- KuQuinones as sensitizers for NiO based p-type dye-sensitized solar cells
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A new series of KuQuinones (KuQs) have been synthesized and employed as dye-sensitizers for NiO-based p-type dye-sensitized solar cells (p-DSSCs). KuQs are pentacyclic quinoid compounds which are characterized by a fully conjugated structure that is responsible for the strong and broad absorption in the visible spectrum. The HOMO/LUMO states of KuQs considered here have matching energy levels with the upper edge of the NiO valence band and I?/I3? redox potential energy. These features render such compounds suitable for NiO sensitization in p-DSSCs. The new carboxylic acid-substituted KuQ derivatives proposed here differ in the length of the alkyl chain. The JV characteristic curves and the external quantum efficiency spectra have been recorded. The results showed that the performances of KuQ-sensitized cells were similar to that of the benchmark sensitizer erythrosine B (Ery B), despite the lack of electronic conjugation between the anchoring group and the light absorbing unit. This result led us to hypothesize that the photoinduced charge transfer between the excited KuQ dyes and the NiO electrode occurred through space and not via chemical bonds as it usually occurs in these systems. The mechanism of charge transfer through space has been supported by data from IR spectroscopy.
- Bonomo, Matteo,Sabuzi, Federica,Di Carlo, Aldo,Conte, Valeria,Dini, Danilo,Galloni, Pierluca
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- Antiproliferative and antimigratory actions of synthetic long chain n-3 monounsaturated fatty acids in breast cancer cells that overexpress cyclooxygenase-2
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Cyclooxygenase-2 (COX-2) is overexpressed in many human cancers and converts the n-6 polyunsaturated fatty acid (PUFA) arachidonic acid to prostaglandin E2 (PGE2), which drives tumorigenesis; in contrast, n-3 PUFA inhibit tumorigenesis. We tested the hypothesis that these antitumor actions of n-3 PUFA may involve the n-3 olefinic bond. n-3 Monounsaturated fatty acids (MUFAs) of chain length C16-C22 were synthesized and evaluated in MDA-MB-468 breast cancer cells that stably overexpressed COX-2 (MDA-COX-2 cells). Longer chain (C19-C22) n-3 MUFAs inhibited proliferation, activated apoptosis, decreased PGE2 formation, and decreased cell invasion; C16-C18 analogues were less active. Molecular modeling showed that interactions of Arg120, Tyr355, and several hydrophobic amino acid residues in the COX-2 active site with C19-C22 MUFA analogues were favored. Thus, longer-chain n-3 MUFAs may be prototypes of novel anticancer agents that decrease the formation of PGE2 in tumor cells that contain high levels of COX-2.
- Cui, Pei H.,Kirsi Bourget, Tristan Rawing,Kim, Terry,Duke, Colin C.,Doddareddy, Munikumar R.,Hibbs, David E.,Zhou, Fanfan,Tattam, Bruce N.,Petrovic, Nenad,Murray, Michael
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- Intramolecular Photocycloadditions of 1-(ω-Alkenyl)-2-pyridones Possessing an Ester Group on the Olefinic Carbon Chain
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Photochemical reactions of three kinds of 1-(ω-alkenyl)-2-pyridones 1-8 were investigated.Photosensitized cyloadditions of 1-(ω-alkenyl)-2-pyridones and 1,3-bis(ω-alkenyl)-2-pyridone 2-6 afforded intramolecular cycloadducts across the 5,6-bonds of the 2-pyridones to give the tricyclic lactams 14-18: the additions were site-, regio-, and stereospecific.The yields of the adducts diminished in proportion to increased side-chain length.The one possessing the shortest alkenyl group, 1, and the 1--2-pyridones 7 and 8, however, gave no products.On the other hand, direct irradiation of 3 afforded a bicyclic lactam 19.The intramolecular cycloaddition mechanism was discussed in terms of the excited state of 2-pyridone, as calculated by MNDO-CI method.
- Somekawa, Kenichi,Okuhira, Hiroyuki,Sendayama, Masayuki,Suishu, Takaaki,Shimo, Tetsuro
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- Straightforward Synthesis of Fluorinated Enals via Photocatalytic α-Perfluoroalkenylation of Aldehydes
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(Per)fluorinated substances represent an important compound class with regard to drug design and material chemistry. We found a mild, operationally simple, and inexpensive photocatalytic perfluoroalkenylation reaction giving tetrasubstituted, highly electron-deficient enals straight from aldehydes. This one-step reaction tolerates various functional groups and can be applied to a wide range of substrates giving the products in yields of 52-84%.
- Wulkesch, Christian,Czekelius, Constantin
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p. 7425 - 7438
(2021/06/21)
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- Palladium-catalyzed C(sp3)–P(III) bond formation reaction with acylphosphines as phosphorus source
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Palladium-catalyzed C(sp3)–P(III) bond formation reaction for alkyl substituted phosphines preparation was developed. In this reaction, various alkyl bromides and limited alkyl chlorides reacted with acylphosphine under relative mild and easily accessible condition, and differential phosphines were afforded in good yields. This reaction made up the application of palladium catalysis in C(sp3)–P(III) bond formation, and indicated a practical application of acylphosphine as a phosphination reagent.
- Zhang, Mengyue,Ma, Zhichao,Du, Hongguang,Wang, Zhiqian
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supporting information
(2020/06/29)
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- Labeled isocyanato-contained fatty acid derivatives and application thereof
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The invention relates to labeled isocyanato-contained fatty acid derivatives and an application thereof. A general formula of the derivatives is represented by a formula I shown in the specification,wherein M is labeled technetium (Tc) or rhenium (Re); R, R1, R2, R3, R4 and R5 are H, aliphatic chains or alicyclic chains, and the above five groups are completely the same, completely differentor partially the same; z is an integer of 1 to 6, p is 0 or 1, and n is a positive integer of 1 to 28; and t is an integer of 0 to 5, and a is an integer of 0 to 5. The invention provides a completely novel structure type, and the derivatives have a lower liver background, lung background and kidney background, but have long residence time and a high retention rate in myocardium, can be used as anovel myocardial metabolism imaging agent, and have important clinical application prospects.
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Paragraph 0098; 0101; 0103
(2020/02/14)
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- Synthesis and Characterization of Novel Acyl-Glycine Inhibitors of GlyT2
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It has been demonstrated previously that the endogenous compound N-arachidonyl-glycine inhibits the glycine transporter GlyT2, stimulates glycinergic neurotransmission, and provides analgesia in animal models of neuropathic and inflammatory pain. However, it is a relatively weak inhibitor with an IC50 of 9 μM and is subject to oxidation via cyclooxygenase, limiting its therapeutic value. In this paper we describe the synthesis and testing of a novel series of monounsaturated C18 and C16 acyl-glycine molecules as inhibitors of the glycine transporter GlyT2. We demonstrate that they are up to 28 fold more potent that N-arachidonyl-glycine with no activity at the closely related GlyT1 transporter at concentrations up to 30 μM. This novel class of compounds show considerable promise as a first generation of GlyT2 transport inhibitors.
- Mostyn, Shannon N.,Carland, Jane E.,Shimmon, Susan,Ryan, Renae M.,Rawling, Tristan,Vandenberg, Robert J.
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p. 1949 - 1959
(2017/09/26)
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- The value of 2JP–CO as a diagnostic parameter for the structure and thermal reactivity of carbonyl-stabilised phosphonium ylides
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A survey of 20 carbonyl-stabilised phosphonium ylides with recently reported X-ray structures shows a strong correlation between the C[dbnd]P to C[dbnd]O torsion angle and the value of 2JP–CO, with high values being associated with an anti configuration and low with syn. Seven new X-ray structural determinations are reported, several for types of ylide not crystallographically characterised before, and these also conform to this pattern. The value of 2JP–CO is then correlated with whether or not thermal extrusion of Ph3PO occurs to give alkynes for over 200 ylides and an empirical rule developed that the extrusion never occurs for ylides where this value is > 11 Hz. This is used to rationalise the anomalous behaviour of some trioxo ylides and cyclic ylides, two of which afford cycloalkynes, isolated after rearrangement as the isomeric 1,3-dienes. The rule also holds for a family of novel highly fluorinated ylides which afford fluorinated alkynes in good yield upon flash vacuum pyrolysis.
- Aitken, R. Alan,Boubalouta, Youcef,Chang, Da,Cleghorn, Lee P.,Gray, Ian P.,Karodia, Nazira,Reid, Euan J.,Slawin, Alexandra M.Z.
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p. 6275 - 6285
(2017/09/29)
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- Synthesis of 7-triazole-substituted camptothecin via click chemistry and evaluation of in vitro antitumor activity
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Camptothecin (CPT) is a natural topoisomerase I inhibitor with powerful antineoplastic activity against colorectal, breast, lung and ovarian cancers. To discover more potent antitumor agents, a series of new CPT derivatives were synthesized utilizing click chemistry. All compounds were assessed for cytotoxicity against A549, HCT-116, HT-29, LoVo, MDA-MB-231 cell lines, and some compounds exhibited good in vitro potency. Furthermore, all compounds kept or enhanced Topo I inhibition. A series of novel 7-triazole substituted camptothecin via click chemistry was designed, synthesized, and evaluated for their in vitro antitumor activity. Copyright
- Wang, Lei,Yuan, Wei,Zhang, Jie,Tong, Linjiang,Luo, Yu,Chen, Yi,Lu, Wei,Huang, Qingqing
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p. 157 - 162
(2014/03/21)
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- Synthesis and biological evaluation of new quinoxaline derivatives of ICF01012 as melanoma-targeting probes
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The aim of this study was the synthesis and pharmacokinetic selection of a best melanin-targeting ligand for addressing anticancer agents to pigmented melanoma. Seven quinoxaline carboxamide derivatives were synthesized and radiolabeled with iodine-125. Biodistribution studies of compounds [ 125I]1a-g performed in melanoma-bearing mice tumor showed significant tumor uptake (range 2.43-5.68%ID/g) within 1 h after i.v. injection. Fast clearance of the radioactivity from the nontarget organs mainly via the urinary system gave high tumor-to-blood and tumor-to-muscle ratios. Given its favorable clearance and high tumor-melanoma uptake at 72 h, amide 1d was the most promising melanoma-targeting ligand in this series. Compound 1d will be used as building block for the design of new melanoma-selective drug delivery systems.
- El Aissi, Radhia,Liu, Jianrong,Besse, Sophie,Canitrot, Damien,Chavignon, Olivier,Chezal, Jean-Michel,Miot-Noirault, Elisabeth,Moreau, Emmanuel
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supporting information
p. 468 - 473
(2014/06/09)
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- In situ phosphine oxide reduction: A catalytic appel reaction
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Several important reactions in organic chemistry thrive on stoichiometric formation of phosphine oxides from phosphines. To avoid the resulting burden of waste and purification, cyclic phosphine oxides were evaluated for new catalytic reactions based on in situ regeneration. First, the ease of silane-mediated reduction of a range of cyclic phosphine oxides was explored. In addition, the compatibility of silanes with electrophilic halogen donors was determined for application in a catalytic Appel reaction based on in situ reduction of dibenzophosphole oxide. Under optimized conditions, alcohols were effectively converted to bromides or chlorides, thereby showing the relevance of new catalyst development and paving the way for broader application of organophosphorus catalysis by in situ reduction protocols. Copyright
- Van Kalkeren, Henri A.,Leenders, Stefan H. A. M.,Hommersom, C. Rianne A.,Rutjes, Floris P. J. T.,Van Delft, Floris L.
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supporting information; experimental part
p. 11290 - 11295
(2011/10/19)
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- A mild, phosphine-free method for the conversion of alcohols into halides (Cl, Br, I) via the corresponding O-alkyl isoureas
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A novel procedure for the conversion of primary and secondary alcohols into the corresponding alkyl chlorides, bromides and iodides is described. The transformation is high-yielding in the case of chlorides and bromides, tolerates a range of functional groups, and does not rely on the use of phosphines.
- Li, Zhengning,Crosignani, Stefano,Linclau, Bruno
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p. 8143 - 8147
(2007/10/03)
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- Esterification of carboxylic acids with boron trichloride
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Treatment of carboxylic acids with boron trichloride followed by addition of alcohol provides the carboxylic ester. This esterification, following BCl3 ether or ester O-C cleavage reaction conditions, proceeds cleanly in good yields with most substrates. Cleavage of benzyl esters with boron trichloride then treating with methanol affords the methyl ester.
- Dyke, Christopher A.,Bryson, Thomas A.
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p. 3959 - 3961
(2007/10/03)
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- Diesters of carbonic acid endowed with antiviral and anti-inflammatory activity
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Diesters of carbonic acid disubstituted with primary, secondary or tertiary amine groups, pharmaceutically acceptable salts thereof, and their use as antiviral and inti-inflammatory agents.
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- FUNCTIONAL GROUP-TOLERANT HYDROALKYLATION OF ELECTRON-DEFICIENT OLEFINS THROUGH COPPER(I)-CATALYZED PHOTOADDITION OF ORGANIC HALIDES FOLLOWED BY REDUCTION WITH ZINC
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A method of accomplishing hydroalkylation of electron-deficient olefins which tolerates a variety of functional groups, in which organic halides and electron-deficient olefins are subjected to a photoreaction catalyzed by the CuBr-Bun3P complex followed by treatment with Zn dust in the presence of AcOH, has been developed.
- Mitani, Michiharu,Hirayama, Hiroyuki
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p. 1562 - 1572
(2007/10/02)
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- Synthesis of (+/-)-11-Hydroxy-trans-8-dodecenoic Acid
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(+/-)-11-Hydroxy-trans-8-dodecenoic acid (2), an intermediate for the synthesis of recifeiolide, has been prepared starting from caprolactone and 1,3-butanediol.
- Bhide, K. S.,Sharma, G. V. M.
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p. 1081 - 1083
(2007/10/02)
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- Enamines and iminium salts from amino-acids
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Distillation of ω-carboxyalkyl lactams from soda-lime leads to the formation of bicyclic enamines or imines with concomitant loss of carbon dioxide and water.Monoamides of dicarboxylic acids afford cyclic ketones.A mechanistic rationale is presented and it is concluded that the reaction is a variant of the classical Ruzicka cyclization of dicarboxylic acids.The method allows the regiospecific formation of iminium salts of bicyclic nitrogen heterocycles.
- McHintosh, John M.,Pillon, Lilianna Z.,Acquaah, Samuel O.,Green, James R.,White, Graham S.
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p. 2016 - 2021
(2007/10/02)
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- Alkyl alkanoate derivatives of substituted piperazine-diones and polymer compositions stabilized thereby
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Alkyl alkanoate derivatives of substituted piperazinediones are stabilizers for synthetic polymeric materials normally subject to deterioration caused by ultraviolet light. The compounds may be formed by reacting a substituted piperazinedione with an acrylate or a crotonate, or reacting the alkali or alkaline earth salt of a substituted piperazine dione with a haloalkanoate. Polymeric compositions containing these stabilizers may also contain a hindered phenolic compound. A typical embodiment is n-octadecyl-β-(15{7,15-diazadispiro[5,1,5,3]hexadecane-14,16-dione}propionate.
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