- Reductive heck reactions of N-methyl-substituted tricyclic imides
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The palladium-catalyzed hydroarylation of N-methyl-substituted tricyclic imides was studied in order to find a new stereoselective access to a series of new exoaryl(hetaryl)-substituted tricyclic N-methylimides.
- Goksu, Gokce,Ocal, Nuket,Kaufmann, Dieter E.
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- Comparison of facially amphiphilic versus segregated monomers in the design of antibacterial copolymers
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A direct comparison of two strategies for designing antimicrobial polymers is presented. Previously, we published several reports on the use of facially amphiphilic (FA) monomers which led to polynorbornenes with excellent antimicrobial activities and sel
- Gabriel, Gregory J.,Maegerlein, Janet A.,Nelson, Christopher F.,Dabkowski, Jeffrey M.,Eren, Tarik,Nuesslein, Klaus,Tew, Gregory N.
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- Substituent effects on the reversibility of furan - Maleimide cycloadditions
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The effects of furan and maleimide substitution on the dynamic reversibility of their Diels - Alder reactivity have been investigated computationally and by 1H NMR spectroscopy. Furan and furan derivatives bearing methoxy, methyl, or formyl groups at their 2- or 3-positions were investigated with maleimide and maleimide derivatives bearing N-methyl, N-allyl, and N-phenyl substituents. Computational predictions indicate that electronic and regiochemical effects of furan substitution significantly influence their Diels - Alder reactivity with maleimide, with reaction free energies of exo adduct formation ranging from ΔG = - 9.4 to 0.9 kcal/mol and transition state barriers to exo adduct formation ranging from ΔG? = 18.9 to 25.6 kcal/mol. Much less variation was observed for the reactivity of N-substituted maleimide derivatives and furan, with reaction and transition state free energies each falling within a range of 1.1 kcal/mol. Dynamic exchange experiments monitored by 1H NMR spectroscopy support computational predictions. The results indicate the reactivity and reversibility of furan - maleimide cycloadditions can be tuned significantly through the addition of appropriate substituents and have implications in the use of furan and maleimide derivatives in the construction of thermally responsive organic materials.
- Boutelle, Robert C.,Northrop, Brian H.
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- Unusual Stability of N-Methylmaleimide Cycloadducts: Characterization of Isobenzofuran Retro-Diels-Alder Reactions
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Many years ago Diels and Thiele noted the unusual stability of maleic anhydride cycloadducts and employed this feature in scavenging anthracene generated in a retro- reaction.N-methylmaleimide, although nearly identical to maleic anhydride in rates of Diels-Alder reactions, forms even more stable cycloadducts.The rate constants for the four reactions that characterize the furan/N-methylmaleimide system were measured under the conditions used by Lee and Herndon to study the furan/maleic anhydride system.Comparison of the two dienophiles indicates thatN-methylmaleimide adducts are ca. 3 kcal*mol-1 more stable than the corresponding exo- and endo-maleic anhydride adducts.Somewhat larger (ca. 4 +/- 0.5 kcal*mol-1) differences in stability were found for the cycloadducts of the much more reactive diene isobenzofuran.N-Methylmaleimide is used as a diene scavenger to obtain rate constants for retro-Diels-Alder reactions of isobenzofuran adducts with maleic anhydride and some substituted analogs.The rates of retro-Diels-Alder reactions of substituted N-methylmaleimide adducts were also determined by an alternative method.The substituents examined enhance the rates of exo retro-Diels-Alder reactions by factors of 15-40, while endo adduct retro-Diels-Alder rates are only slightly affected.Calculations were done at the MP2/6-31G*//HF/6-31G* level to compare the heats of hydrogenation of maleic anhydride and maleimide.The reduction of maleimide is calculated to be 2.5 kcal*mol-1 more exergonic, supporting the experimental observations.
- Tobia, David,Harrison, Roy,Phillips, Brian,White, Thomas L.,DiMare, Marcello,Rickborn, Bruce
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- A simple route for the synthesis of novel norcantharimide derivatives via acidolysis with hydrochloric acid(gas)
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In this work, seven new norcantharimide derivatives were synthesized by an acidolysis method. The compounds were prepared by acidolyzing trans-1,4-diacetate and trans-1,2-chloroacetate structures, which were obtained by stereospecific cleavage of the internal etheric bond of the tricyclic imides. The HCl(gas) was produced from the reaction of H2SO4 with NaCl. The resulting gas was bubbled into the reaction mixture. Trans-1,4-diacetate and trans-1,2-chloroacetate were thus acidolyzed, and the corresponding diol and halohydrin products were obtained respectively in moderate overall yields from low-cost starting materials, using simple and easily scalable chemistry. The products were characterized by means of spectroscopic techniques. The synthesized compounds have high potential as anticancer agents and can be valuable for studies in this area.
- K?se, Aytekin
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p. 1171 - 1178
(2021/03/08)
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- Synthesis and biological evaluation of new chloro/acetoxy substituted isoindole analogues as new tyrosine kinase inhibitors
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We have developed a versatile synthetic approach for the synthesis of new isoindole derivatives via the cleavage of ethers from tricyclic imide skeleton compounds. An exo-cycloadduct prepared from the Diels–Alder reaction of furan and maleic anhydride furnished imide derivatives. The epoxide ring was opened with Ac2O or Ac2O/AcCl in the presence of a catalytic amount of H2SO4 in order to yield new isoindole derivatives 8a-d and 9a-d. The anticancer activity of these compounds was evaluated against the HeLa cell lines. The synthesized compounds showed inhibitory effects on the viability of HeLa cells and the degree of cytotoxicity was increased with the level of bigger branched isoindole derivatives. To better understand the acting mechanism of these molecules, western blot analysis was performed with using mTOR and its downstream substrates. In addition, human mTOR and ribozomal S6 kinase β1 (RS6Kβ1) have been investigated with molecular modelling studies as possible targets for compound series 8 and 9.
- ?ahin, Ertan,?anl?-Mohamed, Gül?ah,Akdemir, Atilla,K?se, Aytekin,Kara, Yunus,Kaya, Meltem,Kishal?, Nurhan H.
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- POTENTIALLY ANTICARCINOGENIC NOVEL ISOINDOLE-1,3-DIONE DERIVATIVES AND SYNTHESIS METHOD FOR SUCH COMPOUNDS
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The invention is related to novel isoindole-1,3-dione derivatives which are determined to be effective in vitro on certain cancer types (e.g., Lung, breast and cervical cancer) as well as the synthesis method of such compounds for use in the chemistry sector, pharmaceuticals industry and pharmacy sector.
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(2019/11/12)
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- Study of Diels–Alder reactions between furan and maleimide model compounds and the preparation of a healable thermo-reversible polyurethane
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A study of the reactions between various furan and maleimide model compounds and the effects of reaction conditions was performed, allowing for a proper design and preparation of a thermo-reversible polyurethane (PU) material crosslinked via Diels–Alder (DA) bonds. Thus, a linear polyurethane containing furan groups along the main chain was synthesized and crosslinked with a bismaleimide by means of DA reaction. The obtained thermoset exhibited thermo-reversibility as evidenced by DSC and FTIR microscopy, providing the material recyclability and scratch healability. Optical microscopy, SEM and tensile analysis of a scratched PU film revealed that efficient scratch healing was enabled by heating at 110 °C for 30 min and subsequently keeping at room temperature for 24 h, resulting in an approximately 80% recovery of the pristine mechanical strength. This material is a promising candidate for the development of self-healing coatings.
- Truong, Thuy Thu,Nguyen, Ha Tran,Phan, Man Ngoc,Nguyen, Le-Thu T.
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p. 1806 - 1814
(2018/08/29)
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- Synthesis and anticancer activity evaluation of new isoindole analogues
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We have developed a versatile synthetic approach for the synthesis of new isoindole derivatives via the cleavage of ethers from tricyclic imide skeleton compounds. An exo-cycloadduct prepared from the Diels–Alder reaction of furan and maleic anhydride furnished imide derivatives. The epoxide ring was opened with Ac2O in the presence of a catalytic amount of H2SO4 in order to yield new isoindole derivatives (8a and 8b). The anticancer activity of these compounds was evaluated against MCF-7 (breast adenocarcinoma) and A549 (adenocarcinomic human alveolar basal epithelial) cell lines. The synthesized compounds showed concentration- and time-dependent inhibitory effects on the viability of both cell lines. Compound 8a was more toxic compared to 8b in both cancer cell lines, having higher cytotoxicity against A549 cells. Testing the toxicity properties of these compounds on the BEAS 2B (human bronchial epithelial) cell line indicated that while both compounds decreased the cell viability of cancer cells, they were less toxic on healthy lung cells. Microscopy images of A549 cells after treatment with the new isoindole derivatives displayed characteristic apoptotic morphology compared to BEAS 2B cells. The results demonstrated here suggest that these new compounds might be considered as possible potential anticancer agents for the treatment of lung and breast cancer.
- K?se, Aytekin,Bal, Y?ld?z,Kishal?, Nurhan H.,?anl?-Mohamed, Gül?ah,Kara, Yunus
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p. 779 - 786
(2017/03/06)
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- A minimalist furan-maleimide AB-type monomer and its thermally reversible Diels-Alder polymerization
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The present study reports an easy and direct route for the synthesis of highly pure 2-furfurylmaleimide, a minimalist furan-maleimide AB-type monomer, which was used for the preparation of a rigid thermally reversible polymer based on the Diels-Alder reaction. This strategy has high potential for the development of novel polymers and copolymers mainly derived from renewable resources.
- Lacerda, Talita M.,Carvalho, Antonio J. F.,Gandini, Alessandro
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p. 45696 - 45700
(2016/06/09)
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- Enantioselective access to bicyclo[4.2.0]octanes by a sequence of [2+2] photocycloaddition/reduction/fragmentation
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Tricks of the trade: Because intramolecular Cu-catalyzed access to bicyclo[4.2.0]octanes is not feasible, an oxygen bridge was introduced to facilitate the [2+2] photocycloaddition. Starting from compounds similar to 1, products such as 2 could be obtaine
- Yin, Guoyin,Herdtweck, Eberhardt,Bach, Thorsten
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supporting information
p. 12639 - 12643
(2013/10/01)
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- 1,3-dipolar cycloaddition reactions of N-methyl-substituted tricyclic imides
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The [3+2]?cycloadditions of N-methyl derivatives of unsaturated imides with various nitrile oxides to yield new bridged isoxazoline derivatives with potential biological activity is described.
- Goksu, Gokce,Ocal, Nuket
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scheme or table
p. 256 - 261
(2012/05/04)
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- Self-activation in de novo designed mimics of cell-penetrating peptides
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DIY transduction: Cell-penetrating peptides (CPPs) efficiently cross the nonpolar biological membrane, but activation by hydrophobic counterions is essential for transport activity. Polymeric mimics of CPPs are coupled with hydrophobic side chains; the "self-activation" in these species is demonstrated by transport of the fluorescent probe CF out of bilayer vesicles. Copyright
- Som, Abhigyan,Tezgel, A. Ozgul,Gabriel, Gregory J.,Tew, Gregory N.
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supporting information; experimental part
p. 6147 - 6150
(2011/08/03)
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- ANTIMICROBIAL POLYMERS
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The invention generally relates to novel polymers (SMAMPs) and their syntheses and use. The polymers exhibit promising properties of AMPs. In particularly, for example, a ring-opening metathesis polymerization (ROMP) platform was developed that allows syntheses of SMAMPs that employ a minimum number of norbornene-based building blocks and/or enable easy and independent variation of hydrophobic and hydrophilic groups in the monomer units and/or along the polymeric backbone to finetune and select desirable properties of the polymers.
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(2010/12/29)
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- Structural studies on cycloadducts of furan, 2-methoxyfuran, and 5-trimethylsilylcyclopentadiene with maleic anhydride and N-methylmaleimide
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(Chemical Equation Presented) The early stages of the retro-Diels-Alder reaction are clearly apparent in the structures of the cycloadducts formed between furan or 5-trimethylsilylcyclopentadiene with maleic anhydride and N-methylmaleimide. The degree of lengthening of the C-C bonds that break in this reaction is clearly related to the known reactivity of these cycloadducts toward this reaction. In the structures of the cycloadducts 21 and 22 derived from 2-methoxyfuran, the early stages of an alternative fragmentation reaction are apparent, consistent with the reactivity of these compounds in solution.
- Yit, Wooi Goh,Pool, Brett R.,White, Jonathan M.
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p. 151 - 156
(2008/09/17)
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- Evidence for an Olefinic Intermediate in the Configurational Inversion Accompanying Hydrogenolysis of a 7-Oxanorbornyl Vicinal Dibromide
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The endo,endo-2,3-dibromo-7-oxanorbornenosuccinimide (1) undergoes complete inversion upon hydrogenolysis of the bromine substituents to form (5) (Zn/Ag couple in THF) or (26) (H2, Pd/C).The highly reactive dienophile, N-methyl 7-oxanorbornadienomaleimide (3) is shown to be a transient intermediates in the Zn/Ag couple experiments by trapping with furan.Deuterium labelling experiments have been used to help elucidate the mechanism of these reactions.
- Warrener, Ronald N.,Maksimovic, Ljiljana
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p. 2389 - 2392
(2007/10/02)
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