions were applied to the preparation of eight substituted flavones and chromones. Conversions up to 88% were obtained using the Ti 100 supported TFMS catalyst.
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Synthesis and characterization of Trifluoromethanesulfonic Acid supported on mesoporous titania
Materials Letters, 2006Co-Authors: Luis R. PizzioAbstract:Abstract Mesoporous titania materials have been synthesized by using urea as a template via sol–gel reactions of titaniumisopropoxide, followed by the removal of urea by extraction with water. The solid was dried, calcined at different temperatures and impregnated with Trifluoromethanesulfonic Acid. They were extracted by a mixture of dichloromethane and diethyl ether using a Soxhlet apparatus in order to remove the loosely adsorbed Acid. The solids were characterized by FT-IR, XRD, DTA–TGA, and BET. The Acidic characteristics of the catalysts were determined by potentiometric titration with n -butylamine and the test reaction of isopropanol dehydration.
Mirta N. Blanco - One of the best experts on this subject based on the ideXlab platform.
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Trifluoromethanesulfonic Acid immobilized on zirconium oxide obtained by the sol gel method as catalyst in paraben synthesis
Applied Catalysis A-general, 2011Co-Authors: Marina Gorsd, Luis R. Pizzio, Mirta N. BlancoAbstract:Abstract The parabens, alkylic esters of p-hydroxybenzoic Acid, were synthesized using Trifluoromethanesulfonic Acid immobilized on zirconium oxide (zirconia) as catalyst. The oxide was obtained by the sol–gel method, using urea as a pore-forming agent. After removing urea by extraction with water, the solid was dried and then calcined at 100, 205, 310 and 425 °C for 24 h. Afterward, it was impregnated with Trifluoromethanesulfonic Acid in toluene at reflux and leached to remove the weakly adsorbed Acid. Mesoporous materials were obtained, whose mean pore diameter increased with the temperature of the thermal treatment of the support, while the specific surface area and the amount of Acid bonded to the support decreased. The samples are crystalline from 400 °C and are thermally stable up to 250 °C. The catalysts have strong Acidity and the number of Acid sites decreased with the Acid content in the support. The catalytic activity in the synthesis of propyl paraben, expressed as moles of ester formed at 5 h/mol Acid in the catalyst, decreased when samples obtained from supports thermally treated at higher temperature were used. The activity also slightly diminished for the synthesis of different parabens in the order propyl > ethyl > methyl ester.
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Trifluoromethanesulfonic Acid immobilized on zirconium oxide obtained by the sol–gel method as catalyst in paraben synthesis
Applied Catalysis A-general, 2011Co-Authors: Marina Gorsd, Luis R. Pizzio, Mirta N. BlancoAbstract:Abstract The parabens, alkylic esters of p-hydroxybenzoic Acid, were synthesized using Trifluoromethanesulfonic Acid immobilized on zirconium oxide (zirconia) as catalyst. The oxide was obtained by the sol–gel method, using urea as a pore-forming agent. After removing urea by extraction with water, the solid was dried and then calcined at 100, 205, 310 and 425 °C for 24 h. Afterward, it was impregnated with Trifluoromethanesulfonic Acid in toluene at reflux and leached to remove the weakly adsorbed Acid. Mesoporous materials were obtained, whose mean pore diameter increased with the temperature of the thermal treatment of the support, while the specific surface area and the amount of Acid bonded to the support decreased. The samples are crystalline from 400 °C and are thermally stable up to 250 °C. The catalysts have strong Acidity and the number of Acid sites decreased with the Acid content in the support. The catalytic activity in the synthesis of propyl paraben, expressed as moles of ester formed at 5 h/mol Acid in the catalyst, decreased when samples obtained from supports thermally treated at higher temperature were used. The activity also slightly diminished for the synthesis of different parabens in the order propyl > ethyl > methyl ester.
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Synthesis and characterization of catalysts obtained by Trifluoromethanesulfonic Acid immobilization on zirconia
Scientific Bases for the Preparation of Heterogeneous Catalysts - Proceedings of the 10th International Symposium Louvain-la-Neuve Belgium July 11-15 , 2010Co-Authors: Marina Gorsd, Mirta N. Blanco, Luis R. PizzioAbstract:Abstract Mesoporous zirconia (zirconium oxide) materials containing mainly mesopores have been synthesized via sol-gel reactions from zirconium propoxide using urea as a template. The solid was dried, extracted with water to remove urea, calcined at different temperatures and impregnated with Trifluoromethanesulfonic Acid. The samples thus obtained were extracted with a mixture of dichloromethane and diethyl ether using a Soxhlet apparatus in order to remove the loosely adsorbed Acid. The solids were characterized by FT-IR, XRD, DTA-TGA, and N 2 adsorption-desorption measurements. The mean pore diameter of the support was higher than 3.7 nm, which increased with the increment of the thermal treatment temperature. At the same time, the specific surface area and the amount of triflic Acid attached on the support decreased. The potentiometric titration with n-butylamine indicated that the catalysts present very strong Acid sites. The catalytic activity of the prepared catalysts in the esterification of 4-hydroxybenzoic Acid with propyl alcohol was evaluated.
Marina Gorsd - One of the best experts on this subject based on the ideXlab platform.
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Trifluoromethanesulfonic Acid immobilized on zirconium oxide obtained by the sol gel method as catalyst in paraben synthesis
Applied Catalysis A-general, 2011Co-Authors: Marina Gorsd, Luis R. Pizzio, Mirta N. BlancoAbstract:Abstract The parabens, alkylic esters of p-hydroxybenzoic Acid, were synthesized using Trifluoromethanesulfonic Acid immobilized on zirconium oxide (zirconia) as catalyst. The oxide was obtained by the sol–gel method, using urea as a pore-forming agent. After removing urea by extraction with water, the solid was dried and then calcined at 100, 205, 310 and 425 °C for 24 h. Afterward, it was impregnated with Trifluoromethanesulfonic Acid in toluene at reflux and leached to remove the weakly adsorbed Acid. Mesoporous materials were obtained, whose mean pore diameter increased with the temperature of the thermal treatment of the support, while the specific surface area and the amount of Acid bonded to the support decreased. The samples are crystalline from 400 °C and are thermally stable up to 250 °C. The catalysts have strong Acidity and the number of Acid sites decreased with the Acid content in the support. The catalytic activity in the synthesis of propyl paraben, expressed as moles of ester formed at 5 h/mol Acid in the catalyst, decreased when samples obtained from supports thermally treated at higher temperature were used. The activity also slightly diminished for the synthesis of different parabens in the order propyl > ethyl > methyl ester.
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Trifluoromethanesulfonic Acid immobilized on zirconium oxide obtained by the sol–gel method as catalyst in paraben synthesis
Applied Catalysis A-general, 2011Co-Authors: Marina Gorsd, Luis R. Pizzio, Mirta N. BlancoAbstract:Abstract The parabens, alkylic esters of p-hydroxybenzoic Acid, were synthesized using Trifluoromethanesulfonic Acid immobilized on zirconium oxide (zirconia) as catalyst. The oxide was obtained by the sol–gel method, using urea as a pore-forming agent. After removing urea by extraction with water, the solid was dried and then calcined at 100, 205, 310 and 425 °C for 24 h. Afterward, it was impregnated with Trifluoromethanesulfonic Acid in toluene at reflux and leached to remove the weakly adsorbed Acid. Mesoporous materials were obtained, whose mean pore diameter increased with the temperature of the thermal treatment of the support, while the specific surface area and the amount of Acid bonded to the support decreased. The samples are crystalline from 400 °C and are thermally stable up to 250 °C. The catalysts have strong Acidity and the number of Acid sites decreased with the Acid content in the support. The catalytic activity in the synthesis of propyl paraben, expressed as moles of ester formed at 5 h/mol Acid in the catalyst, decreased when samples obtained from supports thermally treated at higher temperature were used. The activity also slightly diminished for the synthesis of different parabens in the order propyl > ethyl > methyl ester.
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Trifluoromethanesulfonic Acid immobilized on zirconium oxide obtained by the sol–gel method as catalyst in paraben synthesis
Applied Catalysis A: General, 2011Co-Authors: Marina Gorsd, Luis Pizzio, Mirta BlancoAbstract:The parabens, alkylic esters of p-hydroxybenzoic Acid, were synthesized using Trifluoromethanesulfonic Acid immobilized on zirconium oxide (zirconia) as catalyst. The oxide was obtained by the sol–gel method, using urea as a pore-forming agent. After removing urea by extraction with water, the solid was dried and then calcined at 100, 205, 310 and 425 ◦C for 24 h. Afterward, it was impregnated with Trifluoromethanesulfonic Acid in toluene at reflux and leached to remove the weakly adsorbed Acid. Mesoporous materials were obtained, whose mean pore diameter increased with the temperature of the thermal treatment of the support, while the specific surface area and the amount of Acid bonded to the support decreased. The samples are crystalline from 400 ◦C and are thermally stable up to 250 ◦C. The catalysts have strong Acidity and the number of Acid sites decreased with the Acid content in the support. The catalytic activity in the synthesis of propyl paraben, expressed as moles of ester formed at 5 h/mol Acid in the catalyst, decreased when samples obtained from supports thermally treated at higher temperature were used. The activity also slightly diminished for the synthesis of different parabens in the order propyl > ethyl > methyl ester.Fil: Blanco, Mirta Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Pizzio, Luis Rene. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Gorsd, Marina Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentin
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Synthesis and characterization of catalysts obtained by Trifluoromethanesulfonic Acid immobilization on zirconia
Scientific Bases for the Preparation of Heterogeneous Catalysts - Proceedings of the 10th International Symposium Louvain-la-Neuve Belgium July 11-15 , 2010Co-Authors: Marina Gorsd, Mirta N. Blanco, Luis R. PizzioAbstract:Abstract Mesoporous zirconia (zirconium oxide) materials containing mainly mesopores have been synthesized via sol-gel reactions from zirconium propoxide using urea as a template. The solid was dried, extracted with water to remove urea, calcined at different temperatures and impregnated with Trifluoromethanesulfonic Acid. The samples thus obtained were extracted with a mixture of dichloromethane and diethyl ether using a Soxhlet apparatus in order to remove the loosely adsorbed Acid. The solids were characterized by FT-IR, XRD, DTA-TGA, and N 2 adsorption-desorption measurements. The mean pore diameter of the support was higher than 3.7 nm, which increased with the increment of the thermal treatment temperature. At the same time, the specific surface area and the amount of triflic Acid attached on the support decreased. The potentiometric titration with n-butylamine indicated that the catalysts present very strong Acid sites. The catalytic activity of the prepared catalysts in the esterification of 4-hydroxybenzoic Acid with propyl alcohol was evaluated.
Koichi Narasaka - One of the best experts on this subject based on the ideXlab platform.
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Transformation of Oximes of Phenethyl Ketone Derivatives to Quinolines and Azaspirotrienones Catalyzed by Tetrabutylammonium Perrhenate and Trifluoromethanesulfonic Acid.
Bulletin of the Chemical Society of Japan, 1997Co-Authors: Hiroyuki Kusama, Yuko Yamashita, Katsuya Uchiyama, Koichi NarasakaAbstract:Phenethyl ketone oximes are converted to quinolines by the treatment with tetrabutylammonium perrhenate, Trifluoromethanesulfonic Acid, and chloranil in refluxing 1,2-dichloroethane. Azaspirotrienones can be synthesized from p-hydroxyphenethyl or 3-(p-hydroxyphenyl)propyl ketone oximes by applying the above method. Thus prepared azaspirotrienones are converted to quinolines by Acid treatment.
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beckmann rearrangement of oximes catalyzed with tetrabutylammonium perrhenate and Trifluoromethanesulfonic Acid
Bulletin of the Chemical Society of Japan, 1995Co-Authors: Hiroyuki Kusama, Yuko Yamashita, Koichi NarasakaAbstract:The Beckmann rearrangement of oximes is catalyzed by a combined use of tetrabutylammonium perrhenate (Bu4NReO4) and Trifluoromethanesulfonic Acid in nitromethane under azeotropic conditions, giving amides in high yield. By employing this catalytic system, amides can be prepared directly from ketones and hydroxylamine hydrochloride.
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Synthesis of Quinolines via Intramolecular Cyclization of Benzylacetone Oxime Derivatives Catalyzed with Tetrabutylammonium Perrhenate(VII) and Trifluoromethanesulfonic Acid
Chemistry Letters, 1995Co-Authors: Hiroyuki Kusama, Yuko Yamashita, Koichi NarasakaAbstract:Intramolecular cyclization reaction on the nitrogen atom of benzylacetone oxime derivatives, which have electron donating group(s) on the phenyl group, proceeds by treatment with tetrabutylammonium perrhenate, Trifluoromethanesulfonic Acid, and 4-chloranil in refluxing 1,2-dichloroethane to afford quinoline derivatives in good yield.
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beckmann rearrangement catalyzed by the combined use of tetrabutylammonium perrhenate vii and Trifluoromethanesulfonic Acid
Chemistry Letters, 1993Co-Authors: Koichi Narasaka, Hiroyuki Kusama, Yuko Yamashita, Hiroshi SatoAbstract:Beckmann rearrangement of oximes is catalyzed with tetrabutylammonium perrhenate(VII), Trifluoromethanesulfonic Acid and hydroxylamine hydrochloride in nitromethane under azeotropic conditions, giving amides in high yield.