The Experts below are selected from a list of 3291 Experts worldwide ranked by ideXlab platform
Wenju Wang - One of the best experts on this subject based on the ideXlab platform.
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Complementary and Regioselective Synthesis of Isomeric 3-[Isoxazol-3(or 5)-yl]indoles from β-Ethylthio-β-indolyl-α,β-unsaturated Ketones
Synthesis, 2021Co-Authors: Kehua Wang, Xue Zhang, Wenju WangAbstract:A simple and efficient method for the complementary and regioselective synthesis of isomeric 3-(isoxazol-5-yl)indoles and 3-(isoxazol-3-yl)indoles has been developed by the regioselective Cyclocondensation Reaction of β-ethylthio-β-indolyl-α,β-unsaturated ketones and hydroxylamine hydrochloride. It was found that the Cyclocondensation Reaction in the presence of excess NaOEt in refluxing EtOH gives 3-(isoxazol-5-yl)indoles in good yields, whereas using NaOAc in boiling AcOH gives 3-(isoxazol-3-yl)indoles in good yields.
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green Cyclocondensation of β ethylthio β indolyl α β unsaturated ketones with semicarbazide hydrochloride as hydrazine equivalent in water aqueous synthesis of 3 pyrazolyl indoles
Beilstein Archives, 2019Co-Authors: Yanhui Zhao, Peiqiu Liao, Haifeng Yu, Wenju WangAbstract:A green and efficient Cyclocondensation Reaction of β-ethylthio-β-indolyl-α, β-unsaturated ketones with semicarbazide hydrochloride as hydrazine equivalent to prepare 3-pyrazolyl indoles had been developed in the presence of 3 equiv. of PEG-400 in reflux water. This procedure did not require toxic hydrazine and product purification, eliminating the use of toxic liquid chemicals.
Nikolai Kuhnert - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of novel enantiomerically pure tetra-carbohydrazide cyclophane macrocycles
Organic and Biomolecular Chemistry, 2012Co-Authors: Hany F. Nour, Nadim Hourani, Nikolai KuhnertAbstract:A total of twelve novel enantiomerically pure tetra-carbohydrazide cyclophane macrocycles have been synthesised in quantitative yields by reacting chiral (4R,5R)- and (4S,5S)-1,3-dioxolane-4,5-dicarbohydrazides with aromatic bis-aldehydes in a [2 + 2]-Cyclocondensation Reaction. The compounds show a dynamic behaviour in solution, which has been rationalized in terms of an unprecedented conformational interconversion between two conformers one stabilised by intramolecular hydrogen bonding and π–π stacking interactions.
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Synthesis of diastereomeric trianglamine-β-cyclodextrin-[2]-catenanes
Tetrahedron Letters, 2006Co-Authors: Nikolai Kuhnert, Bing TangAbstract:The synthesis of novel diastereomeric [2]-catenanes derived from β-cyclodextrin and an enantiomeric trianglamine is described using a [3+3] Cyclocondensation Reaction.
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The synthesis and conformation of oxygenated trianglimine macrocycles
Organic & biomolecular chemistry, 2005Co-Authors: Nikolai Kuhnert, Ana M. López-periago, Giulia M. RossignoloAbstract:The synthesis of series of D2h and C2v symmetric oxygenated aromatic dicarboxaldehydes, using dilithiation methodology, is described along with their reactivity in the [3 + 3] Cyclocondensation Reaction with (1R,2R)-diaminocyclohexane to give oxygenated trianglimine macrocycles. Macrocycles derived from C2v symmetric dialdehydes give macrocycles with a stereogenic aromatic plane with complete diastereocontrol, as a mixture of rotamers.
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the synthesis of trianglimines on the scope and limitations of the 3 3 Cyclocondensation Reaction between 1r 2r diaminocyclohexane and aromatic dicarboxaldehydes
Organic and Biomolecular Chemistry, 2003Co-Authors: Nikolai Kuhnert, Giulia M. Rossignolo, Ana M LopezperiagoAbstract:The synthesis of aromatic dicarboxaldehydes, using dilithiation methodology is described along with their reactivity, in the [3 + 3] Cyclocondensation Reaction, with (1R,2R)-diaminocyclohexane to give trianglimine macrocycles. The scope and limitations of the Cyclocondensation Reaction are studied and some comments on the properties of the novel macrocycles are made such as their conformation in solution and temperature dependent dynamic NMR behaviour.
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The synthesis of trianglimines: on the scope and limitations of the [3 + 3] Cyclocondensation Reaction between (1R,2R)-diaminocyclohexane and aromatic dicarboxaldehydes
Organic & biomolecular chemistry, 2003Co-Authors: Nikolai Kuhnert, Giulia M. Rossignolo, Ana M. López-periagoAbstract:The synthesis of aromatic dicarboxaldehydes, using dilithiation methodology is described along with their reactivity, in the [3 + 3] Cyclocondensation Reaction, with (1R,2R)-diaminocyclohexane to give trianglimine macrocycles. The scope and limitations of the Cyclocondensation Reaction are studied and some comments on the properties of the novel macrocycles are made such as their conformation in solution and temperature dependent dynamic NMR behaviour.
Yogesh T. Naliapara - One of the best experts on this subject based on the ideXlab platform.
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Etidronic Acid: a New and Efficient Catalyst for the Synthesis of Novel 5-Nitro-3,4-Dihydropyrimidin-2(1H)-Ones
Catalysis Letters, 2009Co-Authors: Mahesh M. Savant, Akshay M. Pansuriya, Chirag V. Bhuva, Naval P. Kapuriya, Yogesh T. NaliaparaAbstract:A simple, convenient and efficient one-pot Cyclocondensation Reaction of 1-(2-hydroxyphenyl)-2-nitroethanone, arylaldehydes and urea using etidronic acid to furnish nitro dihydropyrimidine derivatives is described. A new and efficient protocol is developed as a homogenous catalyst for the synthesis of dihydropyrimidines using substituted ω-nitro acetophenone. Various bisphosphonic acids were examined to synthesized pyrimidines via multicomponent Cyclocondensation Reaction. This methodology has the advantage of excellent yields with short Reaction time.
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Synthesis of some novel trifluoromethylated tetrahydropyrimidines using etidronic acid and evaluation for antimicrobial activity
2009Co-Authors: Mahesh M. Savant, Akshay M. Pansuriya, Chirag V. Bhuva, Anil S. Patel, Piyush V. Pipaliya, Vipul B. Audichya, Pravin Pawar, Yogesh T. NaliaparaAbstract:A simple and convenient, etidronic acid catalyzed, one-pot Cyclocondensation Reaction of 1, 3- diketone, arylaldehydes and urea to furnish trifluoromethyl tetrahydropyrimidine derivatives with excellent yield is described. The catalytic application of etidronic acid was investigated under various Reaction conditions. All the synthesized compounds were evaluated for antimicrobial activity. The results obtained demonstrated that 40% of the synthesized compounds exhibited significant antimicrobial activity against all the tested micro organisms.
Shahrzad Abdolmohammadi - One of the best experts on this subject based on the ideXlab platform.
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tio2 sio2 nanocomposite as a highly efficient catalyst for the solvent free Cyclocondensation Reaction of isatins cyclohexanones and urea
Zeitschrift für Naturforschung B, 2019Co-Authors: Simin Janitabardarzi, Shahrzad AbdolmohammadiAbstract:A TiO₂–SiO₂ nanocomposite catalyzes the one-pot Cyclocondensation Reaction of 1H-indole-2,3-diones (isatins), 1,3-cyclohexanediones, and urea at T = 70°C under solvent-free conditions with high efficiency. The present method affords the corresponding spiro products in high yields and short Reaction time. The unique features of the TiO₂–SiO₂ nanocomposite are high catalytic activity, ease of preparation, non-toxicity, low loading, and recyclability.
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TiO2–SiO2 nanocomposite as a highly efficient catalyst for the solvent-free Cyclocondensation Reaction of isatins, cyclohexanones, and urea
Zeitschrift für Naturforschung B, 2019Co-Authors: Simin Janitabar-darzi, Shahrzad AbdolmohammadiAbstract:A TiO₂–SiO₂ nanocomposite catalyzes the one-pot Cyclocondensation Reaction of 1H-indole-2,3-diones (isatins), 1,3-cyclohexanediones, and urea at T = 70°C under solvent-free conditions with high efficiency. The present method affords the corresponding spiro products in high yields and short Reaction time. The unique features of the TiO₂–SiO₂ nanocomposite are high catalytic activity, ease of preparation, non-toxicity, low loading, and recyclability.
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ZnO nanoparticles-catalyzed Cyclocondensation Reaction of arylmethylidenepyruvic acids with 6-aminouracils.
Combinatorial chemistry & high throughput screening, 2013Co-Authors: Shahrzad AbdolmohammadiAbstract:A new, efficient, and solvent-free Cyclocondensation Reaction of arylmethylidenepyruvic acids with 6- aminouracils is presented that uses a catalytic amount of ZnO nanoparticles (ZnO Nps) as a recyclable catalyst at 70 °C. This protocol has the advantages of high yields (91-98%), easy work-up, very short Reaction time (2 h), and using environmentally friendly procedure.
Zemin Mei - One of the best experts on this subject based on the ideXlab platform.
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Regioselective Synthesis of Isomeric 3-[1-Substituted Pyrazol-3(5)-yl]indoles from β-Ethylthio-β-indolyl-α,β-unsaturated Ketones
Synthesis, 2020Co-Authors: Peiqiu Liao, Zemin MeiAbstract:An efficient and highly regioselective synthesis of isomeric 3-[1-substituted pyrazol-3(5)-yl]indoles has been developed by the acid-mediated regioselective Cyclocondensation Reaction of β-ethyltho-β-indolyl-α,β-unsaturated ketones and monosubstituted hydrazines. In the presence of 1 equivalent of AcOH in refluxing EtOH, the Cyclocondensation Reaction of β-ethyltho-β- indolyl-α,β-unsaturated ketones with monosubstituted hydrazines yielded 3-(1-substituted pyrazol-5-yl)indoles in excellent yields, while 3-(1-substituted pyrazol-3-yl)indoles were obtained in good yields when the Cyclocondensation Reaction was carried out in refluxing AcOH.
