- Electronic effect control of regioselectivity in the Michael-Addition inspired cascade reaction of 1,3-dimethyl-6-amino-uracil and 2-hydroxychalcones
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An unexpected Brosnted acid-catalyzed cascade reaction of 1,3-dimethyl-6-aminouracil with 2-hydroxychalcone has been developed to afford pyrido[2,3–d]pyrimidine-2,4-diones derivatives and 2,8-dioxabicyclo[3.3.1]nonane derivatives in moderate to good yield
- Cui, Xin,Huang, Chao,Li, Jing-Peng,Lin, Jun-Jie,Wang, Shuang,Xia, Xian-Song
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supporting information
(2022/01/15)
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- Novel isoniazid-spirooxindole derivatives: design, synthesis, biological evaluation, in silico ADMET prediction and computational studies
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In the present scenario, the Synthesis of new and desired antimycobacterial agent has an eternal demand to resist Mycobacterium tuberculosis (MTB). The design and identification of new molecules for the treatment of tuberculosis is an important task in organic as well as medicinal chemistry research. In the present study, we have reported the combination of the desired compound using two versatile and significant moieties, isoniazid and spirooxindole derivatives. A series of novel isoniazid-spirooxindole hybrid molecules (6a-6ao) were designed, synthesized, and well-characterized by various spectroscopic methods. We have evaluated for their in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv (MTB) strain and MDR-TB. Among them, Compound 6ab was found to be the most effective compare to other compounds. ADMET-related descriptors were to be calculated of all the compounds to predict the pharmacokinetic properties for the selection of the effective and bioavailable compounds. In addition, molecular docking and molecular dynamics studies reveal that the binding modes of all the compounds in the active site of isoniazid-resistant enoyl-ACP(COA) reductase, which helped to establish a structural basis of inhibition of Mycobacterium tuberculosis.
- Bhoi, Manoj N.,Borad, Mayuri A.,Jethava, Divya J.,Pandya, Himanshu A.,Patel, Chirag N.,Patel, Hitesh D.
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- Highly enantioselective addition of aliphatic aldehydes to 2-hydroxychalcone enabled by cooperative organocatalysts
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Herein, we developed an enantioselective addition of aliphatic aldehydes to 2-hydroxychalcone promoted by cooperative organocatalysts, giving access to hybrid flavonoids in excellent enantioselectivities. This reaction took advantage of cycloisomerization of 2-hydroxychalcone to form a transient flavylium under the irradiation of 24 W CFL, which was trapped by the in situ generated chiral enamine intermediate. The synergistic action of chiral phosphoric acid secured the excellent outcome of this reaction by ion-pairing with the transient flavylium.
- Chen, Le,Chen, Lu,Gao, Yu-Qi,Hou, Yi,Hu, Jiadong,Wen, Wen,Xie, Weiqing,Xu, Dongyang
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supporting information
p. 10018 - 10021
(2020/09/15)
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- Palladium-Catalyzed Cascade Reactions of 2-(Cyanomethoxy)chalcones with Arylboronic Acids: Selective Synthesis of Emissive Benzofuro[2,3- c]pyridines
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The Pd(II)-catalyzed cascade reactions of 2-(cyanomethoxy)chalcones with arylboronic acids were demonstrated, allowing the rapid construction of benzofuro[2,3-c]pyridine skeletons with excellent selectivity. These transformations involve the domino-style formation of C-C/C-C/C-N bonds through nitrile carbopalladation, intramolecular Michael addition, cyclization, and aromatization. This chemistry allows for the reactions of 2-(cyanomethoxy)chalcones with thiophen-3-ylboronic acid, providing 3-aryl-1-(thiophen-3-yl)benzofuro[2,3-c]pyridines in moderate to good yields. In addition, the resulting products represent a new class of emissive fluorophores.
- Xiong, Wenzhang,Hu, Kun,Lei, Yunxiang,Zhen, Qianqian,Zhao, Zhiwei,Shao, Yinlin,Li, Renhao,Zhang, Yetong,Chen, Jiuxi
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supporting information
p. 1239 - 1243
(2020/01/11)
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- Synthesis, in vitro antigiardial activity, SAR analysis and docking study of substituted chalcones
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A series of 15 chalcones-bearing substituents at positions 2, 4, and 5 of rings A and B were synthesized using microwave-assisted Claissen–Smichdt condensation and evaluated for their activity against Giardia lamblia and Green monkey kidney cells. Five co
- Cáceres-Castillo, David,Carballo, Rubén M.,Graniel-Sabido, Manlio,Mena-Rejón, Gonzalo J.,Mirón-López, Gumersindo,Moo-Puc, Rosa E.,Quijano-Qui?ones, Ramiro
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- Design, synthesis and biological evaluation of tricyclic pyrazolo[1,5-c][1,3]benzoxazin-5(5H)-one scaffolds as selective BuChE inhibitors
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Based on the structural analysis of tricyclic scaffolds as butyrylcholinesterase (BuChE) inhibitors, a series of pyrazolo[1,5-c][1,3]benzoxazin-5(5H)-one derivatives were designed, synthesized and evaluated for their acetylcholinesterase (AChE) and BuChE inhibitory activity. Compounds with 5-carbonyl and 7- or/and 9-halogen substitutions showed potential BuChE inhibitory activity, among which compounds 6a, 6c and 6g showed the best BuChE inhibition (IC50 = 1.06, 1.63 and 1.63 μM, respectively). The structure–activity relationship showed that the 5-carbonyl and halogen substituents significantly influenced BuChE activity. Compounds 6a and 6g were found nontoxic, lipophilic and exhibited remarkable neuroprotective activity and mixed-type inhibition against BuChE (Ki = 7.46 and 3.09 μM, respectively). Docking studies revealed that compound 6a can be accommodated into BuChE via five hydrogen bonds, one Pi–Sigma interaction and three Pi–Alkyl interactions.
- Qiu, Guo-Liang,He, Shao-Sheng,Chen, Shi-Chao,Li, Bo,Wu, Hui-Hui,Zhang, Jing,Tang, Wen-Jian
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p. 1506 - 1515
(2018/10/15)
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- Synthesis of Functionalized Chromene and Chroman Derivatives via Cesium Carbonate Promoted Formal [4 + 2] Annulation of 2′-Hydroxychalcones with Allenoates
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A new strategy has been established for the synthesis of functionalized chromene and chroman derivatives via a Cs2CO3-catalyzed domino addition of 2′-hydroxychalcone derivatives with allenoates, which can serve as a general avenue for the construction of multireplaced chromene derivatives. Chemoselectivity of this synthesis was found to depend on substituents on substrates. Good to excellent yields were achieved under simple and mild conditions at room temperature.
- Rouh, Hossein,Liu, Yangxue,Katakam, Nandakumar,Pham, Lilian,Zhu, Yi-Long,Li, Guigen
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p. 15372 - 15379
(2019/01/04)
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- Novel hybrids derived from aspirin and chalcones potently suppress colorectal cancer in vitro and in vivo
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Colorectal cancer (CRC) remains the fourth leading cause of cancer deaths around the world despite the availability of many approved small molecules for treatment. The issues lie in the potency, selectivity and targeting of these compounds. Therefore, new
- Lu, Shan,Obianom, Obinna N.,Ai, Yong
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p. 1722 - 1732
(2018/10/26)
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- Formal cycloaddition of ethyl 2-aroyl-1-chlorocyclopropanecarboxylates:facile synthesis of diversified tetrahydrocyclopropa[b]chromenes
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Tandem reaction of ortho-hydroxy chalcone with ethyl 2-aroyl-1-chlorocyclopropanecarboxylates has been disclosed, affording facile synthesis of diversified tetrahydrocyclopropa[b]chromenes via electron-deficient cyclopropene intermediate.
- Xiong, Guoxi,Liao, Yong,Liu, Xue-Hui,Tang, Xiangying,Gong, Yuefa
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supporting information
p. 1486 - 1491
(2018/02/23)
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- Synthesis and antimicrobial activity of some 5-chloro-3-phenyl-1H-indole-2-carbonyl azide derivatives
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In the present investigations, a series of new 6-substituted-3-(5-chloro-3-phenyl-lJ?-indole-2yl)-3,4-dihydro-4-substituted-4-substituted-phenacyl-2H-l,3-benzoxazin-2-one 7a-f have been synthesized by two methods making use of 5-chloro-3-phenyl-l/H-ndole-2-carbonyl azide 2 and chalcones 5a-f. In one method, compound 2 on reaction with chalcones 5a-f in presence of triethylamine in dry benzene yields respective open chain carbamates 6a-f, followed by reaction with catalytic amount of potassium hydroxide in dry benzene under reflux condition to afford compounds 7a-f. In another method, compound 5a-f on reaction with compound 2 using dry benzene in presence of catalytic amount of potassium hydroxide under reflux conditions afford cyclized products 7a-f in good yield. Structures of the all the newly synthesized compounds have been confirmed by spectral data. All these compounds have been screened for their antibacterial activity against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, antifungal activity against Aspergillus Niger and Candida albicans and antituberculosis activity against Mycobacterium tuberculosis (H37RV).
- Basavarajaiah,Mramyunjayaswamy
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p. 390 - 399
(2019/05/21)
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- Facile One-Pot Synthesis Methodology for Nitrogen-Containing Heterocyclic Derivatives of 3,5-Disubstituted 4,5-Dihydro-1H-Pyrazole, Their Biological Evaluation and Molecular Docking Studies
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A series of 2-pyrazoline derivatives (PS-1 to PS-16) were synthesized by reacting different aromatic/heteroaromatic aldehydes and ketones, in a two-step reaction through Claisen – Schmidt condensation, followed by cyclization of the resulting chalcones wi
- Upadhyay, Savita,Tripathi, Avinash C.,Paliwal, Sarvesh,Saraf, Shailendra K.
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p. 564 - 575
(2017/11/10)
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- Synthesis of 6,12-Methanobenzo[d]pyrano[3,4-g][1,3]dioxocin-1(12H)-ones and Study of Their Interaction with DNA and β-Lactoglobulin
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An efficient synthesis of 6,12-methanobenzo[d]pyrano[3,4-g][1,3]dioxocin-1(12H)-ones, a new class of 2,8-dioxabicyclo[3.3.1]nonanes, starting from 2-hydroxychalcones or their analogues and 4-hydroxy-6-methyl-2H-pyran-2-one has been achieved by use of amberlyst-15, a sulfonated polystyrene resin, as a recyclable heterogeneous catalyst. The methodology involves a domino sequence of Michael addition and two-stage heterocyclization. Among the synthesized products, two show significant ct-DNA-binding properties and all show strong binding with the carrier protein β-lactoglobulin (β-lg). A study of antibacterial properties conducted on two bacterial species by using four compounds showed that two of them are moderately active.
- Sepay, Nayim,Guha, Chayan,Maity, Sanhita,Mallik, Asok K.
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p. 6013 - 6022
(2017/11/14)
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- Synthesis of several types of 2,8-dioxabicyclo[3.3.1]nonanes using amberlyst-15 as an efficient recyclable heterogeneous catalyst
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A facile synthesis of 2,8-dioxabicyclo[3.3.1]nonane derivatives starting from simple molecules, such as 2-hydroxychalcones as one component and dimedone, 4-hydroxycoumarin, 2-hydroxynaphthoquinone, 2-naphthol or 1-naphthol, as the other has been achieved by use of amberlyst-15, a sulfonated polystyrene resin, as a recyclable heterogeneous catalyst. The methodology involves a domino sequence of Michael addition and two-stage cyclisation.
- Samanta, Swati,Sepay, Nayim,Mallik, Sumitava,Mondal, Rina,Rahaman Molla, Mosidur,Mallik, Asok K.
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supporting information
p. 2195 - 2201
(2017/11/15)
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- Enantioselective synthesis of 2-amino-3-nitrile-chromenes catalyzed by cinchona alkaloids: A remarkable additive effect
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2-Amino-3-nitrile-chromenes with potential antitumor activity were constructed by a novel catalytic system. In combination with α-naphthol, quinine could effectively promote the Michael-cyclization process of malononitrile with functionalized chalcones in high yields and moderate to good enantioselectivity (up to 84% ee). It is notable that the enantioselectivity could be greatly improved when α-naphthol was employed as additive.
- Zheng, Yuan-Qin,Luan, Chun-Feng,Wang, Zhi-Jing,Yao, Yong-Qi,Shi, Zhi-Chuan,Li, Xue-Feng,Zhao, Zhi-Gang,Chen, Feng
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supporting information
p. 25 - 30
(2016/01/25)
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- Novel tricyclic pyrazolo[1,5-d][1,4]benzoxazepin-5(6H)-one: Design, synthesis, model and use as hMAO-B inhibitors
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Based on our recently reported selective hMAO-A inhibitors, on which, the intramolecular cyclization led to a very interesting change of isoform selectivity. A series of selective hMAO-B inhibitors (3a-3u) with novel scaffold of tricyclic pyrazolo[1,5-d][1,4]benzoxazepin-5(6H)-one were designed and synthesized. Compound 3u (IC50 = 221 nM) exhibited the best inhibitory activity and isoform selectivity against hMAO-B, superior to selegiline (IC50 = 321 nM), which is a commercial selective hMAO-B inhibitor used to Parkinson's disease. Modeling study indicated that the selectivity of our compounds to hMAO-B is determined by at least two residues, i.e., Ile 199 and Cys 172 (or corresponded Phe 208 and Asn 181 of hMAO-A). These data support further studies to assess rational design of more efficiently selective hMAO-B inhibitors.
- Chen, Rui,Xiao, Jie,Ni, Yong,Xu, Han-Fei,Zheng, Min,Tong, Xu,Zhang, Tong-Tian,Liao, Chenzhong,Tang, Wen-Jian
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p. 1741 - 1748
(2016/04/05)
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- Design and synthesis of novel 2-pyrazoline-1-ethanone derivatives as selective MAO inhibitors
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Thirty seven novel 2-pyrazoline-1-ethanone derivatives were designed, synthesized and evaluated as selective hMAO inhibitors. Among them, compounds 7h (IC50 = 2.40 μM) and 12c (IC50 = 2.00 μM) exhibited best inhibitory activity and selectivity against hMAO-A, surpassing that of the positive control Clorgyline (IC50 = 2.76 μM). Based on selective activity of hMAO-A, SAR analysis showed that the order of N1 substituent contribution was bromo (3) > piperidinyl (4) > morpholinyl (5) > imidazolyl (6), and compounds with electron-withdrawing substituents (-F, -Cl) at C3 or C5 phenyl ring of 2-pyrazoline nucleus dedicated stronger MAO-A inhibitory activity. Molecular docking showed that compounds 7h and 12c were nicely bound to hMAO-A via two hydrogen bonds (SER209, GLU216), one Pi-Pi interaction and three hydrogen bonds (SER209, GLU216, TYR69), one Sigma-Pi interaction, respectively. In addition, the substituent at C3 position of 2-pyrazoline with the N1 acetyl has little effect on MAO-A inhibitory activity. These data support further studies to assess rational design of more efficiently selective hMAO inhibitors in the future.
- Tong, Xu,Chen, Rui,Zhang, Tong-Tian,Han, Yan,Tang, Wen-Jian,Liu, Xin-Hua
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p. 515 - 525
(2015/01/30)
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- ZrCl4-catalysed synthesis of new 4-(2-hydroxyphenyl)pyrazolo[3,4-b]pyridine derivatives
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In the presence of a catalytic amount of zirconium(IV) chloride, an efficient synthesis of new 4-(2-hydroxyphenyl)pyrazolo[3,4-b]pyridines has been developed by the reaction 2-hydroxychalcones with 3-methyl-1-phenyl-1H-pyrazol-5-amine in refluxing ethanol. All these novel compounds have been characterised by 1H NMR, 13C NMR, HRMS, IR spectra and X-ray crystallographic analysis.
- Liu, Meilin,Yin, Guodong
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p. 236 - 266
(2015/06/02)
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- Tosylhydrazine mediated conjugate reduction and sequential reductive coupling cyclization: Synthesis of 2-arylchromans
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Tosylhydrazine mediated conjugate reduction of 2-hydroxyl chalcones and sequential reductive coupling cyclization is described. This is an unprecedented protocol and an extremely efficient method for a one-pot domino synthesis of 2-arylchromans in good to excellent yields from commercially available, cheap starting materials. More importantly, the two-step reactions can be easily controlled to afford dihydrochalcones or 2-arylchromans by the mole amounts of tosylhydrazine. Furthermore, the operational simplicity of the process and the high functional group tolerance are remarkable.
- Shang, Xuyang,Zhou, Xiaomeng,Zhang, Wei,Wan, Changfeng,Chen, Junmin
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p. 8187 - 8193
(2015/12/30)
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- The design, synthesis, in vitro biological evaluation and molecular modeling of novel benzenesulfonate derivatives bearing chalcone moieties as potent anti-microtubulin polymerization agents
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A series of novel 3,4-dimethoxylbenzenesulfonate derivatives containing a chalcone structure were synthesized and evaluated for their anti-proliferative activities against HepG2, HCT-116, MCF-7 and HeLa cell lines, as well as the effects of compound 10b on mitotic arrest and cell cycle of MCF-7 carcinoma cell line. Most importantly, the results of DAPI staining under co-focal microscope justified that compound 10b functioned even at relatively low concentration. The analogues showed a potent bio-activity towards tumor cells with IC50 values at nano-mole class, compared with those of positive control drug Colchicine, whose IC50 were 150.4 nM for MCF-7, 123.9 nM for HepG2, 125.4 nM for HCT-116 and 131.4 nM for HeLa cells. Also, a molecular docking modeling was utilized to reveal the binding mode of derivatives and microtubule. Among all the synthesized compounds, compound 10b stands out as IC50 values against all the selected cell lines were at average 80 nM (in which the values against MCF-7 and HepG2 were similar; about 79.2 nM). In this research, we gave strong evidence upon the optimized stratagem for ligands targeting the colchicine-binding site on microtubules, explaining the attribution that the analogues were designed upon the structure of chalcone and combretastatin A-4.
- Shen, Yu-Ning,Lin, Lin,Qiu, Han-Yue,Zou, Wen-Yan,Qian, Yong,Zhu, Hai-Liang
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p. 23767 - 23777
(2015/04/14)
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- Intramolecular oxidative coupling: I2/TBHP/NaN3-mediated synthesis of benzofuran derivatives
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A novel intramolecular oxidative coupling reaction has been established to prepare benzofuran derivatives via direct C(sp2)-H functionalization for the formation of C-O bond. This transformation is mediated by I2/TBHP/NaN3 under metal-free conditions and a catalytic amount of NaN3 plays a crucial role in the reaction. Furthermore, the reaction tolerates a broad substrate scope with average to excellent yields.
- Xu, Wengang,Li, Qingcui,Cao, Chuanpeng,Zhang, Fanglin,Zheng, Hua
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supporting information
p. 6158 - 6161
(2015/06/08)
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- An advanced and novel one-pot synthetic method for diverse benzo[c]chromen-6-ones by transition-metal free mild base-promoted domino reactions of substituted 2-hydroxychalcones with β-ketoesters and its application to polysubstituted terphenyls
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Novel and efficient one-pot syntheses of a variety of benzo[c]chromen-6-one derivatives were accomplished using Cs2CO3-promoted reactions between substituted 2-hydroxychalcones and β-ketoesters. These reactions involved domino Michael addition/intramolecular aldol/oxidative aromatization/lactonization and provided a rapid synthetic route for the production of biologically interesting novel benzo[c]chromen-6-one molecules bearing several different substituents on benzene rings. As an application of this methodology, several synthesized benzo[c]chromen-6-ones were transformed into highly functionalized novel terphenyls.
- Poudel, Tej Narayan,Lee, Yong Rok
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p. 919 - 930
(2014/02/14)
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- MW assisted synthesis of some pyrazoles containing benzotriazole moiety: An environmentally benign approach
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MW assisted synthesis of pyrazoles containing benzotriazole moieties 4a-n has been achieved by cyclocondensation of substituted chalcones 3a-n with hydrazide of benzotriazole 2 in presence of glacial acetic acid (GAA). Thus, synthesized compounds 4a-n have been characterized by their spectral data and evaluated for their antibacterial and antifungal activities against various microbes.
- Tiwari, Urvashi,Ameta, Chetna,Rawal, Manish K.,Ameta, Rakshit,Punjabi, Pinki B.
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p. 432 - 439
(2013/05/08)
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- Organocatalyzed michael-michael cascade reaction: Asymmetric synthesis of polysubstituted chromans
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An enantioselective cascade Michael-Michael reaction between chalcones enolates and nitromethane catalyzed by a bifunctional thiourea is developed. This reaction provides a mild but efficient approach to chiral benzopyrans bearing three consecutive stereocenters in high yields with excellent stereoselectivities, and the benzopyrans can be easily transformed to the corresponding tricyclic product.
- Jia, Zhen-Xin,Luo, Yong-Chun,Cheng, Xi-Na,Xu, Peng-Fei,Gu, Yu-Cheng
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p. 6488 - 6494
(2013/07/26)
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- Enantioselective intramolecular formal [2 + 4] annulation of acrylates and α,β-unsaturated imines catalyzed by amino acid derived phosphines
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The first chiral phosphine-catalyzed activation of acrylates for intramolecular formal [2 + 4] reactions with unsaturated imines is described. The catalytic reactions afford N-heterocycles with exceptionally high diastereo- and enantioselectivities. The [2 + 4] products are amenable for further transformations to useful molecules such as chiral piperidines and multicyclic structures.
- Jin, Zhichao,Yang, Ruojie,Du, Yu,Tiwari, Bhoopendra,Ganguly, Rakesh,Chi, Yonggui Robin
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p. 3226 - 3229
(2012/08/08)
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- Synthesis of chalcones with anticancer activities
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Several chalcones were synthesized and their in vitro cytotoxicity against various human cell lines, including human breast adenocarcinoma cell line MCF-7, human lung adenocarcinoma cell line A549, human prostate cancer cell line PC3, human adenocarcinoma cell line HT-29 (colorectal cancer) and human normal liver cell line WRL-68 was evaluated. Most of the compounds being active cytotoxic agents, four of them with minimal IC50 values were chosen and studied in detail with MCF-7 cells. The compounds 1, 5, 23, and 25 were capable in eliciting apoptosis in MCF-7 cells as shown by multiparameter cytotoxicity assay and caspase-3/7, -8, and -9 activities (p 0.05). The ROS level showed 1.3-fold increase (p 0.05) at the low concentrations used and thus it was concluded that the compounds increased the ROS level eventually leading to apoptosis in MCF-7 cells through intrinsic as well as extrinsic pathways.
- Syam, Suvitha,Abdelwahab, Siddig Ibrahim,Al-Mamary, Mohammed Ali,Mohan, Syam
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experimental part
p. 6179 - 6195
(2012/09/07)
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- A simple and efficient access to new functionalized 4- phenacylideneflavenes#
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An innovative and efficient approach towards diversity-oriented synthesis of 4-phenacylideneflavenes has been developed from substituted salicylaldehydes and acetophenones using iodine under solvent-free conditions. Both symmetrical and unsymmetrical func
- Sashidhara, Koneni V.,Kumar, Abdhesh,Agarwal, Shikha,Kumar, Manoj,Kumar, Bikash,Sridhar, Balasubramanian
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scheme or table
p. 1129 - 1140
(2012/05/20)
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- A novel route to synthesis of flavones from salicylaldehyde and acetophenone derivatives
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Convenient, facile, and alternate synthesis of medicinally important flavones is reported. The 2-hydroxychalcones derived from condensation between acetophenones and salicylaldehyde, underwent oxidative cyclization on heating in the presence of catalytic iodine, generating diversified flavones under solvent-free conditions. Eleven compounds have been synthesized in good to excellent yields and their mechanism of formation is described.
- Sashidhara, Koneni V.,Kumar, Manoj,Kumar, Abdhesh
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scheme or table
p. 2355 - 2359
(2012/07/14)
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- Condensation of α-aroylketene dithioacetals and 2- hydroxyarylaldehydes results in facile synthesis of a combinatorial library of 3-aroylcoumarins
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A facile, convenient, efficient, and high yielding synthesis of a combinatorial library of 3-aroylcoumarins has been developed by the condensation of easily available α-aroylketene dithioacetals (AKDTAs) and 2-hydroxybenzaldehydes (salicylaldehydes)/2-hydroxy-1-naphthaldehyde in the presence of catalytic amount of piperidine in THF reflux. The condensation of ferrocene derived α-aroylketene dithioacetal and 2-hydroxybenzaldehyde furnished coumarin installed on a ferrocene platform.
- Rao, H. Surya Prakash,Sivakumar
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p. 8715 - 8723
(2007/10/03)
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- Facile synthesis of aryl-substituted 1,2,5,6-tetrahydropyrimidines and their stereochemical investigation
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The present work is devoted to the investigation of 2,4,6-triaryl-1,2,5,6- tetrahydropyrimidine derivatives. A new facile approach to their synthesis based on the reaction of α,β-unsaturated ketones, carbonyl compounds and ammonia was developed. Some stereochemical features of the compounds obtained were fixed on the base of NMR data (including COSY and NOESY experiments).
- Chebanov, Valentin A.,Muravyova, Elena A.,Sadchikova, Yulia V.,Desenko, Sergey M.,Chernenko, Vitaly N.,Kobzar, Kiril M.,Musatov, Vladimir I.
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p. 897 - 904
(2007/10/03)
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- Hydrolysis of Benzopyrylium Dyes - An Application of the Concept of Chemical Hardness
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A systematic study on the relationship between the substitution pattern, the pKa values, and spectral properties of flavylium cations and the respective-(CH2)2-bridged analoga (5,6-dihydrobenzo[c]xanthylium cations) is given in order to find rules concerning their spectral behaviour and their chemical reactivity. Our results show that the concept of chemical hardness can explain the different reactivity of 4′- and 7-substituted flavylium ions against HO-. The pKa values of these species, which can act as a measure of reactivity with respect to a nucleophile, correlate linearly with the absolute hardness calculated from half the energy gap between the frontier orbitals. Since the longest-wavelength UV/VIS absorption maximum is mainly determined by the HOMO-LUMO transition, an analogous linear correlation is obtained between the spectral 0-0 transition and the pKa value. Deviations from these correlations are assumed to be due to steric effects.
- Lietz, Heike,Haucke, Guenter,Czerney, Peter,John, Birgit
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p. 725 - 730
(2007/10/03)
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- Antitumorigenic activities of chalcones. I. Inhibitory effects of chalcone derivatives on 32Pi-incorporation into phospholipids of HeLa cells promoted by 12-O-tetradecanoyl-phorbol 13-acetate (TPA)
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More than forty chalcone derivatives were synthesized to examine their structure-activity relationship against tumorigenesis. As a primary screening test, the inhibitory activities of the chalcones for the 32pi-incorporation into phospholipids of HeLa cells enhanced by 12-O-tetradecanoyl-phorbol 13- acetate (TPA) were examined. 3-Hydroxy-chalcone derivatives possessing methyl group in 3'-, 4'-, or 2'-position and isoliquiritigenin homologs showed potent inhibitory activities in the phosphorylation test, which suggests their antitumorigenic effects.
- Iwata,Nishino,Nagata,Satomi,Nishino,Shibata
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p. 1710 - 1713
(2007/10/03)
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