147463-97-6Relevant academic research and scientific papers
Organometallic titanocene complex as highly efficient bifunctional catalyst for intramolecular Mannich reaction
Wang, Yunyun,Jian, Yajun,Wu, Ya,Sun, Huaming,Zhang, Guofang,Zhang, Weiqiang,Gao, Ziwei
, (2019/05/07)
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.
Titanocene complex with oxygen-containing carboxylic acid as ligand as well as preparation method and application of titanocene complex
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Paragraph 0039; 0040; 0042, (2018/11/03)
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
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
Kumar, Sumit,Verma, Nishant,Parveen, Iram,Ahmed, Naseem
supporting information, p. 2111 - 2122 (2016/11/23)
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.
Mild and Efficient Silver(I) Triflate Catalyzed Synthesis of 2-Aryl-2,3-dihydroquinolin-4(1 H)-ones, and Their Antioxidant Activities
Pandit, Rameshwar Prasad,Sharma, Kavita,Lee, Yong Rok
, p. 3881 - 3890 (2015/12/18)
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.
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
Kumar, Sumit,Verma, Nishant,Ahmed, Naseem
, p. 85128 - 85138 (2015/10/28)
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.
Aza analogs of flavones as potential antimicrobial agents
Sharma, Sahil,Thakur, Vikas,Ojha, Ritu,Budhiraja, Abhishek,Nepali, Kunal,Singh Bedi, Preet Mohinder
, p. 327 - 334 (2013/07/26)
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
Design and synthesis of aza-flavones as a new class of xanthine oxidase inhibitors
Dhiman, Rajni,Sharma, Sahil,Singh, Gagandip,Nepali, Kunal,Singh Bedi, Preet Mohinder
, p. 7 - 16 (2013/02/23)
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
Silica supported-double metal cyanides (DMCs): A green and highly efficient catalytic protocol for isomerisation of 2′-hydroxychalcones to flavanones
Ahmed, Naseem,Konduru, Naveen Kumar,Praveen,Kumar, Anand,Kamaluddin
, p. 135 - 141 (2013/06/26)
Four different double metal cyanides (NiHCFe, CrHCFe, MnHCFe and ZnHCFe) were synthesized, followed by adsorbed on silica gel and used as Lewis acid catalyst in the isomerisation of substituted 2′-hydroxychalcones to flavanones under solvent-free (dry) condition. Optimization of the reaction condition, temperature effects, DMC catalysts loading and re-useable catalytic activity were further studied during the reaction. Among these catalysts, NiHCFe at 35 mol% loading gave excellent yield (90%) at 100 C temperature in 1.15 h. Catalyst (NiHCFe) easily recovered and re-used six times without much loss of its catalytic activity which gave 80-85% product yields each time. However, these DMCs were failed to give product in the solution phase even prolonging the reaction time at reflux temperature. Similarly, isomerization of substituted 2′-aminochalcones gave 2-5% yields either in solution phase or under solvent-free condition.
(±)-2-Aryl-2,3-dihydro-4(1H)-quinolinones by a tandem reduction-Michael addition reaction
Bunce, Richard A.,Nammalwar, Baskar
experimental part, p. 613 - 619 (2011/07/31)
An efficient synthesis of (±)-2-aryl-2,3-dihydro-4(1H)-quinolinones has been developed from chalcones prepared from 2′-nitroacetophenone and a series of substituted benzaldehydes. The cyclization sequence is initiated by reduction of the nitro group under dissolving metal conditions using iron powder in concentrated hydrochloric acid. Milder conditions, using acetic acid or acetic acid-phosphoric acid as the reaction medium, were less satisfactory. Procedural details as well as a mechanistic discussion and reaction optimization studies are presented.
Lithium tetrafluoroborate catalyzed highly efficient inter- and intramolecular aza-Michael addition with aromatic amines
Lad,Kulkarni,Desai,Wadgaonkar
experimental part, p. 1059 - 1064 (2012/03/11)
Lithium tetrafluoroborate has been demonstrated for the first time to be an efficient catalyst in intermolecular aza-Michael addition aromatic amines to electron deficient alkenes. Suitability of the same catalyst in intramolecular aza-Michael addition leading 2-aryl-2,3-dihydroquinolin-4(1H) ones has also been described.
