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Ying-Chun Chen, Gu Zhan, Ming-Lin Shi, Wei-Jia Lin, Yang Ouyang, Wei Du
Nitrones commonly act as 1,3-dipoles and electrophiles to furnish valuable isoxazolidine and N-hydroxyl products, respectively. They also can be converted to nitrone ylide species, and undergo [3+2] formal cycloadditions to access N-hydroxyl pyrrolidines. Here we first present asymmetric direct aza-vinylogous-type additions of nitrones from isatins to nitroalkenes catalyzed by a bifunctional thiourea-tertiary amine, producing highly functionalized nitrones with extended carbon skeletons in excellent stereoselectivity...
March 23, 2017: Chemistry: a European Journal
A E Medvedev, O A Buneeva, A T Kopylov, O V Tikhonova, M V Medvedeva, L N Nerobkova, I G Kapitsa, V G Zgoda
Mitochondria play an important role in molecular mechanisms of neuroplasticity, adaptive changes of the brain that occur in the structure and function of its cells in response to altered physiological conditions or development of pathological disorders. Mitochondria are a crucial target for actions of neurotoxins, causing symptoms of Parkinson's disease in various experimental animal models, and also neuroprotectors. Good evidence exists in the literature that mitochondrial dysfunction induced by the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) influences functioning of the ubiquitin-proteasomal system (UPS) responsible for selective proteolytic degradation of proteins from various intracellular compartments (including mitochondria), and neuroprotective effects of certain antiparkinsonian agents (monoamine oxidase inhibitors) may be associated with their effects on UPS...
March 2017: Biochemistry. Biokhimii︠a︡
Christian Paul Ortmeyer, Günter Haufe, Katrin Schwegmann, Sven Hermann, Michael Schäfers, Frederik Börgel, Bernhard Wünsch, Stefan Wagner, Verena Hugenberg
BODIPYs (boron dipyrromethenes) are fluorescent dyes which show high stability and quantum yields. They feature the possibility of selective (18)F-fluorination at the boron-core. Attached to a bioactive molecule and labeled with [(18)F]fluorine, the resulting compounds are promising tracers for multimodal imaging in vivo and can be used for PET and fluorescence imaging. A BODIPY containing a phenyl and a hydroxy substituent on boron was synthesized and characterized. Fluorinated and hydroxy substituted dyes were coupled to an isatin-based caspase inhibitor via cycloaddition and the resulting compounds were evaluated in vitro in caspase inhibition assays...
February 16, 2017: Bioorganic & Medicinal Chemistry
Chao-Ming Wang, Peng-Ju Xia, Jun-An Xiao, Jun Li, Hao-Yue Xiang, Xiao-Qing Chen, Hua Yang
Reductive dimerization of isatin and its derivatives can be regarded as a step-economical pathway to construct 3,3'-disubstituted bisoxindoles, which was unfortunately accompanied with severe direct reduction as well as low efficiency. A visible-light driven, photoredox-catalytic protocol was developed to readily furnish 3,3'-dihydroxy- (dl-, >20:1 dr) and 3,3'-diamino-bisoxindoles (meso-, 3.5:1 to 5:1 dr) in moderate to good yields, successfully circumventing the common problem. Two vicinal quaternary carbon centers were effectively assembled under the irradiation of visible light...
March 10, 2017: Journal of Organic Chemistry
Jianfeng Xu, Shiru Yuan, Jingyi Peng, Maozhong Miao, Zhengkai Chen, Hongjun Ren
An asymmetric [2+2] annulation reaction through direct α-carbon functionalization of simple aldehydes via oxidative N-heterocyclic carbene catalysis is disclosed. These in situ generated triazolium enolate intermediates undergo a highly stereoselective Mannich reaction with isatin-derived ketimines followed by intramolecular lactamization to afford enantioenriched spirooxindole β-lactams bearing two vicinal stereogenic centers.
March 9, 2017: Chemical Communications: Chem Comm
Negar Lashgari, Alireza Badiei, Ghodsi Mohammadi Ziarani, Farnoush Faridbod
A highly ordered mesoporous silica material functionalized with isatin (SBA-Pr-IS) was designed and synthesized. Characterization techniques including XRD, TGA, BET, SEM, and FT-IR were employed to characterize the pore structure, textural properties, microscopic morphology, and molecular composition of grafted organic moieties of SBA-Pr-IS. The successful attachment of the organic moiety (0.34 mmol g(-1)) without the SBA-15 structure collapsing after the modification steps was confirmed. Fluorescence characterization of SBA-Pr-IS was examined upon addition of a wide variety of cations in aqueous medium and it showed high sensitivity toward Hg(2+) ions...
March 7, 2017: Analytical and Bioanalytical Chemistry
Shailendra K Singh, Nisha Chandna, Nidhi Jain
An efficient and facile method to synthesize N-Mannich bases has been developed using an inexpensive copper(I) bromide/air catalyst system at ambient temperature. A cross-dehydrogenative coupling of N,N-dimethylarylamines occurs efficiently with aromatic heterocyclic amides (oxindoles, isatins), cyclic amides (lactams), simple amides (benzamide), as well as imides (succinimide, phthalimide) to furnish the corresponding amidated/imidated derivatives in good to excellent yields. Preliminary mechanistic and isotope-labeling studies suggest the reaction follows a radical pathway and involves an iminium ion intermediate...
March 1, 2017: Organic Letters
Huwaida M E Hassaneen, Elshimaa M Eid, Hamid A Eid, Thoraya A Farghaly, Yahia Nasser Mabkhot
This article presents the synthesis of new derivatives of spirooxindole-spiropiperidinone- pyrrolidines 6a-j and spirooxindole-spiropiperidinone-pyrrolizines 8a-j, through a 1,3-dipolar cycloaddition reaction of azomethineylides generated from isatin, sarcosine, and l-proline, through a decarboxylative route with dipolarophile 4a-j. All of the newly synthesized compounds were evaluated for their antimicrobial activities and their minimum inhibitory concentration (MIC) against most of the test organisms. The tested compounds displayed excellent activity against all of the tested microorganisms...
February 26, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Xiangbin Bai, Guangkuo Zeng, Tianju Shao, Zhiyong Jiang
Reported herein is the first example of 2-allylazaarenes in asymmetric catalysis. Highly γ-selective allylation was demonstrated for activated ketones, including isatins and trifluoromethyl ketones. In the presence of either an amino-acid-based tertiary amine or quaternary ammonium salt catalyst, two series of tertiary hydroxy-containing moieties were installed at the remote δ-position of azaarenes in good chemical yields, excellent enantioselectivities, and E/Z ratios. The success of current γ-selective reactions should provide inspiration for expansion to other allylazaarene derivatives and would open up new paradigms for the synthesis of chiral γ- and/or δ-functionalized azaarenes...
February 27, 2017: Angewandte Chemie
Wengang Guo, Yan Liu, Can Li
The first enantioselective catalytic 1,2-hydroperoxidation has been achieved in the presence of PEG-600 using an acid-base bifunctional chiral squaramide as the organocatalyst, affording a range of enantioenriched α-N-substituted hydroperoxides bearing an oxindole moiety with excellent stereoselectivities (up to 99% ee).
February 23, 2017: Organic Letters
Deng Yin, Hui Liu, Chong-Dao Lu, Yan-Jun Xu
Efficient cyclopropanation of α,β-unsaturated ketones using α-ketoesters or isatin derivatives is reported. The cyclopropanation reaction occurs via a cascade transformation that starts with addition of deprotonated dialkyl phosphite to the keto groups of α-ketoesters or isatin derivatives, followed by [1,2]-phosphonate/phosphate rearrangement to generate α-phosphonyloxyenolate intermediates, which are trapped by α,β-unsaturated ketones via Michael addition/ring closure. This protocol was used to synthesize tetra-substituted cyclopropanes with a 1,2-cis-1,3-trans configuration in high yield with excellent diastereoselectivity...
March 2, 2017: Journal of Organic Chemistry
Chaoqun Ma, Jianghui Chen, Dong Xing, Yuan Sheng, Wenhao Hu
An iron catalyzed three-component reaction of alkyl diazoesters, isatins and ammonia is reported. This reaction provided convenient access to non-protected β-hydroxy-α-aminoesters with adjacent quaternary stereocenters. This transformation is achieved via trapping of ammonium ylide which is generated from a diazocompound and ammonia under mild reaction conditions. Poly-functional group unprotected amines are obtained exclusively with up to 77% yield and 62 : 38 dr.
February 20, 2017: Chemical Communications: Chem Comm
Jecika Maciel Velasques, Vanessa Carratu Gervini, Adaílton João Bortoluzzi, Renan Lira de Farias, Adriano Bof de Oliveira
The reaction between 5-nitro-isatin and phenyl-hydrazine in acidic ethanol yields the title compound, C14H10N4O3, whose mol-ecular structure deviates slightly from a planar geometry (r.m.s. deviation = 0.065 Å for the mean plane through all non-H atoms). An intra-molecular N-H⋯O hydrogen bond is present, forming a ring of graph-set motif S(6). In the crystal, mol-ecules are linked by N-H⋯O and C-H⋯O hydrogen-bonding inter-actions into a two-dimensional network along (120), and rings of graph-set motif R2(2)(8), R2(2)(26) and R4(4)(32) are observed...
February 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
Subrata Mukherjee, Sumi Joseph, Anup Bhunia, Rajesh G Gonnade, Santhivardhana Reddy Yetra, Akkattu T Biju
The N-heterocyclic carbene (NHC)-catalyzed enantioselective formal [3 + 2] annulation of α,β-unsaturated aldehydes with 3-hydroxy oxindoles is presented. Under oxidative conditions using the bisquinone oxidant, the reaction resulted in the synthesis of spiro γ-butyrolactones in moderate to good yields, enantioselectivity and diastereoselectivity. The reaction likely proceeds via the generation of the NHC-bound α,β-unsaturated acylazolium intermediate from enals, which was intercepted by the dioxindoles in a formal [3 + 2] pathway to form the spirocyclic compounds...
February 15, 2017: Organic & Biomolecular Chemistry
Wagdy M Eldehna, Hadia Almahli, Ghada H Al-Ansary, Hazem A Ghabbour, Mohamed H Aly, Omnia E Ismael, Abdullah Al-Dhfyan, Hatem A Abdel-Aziz
Treatment of patients with triple-negative breast cancer (TNBC) is challenging due to the absence of well- defined molecular targets and the heterogeneity of such disease. In our endeavor to develop potent isatin-based anti-proliferative agents, we utilized the hybrid-pharmacophore approach to synthesize three series of novel isatin-based hybrids 5a-h, 10a-h and 13a-c, with the prime goal of developing potent anti-proliferative agents toward TNBC MDA-MB-231 cell line. In particular, compounds 5e and 10g were the most active hybrids against MDA-MB-231 cells (IC50 = 12...
December 2017: Journal of Enzyme Inhibition and Medicinal Chemistry
Titiksh L Devale, Jignesh Parikh, Pankaj Miniyar, Pankaj Sharma, Birendra Shrivastava, Prashant Murumkar
A novel series of substituted N-(2-(2,3-dioxoindolin-1-yl)acetyl)-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxamide was designed, synthesized and evaluated for in vitro Reverse Transcriptase (RT) inhibitory activity. This series is a combination of peculiar structural features from leading scaffolds of [(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine (HEPT) and oxyindole. In vitro screening led to identification of two hybrids (9c and 9d) possessing higher RT inhibitory activity than the standard rilpivirine...
January 18, 2017: Bioorganic Chemistry
Moustafa T Gabr, Nadia S El-Gohary, Eman R El-Bendary, Mohamed M El-Kerdawy, Nanting Ni
A new series of isatin-β-thiocarbohydrazones was synthesized based on the pharmacophoric features of triapine required for metal chelation. Our strategy involved the modifications of triapine basic skeleton by replacing pyridinyl moiety with isatin which retains the tridentate feature of triapine needed for metal chelation. The new compounds were esteemed for their antitumor efficacy against cervical cancer (Hela) and kidney fibroblast cancer (COS-7) cell lines. Compounds 4c, 4d, 5c and 5e exhibited remarkable efficacy against Hela cell line...
January 23, 2017: European Journal of Medicinal Chemistry
Gehad Lotfy, Mohamed M Said, El Sayed H El Ashry, El Sayed H El Tamany, Abdullah Al-Dhfyan, Yasmine M Abdel Aziz, Assem Barakat
The 1,3-dipolar cycloadditions of an azomethine ylide generated from isatin and thiazolidinecarboxylic acid to a series of 2,6-bis[(E)-arylmethylidene]cyclohexanones afforded new di-spiro heterocycles incorporating pyrrolidine and oxindole rings in quantitative yields and chemo-, regio-, and stereoselectively. The newly synthesized compounds were characterized using spectroscopic techniques. Furthermore, the molecular structures of 4a, 4e, and 4n were confirmed by X-ray crystallography. These newly synthesized compounds were screened for their in vitro activity against breast cancer cell line MCF-7 and K562-leukemia...
January 16, 2017: Bioorganic & Medicinal Chemistry
Xiao Wang, Peng Yang, Yong Zhang, Chao-Zhe Tang, Fang Tian, Lin Peng, Li-Xin Wang
A new isatin N,N'-cyclic azomethine imine synthon was devised, and an unexpected abnormal [3 + 2]-cycloaddition with maleimide catalyzed by 1,4-diazabicyclo[2.2.2]octane (DABCO) has been disclosed. A variety of tricyclic spiropyrrolidine oxindoles bearing a dinitrogen heterocycle and succinimide scaffold were obtained in excellent yields (up to 96%) and diastereoselectivities (up to 97:3) under mild conditions.
January 23, 2017: Organic Letters
Jing Sun, Guo-Liang Shen, Ying Huang, Chao-Guo Yan
The triethylamine promoted three-component reaction of N-(4-nitrobenzyl), N-ethoxycarbonylmethylisoquinolinium bromide, isatins and malononitrile in ethanol afforded spiro[indoline-3,2'-pyrrolo[2,1-a]isoquinolines] in good yields and with high diastereoselectivity. The similar reaction of N-cyanomethylisoquinolinium chloride mainly gave complex indolo[2″,3″:2',3']pyrrolo[3',4':4,5]pyrrolo[2,1-a]isoquinoline derivatives. However, the three-component reaction of N-cyanomethylisoquinolinium chloride, isatins and ethyl cyanoacetate mainly resulted in functionalized spiro[indoline-3,8'-pyrido[2',3':4,5]pyrrolo[2,1-a]isoquinolines]...
January 20, 2017: Scientific Reports
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