- Host-guest complexes of cucurbit[8]uril with some pentaerythritol derivative guests
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A series of first generation dendritic guests from pentaerythritol derivatives have been designed and synthesized. Investigation of the complex structures of cucurbit[8]uril (Q[8]) and the guests based on the 1H NMR technique have revealed that the host Q[8] selectively included different branch(es) of the first generation dendritic guests and formed inclusion complexes with different structural conformations. The experimental results obtained from electronic absorption spectroscopy showed that the 1:1 ratio of Q[8]-based host-guest inclusion complexes have moderate stability with an average formation constants of 104 L mol-1. The single crystal structures of some of the guests (g5 and g6) and Q[8]-guest complexes (Q[8]-g4 and Q[8]-g6) further confirm but in some cases contradict the research results of the 1H NMR technique and electronic absorption spectroscopy in aqueous solution. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2011.
- Li, Xian-Mei,Fan, Fan,Lu, Jing-Song,Xue, Sai-Feng,Zhang, Yun-Qian,Zhu, Qian-Jiang,Tao, Zhu,Lawrance, Geofferey A.,Wei, Gang
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Read Online
- Synthetic method of tetrabromo neopentane
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The invention discloses a synthetic method of tetrabromo neopentane. The method is characterized by: adopting pentaerythritol or dibromo neopentyl glycol or tribromo neopentyl alcohol as the raw material to react with methylsulfonyl chloride or p-toluenesulfonyl chloride to perform hydroxyl activation, and then taking diethylene glycol or polyethylene glycol as the solvent and using polyethylene glycol as the catalyst, carrying out substitution reaction with sodium bromide to obtain tetrabromo neopentane; or taking dibromo neopentyl glycol or tribromo neopentyl alcohol as the raw material, firstly reacting with p-toluenesulfonyl chloride to carry out hydroxyl activation, and then taking diethylene glycol as the solvent to carry out substitution reaction with sodium bromide to obtain tetrabromo neopentane. The whole process avoids the generation of water vapor, controls the temperature easily, and is environment-friendly, high in yield and good in product purity.
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Paragraph 0017-0018; 0028-0033
(2020/07/21)
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- Synthesis of Size-Tunable Hollow Polypyrrole Nanostructures and Their Assembly into Folate-Targeting and pH-Responsive Anticancer Drug-Delivery Agents
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Chemotherapeutic drugs currently used in clinical settings have high toxicity, low specificity, and short half-lives. Herein, polypyrrole-based anticancer drug nanocapsules were prepared by tailoring the size of the nanoparticles with a template method, controlling drug release by means of an aromatic imine, increasing nanoparticle stability through PEGylation, and improving tumor-cell selectivity by folate mediation. The nanoparticles were characterized by TEM and dynamic light scattering. α-Folate receptor expression levelsof tumor cells and normal cells were investigated by western blot and quantitative polymerase chain reaction analyses. Flow cytometry and fluorescence imaging were used to verify the cell uptake of the different-sized nanoparticles. From the different-sized polypyrrole nanoparticles, the optimally functionalized nanoparticles of 180 nm hydrodynamic diameter were chosen and further usedfor in vitroandin vivotests. The nanoparticles showed excellent biocompatibility and the drug-loaded nanoparticles exhibited effective inhibition of tumor cell growth in vitro. Moreover, the drug-loaded nanoparticles showed substantially enhanced accumulation in tumor regions and effectively inhibitedin vivotumor growth. Furthermore, the nanoparticles showed reduced doxorubicin-induced toxicity andno significant side effects in normal organs of tumor-bearing mice, as measured by body-weight shifts and evaluationof drug distribution. Overall, the functionalized nanoparticles are promising nanocarriers for tumor-targeting drug delivery.
- Chen, Jian,Li, Xiufang,Sun, Yanhua,Hu, Yuwei,Peng, Yulong,Li, Yimin,Yin, Gang,Liu, Hui,Xu, Jiangfeng,Zhong, Shian
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supporting information
p. 17279 - 17289
(2017/11/20)
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- Synthesis of soluble core cross-linked polystyrene star polymer by application of acrylate-nitrile oxide 'click chemistry' using metal-free reagents
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In the present work, we have established a novel and environmentally benign method, whereby a 1,3-dipolar cycloaddition reaction has been applied using a non-toxic reagent, iodosobenzenediacetate [PhI(OAc)2], instead of the conventional copper-based reagents for the development of star-branched polymers. Here we have demonstrated the synthesis of core cross-linked star (CCS) polymers via the formation of isoxazoline ring using 'click reaction' between acrylate functionalities in a polymer chain and in situ generated nitrile oxide groups from a cross-linker added externally. In the initial step, a well-defined styrenic block copolymer with acrylate-functionalized middle-block was synthesized by controlled radical polymerization (RAFT) using α,α′-xylyl-bis(dithiobenzoate) as a chain transfer agent using 4-vinyl benzyl chloride and styrene as comonomers. Thereafter, the chlorobenzyl groups were converted into acrylate by reaction with acrylic acid. In the following step, core cross-linked star (CCS) polymers were synthesized by reacting the above block copolymer and oxime-functionalized cross-linkers (bi- and tetra-functional) using PhI(OAc)2 'click chemistry'. Formation of CCS polymers was confirmed from NMR, FTIR, GPC and DLS studies.
- Banerjee, Rakesh,Maiti, Saikat,Dhara, Dibakar
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p. 1365 - 1373
(2014/03/21)
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- A bright entry to improve the performance of DSSCs with the influence of novel optoelectronic acridinedione based macromolecules in I-/I 3- electrolytes
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The performance of Ru(ii) dye-sensitized nanocrystalline TiO2 solar cells (DSSCs) is described with newly synthesized multivalent macromolecules, containing excellent optoelectronic acridinedione linked with 1,2,3-triazole units, via a novel and convenient Cu(I)-catalyzed alkyne and azide 1,3-dipolar cycloaddition (CuAAC) reaction. These unique macromolecules have proved to be highly suitable for utilizing additives in I -/I3- redox couple electrolytes. Among the various substitutions, the maximum photo-current conversion efficiency of about 6.4% with a Voc of 810 mV was obtained with electron rich substitutions in the nitrogen heteroatom.
- Periyasami, Govindasami,Rajesh, Raju,Arumugam, Natarajan,Raghunathan, Raghavachary,Ganesan, Shanmugam,Maruthamuthu, Picha
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p. 14666 - 14674
(2013/11/19)
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- A novel type of double-calixcrown: Spirobiscalix[4]crowns
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The synthesis and complexation properties of a novel type of double- calixcrown in which two cone-conformational calix[4]crown subunits were linked via a spiro C-atom incorporated into poly(oxyethylene) chains were described.
- Li, Jiansen,Zhong, Zhenlin,Chen, Yuanyin,Lu, Xueran
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p. 6507 - 6510
(2007/10/03)
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- Displacement chromatography of proteins using low molecular weight anionic displacers
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A method for the purification of proteins by displacement chromatography on ion exchange media using low molecular weight displacers is disclosed. Several classes of low molecular weight anionic species are exemplified, including aromatic rings having sulfonic acid or carboxylic acid moieties attached thereon, sulfated sugar derivatives, anionic antibiotics, and dendrimeric polymers. Novel compounds useful as displacers are dendrimers of formula STR1 wherein R1 is lower alkyl, n is 2 to 6 and similar dendritic polymers based thereon.
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- Displacement chromatography of proteins using low molecular weight displacers
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A method for the purification of proteins by displacement chromatography on ion exchange media using low molecular weight displacers is disclosed. Several classes of low molecular weight, charged species are exemplified, including aminoacids, peptides, antibiotics and dendrimeric polymers. Novel compounds useful as displacers are dendrimers of formula STR1 wherein R1 is lower alkyl, n is 2 to 6, and X is a common counter anion and similar dendritic polymers based thereon.
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- Synthesis of Functionalized Cascade Cores: Tetrakis(ω-bromoalkyl)methanes
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A series of tetrakis(bromoalkyl)methanes was synthesized and characterized.The tetrakis(3-bromopropyl)methane was chosen as ideal core to cascade polymers, since it undergoes facile substitution with bulky nucleophiles, denoting the need for at least three carbon atoms between the quaternary center and the leaving group to circumvent major steric problems caused by the core carbon.The readily available 4-nitro-4-(3-hydroxypropyl)-1,7-heptanediol was used to afford a novel entry to tetrakis(3-bromopropyl)methane as well as other building blocks to cascade polymers.
- Newkome, George R.,Arai, Sadao,Fronczek, Frank R.,Moorfield, Charles N.,Lin, Xiaofeng,Weis, Claus D.
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p. 898 - 903
(2007/10/02)
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- Starburst Polyether Dendrimers
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The synthesis of two starburst polyether dendrimers, by a protection-deprotection scheme, is described.A bicyclic ortho ester or a dioxane is used to temporarily mask three or two hydroxyl groups, respectively.Dendrimer type I was synthesized with a pentaerythritol core and a hydroxymethyl bicyclic orthoformate as the dendrimer synthon, while in dendrimer type II, 1,1,1-tris(hydroxymethyl)ethane and a (hydroxymethyl)dioxane were used.Dendrimer type I is the most compact starburst molecule synthesized to date.No spacer groups or excess reagent are needed in the synthesis, even though all reactions occur at neopentyl positions.In just three generations, 108 functionalities are present in the exterior layer.The size of these molecules calculated from CPK models is in excellent agreement with the data obtained from size-exclusion chromatography.
- Padias, Anne Buyle,Hall, H. K.,Tomalia, Donald A.,McConnell, J. R.
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p. 5305 - 5312
(2007/10/02)
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- TETRAKIS-SULFOXIDES AS PHASE TRANSFER CATALYSTS
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Tetrakis(alkyl-sulfinylmethyl)methanes serve as highly efficient phase transfer catalysts in SN2 type displacement reactions of n-octyl bromide with a few nucleophiles.
- Fujihara, Hisashi,Imaoka, Koji,Furukawa, Naomichi,Oae, Shigeru
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p. 1293 - 1296
(2007/10/02)
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