- Isomeric anthracene diimide polymers
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N-type semiconducting polymers are attractive for organic electronics, but desirable electron-deficient units for synthesizing such polymers are still lacking. As a cousin of rylene diimides such as naphthalene diimide (NDI) and perylene diimide (PDI), anthracene diimide (ADI) is a promising candidate; its polymers, however, have not been achieved yet because of synthetic challenges for its polymerizable monomers. Herein, we present ingenious synthesis of two dibromide ADI monomers with dibromination at differently symmetrical positions of the ADI core, which are further employed to construct ADI polymers. More interestingly, the two obtained ADI polymers possess the same main-chain and alkyl-chain structures but different backbone conformations owing to varied linking positions between repeating units. This feature enables their different optoelectronic properties and film-state packing behavior. The ADI polymers offer first examples of conjugated polymer conformational isomers and are highly promising as a new class of n-type semiconductors for various organic electronics applications.
- Tu, Dandan,Yang, Qing,Yu, Shuwen,Guo, Xin,Li, Can
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p. 2848 - 2852
(2021/03/14)
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- Triaminoformate long-carbon-chain organosilane quaternary ammonium salt compound as well as preparation and application thereof
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The invention relates to a triaminoformate long carbon chain organosilane quaternary ammonium salt compound as well as preparation and an application thereof. The structure of the compound is shown ina general formula (I). The preparation method comprises the following steps: firstly, using long-chain aliphatic amine as a raw material to prepare long-carbon-chain isocyanate in an organic solvent;reacting the long-carbon-chain isocyanate with triethanolamine in an organic solvent, and carrying out recrystallization to obtain a triaminoformate fatty chain intermediate; and reacting the obtained intermediate with haloalkyl trimethoxysilane to obtain an organosilane quaternary ammonium salt compound. The organosilane quaternary ammonium salt compound can be applied to preparation of a hierarchical pore ZSM-5 zeolite molecular sieve. The obtained hierarchical pore channel ZSM-5 zeolite molecular sieve is beneficial to diffusion of macromolecular reactants and products, and has a potentialapplication prospect in macromolecular reaction catalysis.
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Paragraph 0042; 0044
(2019/07/04)
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- An investigation on practical synthesis of carboxylic acid derivatives using p-toluenesulfonyl chloride
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Carboxylic acid derivatives are well recognized as important class of reagents frequently used in the preparation of a variety of fine or special chemicals such as amides, esters, peptides, drugs, and dyes. Although several methods were developed for the preparation of these compounds, many of them present difficulties, including low yield, high reaction temperature, harsh reaction conditions, tedious work-up, and incompatibility with scale-up. Methods: The synthesis of carboxylic anhydrides is developed through the reaction of carboxylic acids with TsCl in the presence of K2CO3 and acetonitrile as a solvent under ultrasound irradiation and conventional conditions. In addition, one-pot synthesis of acyl azides was carried out in the presence of produced carboxylic anhydrides and the addition of sodium azide under identical condition. Results: A series of carboxylic anhydrides and acyl azides were synthesized using TsCl under ultrasound irradiation and conventional stirring with simple procedure, mild reaction conditions, high yields, and scale-up ability without any restriction. In most cases, the reaction under ultrasound irradiation was better in both yields and the reaction times compared to the conventional method. Conclusion: A convenient method has been developed for the preparation of carboxylic anhydrides and acyl azides under ultrasound irradiation and conventional stirring. The present method is practical and a highly effective alternative for previous reports. The major advantages of this method are: (i) simplicity of the procedure (ii) high yields and high purity of product (iii) scale-up capacity without considerable limitation in conventional system. Under ultrasound irradiation short reaction times as compared to conventional method are observed; yields are comparable to or better than conventional method.
- Eskandari, Parvin,Kazemi, Foad
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p. 431 - 439
(2017/07/24)
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- N-Guanidino Derivatives of 1,5-Dideoxy-1,5-imino-d-xylitol are Potent, Selective, and Stable Inhibitors of β-Glucocerebrosidase
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A series of lipidated guanidino and urea derivatives of 1,5-dideoxy-1,5-imino-d-xylitol were prepared from d-xylose using a concise synthetic protocol. Inhibition assays with a panel of glycosidases revealed that the guanidino analogues display potent inhibition against human recombinant β-glucocerebrosidase with IC50 values in the low nanomolar range. Related urea analogues of 1,5-dideoxy-1,5-imino-d-xylitol were also synthesized and evaluated in the same fashion and found to be selective for β-galactosidase from bovine liver. No inhibition of human recombinant β-glucocerebrosidase was observed for the urea analogues. Computational studies provided insight into the potent activity of analogues bearing the substituted guanidine moiety in the inhibition of lysosomal glucocerebrosidase (GBA).
- Sev?ek, Alen,?rot, Luka,Rihter, Jakob,?elan, Ma?a,van Ufford, Linda Quarles,Moret, Ed E.,Martin, Nathaniel I.,Pieters, Roland J.
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supporting information
p. 483 - 486
(2017/04/10)
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- Semicarbazides as gel forming agents for common solvents and liquid crystals
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This paper describes the synthesis of 14 new gelling agents with semicarbazide groups as H-bonding motifs and alkyl- and/or azobenzene side groups. They gel solvents like decaline, 1,2-dichlorobenzene and toluene and liquid crystalline mixtures. X-Ray structure analysis shows that the semicarbazides are connected by H-bonds, each molecule to four neighbours. As a result a ribbon is formed with a core of H-bonded semicarbazide groups and alkyl chains sticking to the side. IR measurements show an unchanged H-bonding motif in large crystals and in the gel fibres, even in LC-mixture. During heating the gel melts (rheology), while the H-bonding motif of the crystal disappears (IR and DSC measurements). First experiments show that these gel-forming agents can be used to gel LC-phases and to stabilise the director pattern present during gel formation. The Royal Society of Chemistry 2006.
- Deindoerfer, Pia,Geiger, Thomas,Schollmeyer, Dieter,Ye, Jian Hui,Zentel, Rudolf
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p. 351 - 358
(2007/10/03)
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- IMPROVED INHIBITORS FOR THE SOLUBLE EPOXIDE HYDROLASE
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Inhibitors of the soluble epoxide hydrolase (sEH) are provided that incorporate multiple pharmacophores and are useful in the treatment of diseases
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Page/Page column 67
(2010/11/08)
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- Synthesis and transdermal permeation-enhancing activity of carbonate and carbamate analogs of Transkarbam 12
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Transkarbam 12 (5-(dodecyloxycarbonyl)pentylammonium-5-(dodecyloxycarbonyl)pentylcarbamate, T12) is a highly effective skin permeation enhancer. In this study, ester groups in the molecule of T12 were replaced by carbonate and carbamate ones, respectively. The in vitro permeation-enhancing activities were evaluated using porcine skin and compared with those of T12 and previously prepared series of amide, ketone, and alkyl analogs. According to the activities and behavior of the compounds in donor samples, ester group is essential for the activity of T12; its replacement not only decreases the enhancing potency, but is likely to change the mechanism of action.
- Holas, Tomas,Vavrova, Katerina,Sima, Martin,Klimentova, Jana,Hrabalek, Alexandr
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p. 7671 - 7680
(2007/10/03)
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- Synthesis of carbamate-linked lipids for gene delivery
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Series of lipids 1a-d and 2a,b, with carbamate linkages between hydrocarbon chains and ammonium or tertiary amine head, which were pH sensitive, were synthesized for liposome-mediated gene delivery. The variable length of carbon chains and quaternary ammonium or neutral tertiary amine heads allowed to find the structure-function relationship of how these factors affect cationic lipids on gene delivery performance.
- Liu, Dongliang,Hu, Jianjun,Qiao, Weihong,Li, Zongshi,Zhang, Shubiao,Cheng, Lvbo
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p. 3147 - 3150
(2007/10/03)
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- A new and convenient method of generating alkyl isocyanates from alcohols, thiols and trimethylsilyl ethers using triphenylphosphine/2,3-dichloro-5,6- dicyanobenzoquinone/Bu4NOCN
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Alkyl isocyanates are prepared in good to excellent yields by treatment of alcohols, thiols and trimethylsilyl ethers with triphenylphosphine/2,3-dichloro- 5,6-dicyanobenzoquinone/ Bu4NOCN in acetonitrile. This method is highly selective for conversion of primary alcohols to alkyl isocyanates in the presence of secondary and tertiary alcohols, thiols and trimethysilyl ethers. Georg Thieme Verlag Stuttgart.
- Akhlaghinia, Batool
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p. 1955 - 1958
(2007/10/03)
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- Alkanethioimidoyl Radicals: Evaluation of β-Scission Rates and of Cyclization onto S-Alkenyl Substituents
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Thioimidoyl radicals were generated by addition of alkylsulfanyl radicals to alkyl isonitriles and were characterized by electron paramagnetic resonance (EPR) spectroscopy. The β-scissions of their C·S-C bonds were studied by variable-temperature EPR spectroscopy and the fragmentation rate constants and activation energies were calculated. The scission rates depend on the stability of the released alkyl radicals but in any case, at room temperature, the processes were fast. Data collected on similar oxyimidoyls showed that their fragmentations are slightly slower compared to those of analogous thioimidoyls. The scission rates of selenoimidoyls could not be studied by EPR and were evaluated by theoretical calculations. EPR experiments also enabled both β-scission and 5-exo ring closure rate constants of two S-but-3-enyl-substituted imidoyl radicals to be determined, showing that cyclization prevails only at low temperatures. Density functional theory (DFT) theoretical calculations predicted that the fragmentation process preferentially occurs from the s-cis rotamers (X-C bond) of the imidoyl radicals. Thio- and seleno-imidoyls (but not oxyimidoyls) prefer s-trans conformations so that their fragmentations involve prior rotation about the X-C bond.
- Minozzi, Matteo,Nanni, Daniele,Walton, John C.
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p. 2056 - 2069
(2007/10/03)
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- IMMUNOMODULATORY COMPOUNDS AND METHODS OF USE THEREOF
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The present invention is directed to methods of treating diseases and disorders related to immune responses by administering one or more immunomodulatory compounds. In particular, the invention is directed to methods of stimulating and reducing immune responses, treating autoimmune conditions, treating allergic reactions and asthma, and preventing ischemic damage and asthma by administering one or more immunomodulatory compounds.
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- CHIMIE DES SUCRES SANS GROUPEMENTS PROTECTEURS-II REACTIONS SELECTIVES D'ADDITION DU D-GLUCOSE, DU D-GALACTOSE ET DE D-GLYCOSYLAMINES A DES HETEROCUMULENES
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Alkyl isocyanates reacted with 1.5 equivalent of α-methylglucoside, glucose or galactose in pyridine at room temperature, and selectively gave the corresponding 6-N-alkylcarbamates in good yields.The readily available glucosylamine and lactosylamine (1.5-2 eq.) reacted with alkyl isocyanates and isothiocyanates in polar aprotic solvents (pyridine, NMP or DMF), thus affording good yields of the corresponding N-glycosyl N'-alkyl ureas and thioureas.These new sugar derivatives are non-ionic detergents.
- Plusquellec, Daniel,Roulleau, Fabienne,Lefeuvre, Martine,Brown, Eric
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p. 465 - 474
(2007/10/02)
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- Oxidatively Assisted Alkylation of Sodium Nitrocyanamide and Sodium Azide
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m-Chloroperbenzoic acid (MCPBA) oxidatively assisted reactions at 25 deg C between straight chain primary alkyl iodides and sodium nitrocyanamide to give corresponding alkyl nitrocyanamides (N-alkylation) and N-alkoxy-N'-cyanodiazene N-oxides (O-alkylation).Each alkyl nitrocyanamide thermolysed to an alkyl isocyanate.In the absence of oxidative assistance sodium nitrocyanamide suspended in an inert solvent (25 deg C to 110 deg C) did not convert straight chain primary alkyl halides.Simple secondary and tertiary alkyl iodides and isobutyl iodide in the presence of MCPBA and sodium nitrocyanamide were converted to intractable mixtures that did not contain detectable amounts of alkyl nitrocyanamides, isocyanates, or N-alkoxy-N'-cyanodiazene N-oxides.This differential reactivity between the various types of alkyl iodides was supported by a similar conversion of straight chain primary alkyl iodides to corresponding azides and other alkyl iodides to intractable mixtures on treatment with sodium azide under conditions that brought about no reaction in the absence of oxidative assistance of MCPBA.Alkyl iodides were unreactive (25 deg C to 110 deg C) to sodium cyanate in the presence or absence of peroxides.
- Manimaran, Thanikavelu,Wolford, Lionel T.,Boyer, Joseph H.
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p. 2525 - 2532
(2007/10/02)
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