A facile and efficient one-pot three-component synthesis of bis（5-methyl-2-furyl）methanes has been achieved via the reaction of 2-methylfuran with a series of aliphatic and aromatic aldehydes and aliphatic ketones i...A facile and efficient one-pot three-component synthesis of bis（5-methyl-2-furyl）methanes has been achieved via the reaction of 2-methylfuran with a series of aliphatic and aromatic aldehydes and aliphatic ketones in presence of copper（II） triflate under solvent free conditions. The bis（5-methyl-2-furyl）methanes were obtained in 34%--72% yields and the catalyst was recycled up to four successive cycles without much loss in catalytic activity.展开更多
Sulfanilic acid has been found to be an efficient catalyst for the synthesis of 1,5-benzodiazepines from o-phenylenediamine and ketones. This method is simple, effective and environmentally friendly and gives better y...Sulfanilic acid has been found to be an efficient catalyst for the synthesis of 1,5-benzodiazepines from o-phenylenediamine and ketones. This method is simple, effective and environmentally friendly and gives better yields.展开更多
Nitro aromatic compound can be obtained in high yields via nitration of aromatic compound with wet carbon-based solid acid and NaNO_3 under solvent free oxidation at room temperature.
Tetrabutylammonium hexatungstate,[TBA]2[W6O19],has been used as an efficient,inexpensive,and recyclable green catalyst for the one-pot three-component synthesis of 1,8-dioxodecahydroacridines by the reaction of dimedo...Tetrabutylammonium hexatungstate,[TBA]2[W6O19],has been used as an efficient,inexpensive,and recyclable green catalyst for the one-pot three-component synthesis of 1,8-dioxodecahydroacridines by the reaction of dimedone with aromatic or aliphatic aldehydes in the presence of a nitrogen source(ammonium acetate or aromatic amines) under neat conditions.There are several advantages to the current process over the standard procedures available in the literature,including shorter reaction times(7-14 min),higher yields,facile work-up,and minimal environmental impact.Furthermore,the catalyst can be conveniently recovered and reused.展开更多
A sulfonated carbon material was shown to be a highly efficient,eco-friendly,and recyclable solid acid catalyst for the Biginelli reaction of β-ketoester,aldehyde,and urea or thiourea under solvent-free conditions.It...A sulfonated carbon material was shown to be a highly efficient,eco-friendly,and recyclable solid acid catalyst for the Biginelli reaction of β-ketoester,aldehyde,and urea or thiourea under solvent-free conditions.It gave 3,4-dihydropyrimidin-2(1H)-ones and-thiones in good to excellent yields.This method has the advantages of a simple procedure with easy work-up,short reaction time,and high yields.The catalyst can be recycled after a simple work-up and was reused four times without substantial reduction in activity.展开更多
A convenient and efficient method for the synthesis of pyrazolo[3,4-d]pyrimidin-4-ones via heterocyclization reaction of 5-amino-lH-pyrazole-4-carboxamides with triethyl orthoesters using two BrCnsted-acidic ionic liq...A convenient and efficient method for the synthesis of pyrazolo[3,4-d]pyrimidin-4-ones via heterocyclization reaction of 5-amino-lH-pyrazole-4-carboxamides with triethyl orthoesters using two BrCnsted-acidic ionic liquids, 3-methyl-l-（4-sulfonic acid）butylimidazolium hydrogen sulfate [MIM＋（CH2）4SO3H][ HSO4 ] or N-（4-sulfonic acid）butyl triethylammonium hydrogen sulfate [Et3N＋（CH2）4SO3H][ HSO4 ], as efficient homogeneous catalysts under solvent-free conditions is described.展开更多
Nanosized MCM-41-SO3H based on ordered mesoporous silica material with a covalent sulfonic acid group was synthesized and used as acid catalyst for the new, simple, convenient and green synthesis of 2,4,5-trisubstitut...Nanosized MCM-41-SO3H based on ordered mesoporous silica material with a covalent sulfonic acid group was synthesized and used as acid catalyst for the new, simple, convenient and green synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetra-substituted imidazoles. Also some of synthesis products are new. Echo-friendly protocol, short reaction times, easy and quick isolation of the products and excellent yields are the main advantages of this procedure.展开更多
A newly prepared catalyst consisting of acidic ionic liquid 1-(4-sulfonic acid)butylpyridinium hydrogen sulfate supported on silica was used to catalyze the cross-aldol condensation of ketones with aromatic aldehydes ...A newly prepared catalyst consisting of acidic ionic liquid 1-(4-sulfonic acid)butylpyridinium hydrogen sulfate supported on silica was used to catalyze the cross-aldol condensation of ketones with aromatic aldehydes under solvent-free conditions. The highly active and selective catalyst gave good to excellent yields of the desired cross-aldol products without the occurrence of any self-condensation reactions. Reaction times were short, the procedure and work-up were simple, and no volatile or hazardous organic solvents were necessary. Moreover, the catalyst could be reused at least four times with only a slight reduction in activity.展开更多
An easy, safe, solvent free and effective method for the synthesis of pyrazole-substituted chalcones has been achieved by grinding pyrazole aldehydes and acetophenones in the presence of activated barium hydroxide （C...An easy, safe, solvent free and effective method for the synthesis of pyrazole-substituted chalcones has been achieved by grinding pyrazole aldehydes and acetophenones in the presence of activated barium hydroxide （C-200） in high yield within short span of time. All reactions were carried out just by grinding the two reactants in the presence of activated barium hydroxide （C-200）. Results are also compared with sodium hydroxide and potassium hydroxide.展开更多
Fluoroboric acid adsorbed on silica-gel（HBF4·SiO2） has been found to be an extremely efficient and recyclable catalyst for the preparation of β-enaminones and β-enamino esters under solvent-free conditions.
Carbon-based solid acid catalyst was found to be highly efficient, eco-friendly and recyclable heterogeneous catalyst for the multicomponent reaction of benzil, aromatic aldehyde, primary amine and ammonium acetate, g...Carbon-based solid acid catalyst was found to be highly efficient, eco-friendly and recyclable heterogeneous catalyst for the multicomponent reaction of benzil, aromatic aldehyde, primary amine and ammonium acetate, giving rise to 1,2,4,5-tetrasubstituted imidazoles in good to excellent yields. The present methodology offers several advantages, such as high yields, short reaction time, mild reaction condition and a recyclable catalyst with a very easy work up.展开更多
A direct and efficient approach to synthesize imidazo[1,2-α]pyridines through three-component one-pot reaction of 2-aminopyridine,aldehyde and terminal alkyne catalyzed by Cu-nanoparticles under solvent-free conditio...A direct and efficient approach to synthesize imidazo[1,2-α]pyridines through three-component one-pot reaction of 2-aminopyridine,aldehyde and terminal alkyne catalyzed by Cu-nanoparticles under solvent-free conditions has been developed.This method provides a rapid access to substituted imidazo[1,2-α]pyridines with good yields（up to 85％）.展开更多
Multi-component condensation of 2-naphthol, aromatic aldehydes, and cyclic 1,3-dicarbonyl compounds catalyzed by ionic liquid [NSPTEA][HSO4] was accomplished for the synthesis of a series of 12-aryl-8,9,10,12- tetrahy...Multi-component condensation of 2-naphthol, aromatic aldehydes, and cyclic 1,3-dicarbonyl compounds catalyzed by ionic liquid [NSPTEA][HSO4] was accomplished for the synthesis of a series of 12-aryl-8,9,10,12- tetrahydrobenzo[a]xanthen-11-ones under solvent-free conditions. High yields, ease recovery, short reaction time and reusability of catalyst are significant advantages. ZrOC12＂8H20 was also found to act as an effective catalyst towards this transformation.展开更多
In(OTf)3 plays the role of a Lewis acid catalyst in the Pechmann condensation of phenols with β-ketoesters under solvent-free conditions to give coumarin derivatives. This novel and inexpensive method has advantages ...In(OTf)3 plays the role of a Lewis acid catalyst in the Pechmann condensation of phenols with β-ketoesters under solvent-free conditions to give coumarin derivatives. This novel and inexpensive method has advantages such as short reaction time, excellent product yields, and avoids the use of organic solvents in agreement with green chemistry principles. Catalyst loadings can be as low as 1 mol% to give high yields of the corresponding coumarins at 80 °C. The catalyst can be recovered after the reaction, and reused with only a slight decrease in the yield.展开更多
Iron zirconium phosphate(ZPFe) nanoparticles were found to function as an efficient catalyst for the acetylation of a wide range of alcohols and phenols using acetic anhydride, generating good to excellent yields unde...Iron zirconium phosphate(ZPFe) nanoparticles were found to function as an efficient catalyst for the acetylation of a wide range of alcohols and phenols using acetic anhydride, generating good to excellent yields under solvent-free conditions. The steric and electronic properties of various sub-strates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively coupled plasma-optical emission spectrometry, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. These analyses revealed that the interlayer distance in the catalyst increased from 7.5 to 9.3 when Fe3+ was intercalated between the layers, whereas the crystallinity of the material was reduced. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. This new method for the acetylation of alcohols and phenols has several important advantages, including mild and environ-mentally friendly reaction conditions, as well as good to excellent yields and a facile work-up.展开更多
文摘A facile and efficient one-pot three-component synthesis of bis（5-methyl-2-furyl）methanes has been achieved via the reaction of 2-methylfuran with a series of aliphatic and aromatic aldehydes and aliphatic ketones in presence of copper（II） triflate under solvent free conditions. The bis（5-methyl-2-furyl）methanes were obtained in 34%--72% yields and the catalyst was recycled up to four successive cycles without much loss in catalytic activity.
文摘Sulfanilic acid has been found to be an efficient catalyst for the synthesis of 1,5-benzodiazepines from o-phenylenediamine and ketones. This method is simple, effective and environmentally friendly and gives better yields.
文摘Nitro aromatic compound can be obtained in high yields via nitration of aromatic compound with wet carbon-based solid acid and NaNO_3 under solvent free oxidation at room temperature.
基金supported by Islamic Azad University,Mashhad Branch
文摘Tetrabutylammonium hexatungstate,[TBA]2[W6O19],has been used as an efficient,inexpensive,and recyclable green catalyst for the one-pot three-component synthesis of 1,8-dioxodecahydroacridines by the reaction of dimedone with aromatic or aliphatic aldehydes in the presence of a nitrogen source(ammonium acetate or aromatic amines) under neat conditions.There are several advantages to the current process over the standard procedures available in the literature,including shorter reaction times(7-14 min),higher yields,facile work-up,and minimal environmental impact.Furthermore,the catalyst can be conveniently recovered and reused.
基金supported by Islamic Azad University,Mashhad Branch
文摘A sulfonated carbon material was shown to be a highly efficient,eco-friendly,and recyclable solid acid catalyst for the Biginelli reaction of β-ketoester,aldehyde,and urea or thiourea under solvent-free conditions.It gave 3,4-dihydropyrimidin-2(1H)-ones and-thiones in good to excellent yields.This method has the advantages of a simple procedure with easy work-up,short reaction time,and high yields.The catalyst can be recycled after a simple work-up and was reused four times without substantial reduction in activity.
文摘A convenient and efficient method for the synthesis of pyrazolo[3,4-d]pyrimidin-4-ones via heterocyclization reaction of 5-amino-lH-pyrazole-4-carboxamides with triethyl orthoesters using two BrCnsted-acidic ionic liquids, 3-methyl-l-（4-sulfonic acid）butylimidazolium hydrogen sulfate [MIM＋（CH2）4SO3H][ HSO4 ] or N-（4-sulfonic acid）butyl triethylammonium hydrogen sulfate [Et3N＋（CH2）4SO3H][ HSO4 ], as efficient homogeneous catalysts under solvent-free conditions is described.
文摘Nanosized MCM-41-SO3H based on ordered mesoporous silica material with a covalent sulfonic acid group was synthesized and used as acid catalyst for the new, simple, convenient and green synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetra-substituted imidazoles. Also some of synthesis products are new. Echo-friendly protocol, short reaction times, easy and quick isolation of the products and excellent yields are the main advantages of this procedure.
基金supported by Islamic Azad University,Mashhad Branch
文摘A newly prepared catalyst consisting of acidic ionic liquid 1-(4-sulfonic acid)butylpyridinium hydrogen sulfate supported on silica was used to catalyze the cross-aldol condensation of ketones with aromatic aldehydes under solvent-free conditions. The highly active and selective catalyst gave good to excellent yields of the desired cross-aldol products without the occurrence of any self-condensation reactions. Reaction times were short, the procedure and work-up were simple, and no volatile or hazardous organic solvents were necessary. Moreover, the catalyst could be reused at least four times with only a slight reduction in activity.
文摘An easy, safe, solvent free and effective method for the synthesis of pyrazole-substituted chalcones has been achieved by grinding pyrazole aldehydes and acetophenones in the presence of activated barium hydroxide （C-200） in high yield within short span of time. All reactions were carried out just by grinding the two reactants in the presence of activated barium hydroxide （C-200）. Results are also compared with sodium hydroxide and potassium hydroxide.
文摘Fluoroboric acid adsorbed on silica-gel（HBF4·SiO2） has been found to be an extremely efficient and recyclable catalyst for the preparation of β-enaminones and β-enamino esters under solvent-free conditions.
文摘Carbon-based solid acid catalyst was found to be highly efficient, eco-friendly and recyclable heterogeneous catalyst for the multicomponent reaction of benzil, aromatic aldehyde, primary amine and ammonium acetate, giving rise to 1,2,4,5-tetrasubstituted imidazoles in good to excellent yields. The present methodology offers several advantages, such as high yields, short reaction time, mild reaction condition and a recyclable catalyst with a very easy work up.
基金Supported by the National Natural Science Foundation of China（Nos.20772088, 21172163） and the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘A direct and efficient approach to synthesize imidazo[1,2-α]pyridines through three-component one-pot reaction of 2-aminopyridine,aldehyde and terminal alkyne catalyzed by Cu-nanoparticles under solvent-free conditions has been developed.This method provides a rapid access to substituted imidazo[1,2-α]pyridines with good yields（up to 85％）.
文摘Multi-component condensation of 2-naphthol, aromatic aldehydes, and cyclic 1,3-dicarbonyl compounds catalyzed by ionic liquid [NSPTEA][HSO4] was accomplished for the synthesis of a series of 12-aryl-8,9,10,12- tetrahydrobenzo[a]xanthen-11-ones under solvent-free conditions. High yields, ease recovery, short reaction time and reusability of catalyst are significant advantages. ZrOC12＂8H20 was also found to act as an effective catalyst towards this transformation.
文摘In(OTf)3 plays the role of a Lewis acid catalyst in the Pechmann condensation of phenols with β-ketoesters under solvent-free conditions to give coumarin derivatives. This novel and inexpensive method has advantages such as short reaction time, excellent product yields, and avoids the use of organic solvents in agreement with green chemistry principles. Catalyst loadings can be as low as 1 mol% to give high yields of the corresponding coumarins at 80 °C. The catalyst can be recovered after the reaction, and reused with only a slight decrease in the yield.
基金supported by the Isfahan University of Technology (IUT), IR Iran
文摘Iron zirconium phosphate(ZPFe) nanoparticles were found to function as an efficient catalyst for the acetylation of a wide range of alcohols and phenols using acetic anhydride, generating good to excellent yields under solvent-free conditions. The steric and electronic properties of various sub-strates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively coupled plasma-optical emission spectrometry, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. These analyses revealed that the interlayer distance in the catalyst increased from 7.5 to 9.3 when Fe3+ was intercalated between the layers, whereas the crystallinity of the material was reduced. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. This new method for the acetylation of alcohols and phenols has several important advantages, including mild and environ-mentally friendly reaction conditions, as well as good to excellent yields and a facile work-up.
