The Ni samples were electroformed from additive-free(AF) and saccharin-containing(SC) sulfamate solutions, respectively. In situ backscattered electron(BSE) imaging, electron backscatter diffraction(EBSD), and electro...The Ni samples were electroformed from additive-free(AF) and saccharin-containing(SC) sulfamate solutions, respectively. In situ backscattered electron(BSE) imaging, electron backscatter diffraction(EBSD), and electron-probe microanalysis(EPMA) were used to investigate the effect of annealing on the deformation behaviors of the AF and SC samples. The results indicate that columnar grains of the as-deposited AF sample had an approximated average width of 3 μm and an approximated aspect ratio of 8. The average width of columnar grains of the as-deposited SC sample was reduced to approximately 400 nm by the addition of saccharin to the electrolyte. A few very-large grains distributed in the matrix of the SC sample after annealing. No direct evidence indicated that S segregated at the grain boundaries before or after annealing. The average value of the total elongations of the SC samples decreased from 16% to 6% after annealing, whereas that of the AF samples increased from 18% to 50%. The dislocation recovery in grain-boundary areas of the annealed AF sample was reduced, which contributed to the appearance of microvoids at the triple junctions. The incompatibility deformation between very-large grains and fine grains contributed to the brittle fracture behavior of the annealed SC Ni.展开更多
[Objectives]This study was conducted to investigate the effects of different concentrations of sodium cyclohexyl sulfamate on the growth and development of Drosophila melanogaster.[Methods]Different concentrations of ...[Objectives]This study was conducted to investigate the effects of different concentrations of sodium cyclohexyl sulfamate on the growth and development of Drosophila melanogaster.[Methods]Different concentrations of sodium cyclohexyl sulfamate were added to the culture medium,and the effects of different concentrations of sodium cyclohexyl sulfamate on the development time and weight of D.melanogaster in various life stages were statistically analyzed.[Results]High concentration of sodium cyclohexyl sulfamate delayed the time of pupation and eclosion of D.melanogaster,which made D.melanogaster lose weight.The number of male D.melanogaster in the first generation was much larger than that of female individuals,which indicated that the effect of sodium cyclohexyl sulfamate on male D.melanogaster was greater than that of female individuals.In a word,high concentration of sodium cyclohexyl sulfamate significantly inhibited the growth and development of D.melanogaster.[Conclusions]This study provides some reference data for the research perspective of food additives and the safe use of sodium cyclohexyl sulfamate.展开更多
An electrochemical cinnamyl C—H amination reaction in the absence of transition metal catalyst and oxidant was reported. The choice of carbonyl sulfamate as nitrogen source is the key to achieve desired chemoselectiv...An electrochemical cinnamyl C—H amination reaction in the absence of transition metal catalyst and oxidant was reported. The choice of carbonyl sulfamate as nitrogen source is the key to achieve desired chemoselectivity. A series of terminal amine derivatives are prepared using this protocol and the sulfonyl group can be removed with basic hydrolysis. The reaction is suggested to proceed via a continuous anodic oxidation, deprotonation, anodic oxidation, and intermolecular nucleophilic addition pathway, demonstrating the first example of electrochemical cinnamyl C—H amination.展开更多
The effect of ammonium sulfamate (AS) content on the flame retardancy of polyamide 6 (PA6) was studied. It is found that the limiting oxygen index (LOI) of PA6 increases with the increase of AS content and the f...The effect of ammonium sulfamate (AS) content on the flame retardancy of polyamide 6 (PA6) was studied. It is found that the limiting oxygen index (LOI) of PA6 increases with the increase of AS content and the flame retardancy of PA6 is significantly improved. The morphology of the residues after combustion was examined by means of scanning electron microscopy (SEM). SEM results show that AS facilitates the formation of the intumescent char layer with honeycomb-like structure, which inhibits the transfer of heat and mass, and thus improves the flame retardancy of PA6. The thermal degradation of AS flame retarded PA6 was studied by thermogravimetric analysis (TGA). The Kissinger method was applied to estimate the activation energy (Ea) of the degradation. The activation energy of the thermal degradation of PA6 decreases by adding AS, indicating that AS can promote the degradation of PA6.展开更多
Sulfamic acid (SA), which possesses a zwitterionic structure, was applied as a leaching reagent for the first time for extracting copper from copper oxide ore. The effects of reaction time, temperature, particle siz...Sulfamic acid (SA), which possesses a zwitterionic structure, was applied as a leaching reagent for the first time for extracting copper from copper oxide ore. The effects of reaction time, temperature, particle size, reagent concentration, and stirring speed on this leach- ing were studied. The dissolution kinetics of malachite was illustrated with a three-dimensional diffusion model. A novel leaching effect of SA on malachite was eventually demonstrated. The leaching rate increased with decreasing particle size and increasing concentration, reac- tion temperature and stirring speed. The activation energy for SA leaching malachite was 33.23 kJ/mol. Furthermore, the effectiveness of SA as a new reagent for extracting copper from copper oxide ore was confirmed by experiment. This approach may provide a solution suitable for subsequent electrowinning. In addition, results reported herein may provide basic data that enable the leaching of other carbonate miner- als of copper, zinc, cobalt and so on in an SA system.展开更多
Silica-bonded N-propyl diethylenetriamine sulfamic acid (SBPDSA) is employed as a recyclable catalyst to synthesize α-aminonitriles. These syntheses involved one-pot condensation of an aldehyde, an amine, and trimeth...Silica-bonded N-propyl diethylenetriamine sulfamic acid (SBPDSA) is employed as a recyclable catalyst to synthesize α-aminonitriles. These syntheses involved one-pot condensation of an aldehyde, an amine, and trimethylsilyl cyanide under mild reaction conditions at room temperature. SBPDSA was recycled seven times in the condensation of benzaldehyde, aniline, and trimethylsilyl cyanide without reduction of its catalytic activity.展开更多
Sulfamic acid has been proved to be the most efficient and recyclable catalyst in carbamate synthesis from alkylamine and dialkyl carbonate.High selectivity,cost-efficiency and simple product separation were the advan...Sulfamic acid has been proved to be the most efficient and recyclable catalyst in carbamate synthesis from alkylamine and dialkyl carbonate.High selectivity,cost-efficiency and simple product separation were the advantageous features obtained in this process.Sulfamic acid could be reused several times and keep its initial activity in the recycle runs.In addition,sulfamic acid has also exhibited the potential catalytic ability for alkylation of aromatic amines.展开更多
Sulfuric acid ([3-(3-silicapropyl)sulfanyl]propyl)ester is employed as a recyclable catalyst for the condensation reaction between aromatic aldehydes and 3-methyl-l-phenyl-5-pyrazolone. This condensation reaction was ...Sulfuric acid ([3-(3-silicapropyl)sulfanyl]propyl)ester is employed as a recyclable catalyst for the condensation reaction between aromatic aldehydes and 3-methyl-l-phenyl-5-pyrazolone. This condensation reaction was performed in ethanol under refluxing conditions giving 4,4'-alkylmethylene-bis(3-methyl-5-pyrazolones) in 74-90% yields. The heterogeneous catalyst was recycled and used in eleven runs for the reaction between benzaldehyde and 3-methyl-l-phenyl-5-pyrazolone without losing catalytic activity.展开更多
Rapid synthesis of 1,2,3,4-tetrahydropyrimidin-2-ones (THPO) from aromatic aldehydes, β-ketoester and urea (or thiourea) using zinc sulfamate as the catalyst under microwave irradiation was described here. Compar...Rapid synthesis of 1,2,3,4-tetrahydropyrimidin-2-ones (THPO) from aromatic aldehydes, β-ketoester and urea (or thiourea) using zinc sulfamate as the catalyst under microwave irradiation was described here. Compared with the classical Biginelli reaction, this new method consistently has the advantages of good yields (76%-96%), short reaction time (3-15 min), no corrosion to equipments, ease of manipulation, and low cost catalyst.展开更多
A series of 2,3-dihydroquinazolin-4(1H)-ones have been synthesized in good to excellent yields through direct cyclocondensation of anthranilamide and aryl aldehydes or ketones in water or methanol under mild conditi...A series of 2,3-dihydroquinazolin-4(1H)-ones have been synthesized in good to excellent yields through direct cyclocondensation of anthranilamide and aryl aldehydes or ketones in water or methanol under mild conditions.The reaction was efficiently promoted by 10 mol%sulfamic acid(SA,H_2NSO_3H) and the catalyst could be recovered easily after the reactions and reused without evident loss of reactivity.展开更多
α-Aminonitriles were synthesized via a one-pot three-component condensation of aldehydes, amines, and trimethylsilyl cyanide using silica-bonded N-propylpiperazine sulfamic acid (SBPPSA) as a recyclable solid acid ...α-Aminonitriles were synthesized via a one-pot three-component condensation of aldehydes, amines, and trimethylsilyl cyanide using silica-bonded N-propylpiperazine sulfamic acid (SBPPSA) as a recyclable solid acid at room temperature. SBPPSA showed much the same efficiency when used in consecutive reaction runs.展开更多
Aromatic aldehydes undergo crossed-aldol condensation with ketones in the presence of catalytic amount of sulfamic acid (SA) to afford the corresponding α,β-unsaturated aldol products under solvent-free conditions...Aromatic aldehydes undergo crossed-aldol condensation with ketones in the presence of catalytic amount of sulfamic acid (SA) to afford the corresponding α,β-unsaturated aldol products under solvent-free conditions in good to high yields at 45-80 ℃.展开更多
SA (sulfamic acid) catalyzes the reaction of indole with aldehyde and ketone to afford bis(indol-3-yl)methanes in good to excellent yields under solvent-free condition at ambient temperature.
An efficient approach to 1,4-dihydropyridines containing novel substituted pyrazole is achieved via threecomponent reaction of pyrazolyl aldehyde, β-ketoester, and ammonium acetate in one-pot under sulfamic acid cata...An efficient approach to 1,4-dihydropyridines containing novel substituted pyrazole is achieved via threecomponent reaction of pyrazolyl aldehyde, β-ketoester, and ammonium acetate in one-pot under sulfamic acid catalysis.展开更多
Silica-bonded N-propyl sulfamic acid (SBNPSA) catalyzed one-pot three component Biginelli condensation of different substituted aromatic aldehydes with ethyl acetoacetate and urea/thoiurea to the respective 3,4-dihy...Silica-bonded N-propyl sulfamic acid (SBNPSA) catalyzed one-pot three component Biginelli condensation of different substituted aromatic aldehydes with ethyl acetoacetate and urea/thoiurea to the respective 3,4-dihydropyrimidin-2-(lH)-ones and thiones in environment friendly procedure is described. The facile reaction conditions, simple isolation and purification procedures of this method make it a good option for the svnthesis of dihydropyrimidinones.展开更多
1 Results Pyrimidinones (PMs) are a class of important heterocycles which have been well documented throughout the literature due to their biological importance. They exhibit a wide range of pharmaceutical and therape...1 Results Pyrimidinones (PMs) are a class of important heterocycles which have been well documented throughout the literature due to their biological importance. They exhibit a wide range of pharmaceutical and therapeutic properties[1].A rapid and efficient one-pot method for the synthesis of 4,6-diarylpyrimidin-2(1H)- ones and related heterocycles is described.The condensation of acetophenone derivatives,aldehydes and urea in the presence of sulfamic acid was employed to synthesize a variety of pyrimid...展开更多
An efficient and green procedure for the synthesis of novel 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen- 11- one derivatives has been described through one-pot condensation of 2-naphthol, arylaldehyde and 5,5-dimethyl...An efficient and green procedure for the synthesis of novel 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen- 11- one derivatives has been described through one-pot condensation of 2-naphthol, arylaldehyde and 5,5-dimethyl- cyclohexane-l,3-dione in the presence of sulfamic acid (NH2SO3H) in ionic liquid 1-n-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4). These reactions proceed with good yields under short reaction time. Furthermore, the green catalytic system can be recycled specific times with no decreases in yields and reaction rates.展开更多
Sulfamic acid(SA) is a bi-functional, cost-effective and reusable green catalyst for the synthesis of 4-(pyrazol-4-yl)methylenepyrazol-5(4H)-one derivatives by one-pot, three-component condensation of pyrazol-4-...Sulfamic acid(SA) is a bi-functional, cost-effective and reusable green catalyst for the synthesis of 4-(pyrazol-4-yl)methylenepyrazol-5(4H)-one derivatives by one-pot, three-component condensation of pyrazol-4-carbaxaldehydes, b-ketoesters and phenyl hydrazine(Route-I). In addition to this method,another simple condensation of pyrazol-4-carbaxaldehydes with pyrazolone in the presence of SA under the solvent-free condition in good yield is reported. The merits of these protocols are mild conditions,non-aqueous workup, high yields, easy availability of the catalyst, no chromatographic separation and inexpensive solid acid catalyst. Furthermore, SA could be recycled and reused for five times without losing its catalytic activity.展开更多
基金financially supported by the China Scholarship Council(No.201606460015)the support of the H.Nakano laboratory of Kyushu University for the study
文摘The Ni samples were electroformed from additive-free(AF) and saccharin-containing(SC) sulfamate solutions, respectively. In situ backscattered electron(BSE) imaging, electron backscatter diffraction(EBSD), and electron-probe microanalysis(EPMA) were used to investigate the effect of annealing on the deformation behaviors of the AF and SC samples. The results indicate that columnar grains of the as-deposited AF sample had an approximated average width of 3 μm and an approximated aspect ratio of 8. The average width of columnar grains of the as-deposited SC sample was reduced to approximately 400 nm by the addition of saccharin to the electrolyte. A few very-large grains distributed in the matrix of the SC sample after annealing. No direct evidence indicated that S segregated at the grain boundaries before or after annealing. The average value of the total elongations of the SC samples decreased from 16% to 6% after annealing, whereas that of the AF samples increased from 18% to 50%. The dislocation recovery in grain-boundary areas of the annealed AF sample was reduced, which contributed to the appearance of microvoids at the triple junctions. The incompatibility deformation between very-large grains and fine grains contributed to the brittle fracture behavior of the annealed SC Ni.
基金Supported by Undergraduate Innovation and Entrepreneurship Training Program(202314390006)Undergraduate Innovation and Entrepreneurship Training Program(2024DC078)Construction Project of Biological Experiment Teaching Demonstration Center in Colleges and Universities in Shaanxi Province.
文摘[Objectives]This study was conducted to investigate the effects of different concentrations of sodium cyclohexyl sulfamate on the growth and development of Drosophila melanogaster.[Methods]Different concentrations of sodium cyclohexyl sulfamate were added to the culture medium,and the effects of different concentrations of sodium cyclohexyl sulfamate on the development time and weight of D.melanogaster in various life stages were statistically analyzed.[Results]High concentration of sodium cyclohexyl sulfamate delayed the time of pupation and eclosion of D.melanogaster,which made D.melanogaster lose weight.The number of male D.melanogaster in the first generation was much larger than that of female individuals,which indicated that the effect of sodium cyclohexyl sulfamate on male D.melanogaster was greater than that of female individuals.In a word,high concentration of sodium cyclohexyl sulfamate significantly inhibited the growth and development of D.melanogaster.[Conclusions]This study provides some reference data for the research perspective of food additives and the safe use of sodium cyclohexyl sulfamate.
基金the National Science Foundation of China (No.21572099)the Open Project of State Key Laboratory Cultivation Base for TCM Quality and Efficacy,Nanjing University of Chinese Medicine (Nos.TCMQ&E 201702)the open training program of the undergraduate experiment course (No.0205145031-6).
文摘An electrochemical cinnamyl C—H amination reaction in the absence of transition metal catalyst and oxidant was reported. The choice of carbonyl sulfamate as nitrogen source is the key to achieve desired chemoselectivity. A series of terminal amine derivatives are prepared using this protocol and the sulfonyl group can be removed with basic hydrolysis. The reaction is suggested to proceed via a continuous anodic oxidation, deprotonation, anodic oxidation, and intermolecular nucleophilic addition pathway, demonstrating the first example of electrochemical cinnamyl C—H amination.
基金supported by Science and Technology Department of Zhejiang Province(No.2009C11127).
文摘The effect of ammonium sulfamate (AS) content on the flame retardancy of polyamide 6 (PA6) was studied. It is found that the limiting oxygen index (LOI) of PA6 increases with the increase of AS content and the flame retardancy of PA6 is significantly improved. The morphology of the residues after combustion was examined by means of scanning electron microscopy (SEM). SEM results show that AS facilitates the formation of the intumescent char layer with honeycomb-like structure, which inhibits the transfer of heat and mass, and thus improves the flame retardancy of PA6. The thermal degradation of AS flame retarded PA6 was studied by thermogravimetric analysis (TGA). The Kissinger method was applied to estimate the activation energy (Ea) of the degradation. The activation energy of the thermal degradation of PA6 decreases by adding AS, indicating that AS can promote the degradation of PA6.
基金financially supported by the National Natural Science Foundation of China (Nos. 51168020, 51404119, and 51464029)the Natural Science Foundation of Yunnan Province, China (No. 2014Y0845)the Excellent Doctoral Dissertation and Talent Cultivation Foundation of Kunming University of Science and Technology (Nos. 41118011 and 201421066)
文摘Sulfamic acid (SA), which possesses a zwitterionic structure, was applied as a leaching reagent for the first time for extracting copper from copper oxide ore. The effects of reaction time, temperature, particle size, reagent concentration, and stirring speed on this leach- ing were studied. The dissolution kinetics of malachite was illustrated with a three-dimensional diffusion model. A novel leaching effect of SA on malachite was eventually demonstrated. The leaching rate increased with decreasing particle size and increasing concentration, reac- tion temperature and stirring speed. The activation energy for SA leaching malachite was 33.23 kJ/mol. Furthermore, the effectiveness of SA as a new reagent for extracting copper from copper oxide ore was confirmed by experiment. This approach may provide a solution suitable for subsequent electrowinning. In addition, results reported herein may provide basic data that enable the leaching of other carbonate miner- als of copper, zinc, cobalt and so on in an SA system.
文摘Silica-bonded N-propyl diethylenetriamine sulfamic acid (SBPDSA) is employed as a recyclable catalyst to synthesize α-aminonitriles. These syntheses involved one-pot condensation of an aldehyde, an amine, and trimethylsilyl cyanide under mild reaction conditions at room temperature. SBPDSA was recycled seven times in the condensation of benzaldehyde, aniline, and trimethylsilyl cyanide without reduction of its catalytic activity.
基金the Beijing Forestry University Excellent Young Scientist Fund(No.BLYX200904)National Innovation Experiment Program for University Students(No.091002234)Major State Basic Research Development Program of China(973 Program,No.2010CB732204) are gratefully acknowledged.
文摘Sulfamic acid has been proved to be the most efficient and recyclable catalyst in carbamate synthesis from alkylamine and dialkyl carbonate.High selectivity,cost-efficiency and simple product separation were the advantageous features obtained in this process.Sulfamic acid could be reused several times and keep its initial activity in the recycle runs.In addition,sulfamic acid has also exhibited the potential catalytic ability for alkylation of aromatic amines.
基金the Islamic Azad University Research Council for partial support of this work
文摘Sulfuric acid ([3-(3-silicapropyl)sulfanyl]propyl)ester is employed as a recyclable catalyst for the condensation reaction between aromatic aldehydes and 3-methyl-l-phenyl-5-pyrazolone. This condensation reaction was performed in ethanol under refluxing conditions giving 4,4'-alkylmethylene-bis(3-methyl-5-pyrazolones) in 74-90% yields. The heterogeneous catalyst was recycled and used in eleven runs for the reaction between benzaldehyde and 3-methyl-l-phenyl-5-pyrazolone without losing catalytic activity.
基金Project supported by the National Natural Science Foundation of China (No. 20272018) and the Guangdong Natural Science Foundation (Nos. 021166 and 04010458).
文摘Rapid synthesis of 1,2,3,4-tetrahydropyrimidin-2-ones (THPO) from aromatic aldehydes, β-ketoester and urea (or thiourea) using zinc sulfamate as the catalyst under microwave irradiation was described here. Compared with the classical Biginelli reaction, this new method consistently has the advantages of good yields (76%-96%), short reaction time (3-15 min), no corrosion to equipments, ease of manipulation, and low cost catalyst.
文摘A series of 2,3-dihydroquinazolin-4(1H)-ones have been synthesized in good to excellent yields through direct cyclocondensation of anthranilamide and aryl aldehydes or ketones in water or methanol under mild conditions.The reaction was efficiently promoted by 10 mol%sulfamic acid(SA,H_2NSO_3H) and the catalyst could be recovered easily after the reactions and reused without evident loss of reactivity.
基金the Islamic Azad University Research Council for the partial support
文摘α-Aminonitriles were synthesized via a one-pot three-component condensation of aldehydes, amines, and trimethylsilyl cyanide using silica-bonded N-propylpiperazine sulfamic acid (SBPPSA) as a recyclable solid acid at room temperature. SBPPSA showed much the same efficiency when used in consecutive reaction runs.
文摘Aromatic aldehydes undergo crossed-aldol condensation with ketones in the presence of catalytic amount of sulfamic acid (SA) to afford the corresponding α,β-unsaturated aldol products under solvent-free conditions in good to high yields at 45-80 ℃.
文摘SA (sulfamic acid) catalyzes the reaction of indole with aldehyde and ketone to afford bis(indol-3-yl)methanes in good to excellent yields under solvent-free condition at ambient temperature.
文摘An efficient approach to 1,4-dihydropyridines containing novel substituted pyrazole is achieved via threecomponent reaction of pyrazolyl aldehyde, β-ketoester, and ammonium acetate in one-pot under sulfamic acid catalysis.
基金Madhya Pradesh Council of Science & Technology (MPCOST, Bhopal) for their financial support
文摘Silica-bonded N-propyl sulfamic acid (SBNPSA) catalyzed one-pot three component Biginelli condensation of different substituted aromatic aldehydes with ethyl acetoacetate and urea/thoiurea to the respective 3,4-dihydropyrimidin-2-(lH)-ones and thiones in environment friendly procedure is described. The facile reaction conditions, simple isolation and purification procedures of this method make it a good option for the svnthesis of dihydropyrimidinones.
文摘1 Results Pyrimidinones (PMs) are a class of important heterocycles which have been well documented throughout the literature due to their biological importance. They exhibit a wide range of pharmaceutical and therapeutic properties[1].A rapid and efficient one-pot method for the synthesis of 4,6-diarylpyrimidin-2(1H)- ones and related heterocycles is described.The condensation of acetophenone derivatives,aldehydes and urea in the presence of sulfamic acid was employed to synthesize a variety of pyrimid...
基金The work was supported by the Tianjin National Natural Science Foundation (Nos. 11JCZDJC21300 and 10JCZDJC22200) and NSFC (No. 51076174).
文摘An efficient and green procedure for the synthesis of novel 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen- 11- one derivatives has been described through one-pot condensation of 2-naphthol, arylaldehyde and 5,5-dimethyl- cyclohexane-l,3-dione in the presence of sulfamic acid (NH2SO3H) in ionic liquid 1-n-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4). These reactions proceed with good yields under short reaction time. Furthermore, the green catalytic system can be recycled specific times with no decreases in yields and reaction rates.
基金University Grants Commission,Govt.of India for providing financial support to one of them(K.V.S)in form of UGC-SRF scheme
文摘Sulfamic acid(SA) is a bi-functional, cost-effective and reusable green catalyst for the synthesis of 4-(pyrazol-4-yl)methylenepyrazol-5(4H)-one derivatives by one-pot, three-component condensation of pyrazol-4-carbaxaldehydes, b-ketoesters and phenyl hydrazine(Route-I). In addition to this method,another simple condensation of pyrazol-4-carbaxaldehydes with pyrazolone in the presence of SA under the solvent-free condition in good yield is reported. The merits of these protocols are mild conditions,non-aqueous workup, high yields, easy availability of the catalyst, no chromatographic separation and inexpensive solid acid catalyst. Furthermore, SA could be recycled and reused for five times without losing its catalytic activity.