- Readily useable bulk phenoxazine-based covalent organic framework cathode materials with superior kinetics and high redox potentials
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Redox-active covalent organic frameworks (COFs) with dense redox sites are promising electrical energy storage materials with robust architectures, high surface areas, insolubility in electrolytes, and open pores for electrolyte transportation. However, low redox potentials and poor electrical conductivity of pristine COFs often result in low accessibilities of redox-active sites and slow redox kinetics, greatly limiting their practical applications. Herein, we report the design and synthesis of two novel p-type phenoxazine-based COFs (DAPO-COFs) with high redox potentials (～3.6 V vs. Li/Li+) and excellent electrical conductivities. Simply blended with conductive additives (CAs) and binders, pristine bulk DAPO-COFs without pre-composition with CAs or extra exfoliation are readily useable as cathode materials for lithium-ion batteries. Both as-synthesized DAPO-COF powders displayed superior active-site accessibility, ultrafast redox kinetics, and remarkable cycling stability. This work provides new perspectives on the development of readily useable COF-based cathode materials, and contributes to the advancement of eco-friendly and sustainable organic-based energy storage devices. This journal is
- Meng, Zhiying,Zhang, Ying,Dong, Mengqing,Zhang, Yue,Cui, Fengmin,Loh, Teck-Peng,Jin, Yinghua,Zhang, Wei,Yang, Haishen,Du, Ya
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supporting information
p. 10661 - 10665
(2021/05/14)
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- A porous fluorinated organic [4+4] imine cage showing CO2and H2adsorption
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We present the synthesis of a porous, organic [4+4] imine cage containing perfluorinated aromatic panels. Gas adsorption experiments show an uptake of 19.0 wt% CO2(4.2 mmol g-1, 273 K and at 1 bar) and 1.5 wt% H2(7.5 mmol g-1, 77 K and at 1 bar) for the specific surface area of 536 m2g-1of the crystalline material obtained directly from the reaction mixture, combined with an outstanding thermal stability, making it a very interesting porous material suitable for gas adsorption.
- Kunde, Tom,Nieland, Esther,Schr?der, Hendrik V.,Schalley, Christoph A.,Schmidt, Bernd M.
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supporting information
p. 4761 - 4764
(2020/05/13)
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- Aromatic Linkers Unleash the Antiproliferative Potential of 3-Chloropiperidines Against Pancreatic Cancer Cells
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In this study, we describe the synthesis and biological evaluation of a set of bis-3-chloropiperidines (B?CePs) containing rigid aromatic linker structures. A modification of the synthetic strategy also enabled the synthesis of a pilot tris-3-chloropiperidine (Tri-CeP) bearing three reactive meta-chloropiperidine moieties on the aromatic scaffold. A structure–reactivity relationship analysis of B?CePs suggests that the arrangement of the reactive units affects the DNA alkylating activity, while also revealing correlations between the electron density of the aromatic system and the reactivity with biologically relevant nucleophiles, both on isolated DNA and in cancer cells. Interestingly, all aromatic 3-chloropiperidines exhibited a marked cytotoxicity and tropism for 2D and 3D cultures of pancreatic cancer cells. Therefore, the new aromatic 3-chloropiperidines appear to be promising contenders for further development of mustard-based anticancer agents aimed at pancreatic cancers.
- Helbing, Tim,Carraro, Caterina,Francke, Alexander,Sosic, Alice,De Franco, Michele,Gandin, Valentina,G?ttlich, Richard,Gatto, Barbara
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supporting information
p. 2040 - 2051
(2020/09/21)
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- Design, synthesis, and biological characterization of a new class of symmetrical polyamine-based small molecule CXCR4 antagonists
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CXCR4, a well-studied coreceptor of human immunodeficiency virus type 1 (HIV-1) entry, recognizes its cognate ligand SDF-1α (also named CXCL12) which plays many important roles, including regulating immune cells, controlling hematopoietic stem cells, and directing cancer cells migration. These pleiotropic roles make CXCR4 an attractive target to mitigate human disorders. Here a new class of symmetrical polyamines was designed and synthesized as potential small molecule CXCR4 antagonists. Among them, a representative compound 21 (namely HF50731) showed strong CXCR4 binding affinity (mean IC50 = 19.8 nM) in the CXCR4 competitive binding assay. Furthermore, compound 21 significantly inhibited SDF-1α-induced calcium mobilization and cell migration, and blocked HIV-1 infection via antagonizing CXCR4 coreceptor function. The structure-activity relationship analysis, site-directed mutagenesis, and molecular docking were conducted to further elucidate the binding mode of compound 21, suggesting that compound 21 could primarily occupy the minor subpocket of CXCR4 and partially bind in the major subpocket by interacting with residues W94, D97, D171, and E288. Our studies provide not only new insights for the fragment-based design of small molecule CXCR4 antagonists for clinical applications, but also a new and effective molecular probe for CXCR4-targeting biological studies.
- An, Jing,Fang, Xiong,Huang, Lina S.,Huang, Ziwei,Liang, Boqiang,Meng, Qian,Schooley, Robert T.,Wang, Juan,Xu, Yan,Zhang, Chaozai,Zhang, Huijun,Zhang, Xingquan,Zhu, Siyu
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supporting information
(2020/06/03)
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- Shape-Persistent [4+4] Imine Cages with a Truncated Tetrahedral Geometry
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The synthesis of shape-persistent organic cage compounds is often based on the usage of multiple dynamic covalent bond formation (such as imines) of readily available precursors. By careful choice of the precursors geometry, the geometry and size of the resulting cage can be accurately designed and indeed a number of different geometries and sizes have been realized to date. Despite of this fact, little is known about the precursors conformational rigidity and steric preorganization of reacting functional groups on the outcome of the reaction. Herein, the influence of conformational rigidity in the precursors on the formation of a [4+4] imine cage with truncated tetrahedral geometry is discussed.
- Lauer, Jochen C.,Zhang, Wen-Shan,Rominger, Frank,Schr?der, Rasmus R.,Mastalerz, Michael
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p. 1816 - 1820
(2018/01/22)
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- Octupolar organometallic Pt(II) NCN-pincer complexes; Synthesis, electronic, photophysical, and NLO properties
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A series of organometallic octupolar 1,3,5-substituted-2,4,6-styryl-benzene complexes was synthesized by post-modification of parent [PtCl(NCN-CHO-4)], i.e. 1,3,5-tri-R-2,4,6-tris[(4-(PtCl)(3,5-bis[(dimethylamino)methyl]styryl)]benzene (NCN = [C6H2(CH2NMe2)2-2,6]– in which R = OMe, H, Br (1–3). Their synthesis involved a triple Horner-Wadsworth-Emmons reaction of [PtCl(NCN-CHO-4)] with the appropriate tris[(diethoxyphosphoryl)]methyl]benzene derivative. The 195Pt{1H} NMR chemical shift reflects the electronic properties of the π-system to which it is connected. The UV/Vis bands of the octupolar platinum complexes are only slightly red-shifted (by 5–12 nm) with respect to those of corresponding stilbenoid Pt-Cl pincer compounds (i.e., the separate branches), suggesting that there is only a limited electronic interaction between these branches. The fluorescence Stokes shift, quantum yields and lifetimes of 1–3 also are of the same order of magnitude as those of stilbenoid Pt-Cl pincer compounds, indicating that a dipolar excited state is formed, which is localized on one of the three branches. The hyper-Rayleigh scattering technique revealed hyperpolarizabilites βHRS of 430, 870 and 183 × 10?30 esu for 1, 2 and 3, respectively, which are among the highest for transition metal complexes. The highest value was found for the compound lacking a donor or acceptor group at the central core, lending support to the idea that dispersion overwhelms charge transfer in determining the magnitude of the first hyperpolarizability in octupolar compounds.
- Batema, Guido D.,van Walree, Cornelis A.,van Klink, Gerard P.M.,de Mello Donegá, Celso,Meijerink, Andries,Perez-Moreno, Javier,Clays, Koen,van Koten, Gerard
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p. 246 - 252
(2018/02/06)
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- A Degradable and Recyclable Photothermal Conversion Polymer
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Decomposition and repolymerization of conjugated polymers offer great promise for developing recyclable photothermal conversion materials, which yet remain challenging. Herein, a crosslinked conjugated polymer based on a dynamic covalent bond of Schiff base is developed. This polymer possesses photothermal conversion efficiency as high as 90.4 %. Decomposition of the polymer under specialized conditions is corroborated by various characterizations. The kinetics study is also investigated to understand this degradation process. Furthermore, those decomposed species can be repolymerized back to conjugated polymers which possess the same photothermal conversion efficiency as the pristine polymer. Such a degradable and recyclable photothermal polymer is successfully used as a heat source for photothermal-electrical conversion to generate Seebeck voltage under either near infrared (NIR) irradiation or solar illumination.
- Xu, Xiao-Qi,Wang, Zhen,Li, Ruiting,He, Yonglin,Wang, Yapei
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supporting information
p. 9769 - 9772
(2018/07/25)
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- Method for synthetizing 1,3,5-benzenetricarboxaldehyde from trimesic acid
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The invention provides an experiment method for synthetizing 1,3,5-benzenetricarboxaldehyde by using trimesic acid as raw materials. The experiment conditions are improved; the purification process of the 1,3,5-benzenetricarboxaldehyde is optimized; a 1,3,5-benzenetricarboxaldehyde synthetizing method with mild reaction conditions, low production cost and high product yield is obtained.
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Paragraph 0020
(2018/01/17)
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- Synthetic study and structure of cage-type cyclophane C36H36S6
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A cage compound was synthesized in order to investigate the structure and cation-π interactions of the metal ion complex. The multi-step synthesis was achieved starting from trimesic acid triethyl ester. In solution, a completely symmetrical structure that was anticipated by the molecular design was observed by 1H and 13C NMR spectroscopy. However, in the solid state, X-ray crystallographic analysis revealed that the compound had a collapsed structure.
- Takemura, Hiroyuki,Nagaoka, Maiko,Kawasaki, Chihiro,Tokumoto, Kasumi,Tobita, Noriko,Takano, Yuki,Iwanaga, Tetsuo
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p. 1066 - 1070
(2017/03/31)
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- Photoinduced charge transfer in a conformational switching chlorin dimer-azafulleroid in polar and nonpolar media
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In the present study, a biomimetic reaction center model, that is, a molecular triad consisting of a chlorin dimer and an azafulleroid, is synthesized and its photophysical properties are studied in comparison with the corresponding molecular dyad, which consists only of a chlorin monomer and an azafulleroid. As evidenced by 1H NMR, UV/Vis, and fluorescence spectroscopy, the chlorin dimer-azafulleroid folds in nonpolar media into a C2-symmetric geometry through hydrogen bonding, resulting in appreciable electronic interactions between the chlorins, whereas in polar media the two chlorins diverge from contact. Femtosecond transient absorption spectroscopy studies reveal longer charge-separated states for the chlorin dimer-azafulleroid; 1.6 ns in toluene, compared with the lifetime of ≈0.9 ns for the corresponding chlorin monomer-azafulleroid in toluene. In polar media, for example, benzonitrile, similar charge-separated states are observed, but the lifetimes are inevitably shorter: 65 and 73 ps for the dimeric and monomeric chlorin-azafulleroids, respectively. Nanosecond transient absorption and singlet oxygen phosphorescence studies corroborate that in toluene, the charge-separated state decays indirectly via the triplet excited state to the ground state, whereas in benzonitrile, direct recombination to the ground state is observed. Complementary DFT studies suggest two energy-minima conformations, that is, a folded chlorin dimer-azafulleroid, which is present in nonpolar media, and another conformation in polar media, in which the two hydrophobic chlorins wrap the azafulleroid. Inspection of the frontier molecular orbitals shows that in the folded conformation, the HOMO on each chlorin is equivalent and is shared owing to partial π-π overlap, resulting in delocalization of the conjugated π electrons, whereas the wrapped conformation lacks this stabilization. As such, the longer charge-separated lifetime for the dimer is rationalized by both the electron donor-acceptor separation distance and the stabilization of the radical cation through delocalization. The chlorin folding seems to change the photophysical properties in a manner similar to that observed in the chlorophyll dimer in natural photosynthetic reaction centers.
- Nikkonen, Taru,Muuronen, Mikko,Helaja, Juho,Oliva, Mara Moreno,Kahnt, Axel,Guldi, Dirk M.
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supporting information
p. 590 - 600
(2015/08/26)
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- A facile synthesis of microporous organic polymers for efficient gas storage and separation
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A series of porous hyper-cross-linked polymers with excellent physiochemical stability have been designed and prepared facilely through template-free Friedel-Crafts alkylation reactions between benzene/biphenyl/1,3,5-triphenylbenzene as co-condensing rigid aromatic building blocks and 1,3,5-tris(bromomethyl)benzene or 1,3,5-tris(bromomethyl)-2,4,6-trimethylbenzene as cross-linkers under the catalysis of anhydrous AlCl3 or FeCl3. The systematic study of gas uptake ability shows that anhydrous AlCl3 is a much more effective catalyst than anhydrous FeCl3. The synthesized polymers are thermally stable and are predominantly microporous with high surface areas up to 1783 m2 g-1. In addition, they exhibit high H2 and CO2 uptake capacity/selectivity. Among these materials, C1M3-Al has the highest H2 uptake capacity at 77 K and 1 bar (19.1 mg g-1) and CO2 uptake capacity at 273 K and 1 bar (181 mg g-1); the best CO2/N2 (15/85) selectivity calculated by IAST at 273 K and 1 bar belongs to C1M2-Al (32.3). Moreover, the synthesis route exhibits cost-effective advantages, which are essential for scale-up preparation, thus showing great potential for clean energy applications.
- Liu, Guoliang,Wang, Yangxin,Shen, Chaojun,Ju, Zhanfeng,Yuan, Daqiang
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supporting information
p. 3051 - 3058
(2015/02/19)
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- Synthesis of C3-symmetric tri(alkylamino) guests and their interaction with cyclodextrins
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The synthesis of a series of star-shaped C3-symmetric amines and their inclusion complexation properties toward α-, β-, γ-cyclodextrins and their permethylated derivatives has been described. The star molecules comprise of 1, 3, 5-trisubstited benzene core and the points formed by (alkylamino)methyl or 4-((alkylamino)methyl)phenyl groups. The modes of host-guest interaction were studied by UV-Vis spectroscopy, ITC, 1H NMR and 2D-NMR (NOESY). It was found that star molecules containing (tert-butylamino)methyl, (adamantan-1-ylamino)methyl, 4-((isopropylamino)methyl) phenyl, 4-((tert-butylamino)methyl)phenyl and protonated 4-((adamantan-1-ylamino)methyl)phenyl points form strong host-guest complexes with β-cyclodextrin. It was also proved that the largest C3-symmetric guest can form complexes with bcyclodextrin with stoichiometry 3 which is required for construction of dendrimer supramolecular structures. None of the investigated amines forms a strong complex with permethylated cyclodextrins.
- Bedna?íková, Tereza,Tosňer, Zdeněk,Horsky, Ji?í,Jind?ich, Jind?ich
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p. 141 - 152
(2015/04/22)
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- Synthesis and characterization of linear and cyclic endothelin peptides on PEGylated poly(O-benzyl ether) dendrimeric supports
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Synthesis and evaluation of poly(ethylene glycol) grafted poly(O-benzyl ether) dendrimers for polymer assisted organic reaction is presented here. Initially a cross-linked polymer Polystyrene-Poly(ethyleneglycol)dimethacrylate-Vinylbenzylchloride (PS-PEGDMA-VBC) was synthesized by radical suspension polymerization. 1,3,5-tris(hydroxymethyl)benzene dendron was prepared by the reduction of trimesic acid using LiAlH4. Dendrimers were generated on 2 mol% cross-linked resin by repetitive Williamson etherification and thionyl chloride reactions. The dendrimer was cleanly and efficiently prepared up to third generations (G3) and each stage of reaction was quantitatively and qualitatively analyzed. Poly(ethylene glycol) having different chain lengths (400 Da and 1500 Da) were grafted to G3 generation and tested for various physico-chemical properties. The utility of supports were checked by synthesizing linear as well as disulfide bonded endothelin peptides in high yield and purity by standard Fmoc method.
- Siyad,Kumar, G.S. Vinod
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- Polyamine transport inhibitors: Design, synthesis, and combination therapies with difluoromethylornithine
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The development of polyamine transport inhibitors (PTIs), in combination with the polyamine biosynthesis inhibitor difluoromethylornithine (DFMO), provides a method to target cancers with high polyamine requirements. The DFMO+PTI combination therapy results in sustained intracellular polyamine depletion and cell death. A series of substituted benzene derivatives were evaluated for their ability to inhibit the import of spermidine in DFMO-treated Chinese hamster ovary (CHO) and L3.6pl human pancreatic cancer cells. Several design features were discovered which strongly influenced PTI potency, sensitivity to amine oxidases, and cytotoxicity. These included changes in (a) the number of polyamine chains appended to the ring system, (b) the polyamine sequence, (c) the attachment linkage of the polyamine to the aryl core, and (d) the presence of a terminal N-methyl group. Of the series tested, the optimal design was N1,N1′,N1″-(benzene-1,3, 5-triyltris(methylene))tris(N4-(4-(methylamino)butyl)butane-1,4- diamine, 6b, which contained three N-methylhomospermidine motifs. This PTI exhibited decreased sensitivity to amine oxidases and low toxicity as well as high potency (EC50 = 1.4 μM) in inhibiting the uptake of spermidine (1 μM) in DFMO-treated L3.6pl human pancreatic cancer cells.
- Muth, Aaron,Madan, Meenu,Archer, Jennifer Julian,Ocampo, Nicolette,Rodriguez, Luis,Phanstiel, Otto
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p. 348 - 363
(2014/02/14)
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- Synthesis and analysis of in vitro anti-arthritic activity of dendrimers with methyl, ethyl and isopropyl salicylates as surface groups
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Frchet type dendrimers with salicylates as surface groups have been synthesized using the divergent approach and their in vitro anti-arthritic activity was analyzed by inhibition of protein denaturation.
- Jayanthi, Mani,Rajakumar, Perumal
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p. 63208 - 63215
(2015/02/19)
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- A collection of fullerenes for synthetic access toward oriented charge-transfer cascades in triple-channel photosystems
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The development of synthetic methods to build complex functional systems is a central and current challenge in organic chemistry. This goal is important because supramolecular architectures of highest sophistication account for function in nature, and synthetic organic chemistry, contrary to high standards with small molecules, fails to deliver functional systems of similar complexity. In this report, we introduce a collection of fullerenes that is compatible with the construction of multicomponent charge-transfer cascades and can be placed in triple-channel architectures next to stacks of oligothiophenes and naphthalenediimides. For the creation of this collection, modern fullerene chemistry - methanofullerenes and 1,4-diarylfullerenes - is combined with classical Nierengarten-Diederich-Bingel approaches.
- Bolag, Altan,Lopez-Andarias, Javier,Lascano, Santiago,Soleimanpour, Saeideh,Atienza, Carmen,Sakai, Naomi,Martin, Nazario,Matile, Stefan
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p. 4890 - 4895
(2014/05/20)
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- Synthesis and properties of poly(p-phenylene vinylene) derivatives with hyperbranched structure and containing a nitro substituent
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In order to improve efficiency, processability, and stability, two groups of novel poly(p-phenylene vinylene) (PPV) derivatives (P1-P 3 and P4-P6) with hyperbranched structure and containing a nitro substituent were synthesized via a Gilch reaction in different monomer ratios. The properties of the polymers were investigated by using UV-Vis absorption, fluorescence spectroscopy, cyclic voltammetry, and thermogravimetric analysis. The result shows that the band gaps of the PPV derivatives with a nitro substituent were decreased and the polymers had higher molecular weights (106), excellent solubility in common organic solvents, good film-forming ability, and better thermal stability. The polymers can be used as an efficient acceptor material in polymeric solar cells. Graphical abstract: [Figure not available: see fulltext.]
- Li, Ruyu,Mo, Yanjiao,Shi, Rong,Li, Peng,Li, Chengyu,Wang, Zhenjiang,Wang, Xun,Li, Shengbiao
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- A new selective turn-on fluorogenic dipodal-cobalt(II) ensemble probe for nitrite ion detection and live cell imaging
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A new dipodal-triazole-Co2+-ensemble with a ligand containing quinoline moiety was designed and synthesized as a highly sensitive fluorescent sensor for nitrite in aqueous media. Based on in situ-formed Co2+-DTQ (Co2+ chelated dipodal of triazole-quinoline) ensembles having the specific binding affinity for nitrite anions over other anions, this sensory system allows rapid recognition and quantitative detection of nitrite in neutral aqueous media in an 'off-on' fashion. To confirm the suitability of DTQ for biological applications, we also employed it for the fluorescence detection of the changes of intracellular NO2- in three different species of cultured cells in the presence of nitrite ions.
- Mahapatra, Ajit Kumar,Hazra, Giridhari,Mukhopadhyay, Subhra Kanti,Mukhopadhyay, Anindita Roy
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supporting information
p. 1164 - 1168
(2013/04/10)
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- Novel analogues of resveratrol: Metabolism and inhibition of colon cancer cell proliferation
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Resveratrol is a phytochemical present in the skin of red grapes, and hence red wine as well as a variety of berries and nuts. It is an anti-oxidant, which has shown cancer chemopreventive properties in preclinical rodent models of carcinogenesis. The bioavailability of resveratrol is low, as it is rapidly metabolised to glucuronides and sulfates. The pharmacological activities of conjugate metabolites of phenols are often much lower than those of their metabolic progenitors. Therefore chemical synthetic manipulations aimed at slowing the rate of metabolic conjugation of phenols may generate analogues with increased bioavailability and efficacy. Here we describe the synthesis using the Wittig-Horner-Emmons reaction of a new series of resveratrol analogues in which the phenol moieties were systematically replaced by hydroxymethyl and/or methoxy groups. Incubation of analogues, which lack phenol groups with phase II metabolising enzyme preparations generated hardly any, or only small amounts of, conjugates. Four of the new analogue inhibited the growth of human-derived HCA-7 colon cancer cells, but with much less potency than resveratrol.
- Simon, Charles,Britton, Robert G.,Cai, Hong,Gescher, Andreas J.,Brown, Karen,Jenkins, Paul R.
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p. 6203 - 6212
(2013/07/19)
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- Enhanced fluorescence of silver nanoclusters stabilized with branched oligonucleotides
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DNA stabilized silver nanoclusters (AgNCs) are promising optical materials, whose fluorescence properties can be tuned by the selection of the DNA sequence employed. In this work we have used modified oligonucleotides in the preparation of AgNCs. The fluorescent intensity obtained was 60 times higher than that achieved with standard oligonucleotides. The Royal Society of Chemistry.
- Latorre, Alfonso,Lorca, Romina,Zamora, Felix,Somoza, Alvaro
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supporting information
p. 4950 - 4952
(2013/06/26)
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- PROCESS FOR PRODUCTION OF AROMATIC ALCOHOL OR HETEROCYCLIC AROMATIC ALCOHOL
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A process of production of an aromatic alcohol or a heterocyclic aromatic alcohol, containing a step of reacting an aromatic amine or a heterocyclic aromatic amine having an aromatic ring or a heterocyclic aromatic ring having thereon at least one substituent -CHR1NR2R3 (wherein R1, R2 and R3 each independently represent hydrogen, an alkyl group having from 1 to 4 carbon atoms, or a benzyl group), with an alcohol, in the presence of a basic catalyst.
- -
-
Paragraph 0030; 0032
(2013/11/19)
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- The effect of the oxidation state of molybdenum complexes on the catalytic transformation of terminal alkynes: Cyclotrimerization vs. polymerization
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Reactions of monosubstituted alkynes (PhC≡CH, tBuC≡ CH, nBuC≡CH, HOCH2C≡CH, HO(CH 3)2CC≡CH) in the presence of molybdenum(0) and molybdenum(II) carbonyl complexes (Mo(CO)6/hv, [Mo(CO) 4(pip)2] (pip = piperidine), [Mo(CO)4(pip) 2]/SnCl4, [Rpip]2[{(μ-Cl)Mo(μ-Cl) (SnCl3)(CO)3}2] (R = C3H 5, H)) lead to the formation of cyclotrimerization and polymerization products, which were characterized by chromatography (GC-MS, GPC) and by 1H and 13C NMR spectroscopy. The effect of the oxidation state of the molybdenum catalyst on the transformation of the terminal alkynes was observed: cyclotrimerization vs. polymerization. Only molybdenum(II) complexes lead to the formation of polyenic polymers. Moreover, reaction of prop-2-yn-1-ol initiated by [Mo(CO)4(pip)2] in dichloromethane leads to the formation of oligomers containing the vinylidene unit. Mechanistic NMR studies show that η2-alkyne complex formation is the principal feature of all transformations of alkynes catalyzed by molybdenum complexes.
- Czelu?niak, Izabela,Kociecka, Paulina,Szymańska-Buzar, Teresa
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- Poly(ethylene glycol) grafted polystyrene dendrimer resins: Novel class of supports for solid phase peptide synthesis
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Poly(propyleneglycol)dimethacrylate cross-linked support using monomers Styrene and 4-chloromethyl styrene (PS-PPGDMA-VBC resin) was prepared by suspension polymerization method. Dendritic templates were synthesized from Schiff base and trimesic acid molecules and assembled independently on PS-PPGDMA-VBC support to the second generation. N,N-bischloro ethyl amine dendrimer was generated from Schiff base units and introduced to the chloromethyl groups uniquely through secondary amine. It was followed by acidolytic cleavage, diazotization and thionyl chloride reactions leading to first generation dendrimer. O-benzyl ether dendrimer was created using 1,3,5-tris(hydroxyl methyl)benzene unit which was produced by the LiAlH 4 reduction of carbonyl groups of trimesic acid molecule. The hydroxyl methyl groups formed were converted to chloro methyl groups by adding thionyl chloride that leads to first generation dendrimer. Similar synthetic routes were followed to produce second generation dendrimers too. Poly(ethylene glycol), Mn ≈ 1500) has been grafted to chlorine termini of both dendrimers and used to check various physical and chemical properties of different peptide synthetic conditions. Reactions were qualitatively analyzed by FTIR, 13C NMR, SEM and quantitatively analyzed by UV measurements and CHN analysis. Classically difficult ACP sequence was synthesized on both PEGylated dendrimer supports and compared to Tenta Gel. Biologically significant disulfide bonded endothelin class of peptides were also synthesized using novel supports using various literature reported methods.
- Siyad,Kumar, G.S. Vinod
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p. 4076 - 4090
(2012/11/13)
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- Crystal engineering of a microporous, catalytically active fcu topology MOF using a custom-designed metalloporphyrin linker
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A 12-connected fcu metal-organic framework (MOF), MMPF-3, has been prepared using a CoII metalloporphyrin. MMPF-3 is comprised of the same polyhedral supermolecular building blocks as the prototypal fcu-MOF, fcu-MOF-1, and its nanoscale cavities feature 18 catalytically active cobalt centers. The high density (ca. 5 cobalt sites/nm3) affords MMPF-3 superior performance in catalytic epoxidation of trans-stilbene compared to other MOFs. Copyright
- Meng, Le,Cheng, Qigan,Kim, Chungsik,Gao, Wen-Yang,Wojtas, Lukasz,Zaworotko, Michael J.,Zhang, X. Peter,Ma, Shengqian,Chen, Yu-Sheng
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supporting information
p. 10082 - 10085,4
(2020/09/09)
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- One-pot click synthesis of 1N-alkyl-4-aryl-1,2,3-triazoles from protected arylalkynes and alkyl bromides
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1N-Alkyl-4-aryl-1,2,3-triazoles have been prepared through a multicomponent one-pot protocol from the corresponding (arylethynyl)trimethylsilanes and alkyl bromides. In situ alkyl azide formation and alkyne deprotection followed by copper(I)-catalyzed click cycloaddition afforded the desired 1,4-disubstituted 1,2,3-triazoles in generally good to excellent yield, with only minor observation of the undesired 1,5-regioisomeric cycloadduct. The protocol eliminates the need to use reactive organic azides and terminal alkynes. Georg Thieme Verlag Stuttgart. New York.
- Ladouceur, Sebastien,Soliman, Ahmed M.,Zysman-Colman, Eli
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supporting information; experimental part
p. 3604 - 3611
(2011/12/16)
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- Cyclotrimerization of alkynes catalyzed by the naphthalene ruthenium complex [CpRu(10H8)] +
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The naphthalene ruthenium complex [CpRu(10H8)] + (in the presence of Cl- ions) catalyzes the cyclotrimerization of 2,2-dimethyl-5,5-dipropargyl-1,3-dioxane-4,6-dione with alkynes (acetylene, hex-1-yne, hex-3-yne, oct-1-yne, phenylacetylene, trimetylsilylacetylene, octa-1,7-diyne, pent-1-yn-5-ol, methyl propargyl ether, and propargyl acetate) giving tricyclic aromatic compounds in 55-85% yields.
- Perekalin,Trifonova,Petrovskii,Kudinov
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experimental part
p. 2110 - 2113
(2012/09/22)
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- Flexible and rigid core molecules in the synthesis of poly(lactic acid) star polymers
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This study presents the synthesis and physical characterization of a series of structurally well-defined starshaped poly(lactic acids). Polymer stars are prepared from a series of multifunctional alcohol cores including flexible polyols pentaerythritol and dipentaerythritol (four-armed and six-armed cores, respectively) and rigid substituted arenes tri(hydroxymethyl) benzene and hexa(hydroxymethyl)benzene. Utilizing a tin(II) octanoate catalyst, arms of 10 monomer units long are built from rac-lactide and L-lactide to form atactic and isotactic star polymers. Polymers were subsequently characterized by means of NMR spectroscopy, gel permeation chromatography, differential scanning calorimetry, and thermogravimetric analysis. Our results support previous work that suggests that the length of the individual arms, not the total molecular weight, correlates to physical characteristics including glass, melt, crystallization, and decomposition temperatures. In addition, differences between core molecules suggest that the chemical nature of the core can significantly alter the physical properties of the star polymer. Trends in crystallization and glass transition temperatures relative to the core used merit further study and correlate closest to the molecular weight and the number of arms emanating from the star core. It is also clear that the rigidity provided by aromatic cores has a significant effect on the melting temperatures of these macromolecules.
- Perry, Mitchell R.,Shaver, Michael P.
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experimental part
p. 499 - 505
(2011/06/22)
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- Viologen-based benzylic dendrimers: selective synthesis of 3,5-bis(hydroxymethyl)benzylbromide and conformational analysis of the corresponding viologen dendrimer subunit
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Convergent and divergent strategies for the synthesis of viologen dendrimers with 1,3,5-tri-methylene-branching units are discussed. The title compound is easily transformed into 1-[3,5-bis(hydroxymethyl)benzyl]-4-(pyridin-4-yl)pyridinium hexafluorophosphate, which is used in sequential growth and activation steps as a CB2 compound in the cascade-type dendrimer synthesis (B = -OH, activation = -OH → Br). Analysis of the dendrimer structure reveals that three torsional angles, that is, τ1 between the two pyridinium units, τ2 between the methylene and pyridinium and τ3 between the methylene and phenyl, determine the conformational space of the dendrimers. We report here the crystal structure of 1-[3,5-bis(hydroxymethyl)benzyl]-4-(pyridin-4-yl)pyridinium as PF6- salt which represents the smallest subunit of the dendrimer that shows the same three torsional angles. The crystal structure together with the results from PM3 calculations opens an avenue to judge the structure of benzylic viologen-based dendrimers.
- Kathiresan, Murugavel,Walder, Lorenz,Ye, Fei,Reuter, Hans
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supporting information; experimental part
p. 2188 - 2192
(2010/06/19)
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- "viologen"dendrimers as antiviral agents: The effect of charge number and distance
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A series of "viologen"derivatives (4,4′-bipyridinium salts) carrying between 1 and 90 charges per molecule have been prepared and investigated for their activity against human immunodeficiency virus (HIV), herpes simplex virus (HSV), vesicular stomatitis, Punta Toro virus, Sindbis virus, Reovirus, and respiratory syncytial viruses. In general, most of the compounds showed good activities against HIV-1 (strain IIIB). In particular, compound 36 exhibited the highest in vitro activity and selectivity index against HIV-1 (strain IIIB) (EC50 = 0.26 ± 0.08 μM, SI = 75.7) in MT-4 cells. The results imply that the antiviral activity requires an optimal number and distance of the positive charges.
- Asaftei, Simona,De Clercq, Erik
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supporting information; experimental part
p. 3480 - 3488
(2010/09/04)
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- POLYAMINE TRANSPORT INHIBITORS AS NOVEL THERAPEUTICS
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Novel polyamine transport inhibitors have been synthesized and demonstrated to block the uptake of native polyamines into human cancer cells. A combination therapy of the transport inhibitor and DFMO (a drug which blocks polyamine biosynthesis) provided synergistic activity against a metastatic human colon cancer cell line. The strategy uses polyamine depletion and polyamine metabolism to generate reactive oxygen species within cells as a novel way to treat cancers. This approach may be implemented for widespread use in the treatment of diseases which rely upon polyamine transport activity for proliferation.
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Page/Page column 13; 14
(2010/12/31)
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- A click chemistry approach to C3 symmetric, G-quadruplex stabilising ligands
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Described is the structure-based design and synthesis of a series of tris-triazole G-quadruplex binding ligands utilising the copper catalysed azide-alkyne 'click' reaction. The results of G-quadruplex stabilisation by the ligands are reported and discussed.
- Moses, John E.,Ritson, Dougal J.,Zhang, Fengzhi,Lombardo, Caterina Maria,Haider, Shozeb,Oldham, Neil,Neidle, Stephen
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scheme or table
p. 2926 - 2930
(2010/09/06)
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- Synthesis and orthogonal functionalization of [60]fullerene e,e,e-trisadducts with two spherically defined addend zones
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e,e,e-Trisadducts 13 and 15 have been prepared by a highly regioselective threefold cyclopropanation of tripodal malonates 10 and 12 with C60. The yield and regioselectivity depend on the length and structure of the tethers that connect the malonate units to the focal benzene core of 13-15. As a consequence of the template-directed synthesis, all ce.e-trisadducts were formed as in/out isomers exclusively and contain two spherically well-defined addend zones with equatorial and polar orientation, respectively. By variation of the outer malonate termini of the tethers, selective functionalization of the equatorial addend zone could be achieved, thus leading to fine-tuning of intermolecular interactions, such as solubility or aggregation phenomena. After removal of the focal benzene moiety in 14 and 15, selective functionalization of the polar addend zone could be achieved. Strong intramolecular hydrogen-bonding networks of the polar substituents in the polar addend zone could be observed by 1H NMR spectroscopic analysis. By orthogonal functionalization of both addend zones, fullerene derivatives 44-48 could be synthesized as one single in/out isomer, thus greatly enhancing the potential of e,e,e-trisadducts as building blocks in supramolecular architectures.
- Beuerle, Florian,Hirsch, Andreas
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scheme or table
p. 7434 - 7446
(2010/03/24)
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- Synthesis and supramolecular properties of a novel octaphosphonate porphyrin
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Two complementary routes were developed for preparing novel octaphosphonate porphyrins. The use of protected/deprotected phosphonate-substituted precursors in the rational synthesis gave an overall yield 16%. A more streamlined synthetic path gave 21 % overall yield, of the target molecule. Octaphosphonate porphyrin possesses promising properties in supramolecular aggregate formation with cyclam. Cofacial reversible self-assembly of a meso-substituted octaphosphonate porphyrin with cyclam yields micrometer-long nanowires with a height of about 1-1.5 nm. The resulting wires were characterized by UV/Vis absorption, emission and atomic force microscopy and transmission electron microscopy. ( Wiley-VCH Verlag GmbH & Co. KGaA.
- Bhosale, Sheshanath V.,Kalyankar, Mohan B.,Langibrd, Steven J.,Bhosale, Sidhanath V.,Oliver, Ruth F.
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scheme or table
p. 4128 - 4134
(2009/12/26)
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- Synthesis of nuclease-resistant siRNAs possessing benzene-phosphate backbones in their 3′-overhang regions
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We describe the synthesis and silencing activities of siRNA possessing N1-[3,5-bis(hydroxymethyl)phenyl]thymine (bt) in their 3′-overhang regions. We found that an siRNA possessing bt in the 3′-overhang region was more effective than an siRNA with natural nucleosides and the siRNA possessing 1,3-bis(hydroxymethyl)benzene (b) without a nucleobase at the 3′-overhang region in in vitro experiment using HeLa cells system. Furthermore, the RNA possessing bt at its 3′-end was more resistant to nucleolytic hydrolysis by snake venom phosphodiesterase (a 3′-exonuclease) than the RNA possessing the natural nucleoside 2′-deoxythymidine at the 3′-end. Thus, the compound bt will be a novel 3′-overhang moiety that can enhance the silencing activity and nuclease-resistant property of siRNAs.
- Ueno, Yoshihito,Inoue, Takumi,Yoshida, Mahito,Yoshikawa, Kayo,Shibata, Aya,Kitamura, Yoshiaki,Kitade, Yukio
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scheme or table
p. 5194 - 5196
(2009/05/07)
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- A comparison of chloroambucil- and xylene-containing poly amines leads to improved ligands for accessing the polyamine transport system
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Several disubstituted arylene- and chloroambucil-polyamine conjugates were synthesized and evaluated for their ability to target cells via their polyamine transport system (PAT). As compared to the monosubstituted analogues, the disubstituted arylene systems were superior PAT targeting agents. Using a Chinese hamster ovary (CHO) cell line (PAT active) and its CHO-MG mutant (PAT inactive), the series was screened for their PAT targeting ability. The data were expressed as a CHOMG/CHO IC50 ratio. Indeed, the disubstituted systems gave high IC50 ratios (e.g., ratio > 2000), which indicated high selectivity for the PAT. The chloroambucil adducts were less toxic than the corresponding arylmethyl compounds. In this regard, having the proper recognition element (i.e., homospermidine) and cytotoxic "cargo" were deemed paramount for successful drug delivery via the PAT.
- Kaur, Navneet,Delcros, Jean-Guy,Imran, Jon,Khaled, Annette,Chehtane, Mounir,Tschammer, Nuska,Martin, Bénédicte,Phanstiel IV, Otto
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p. 1393 - 1401
(2008/12/20)
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- Cytotoxic agents comprising new tomaymycin derivatives
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The present invention is related to new tomaymycin derivatives of formula (I), their process of preparation and their therapeutic uses.
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Page/Page column 38
(2008/06/13)
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- Synthesis and degradation of photolabile dendrimers based on o-nitrobenzyl ether photolabile cores
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Two dendrimer cores, 1a and 2a, that contain o-nitrobenzyl photolabile moieties, lack hydrolytically sensitive ester linkages and possess three and six sites for dendron attachment, respectively, have been alkylated to provide methylated core analogs 1b and 2b as well as second-generation benzylaryl ether dendrimer 1c and third-generation dendrimer 2c. These dendrimers undergo clean photocleavage as indicated by the evolution of isosbestic points in the UV spectra during photolysis. In addition, the nature of the photodegradation products was confirmed by observing the photolyses by both 1H NMR and GPC. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
- Kevwitch, Robert M.,McGrath, Dominic V.
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p. 1332 - 1336
(2008/03/12)
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- Mesoporous graphitic carbon nitride as a versatile, metal-free catalyst for the cyclisation of functional nitriles and alkynes
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Mesoporous graphitic C3N4 was successfully employed as an effective catalyst for the cyclotrimerisation of various nitriles into triazine derivatives and the cyclisation of functional alkynes. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
- Goettmann, Frederic,Fischer, Anna,Antonietti, Markus,Thomas, Arne
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p. 1455 - 1460
(2008/02/13)
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- Nitric oxide enhancing diuretic compounds, compositions and methods of use
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The invention describes novel compositions and kits comprising at least one nitric oxide enhancing diuretic compound, or pharmaceutically acceptable salts thereof, and, optionally, at least one nitric oxide enhancing compound and/or at least one therapeutic agent. The invention also provides methods for (a) treating conditions resulting from excessive water and/or electrolyte retention; (b) treating cardiovascular diseases; (c) treating renovascular diseases; (d) treating diabetes; (e) treating diseases resulting from oxidative stress; (f) treating endothelial dysfunctions; (g) treating diseases caused by endothelial dysfunctions; (h) treating cirrhosis; (j) treating pre-eclampsia; (k) treating osteoporosis; (l) treating nephropathy; (m) treating peripheral vascular diseases; (n) treating portal hypertension; (o) treating central nervous system disorders; (p) treating metabolic syndrome; (q) treating sexual dysfunctions; and (r) hyperlipidemia. The nitric oxide enhancing diuretic compounds comprise at least one nitric oxide enhancing group linked to the diuretic compound through one or more sites such as carbon, oxygen and/or nitrogen via a bond or moiety that cannot be hydrolyzed.
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Page/Page column 56
(2008/06/13)
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- A new approach to enantiopure C3-symmetric molecules
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Chiral base chemistry has been used to create three chiral centres in one pot on a C3-symmetric substrate. The potential of this new approach to C3-symmetric molecules is exemplified by the creation of an enantiopure C3v-symmetric triol, triphosphane and tripyridine. A ruthenium complex of the last compound has been studied by X-ray crystallography.
- Castaldi, M. Paola,Gibson, Susan E.,Rudd, Matthew,White, Andrew J. P.
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p. 138 - 148
(2007/10/03)
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- SYNTHESIS AND USE OF GLYCODENDRIMER REAGENTS
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The present invention relates to a chemically modified mutant protein including a cysteine residue substituted for a residue other than cysteine n a precursor protein, the substituted cysteine residue being subsequently modified by reacting the cysteine residue with a glycosylated thiosulfonate. Also a method of producing the chemically modified mutant protein is provided. The present invention also relates to a glycosylated methanethiosulfonate. Another aspect of the present invention is a method of modifying the functional characteristics of a protein including providing a protein and reacting the protein with a glycosylated methanethiosulfonate reagent under conditions effective to produce a glycoprotein with altered functional characteristics as compared to the protein. In addition, the present invention relates to methods of determining the structure-function relationships of chemically modified mutant proteins. The present invention also relates to synthetic methods for producing thio-glycoses, the thio-glycoses so produced, and to methods for producing glycodendrimer reagents.
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Page/Page column 42; sheet 25
(2010/11/08)
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- Method of synthesis of water soluble fullerene polyacids using a malonate reactant
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In one embodiment, the present invention is directed to a method for synthesizing compounds of the formula where Cm is a fullerene having m carbon atoms, the method comprising the steps of forming a linear malonate compound of the formula where each Z is the same or different and is a straight-chain or branched-chain aliphatic radical having from 1-30 carbon atoms which may be unsubstituted or monosubstituted or polysubstituted by identical or different substitutents, in which radicals up to every third —CH2— unit can be replaced by O or NR″, n is an integer from 2 to 10, and the unfilled valences of the first and nth malonate groups are filled with bonds to hydrogen, a hydrocarbon group or substituted hydrocarbon group having 1-20 carbon atoms, or a chain containing unsubstituted or substituted aryl or other cyclic groups; or (ii) a branched malonate compound of the formula where Z′ is an aliphatic radical having from 1-30 carbon atoms which may be unsubstituted or monosubstituted or polysubstituted by identical or different substitutents, in which radicals up to every third —CH2— unit can be replaced by O or NR″; and n is an integer from 2 to 10; reacting said malonate compound with Cm to form an adduct of the formula each Z is bonded to both one carboxylate group of a first malonate moiety and one carboxylate group of a second malonate moiety and the unfilled valences of the first and nth malonate groups are filled with bonds to hydrogen, a hydrocarbon group or substituted hydrocarbon group having 1-20 carbon atoms, or a chain containing unsubstituted or substituted aryl or other cyclic groups; and hydrolyzing said adduct to form the compound.
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Page/Page column 5; Sheet 9; Sheet 11
(2008/06/13)
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- Synthesis of a homotrifunctional conjugation reagent based on maleimide chemistry
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A novel homotrifunctional conjugation reagent, 1,3,5-tris-(N- maleimidomethyl)benzene has been synthesized in high yield with minimum purification. The reactivity of this compound was examined by using l-cysteine as a nucleophile.
- Farha, Omar K.,Julius, Richard L.,Hawthorne, M. Frederick
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p. 2619 - 2622
(2007/10/03)
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- Regioselective synthesis and zone selective deprotection of [60]fullerene tris-adducts with an e,e,e addition pattern
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D3h-symmetrical tripodal tris(malonate) tethers have been used for the synthesis of [60]fullerene tris-adducts with an e,e,e addition pattern bearing topologically distinct polar and equatorial addend zones that can selectively be deprotected. The Royal Society of Chemistry 2005.
- Beuerle, Florian,Chronakis, Nikos,Hirsch, Andreas
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p. 3676 - 3678
(2007/10/03)
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- A highly efficient, preorganized macrobicyclic receptor for halides based on CH... and NH...anion interactions
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The preorganized, macrobicyclic azaphane (1) exhibits remarkable strong, selective fluoride binding comparable to the most effective bis(tren) cryptands despite binding anions via only three NH groups coupled with three CH hydrogen bond donors. The lower intrinsic affinity of CH donors is compensated by the high degree of preorganization exhibited by azacyclophane 1. Compound 1 is prepared via a tripod-tripod cyclization reaction between 1,3,5-tris- bromomethyl-benzene and an aliphatic tripodal hexatosylated polyamine, followed by the reduction of the resulting bicyclic tosylamine. The crystal structures of the bicyclic tosylamine 2 and four macrobicyclic polyammonium halide salts of 1 are reported. X-ray studies revealed the formation of inclusive 1:1 complexes of 1 with fluoride, chloride, bromide, and iodide. Potentiometric titrations showed very high binding constants for fluoride and chloride with a F -/Cl- selectivity of more than five logarithmic units. The final geometry of the anion cryptates is largely determined by optimization of NH and CH...anion interactions coupled with unfavorable anion-π repulsion for the larger anions.
- Ilioudis, Christos A.,Tocher, Derek A.,Steed, Jonathan W.
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p. 12395 - 12402
(2007/10/03)
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- Synthesis of enantiopure axially chiral C3-symmetric tripodal ligands and their application as catalysts in the asymmetric addition of dialkylzinc to aldehydes
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The enantioselective synthesis of a novel-type C3-symmetric tripodal ligand that is composed of a central mesitylene-derived core and three functionalized, axially chiral biaryl subunits is described. The triol (M,M,M) -3 is a suitable catalyst for the enantioselective addition of dialkylzinc to various aromatic aldehydes with asymmetric inductions of up to 98% ee.
- Bringmann, Gerhard,Pfeifer, Robert-Michael,Rummey, Christian,Hartner, Kristina,Breuning, Matthias
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p. 6859 - 6863
(2007/10/03)
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- Synthesis of a mechanically linked oligo[2]rotaxane
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A bifunctional [2]rotaxane, bearing two free functional groups each in the ring and axial parts, was synthesized, followed by its polycondensation with methylene diphenyl diisocyanate leading to a mechanically linked oligo[2]rotaxane.
- Belaissaoui, Abdelhak,Shimada, Satoru,Ohishi, Akihiro,Tamaoki, Nobuyuki
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p. 2307 - 2310
(2007/10/03)
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- PROSTAGLANDIN CONJUGATES FOR TREATING OR PREVENTING BONE DISEASES
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This invention relates to prostaglandin-bisphosphonate conjugates. These conjugates are effective for treating or preventing bone diseases such as osteoporosis. These conjugates simultaneously deliver a prostaglandin agent for increasing bone formation and a bisphosphonate agent for inhibiting bone resorption.
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- The first cobalt catalyzed [2 + 2 + 2] alkyne cyclotrimerization in aqueous medium at room temperature
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Chelate complex 1 (5 mol%) was found to catalyze the [2 + 2 + 2] cyclization of terminal alkynes in good yields in a 80/20 mixture of water and ethanol at room temperature without further activation.
- Yong, Li,Butenschoen, Holger
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p. 2852 - 2853
(2007/10/03)
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- Synthesis of bis- and tris(indolinylidenemethyl)benzenes by one-pot reactions of polylithiated nitriles with bis(imidoyl)chlorides of oxalic acid
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The reaction of polylithiated di- and tricyanomethylbenzenes with oxalic acid-bis(imidoyl)chlorides afforded novel oligo(indolinylidenemethyl)benzenes with the formation of up to six carbon-carbon bonds. The UV/Vis spectroscopic features of these and related compounds were studied. 1,4-Disubstituted benzenes containing a large π-system have been efficiently prepared by the reaction of dianions with 1,4-dicyanobenzene. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
- Langer, Peter,Anders, Joachim T.
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p. 686 - 691
(2007/10/03)
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