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Keisuke Kobayashi, Taichi Ohshiro, Hiroshi Tomoda, Feng Yin, Hai-Lei Cui, Pandurang V Chouthaiwale, Fujie Tanaka
Synthesis of new functionalized molecules and identification of biofunctional molecules can lead to the development of therapeutic leads and molecular tools for biomedical research. We have recently reported oxa-hetero-Diels-Alder reactions of enones with isatins to provide functionalized spirooxindole tetrahydropyran derivatives. Twenty-one compounds from the spirooxindole tetrahydropyran derivatives and related molecules were screened for inhibition of sterol O-acyltransferase (SOAT) isozymes SOAT1 and SOAT2...
December 15, 2016: Bioorganic & Medicinal Chemistry Letters
Mayuri A Borad, Manoj N Bhoi, Sanjay K Rathwa, Mahesh S Vasava, Hitesh D Patel, Chirag N Patel, Himanshu A Pandya, Edwin A Pithawala, John J Georrge
In the current investigation, we prepared a series of novel spiro[indole-thiazolidines] derivatives (5a-5h) from 5-substituted isatin derivatives and thioglycolic acid (TGA) with ZrSiO2 as an efficient catalyst under microwave irradiation. The significant merits of this protocol have some significant merits such as simplicity in operation, simple, efficient workup, good practical yields of product and the employment of recyclable catalyst. All the new synthesized scaffold has been well characterized by various spectroscopic methods and elemental analysis...
November 11, 2016: Interdisciplinary Sciences, Computational Life Sciences
Jian-Qiang Zhao, Deng-Feng Yue, Xiao-Mei Zhang, Xiao-Ying Xu, Wei-Cheng Yuan
The asymmetric Neber reaction of 3-O-sulfonyl ketoxime, in situ generated from isatin ketoxime and sulfonyl chloride, for the synthesis of chiral spirocyclic oxindole compounds is reported. With the developed protocol, a range of chiral spirooxindole 2H-azirines could be obtained in good to excellent yields and up to a 92 : 8 enantiomeric ratio by using (DHQD)2PHAL as the catalyst. This methodology is the only example of the catalytic asymmetric construction of spirooxindole 2H-azirine compounds.
November 7, 2016: Organic & Biomolecular Chemistry
Claudia Melis, Rita Meleddu, Andrea Angeli, Simona Distinto, Giulia Bianco, Clemente Capasso, Filippo Cottiglia, Rossella Angius, Claudiu T Supuran, Elias Maccioni
The isatin scaffold is the constitutive fragment of several natural and synthetic bioactive molecules. Albeit several benzene sulphonamide-based carbonic anhydrase inhibitors (CAIs) have been reported, only recently isatin benzene sulphonamides have been studied and proposed as CAIs. In this study we have designed, synthesised, and evaluated the biological activity of a series of differently substituted isatin-based benzene sulphonamides which have been designed for the inhibition of carbonic anhydrase isoforms...
October 24, 2016: Journal of Enzyme Inhibition and Medicinal Chemistry
Nadia G Kandile, Mansoura I Mohamed, Hind M Ismaeel
New compounds based on oxindole moiety were synthesized via the reaction of 5-substitued isatins 1a-e with different nucleophiles such as benzidine, 3,3'-dimethoxybenzidine 2a,b and 2,6-diaminopyridine 3 to afford three different classes of bis-Schiff bases 4a-e, 5a-e and 6a-e, respectively. The structures of the new compounds were elucidated on the basis of their FTIR, (1)H NMR, (13)C NMR, GC/MS spectral data and elemental analysis. The in vitro antimicrobial activity of the new compounds was evaluated using a broth dilution technique in terms of minimal inhibitory concentration (MIC) against four bacterial and two fungal pathogens and anticancer activities against HELA cervix...
October 21, 2016: Journal of Enzyme Inhibition and Medicinal Chemistry
Rita Meleddu, Simona Distinto, Angela Corona, Enzo Tramontano, Giulia Bianco, Claudia Melis, Filippo Cottiglia, Elias Maccioni
A series of 3-3-{2-[2-3-methyl-4-phenyl-2,3-dihydro-1,3-thiazol-2-ylidene]hydrazin-1-ylidene-2,3-dihydro-1H-indol-2-one derivatives has been designed and synthesized to study their activity on both HIV-1 (Human Immunodeficiency Virus type 1) RT (Reverse Transcriptase) associated functions. These derivatives are analogs of previously reported series whose biological activity and mode of action have been investigated. In this work we investigated the influence of the introduction of a methyl group in the position 3 of the dihydrothiazole ring and of a chlorine atom in the position 5 of the isatin nucleus...
October 21, 2016: Journal of Enzyme Inhibition and Medicinal Chemistry
Nagaraju Molleti, Jun Yong Kang
A highly efficient phospha-aldol reaction for the synthesis of α(1)-oxindole-α-hydroxyphosphonates is developed utilizing N-heterocyclic phosphine (NHP)-thiourea as a phosphonylation reagent under catalyst, additive free conditions. This methodology encompasses a variety of isatin derivatives to provide α(1)-oxindole- α-hydroxyphosphonates up to 99% yield.
September 26, 2016: Organic & Biomolecular Chemistry
Yunsheng Xue, Yuhui Wang, Zhongyan Cao, Jian Zhou, Zhao-Xu Chen
Density functional theory (DFT) calculations were performed to elucidate the mechanism and the origin of the high enantioselectivity of the aza-Henry reaction of isatin-derived N-Boc ketimine catalyzed by a quinine-derived catalyst (QN). The C-C bond formation step is found to be both the rate-determining and the stereo-controlled step. The results revealed the important role of the phenolic OH group in pre-organizing the complex of nitromethane and QN and stabilizing the in situ-generated nitronate and protonated QN...
October 12, 2016: Organic & Biomolecular Chemistry
Juanjuan Wang, Danfeng Huang, Ke-Hu Wang, Xiansha Peng, Yingpeng Su, Yulai Hu, Ying Fu
A convenient and efficient method for the constructions of 3-spirooxindole derivatives or 3,3'-disubstituted oxindoles has been developed from one-pot reactions of isatins, hydrazides or aromatic amines, 2-(bromomethyl)acrylic ester and tin powder in the presence of a catalytic amount of Brønsted or Lewis acid. The method avoids the use of toxic stannanes and allows easy operation. It is also proved that hydrazides are more favorable for intramolecular cyclization than amines.
October 12, 2016: Organic & Biomolecular Chemistry
James T Fleming, Corinne Wills, Paul G Waddell, Ross W Harrington, Lee J Higham
Six chiral MOP-phosphonites have been synthesised and compared via experimental and computational methods in an effort to quantify their differing structural and electronic profiles. They were found to be electron-poor ligands in comparison to their arylphosphine analogues and have a larger trans influence in square planar Pt(ii) complexes. Four [Rh(L(P))(η(2):η(2)-cod)Cl] complexes were synthesised and characterised by NMR, HRMS and X-ray crystallography. Two [Rh(L(P))2]BF4 complexes were prepared where one ligand acts as a chelating P,C-π-donor; detailed NMR studies demonstrated a hemilabile η(6)-coordination mode, which in one case was confirmed by X-ray crystallography...
October 4, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Andrea Nitti, Marco Signorile, Massimo Boiocchi, Gabriele Bianchi, Riccardo Po, Dario Pasini
We report on the design, synthesis and properties of innovative, planar, pi-conjugated compounds in which a thiophene ring is fused with the skeleton of the naturally-occurring dye isatin. The synthesis is achieved in high yields making use of an intramolecular Direct Arylation reaction as the key step, making the overall process potentially scalable. The synthetic sequence has been demonstrated also for an isatin bearing fluorine substituents on the aromatic ring. NMR and X-ray studies demonstrate the crosstalk occurring between the fused, coplanar and conjugated moieties, making these novel dyes with a Donor-Acceptor character...
October 6, 2016: Journal of Organic Chemistry
Jianfeng Xu, Shiru Yuan, Maozhong Miao, Zhengkai Chen
A 1-hydroxybenzotriazole (HOBt) assisted, N-heterocyclic carbene (NHC) catalyzed direct beta-functionalization of saturated carboxylic esters is disclosed. This formal [3+2] annulation reaction of carboxylic esters with isatins affords optically pure spirooxindole lactones (on gram scale) bearing two vicinal stereogenic centers. A dual role of HOBt is proposed based on controlled experiments to rationalize the enhancement of diastereoselectivity and enantioselectivity.
October 6, 2016: Journal of Organic Chemistry
Dinesh Kumar, Sandeep R Vemula, Narayanaganesh Balasubramanian, Gregory R Cook
Stereoselective indium-mediated organic reactions have enjoyed tremendous growth in the last 25 years. This is in part due to the insensitivity of allylindium to moisture, affording facile and practical reaction conditions coupled with outstanding functional group tolerance and minimal side reactions. Despite the plethora of articles about allylindium, there is much yet to be discovered and exploited for efficient and sustainable synthesis. In this Account, we describe indium-mediated synthetic methods for the preparation of chiral amines with the aim to present a balance of practical method development, novel asymmetric chemistry, and mechanistic understanding that impact multiple chemical and materials science disciplines...
October 4, 2016: Accounts of Chemical Research
Rong Zeng, Peng-Hao Chen, Guangbin Dong
The first decarbonylative cycloaddition of less-strained cyclic ketones (isatins) with isocyanates is reported. Initiated by C-C activation, this distinct [5-2+2] transformation provides a rapid entry to access various benzimidazolidinone derivatives, through which a wide range of isocyanates can be efficiently coupled with broad functional group tolerance. A modified one-pot process, combining Curtius rearrangement and C-C activation, was also achieved by using acyl azides as the starting materials. Detailed mechanistic study revealed a surprising double-decarbonylative reaction pathway...
February 5, 2016: ACS Catalysis
Atulya Nagarsenkar, Lalita Guntuku, Sravanthi Devi Guggilapu, Danthi Bai K, Srinivasulu Gannoju, V G M Naidu, Nagendra Babu Bathini
In our venture towards the development of effective cytotoxic agents, a panel of triazole linked 3-benzylidene isatin hybrids were synthesized and characterized by IR, (1)H NMR, (13)C NMR and Mass spectral analysis. All the newly synthesized target compounds were assessed against DU145 (prostate), PC-3 (prostate), MDA-MB-231 (breast), BT549 (breast), A549 (lung) and HeLa (cervical) human cancer cell lines by employing MTT assay for their cytotoxic potential. Significantly, compound Z-8l was found to be most potent amongst all the tested compounds with an IC50 value of (3...
September 4, 2016: European Journal of Medicinal Chemistry
Christopher Foley, Arthur Shaw, Christopher Hulme
Two-step methodology described herein showcases the first example of an oxidation/oxidative amidation cyclization cascade of MCR products toward diverse N-functionalized isatins. Products of both the Ugi 3CR and the Ugi azide reactions are oxidatively cyclized through a postcondensation process utilizing selenium dioxide. This methodology was found to be applicable for the generation of bis-peptidomimetic-like isatins containing multiple points of diversification.
October 7, 2016: Organic Letters
Hong-Yu Wang, Chang-Wu Zheng, Zhuo Chai, Jia-Xing Zhang, Gang Zhao
Over the past few decades, enantioselective phosphine organocatalysis has evolved rapidly into a highly efficient catalytic strategy for a range of useful reactions. However, as restricted by the traditional catalytic modes, some important reactions, such as asymmetric Strecker-type reactions, have thus far been out of reach of this strategy. Reported herein is an application of enantioselective phosphine organocatalysis for asymmetric Strecker-type reactions, enabled by a dual-reagent catalyst system in which the key organophosphorus zwitterion intermediate, generated in situ by mixing a chiral dipeptide-derived multifunctional organophosphine with methyl acrylate, is used as a highly efficient chiral Lewis base catalyst...
2016: Nature Communications
Bochra Tourki, Philippe Matéo, Jessica Morand, Mohamed Elayeb, Diane Godin-Ribuot, Naziha Marrakchi, Elise Belaidi, Erij Messadi
Cardiac ischemia is one of the leading causes of death worldwide. It is now well established that natriuretic peptides can attenuate the development of irreversible ischemic injury during myocardial infarction. Lebetin 2 (L2) is a new discovered peptide isolated from Macrovipera lebetina venom with structural similarity to B-type natriuretic peptide (BNP). Our objectives were to define the acute cardioprotective actions of L2 in isolated Langendorff-perfused rat hearts after regional or global ischemia-reperfusion (IR)...
2016: PloS One
Guangcheng Wang, Jing Wang, Dianxiong He, Xin Li, Juan Li, Zhiyun Peng
This study synthesized a series of novel coumarin-isatin derivatives and evaluated them for α-glucosidase inhibitory activity. The majority of the screened compounds exhibited excellent inhibition activities with IC50 values of 2.56 ± 0.08-268.79 ± 3.04 μm, when compared to acarbose. Among the newly derivatives, compound 5p was found to be the most active compound in the library of coumarin-isatin derivatives. Furthermore, enzyme kinetic studies showed that compound 5p is a non-competitive inhibitor with a Ki of 2...
September 12, 2016: Chemical Biology & Drug Design
G Rainoldi, M Faltracco, L Lo Presti, A Silvani, G Lesma
A diastereoselective, DABCO-catalyzed reaction of isatin-derived ketimines with allenoates is described. Exploiting the stereodirecting effect of the bulky tert-butanesulfinyl chiral auxiliary, the method provides an efficient access to single diastereoisomers of unprecedented spirocyclic oxindoles, bearing a 4-methyleneazetidine ring at the spiro junction. The versatility of the method is fully demonstrated by further transformations including the conversion to relevant spirocyclic oxindolo-β-lactams.
October 4, 2016: Chemical Communications: Chem Comm
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