An environmentally benign un-catalyzed one-pot synthesis of 4,4＇-（arylmethylene）bis（1H-pyrazol-5-ols） has been reported via tandem Knoevenagel-Michael reaction of aldehydes with two equivalents of 3-methyl-1-phen...An environmentally benign un-catalyzed one-pot synthesis of 4,4＇-（arylmethylene）bis（1H-pyrazol-5-ols） has been reported via tandem Knoevenagel-Michael reaction of aldehydes with two equivalents of 3-methyl-1-phenyl-1H-pyrazol-5（4H）-one in aqueous medium.展开更多
The one-pot three-component reaction of 2-aminobenzothiazole, benzaldehyde derivatives and β-ketoester, β-diketone or malonate derivatives in solvent-free conditions provides the corresponding pyrimido [2,1-b] benzo...The one-pot three-component reaction of 2-aminobenzothiazole, benzaldehyde derivatives and β-ketoester, β-diketone or malonate derivatives in solvent-free conditions provides the corresponding pyrimido [2,1-b] benzothiazole derivatives at 60?C in 60% - 72% yields without using any catalyst in an optimistic time.展开更多
Sulfonic acid-functionalized silica-coated nano-Fe3O4 particles(Fe3O4@SiO2-SO3H) have been prepared as a novel heterogeneous acid using a facile process.The material was subsequently identified as an efficient catalys...Sulfonic acid-functionalized silica-coated nano-Fe3O4 particles(Fe3O4@SiO2-SO3H) have been prepared as a novel heterogeneous acid using a facile process.The material was subsequently identified as an efficient catalyst for the synthesis of a variety of tetraketone derivatives via the Knoevenagel condensation and Michael addition reactions of aromatic aldehydes to dimedone,1,3-indanedione,and 1,3-dimethyl barbituric acid.The catalyst could be readily recovered using a simple external magnet and reused several times without any significant loss in activity.The current catalytic process is both sustainable and economical because it operates under aqueous conditions,the catalyst can be recovered and reused,and the reactions themselves require only a short time and provide the products in high yield.展开更多
A three component one-pot protocol was investigated for the synthesis of methylene bis isoxazolo[4,5-b]-pyridine-N-oxides from commercially available materials.
A versatile synthetic approach toward a series of benzothiazepines with medicinal potential (for example, compound <strong>1</strong>) that allows incorporation of structural variation at the three aromati...A versatile synthetic approach toward a series of benzothiazepines with medicinal potential (for example, compound <strong>1</strong>) that allows incorporation of structural variation at the three aromatic regions of the structure, and at the sulfur atom, was developed. Knoevenagel condensation of indan-1,3-diones with benzaldehydes, yielded 2-benzylidineindan-1,3-diones, which undewent thio-Michael addition and intramolecular imine formation upon reaction with 2-aminothiophenols, to produce the target benzothiazepines. Use of indan-1,3-diones, benzaldehydes or 2-aminothiophenols bearing further substitution enabled production of novel 5,11-dihydro-12H-benzo[b]indeno [1,2-e][1,4]thiazepin-12-one analogs <strong>1</strong> - <strong>14</strong>, including compounds bearing substitution at novel positions within the scaffold.展开更多
A simple and efficient method was developed for the synthesis of 2.2＇-arylmethylene dicyclohexane-1,3- dione derivatives via the Knoevenagel-Michael cascade reactions of aromatic aldehydes and 1,3-cyclic diketones ca...A simple and efficient method was developed for the synthesis of 2.2＇-arylmethylene dicyclohexane-1,3- dione derivatives via the Knoevenagel-Michael cascade reactions of aromatic aldehydes and 1,3-cyclic diketones catalyzed by ＂Amano＂ lipase DF, which expands the application field of enzyme catalytic promiscuity. This protocol provides several advantages over the traditional chemical synthesis, such as simple work-up procedure, high yields Cup to 94%） and environmental friendliness.展开更多
A convenient and efficient method was developed for the synthesis of 2,2＇-（arylmethylene）bis（3-hydrox- ycyclohex-2-enone） derivatives via the oleylamine-catalyzed tandem Knoevenagel/Michael addition reactions of ...A convenient and efficient method was developed for the synthesis of 2,2＇-（arylmethylene）bis（3-hydrox- ycyclohex-2-enone） derivatives via the oleylamine-catalyzed tandem Knoevenagel/Michael addition reactions of aromatic aldehydes and cyclohexane-1,3-diones. This transformation proceeded without any metal catalyst in non-toxic solvent at room temperature with high isolated yields. A plausible mechanism for this process was pro- posed.展开更多
基金the University Grants Commission,New Delhi,India(No.MRP 32-245/2006 SR) for the financial support
文摘An environmentally benign un-catalyzed one-pot synthesis of 4,4＇-（arylmethylene）bis（1H-pyrazol-5-ols） has been reported via tandem Knoevenagel-Michael reaction of aldehydes with two equivalents of 3-methyl-1-phenyl-1H-pyrazol-5（4H）-one in aqueous medium.
文摘The one-pot three-component reaction of 2-aminobenzothiazole, benzaldehyde derivatives and β-ketoester, β-diketone or malonate derivatives in solvent-free conditions provides the corresponding pyrimido [2,1-b] benzothiazole derivatives at 60?C in 60% - 72% yields without using any catalyst in an optimistic time.
基金supported by the Faculty of Chemistry and Office of Gifted Student at Semnan University
文摘Sulfonic acid-functionalized silica-coated nano-Fe3O4 particles(Fe3O4@SiO2-SO3H) have been prepared as a novel heterogeneous acid using a facile process.The material was subsequently identified as an efficient catalyst for the synthesis of a variety of tetraketone derivatives via the Knoevenagel condensation and Michael addition reactions of aromatic aldehydes to dimedone,1,3-indanedione,and 1,3-dimethyl barbituric acid.The catalyst could be readily recovered using a simple external magnet and reused several times without any significant loss in activity.The current catalytic process is both sustainable and economical because it operates under aqueous conditions,the catalyst can be recovered and reused,and the reactions themselves require only a short time and provide the products in high yield.
文摘A three component one-pot protocol was investigated for the synthesis of methylene bis isoxazolo[4,5-b]-pyridine-N-oxides from commercially available materials.
文摘A versatile synthetic approach toward a series of benzothiazepines with medicinal potential (for example, compound <strong>1</strong>) that allows incorporation of structural variation at the three aromatic regions of the structure, and at the sulfur atom, was developed. Knoevenagel condensation of indan-1,3-diones with benzaldehydes, yielded 2-benzylidineindan-1,3-diones, which undewent thio-Michael addition and intramolecular imine formation upon reaction with 2-aminothiophenols, to produce the target benzothiazepines. Use of indan-1,3-diones, benzaldehydes or 2-aminothiophenols bearing further substitution enabled production of novel 5,11-dihydro-12H-benzo[b]indeno [1,2-e][1,4]thiazepin-12-one analogs <strong>1</strong> - <strong>14</strong>, including compounds bearing substitution at novel positions within the scaffold.
基金financially supported by the Outstanding Young Scholar Grant of Zhejiang University (No. R4110092)the National Natural Science Foundation of China (No. 21176215/21176102)the Program for Zhejiang leading team of S&T Innovation (No. 2011R50007)
文摘A simple and efficient method was developed for the synthesis of 2.2＇-arylmethylene dicyclohexane-1,3- dione derivatives via the Knoevenagel-Michael cascade reactions of aromatic aldehydes and 1,3-cyclic diketones catalyzed by ＂Amano＂ lipase DF, which expands the application field of enzyme catalytic promiscuity. This protocol provides several advantages over the traditional chemical synthesis, such as simple work-up procedure, high yields Cup to 94%） and environmental friendliness.
基金Supported by the National Natural Science Foundation of China（Nos.21772001, 21372008）, the Natural Science Foundation of Education Administration of Anhui Province, China（No.KJ2016A267）, the Special and Excellent Research Fund of Anhui Normal Universit and the Doctoral Scientific Research Foundation of Anhui Normal University, China（No.2016XJJ110）.
文摘A convenient and efficient method was developed for the synthesis of 2,2＇-（arylmethylene）bis（3-hydrox- ycyclohex-2-enone） derivatives via the oleylamine-catalyzed tandem Knoevenagel/Michael addition reactions of aromatic aldehydes and cyclohexane-1,3-diones. This transformation proceeded without any metal catalyst in non-toxic solvent at room temperature with high isolated yields. A plausible mechanism for this process was pro- posed.
