- Organometallic titanocene complex as highly efficient bifunctional catalyst for intramolecular Mannich reaction
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Bifunctional catalysts bearing two catalytic sites, Lewis acidic organometallic titanocene and Br?nsted acidic COOH, have been assembled in situ from Cp2TiCl2 with carboxylic acid ligands, showing high catalytic activity over an intramolecular Mannich reaction towards synthesis of 2-aryl-2,3-dihydroquinolin-4(1H)-ones. The determination of the bifunctional catalyst Cp2Ti(C8H4NO6)2 was elucidated by single X-ray HR-MS and investigation of catalytic behavior. In particular, masking the Br?nsted acidic COOH catalytic site with dormant COOMe lowered the reaction yield greatly, indicating that two catalytic sites work together to maintain high catalytic efficiency.
- Wang, Yunyun,Jian, Yajun,Wu, Ya,Sun, Huaming,Zhang, Guofang,Zhang, Weiqiang,Gao, Ziwei
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- Titanocene complex with oxygen-containing carboxylic acid as ligand as well as preparation method and application of titanocene complex
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The invention discloses a titanocene complex with oxygen-containing carboxylic acid as well as a preparation method and an application of the titanocene complex. The structural formula of the complexis shown in the description. The titanocene complex is p
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Paragraph 0039; 0040; 0042
(2018/11/03)
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- Zirconyl Nitrate as an Efficient Catalyst for Facile Synthesis of 2-Aryl-2,3-dihydroquinolin-4(1 H)-one Derivatives in Aqueous Medium
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A simple, green, and efficient method is introduced for the synthesis of 2-aryl-2,3-dihydroquinolin-4(1 H)-ones under mild reaction conditions with improved yields by intramolecular cyclization of o -aminochalcones with zirconyl nitrate [Zn(O)(NO 3/
- Gorepatil, Amarsinha,Gorepatil, Pratapsinha,Gaikwad, Mahadev,Mhamane, Dattakumar,Phadkule, Ajit,Ingle, Vilas
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p. 235 - 237
(2017/09/28)
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- Method for synthesizing 2-aryl-2,3-dihydro-4(1H)-quinolinone derivative under catalysis of high-acidity ionic liquid
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The invention discloses a method for synthesizing a 2-aryl-2,3-dihydro-4(1H)-quinolinone derivative under the catalysis of high-acidity ionic liquid, belonging to the technical field of chemical material preparation. According to the method, o-aminoacetophenone and aromatic aldehyde are used as reaction raw materials and subjected to a reaction under the catalysis of a high-acidity ionic liquid catalyst so as to synthesize the 2-aryl-2,3-dihydro-4(1H)-quinolinone derivative. Through selection of specific high-acidity ionic liquid as the catalyst and optimization of reaction process parameters, the method provided by the invention can effectively overcome the disadvantages of great usage amounts of catalysts, poor recycling performance, complex product purification process and insufficient product yield in conventional synthesis processes.
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Paragraph 0050; 0051; 0052
(2017/10/07)
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- [C8dabco]Br: a mild and convenient catalyst for intramolecular cyclization of 2-aminochalcones to the corresponding 2-aryl-2,3-dihydroquinolin-4(1H)-ones
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[Figure not available: see fulltext.] A new and convenient synthesis of 2-aryl-2,3-dihydroquinolin-4(1H)-ones has been described using the intramolecular cyclization of 2-aminochalcones catalyzed by 1-octyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide ([Cs
- Derabli, Chamseddine,Mahdjoub, Sara,Boulcina, Raouf,Boumoud, Boudjemaa,Merazig, Hocine,Debache, Abdelmadjid
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- A Green, Solvent-Free, Microwave-Assisted, High-Yielding YbCl3Catalyzed Deprotection of THP/MOM/Ac/Ts Ethers of Chalcone Epoxide and 2′-Aminochalcone and Their Sequel Cyclization
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Under microwave and solvent-free conditions, YbCl3efficiently catalyzed the deprotection of tetrahydropyran-2-yl, methoxymethyl (MOM), acetyl, and tosyl groups and sequel cyclization of chalcone epoxide to 2-hydroxyindanone and 2′-aminochalcone to aza-flavanone. The reaction afforded the products in excellent yield (78–99%) at 850 W microwave heating within 1–5 min under eco-friendly conditions. The merits of the presented protocol include high yield, use of microwave irradiation, solvent-free condition, catalyst reusability, and no need for purification with column chromatography. The present method is very much milder but more advanced than those reported earlier.
- Kumar, Sumit,Verma, Nishant,Parveen, Iram,Ahmed, Naseem
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supporting information
p. 2111 - 2122
(2016/11/23)
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- A general and efficient synthesis of 5,6-dihydrodibenzo[b,h][1,6]naphthyridine derivatives
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A two-step procedure for the synthesis of dihydrodibenzonaphthyridine derivatives from benzaldehydes and 2-aminoacetophenones, proceeding through a substituted dihydroquinolone intermediate, is described. The synthetic protocol allows for a versatile and robust coupling method between a range of 2-aminoacetophenones or 2-aminobenzophenones and a selection of substituted dihydroquinolones.
- Dobrowolski, Jeremy C.,Katen, Alice,Fraser, Benjamin H.,Bhadbhade, Mohan,Black, David StC.,Kumar, Naresh
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p. 5442 - 5445
(2016/11/19)
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- Synthesis and biological evaluation of a new series of 4-alkoxy-2-arylquinoline derivatives as potential antituberculosis agents
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Three new series of 33 quinolone compounds, 2-(2-, 3-, and 4-fluorophenyl)-4-O-alkyl(C5-15)quinolines (7a-k, 8a-k, and 9a-k), were synthesized from 2-(2-, 3-, and 4-fluorophenyl)-2,3-dihydroquinolin-4(1H )-one (4, 5, and 6) by the reaction of a
- Tosun, Gonca,Arslan, Tayfun,Iskefiyeli, Zeynep,Küük, Murat,Karaolu, engül Alpay,Yayli, Nurettin
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p. 850 - 866
(2015/08/06)
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- Mild and Efficient Silver(I) Triflate Catalyzed Synthesis of 2-Aryl-2,3-dihydroquinolin-4(1 H)-ones, and Their Antioxidant Activities
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Biologically interesting 2-aryl-2,3-dihydroquinolin-4(1H)-ones were synthesized using a mild and efficient one-pot procedure starting from o-aminoacetophenones and aromatic aldehydes in the presence of silver(I) triflate. This synthetic protocol provides rapid access to a variety of 2-aryl-2,3-dihydroquinolin-4(1H)-ones. This technique has several advantages, such as the use of easily available starting materials, the efficiency of the catalyst, a simple operation, and tolerance of a wide range of functionality in the aldehydes. Screening of the synthesized compounds for their antioxidant properties revealed that two compounds (with EC50 = 15.42 μM and 15.16 μM) exhibit a potent free-radical scavenging ability towards TEAC free radicals compared to the standard, Trolox.
- Pandit, Rameshwar Prasad,Sharma, Kavita,Lee, Yong Rok
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p. 3881 - 3890
(2015/12/18)
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- β-Cyclodextrin in water: Highly facile biomimetic one pot deprotection of phenolic THP/MOM/Ac/Ts ethers and concomitant regioselective cyclization of chalcone epoxides and 2′-aminochalcones
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A mild and efficient one-pot deprotection of THP/MOM/Ac/Ts ethers and the concomitant cyclization of chalcone epoxides to 2-hydroxyindanones or 2′-aminochalcones to aza-flavanones using β-cyclodextrin in water has been developed. β-CD was found to be highly effective at carrying out the deprotection and sequential transformations in an eco-friendly environment affording moderate to excellent yields (59-99%) at 60 °C in 8-22 min. Water, an eco-friendly reaction medium, has been utilized for the first time in this reaction. The merits of the presented protocol include the high yields and catalyst reusability and the protocol precludes the use of metals and organic solvents. The present method is much milder but more advanced than those reported earlier.
- Kumar, Sumit,Verma, Nishant,Ahmed, Naseem
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p. 85128 - 85138
(2015/10/28)
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- Aza analogs of flavones as potential antimicrobial agents
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In search for the new antimicrobial agents owing to drug resistant bacteria and fungi, a series of rationally designed aza analogs of flavones has been designed and synthesized. The design of the analogs involved incorporation of quinolone nucleus within
- Sharma, Sahil,Thakur, Vikas,Ojha, Ritu,Budhiraja, Abhishek,Nepali, Kunal,Singh Bedi, Preet Mohinder
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p. 327 - 334
(2013/07/26)
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- Design and synthesis of aza-flavones as a new class of xanthine oxidase inhibitors
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In an attempt to develop non-purine-based xanthine oxidase (XO) inhibitors, keeping in view the complications reported with the use of purine-based XO inhibitors, the flavone framework (a class possessing XO inhibitory potential) was used as lead structure for further optimization. By means of structure-based classical bioisosterism, quinolone was used as an isoster for chromone (a bicyclic unit present in flavones), owing to the bioactive potential and drug-like properties of quinolones. This type of replacement does not alter the shape and structural features required for XO inhibition, and also provides some additional interaction sites, without the loss of hydrogen bonding and hydrophobic and arene-arene interactions. In the present study, a series of 2-aryl/heteroaryl-4-quinolones (aza analogs of flavones) was rationally designed, synthesized and evaluated for in vitro XO inhibitory activity. Some notions about structure-activity relationships are presented indicating the influence of the nature of the 2-aryl ring on the inhibitory activity. Important interactions of the most active compound 3l (IC50 = 6.24 μM) with the amino acid residues of the active site of XO were figured out by molecular modeling. To develop non-purine-based xanthine oxidase inhibitors, the flavone framework was used as lead structure for further optimization. By means of structure-based classical bioisosterism, quinolone was used as an isoster for chromone. This type of replacement does not alter the shape and structural features required for xanthine oxidase inhibition. The rationally designed and synthesized series of 2-aryl/heteroaryl-4-quinolones (aza analogs of flavones) was evaluated for in vitro xanthine oxidase inhibitory activity. Copyright
- Dhiman, Rajni,Sharma, Sahil,Singh, Gagandip,Nepali, Kunal,Singh Bedi, Preet Mohinder
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- Antimony trichloride: An efficient and mild catalyst for cyclization of 2-aminochalcones to the corresponding 2-aryl-2,3-dihydroquinolin-4(1H)-ones
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Antimony trichloride is an efficient catalyst for the cyclization of 2-amino chalcones to the corresponding 2-aryl-2,3-dihydroquinolin-4(1H)-ones under mild reaction conditions and in almost quantitative yields. Copyright Taylor & Francis Group, LLC.
- Bhattacharya,Kundu, Pradip,Maiti, Gourhari
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experimental part
p. 476 - 481
(2010/04/04)
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- Simple and efficient synthesis of 2-aryl-2,3-dihydroquinolin-4(1H)-ones using silica chloride as a new catalyst under solvent-free conditions
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A mild, efficient, and high-yielding method for the synthesis of 2-aryl-2,3-dihydroquinolin-4(1H)-ones from their corresponding 2-amino chalcones using silica chloride (SiO2Cl) under solvent-free conditions is described. A series of 2-aryl-2,3-dihydroquinolin-4(1H)-ones containing both electron-donating and electron-withdrawing substituents were synthesized.
- Muthukrishnan,Mujahid,Punitharasu,Dnyaneshwar
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experimental part
p. 1391 - 1398
(2010/06/21)
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- l-Proline-catalyzed one-pot synthesis of 2-aryl-2,3-dihydroquinolin-4(1H)-ones
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l-Proline is utilized as an organocatalyst for the synthesis of substituted 2-aryl-2,3-dihydroquinolin-4(1H)-ones, in good yields. The efficiency of the catalyst was proved with a variety of substrates ranging from electron-deficient to electron-rich aryl
- Chandrasekhar,Vijeender,Sridhar
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p. 4935 - 4937
(2008/02/08)
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- Alumina supported-CeCl3·7H2O-NaI: an efficient catalyst for the cyclization of 2′-aminochalcones to the corresponding 2-aryl-2,3-dihydroquinolin-4(1H)-ones under solvent free conditions
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We recently advanced silica gel supported-TaBr5 as an efficient catalyst for the isomerization of 2′-aminochalcones to the corresponding 2-aryl-2,3-dihydroquinolin-4(1H)-ones under solvent free conditions (Tetrahedron Lett. 2006, 47, 2725-2729)
- Ahmed, Naseem,van Lier, Johan E.
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- Silica gel supported TaBr5: New catalyst for the facile and rapid cyclization of 2′-aminochalcones to the corresponding 2-aryl-2,3-dihydroquinolin-4(1H)-ones under solvent-free conditions
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Silica gel supported TaBr5 (5-10 mol %) is a new solid-support catalyst that can be used under solvent-free conditions for the facile and efficient isomerization of 2′-aminochalcones to the corresponding 2-aryl-2,3-dihydroquinolin-4(1H)-ones. The catalyst is easily prepared, stable and employed under environmentally friendly conditions.
- Ahmed, Naseem,Van Lier, Johan E.
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p. 2725 - 2729
(2007/10/03)
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- Fragmentation pathways in the electron impact mass spectra of 2-aryl-1,2,3,4-tetrahydro-4-quinolones
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The major feagmentation pathways in the electron impact mass spectra of a series of 2-aryl-1,2,3,4-tetrahydro-4-quinolones have been determined using a combination of low- and high-resolution mass spectrometry and matastable peak analysis.
- Kaye, Perry T.,Mphahlele, M. Jack
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