Heterocyclic skeleton building blocks to afford dihydropyrimidinones and dihydropyridines based on neat adducts of diketene, alcohols and aldehydes via silica sulfuric acid （SSA） catalyzed ring opening of diketene i...Heterocyclic skeleton building blocks to afford dihydropyrimidinones and dihydropyridines based on neat adducts of diketene, alcohols and aldehydes via silica sulfuric acid （SSA） catalyzed ring opening of diketene in four-component Biginelli-type and Hantzsch-type reactions are presented.展开更多
A mixture of ammonium nitrate or nitro urea and silica sulfuric acid was found to be efficient and environmentally friendly nitrating media for the preparation of orto-nitro phenols in dichloromethane at room temperat...A mixture of ammonium nitrate or nitro urea and silica sulfuric acid was found to be efficient and environmentally friendly nitrating media for the preparation of orto-nitro phenols in dichloromethane at room temperature.展开更多
A mixture of guanidinium nitrate and silica sulfuric acid acts as mild and heterogeneous media for the efficient mono nitration of phenolic compounds in dichloromethane at room temperature.
This procedure works efficiently for high selective mono nitration of phenol and substituted phenol to corresponding nitro compounds in moderate to high yield using poly（4-vinylpyridinium nitrate） and silica sulfuri...This procedure works efficiently for high selective mono nitration of phenol and substituted phenol to corresponding nitro compounds in moderate to high yield using poly（4-vinylpyridinium nitrate） and silica sulfuric acid in dichloromethane at room temperature.展开更多
A series of 1,4-dihydropyridines have been prepared by a one-pot condensation of aldehydes,ethyl acetoacetate,and ammonium acetate in the presence of a heterogeneous catalyst silica sulfuric acid at room temperature u...A series of 1,4-dihydropyridines have been prepared by a one-pot condensation of aldehydes,ethyl acetoacetate,and ammonium acetate in the presence of a heterogeneous catalyst silica sulfuric acid at room temperature under solvent-free condition. This new protocol has the advantage of short reaction time and excellent yields,and is an environmentally benign route to the synthesis of 1,4-dihydropyridines.展开更多
A new catalytic procedure for the chemoselective oxidation of sulfides to sulfoxides was studied.A variety of aliphatic and aromatic sulfides were subjected to sulfoxidation by combining poly(4-vinyl pyridinium nitrat...A new catalytic procedure for the chemoselective oxidation of sulfides to sulfoxides was studied.A variety of aliphatic and aromatic sulfides were subjected to sulfoxidation by combining poly(4-vinyl pyridinium nitrate),silica sulfuric acid(SiO2-OSO3H),and catalytic amounts of ammonium bromide in CH2Cl2 in the presence of a few drops of water at room temperature.Excellent yields were obtained.展开更多
文摘Heterocyclic skeleton building blocks to afford dihydropyrimidinones and dihydropyridines based on neat adducts of diketene, alcohols and aldehydes via silica sulfuric acid （SSA） catalyzed ring opening of diketene in four-component Biginelli-type and Hantzsch-type reactions are presented.
文摘A mixture of ammonium nitrate or nitro urea and silica sulfuric acid was found to be efficient and environmentally friendly nitrating media for the preparation of orto-nitro phenols in dichloromethane at room temperature.
基金supported by the research affairs of Ilam University,Ilam,Iran
文摘A mixture of guanidinium nitrate and silica sulfuric acid acts as mild and heterogeneous media for the efficient mono nitration of phenolic compounds in dichloromethane at room temperature.
基金supported by the research affairs of Ilam University,Ilam,Iran
文摘This procedure works efficiently for high selective mono nitration of phenol and substituted phenol to corresponding nitro compounds in moderate to high yield using poly（4-vinylpyridinium nitrate） and silica sulfuric acid in dichloromethane at room temperature.
文摘A series of 1,4-dihydropyridines have been prepared by a one-pot condensation of aldehydes,ethyl acetoacetate,and ammonium acetate in the presence of a heterogeneous catalyst silica sulfuric acid at room temperature under solvent-free condition. This new protocol has the advantage of short reaction time and excellent yields,and is an environmentally benign route to the synthesis of 1,4-dihydropyridines.
基金Supported by the research facilities of Ilam University,Ilam,Iran
文摘A new catalytic procedure for the chemoselective oxidation of sulfides to sulfoxides was studied.A variety of aliphatic and aromatic sulfides were subjected to sulfoxidation by combining poly(4-vinyl pyridinium nitrate),silica sulfuric acid(SiO2-OSO3H),and catalytic amounts of ammonium bromide in CH2Cl2 in the presence of a few drops of water at room temperature.Excellent yields were obtained.
