- Double "open and Shut" Transformation of γ-Carbolines Triggered by Ammonium Salts: One-Pot Synthesis of Multiheterocyclic Compounds
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A novel cascade reaction of indole-2,3-epoxide equivalents with γ-carbolines by utilizing a double "open and shut" transformation to access multiheterocyclic compounds containing both isotryptamines and pyrimido[1,6-a]indoles has been developed. This strategy utilizes the in situ formation of a bulky quaternary ammonium salt via ammonium exchange, which undergoes Hofmann elimination/vinylogous Mannich/retro-Mannich/cyclization cascade sequences.
- Abe, Takumi,Shimizu, Haruka,Takada, Shiori,Tanaka, Takahiro,Yoshikawa, Mai,Yamada, Koji
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- 1,2,3,4-Tetrahydro-γ-carbolinium salts: Novel reactions with thiols, mediated by polymer-supported reagents
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A series of dialkyl-[2-(3-alkylsulfanylmethyl-1H-indol-2-yl)-ethyl]amines was produced using a novel route involving nucleophilic ring opening of 2,2-dialkyl-1,2,3,4-tetrahydro-γ-carbolinium salts with thiols. The insertion reaction was mediated by a strong, polymer-supported base, and the purification of the target compounds was facilitated using resin-bound sulfonic acid.
- Lizarzaburu, Mike E.,Shuttleworth, Stephen J.
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Read Online
- Direct Synthesis of Indoles from Azoarenes and Ketones with Bis(neopentylglycolato)diboron Using 4,4′-Bipyridyl as an Organocatalyst
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Multifunctionalized indole derivatives were prepared by reducing azoarenes in the presence of ketones and bis(neopentylglycolato)diboron (B2nep2) with a catalytic amount of 4,4′-bipyridyl under neutral reaction conditions, where 4,4′-bipyridyl acted as an organocatalyst to activate the B-B bond of B2nep2 and form N,N′-diboryl-1,2-diarylhydrazines as key intermediates. Further reaction of N,N′-diboryl-1,2-diarylhydrazines with ketones afforded N-vinyl-1,2-diarylhydrazines, which rearranged to the corresponding indoles via the Fischer indole mechanism. This organocatalytic system was applied to diverse alkyl cyclic ketones, dialkyl, and alkyl/aryl ketones, including heteroatoms. Methyl alkyl ketones gave the corresponding 2-methyl-3-substituted indoles in a regioselective manner. This protocol allowed us to expand the preparation of indoles having high compatibility with not only electron-donating and electron-withdrawing groups but also N- and O-protecting functional groups.
- Misal Castro, Luis C.,Sultan, Ibrahim,Nishi, Kohei,Tsurugi, Hayato,Mashima, Kazushi
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p. 3287 - 3299
(2021/03/01)
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- Careful investigation of the hydrosilylation of olefins at poly(ethylene glycol) chain ends and development of a new silyl hydride to avoid side reactions
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Hydrosilylation of olefin groups at poly(ethylene glycol) chain ends catalyzed by Karstedt catalyst often results in undesired side reactions such as olefin isomerization, hydrogenation, and dehydrosilylation. Since unwanted polymers obtained by side reactions deteriorate the quality of end-functional polymers, maximizing the hydrosilylation efficiency at polymer chain ends becomes crucial. After careful investigation of the factors that govern side reactions under various conditions, it was related that the short lifetime of the unstable Pt catalyst intermediate led to the formation of more side products under the inherently dilute conditions for polymers. Based on these results, two new chelating hydrosilylation reagents, tris(2-methoxyethoxy)silane (5) and 2,10-dimethyl-3,6,9-trioxa-2,10-disilaundecane (6), have been developed. It was demonstrated that the hydrosilylation efficiency at polymer chain ends was significantly increased by employing the internally coordinating hydrosilane 5. In addition, employment of the internally coordinating disilane species 6 in an addition polymerization with 1,5-hexadiene by hydrosilylation reaction yielded a polymer with high molecular weight (Mn = 9300 g/mol), which was significantly higher than that (Mn = 2600 g/mol) of the corresponding polymer obtained with non-chelating dihydrosilane, 1,1,3,3-tetramethyldisiloxane.
- Shin, Hyunseo,Moon, Bongjin
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p. 527 - 536
(2018/01/27)
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- Anion Receptor, Electrolyte Containing the Anion Receptor and Lithium Ion Battery and Lithium Ion Capacitor Using the Electrolyte
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The present invention relates to a novel anion acceptor having a high cation transport rate and improved lifespan, an electrolyte containing the same, and a lithium ion battery and a lithium ion capacitor manufactured using the electrolyte and, more specifically, to a compound represented by chemical formula 1. In the chemical formula 1, n is an integer from 1 to 50, and X is one or more selected from the group consisting of -NR_1R_2, -NR_3R_4, -Ph(-(m)-R_5), and -O-(CH_2CH_2O)_y-CH_3.COPYRIGHT KIPO 2018
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Paragraph 0088-0090
(2018/09/30)
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- Plasticizing Li single-ion conductors with low-volatility siloxane copolymers and oligomers containing ethylene oxide and cyclic carbonates
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To prepare a safe electrolyte for lithium ion batteries, two groups of novel low-volatility plasticizers combining pendant cyclic carbonates and short ethylene oxide chains have been successfully synthesized, as confirmed by 1H, 13C and 29Si NMR spectroscopy. The Fox equation describes the composition dependence of the glass transition temperature (Tg) very well for the random polysiloxane-based copolymer plasticizers (11000 g as much as 20 K lower than the Fox equation prediction because of their lower molecular weight (450 g. Mixing with 20 wt% polysiloxane tetraphenyl borate-Li ionomer (14 mol% borate and 86 mol% cyclic carbonate) increases conductivity relative to the neat ionomer by lowering Tg, increasing dielectric constant and providing better solvation of Li+. The best oligomeric plasticizer only has Tg 10 K lower than the Fox prediction but has dielectric constant 30% larger than expected by the Landau-Lifshitz mixing rule, owing to a surprisingly low viscosity, resulting in ambient conductivity 2 × 10-5 S cm-1. For both groups of plasticizers, the fraction of cyclic carbonates relative to ethylene oxide governs the magnitude and temperature dependence of the ionic conductivity.
- Liang, Siwei,Chen, Quan,Choi, U Hyeok,Bartels, Joshua,Bao, Nanqi,Runt, James,Colby, Ralph H.
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p. 21269 - 21276
(2015/11/09)
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- Thermodynamic Properties of Carbosilane Dendrimers of the Sixth Generation with Ethylene Oxide Terminal Groups
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The temperature dependences of heat capacities of carbosilane dendrimers of the sixth generation with ethyleneoxide terminal groups, denoted as G6[(OCH2CH2)1OCH3]256 and G6[(OCH2CH2)3OCH3]256, were measured in the temperature range from T = (6 to 520) K by precision adiabatic calorimetry and differential scanning calorimetry (DSC). In the above temperature range the physical transformations, such as glass transition and high-temperature relaxation transition, were detected. The standard thermodynamic characteristics of the revealed transformations were determined and analyzed. The standard thermodynamic functions, namely, heat capacity Cp°(T), enthalpy H°(T) - H°(0), entropy S°(T) - S°(0), and Gibbs energy G°(T) - H°(0) for the range from T → 0 to 520 K, and the standard entropies of formation ΔfS°of the investigated dendrimers in the devitrified state at T = 298.15 K, were calculated per corresponding moles of the notional structural units. The standard thermodynamic properties of dendrimers under study were discussed and compared with literature data for carbosilane dendrimers with different functional terminal groups.
- Sologubov, Semen S.,Markin, Alexey V.,Smirnova, Natalia N.,Novozhilova, Natalia A.,Tatarinova, Elena A.,Muzafarov, Aziz M.
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p. 14527 - 14535
(2015/11/23)
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- New route of benzyne cyclization for synthesis of 2,3,4,5-tetrahydro-1h-pyrido[4,3-b]indole derivatives avoiding highly toxic aryl hydrazines
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A new route for the regioselective synthesis of 2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole derivatives was developed based on cyclization of 3-chlorophenylimine-N-alkyl-4-piperidones by "the complex bases" of NaNH2 or KNH2. The procedure was performed under variable reaction conditions in inert proton-free solvents, such as THF, dioxane, 1,2-dimethoxyethane, toluene, and xylene, at temperatures varying from 20C to boiling point of the solvent used. Toxic arylhydrazine intermediates occurring in the classical Fischer indole synthesis are avoided.
- Kovacikova, Lucia,Stefek, Milan
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p. 1257 - 1263
(2015/04/27)
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- Pyrido[4,3-b]indole and pyrido[3,4-b]indole derivatives and methods of use
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This disclosure is directed to pyrido[4,3-b]indole and pyrido[3,4-b]indole derivatives. Pharmaceutical compositions comprising the compounds are also provided, as are methods of using the compounds in a variety of therapeutic applications, including the treatment of a cognitive disorder, psychotic disorder, neurotransmitter-mediated disorder and/or a neuronal disorder. The compounds may bind to and antagonize receptor α2B, α1B or α2A. The compounds may find use in therapy, e.g., to (i) reduce blood pressure and/or (ii) promote renal blood flow and/or (iii) decrease or inhibit sodium reabsorption, or to regulate blood glucose level, increase insulin secretion and treat diseases or conditions that are, or are expected to be, responsive to an increase in insulin production. The compounds may also be used to treat diseases or conditions that are expected to be responsive to a decrease in blood pressure. Use of the compounds to treat cardiovascular, renal disorders or type 2 diabetes is particularly described.
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Page/Page column 182; 183
(2016/03/05)
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- High ion content siloxane phosphonium ionomers with very low T g
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Polysiloxane phosphonium single-ion conductors grafted with oligomeric PEO and with ion contents ranging from 5 to 22 mol % were synthesized via hydrosilylation reaction. The parent Br- anion was exchanged to F- or bis(trifluoromethanesulfonyl)imide (TFSI-). X-ray scattering data suggest ion aggregation is absent in these phosphonium ionomers, which contributes to low glass transition temperatures (below -70 °C) with only a weak dependence on both ion content and counteranion type. Conductivities weakly increase with ion content but exhibit a strong dependence on anion type. The highest conductivity at 30 °C is 20 μS/cm for dry neat ionomer, with the TFSI- anion, consistent with its relatively delocalized negative charge and large size that weaken interactions between TFSI- and the phosphonium cation.
- Liang, Siwei,Oreilly, Michael V.,Choi, U Hyeok,Shiau, Huai-Suen,Bartels, Joshua,Chen, Quan,Runt, James,Winey, Karen I.,Colby, Ralph H.
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p. 4428 - 4437
(2014/07/22)
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- Synthesis and properties of carbosilane dendrimers of the third and sixth generations with the ethylene oxide surface layer in bulk and in monolayers at the air-water interface
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A number of carbosilane dendrimers with the ethylene oxide surface layer was synthesized. The density of the surface layer determines their capability to form a physical network due to intermolecular entanglements. The specific interactions of the ethylene oxide fragments exert a minor effect on the thermal behavior of dendritic macromolecules. The compression-expansion isotherms of Langmuir films together with Brewster angle microscopy data show that an increase in the core rigidity with increasing the generation number favors the formation of ordered molecular multilayers. The appearance of a pronounced hysteresis in the compression-expansion cycles is a common phenomenon for amphiphilic dendrimers of high generations.
- Novozhilova,Malakhova,Buzin,Buzin,Tatarinova,Vasilenko,Muzafarov
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p. 2514 - 2526
(2014/11/08)
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- Constructions of tetrahydro-γ-carboline skeletons via intramolecular oxidative carbon-carbon bond formation of enamines
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The synthetically and biologically important 4-methyl and 4-methoxy tetrahydro-γ-carboline compounds were readily synthesized in high yields from an aryl amine and a 5-amino-3-oxopentanoate derivative through a series of reactions of enamination, oxidative annulation, deprotection/lactamization and the final reduction reaction of the carbonyl group. The underpinning strategy involves the oxidative C(sp2)-C(sp2) bond formation realized by either Pd(OAc)2/Cu(OAc)2 or a hypervalent iodine reagent.
- Lv, Jinglei,Li, Ji,Zhang-Negrerie, Daisy,Shang, Siyun,Gao, Qingzhi,Du, Yunfei,Zhao, Kang
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p. 1929 - 1932
(2013/06/04)
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- OLEFIN METATHESIS REACTIONS OF AMINO ACIDS, PEPTIDES AND PROTEINS CONTAINING ALLYL SULFIDE GROUPS
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A method for the modification of an amino acid, protein or peptide is disclosed. The method comprises reacting a carbon-carbon double bond-containing compound with an amino acid, a protein or a peptide containing an allyl sulfide group in the presence of a catalyst which promotes olefin metathesis, to form a modified amino acid, protein or peptide. Preferred carbon-carbon double bond-containing compounds include carbohydrates.
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Page/Page column 12
(2012/07/27)
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- Second-generation histone deacetylase 6 inhibitors enhance the immunosuppressive effects of Foxp3+ T-regulatory cells
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Second-generation Tubastatin A analogues were synthesized and evaluated for their ability to inhibit selectively histone deacetylase 6 (HDAC6). Substitutions to the carboline cap group were well-tolerated with substitution at the 2-position of both β- and γ-carbolines being optimal for HDAC6 activity and selectivity. Some compounds in this series were determined to have subnanomolar activity at HDAC6 with more than 7000 fold selectivity for HDAC6 versus HDAC1. Selected compounds were then evaluated for their ability to augment the immunosuppressive effect of Foxp3+ regulatory T cells. All compounds tested were found to enhance the ability of regulatory T cells to inhibit the mitotic division of effector T cells both in vitro and in vivo, suggesting that further investigation into the use of these compounds for the treatment of autoimmune disorders is warranted.
- Kalin, Jay H.,Butler, Kyle V.,Akimova, Tatiana,Hancock, Wayne W.,Kozikowski, Alan P.
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experimental part
p. 639 - 651
(2012/03/11)
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- Fischer indole synthesis in low melting mixtures
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Functionalized indoles are synthezised under mild conditions in a tartaric acid-dimethylurea melt. The melt serves as the solvent and as the catalyst. Under these reaction conditions, sensitive functional groups such as N-Boc, N-Cbz, or azides are stable, and indolenines are obtained regioselectively in excellent yields. The practical use of the method is demonstrated in the synthesis of the hormone melatonin.
- Gore, Sangram,Baskaran, Sundarababu,K?nig, Burkhard
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supporting information
p. 4568 - 4571
(2012/10/30)
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- PROCESS FOR THE PREPARATION OF 2,3,4,5-TETRAHYDRO-1H-PYRIDO[4,3-B]INDOLE DERIVATIVES
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The value of the invention is the application of the cyclization of Schiff-bases of the general formula (3a-i), where R1 - R8 are substituents defined in example 1, whereby R9 = Cl using complex bases of amides of group I of the periodic table (NaNH2, KNH2) from 2.1 - 5 equiv. and alcoholates of group I of the periodic table (t-BuONa, tBuOK) from 0.05 - 2 equiv. with the advantage of application of 3 equiv. of NaNH2 and 0.05 equiv. of t-BuONa, or their mixtures with PEG (m.w. = 500 - 6000), or crown ethers, or catalysts of phase transfer lithium in inert proton-free diluents, such as benzene, cyclohexane, toluene, xylene, 1,2-dimethoxyethane, dioxane, etc., with the advantage of using THF, at a temperature from 20 °C to boiling point of the diluent used, or with the application of organo-metallic bases such as LDA, t-BuLi in inert proton-free diluents at a temperature from -80°C to 25 °C.
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Page/Page column 9
(2011/11/30)
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- Ruthenium-catalyzed γ-carbolinium ion formation from aryl azides; Synthesis of dimebolin
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A range of γ-carbolines were produced stereoselectively from ruthenium(III)-catalyzed reactions of 3-pyridyl substituted aryl azides. Other catalysts and conditions were neither as selective nor as high-yielding. This method was used to synthesize dimebolin in a concise and efficient manner.
- Dong, Huijun,Latka, Regina T.,Driver, Tom G.
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p. 2726 - 2729
(2011/06/28)
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- METHODS AND COMBINATION THERAPIES FOR TREATING ALZHEIMER'S DISEASE
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The invention provides methods and combination therapies for treating and/or preventing and/or slowing the onset and/or development of Alzheimer's disease using a hydrogenated pyrido (4,3-b) indole (e.g., dimebon) in conjunction with another compound, pharmaceutically acceptable salt thereof or therapy for Alzheimer's disease.
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- PYRIDO (4,3-B) INDOLES CONTAINING RIGID MOIETIES
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This disclosure is directed to pyrido[4,3-b]indoles having rigid moieties. The compounds in one embodiment are pyrido[4,3-b]indoles having an unsaturated hydrocarbon moiety. The compounds in another embodiment are pyrido[4,3-b]indoles having a cycloalkyl, cycloalkenyl or heterocyclyl moiety. Pharmaceutical compositions comprising the compounds are also provided, as are methods of using the compounds in a variety of therapeutic applications, including the treatment of a cognitive disorder, psychotic disorder, neurotransmitter-mediated disorder and/or a neuronal disorder.
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Page/Page column 234
(2010/05/14)
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- PYRIDOINDOLE MODULATORS OF NMDA RECEPTOR AND ACETYLCHOLINESTERASE
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The present invention relates to new pyridoindole modulators of NMDA receptors, AMPA receptors, and/or L-type calcium channels, and/or inhibitors of acetylcholinesterase, pharmaceutical compositions thereof, and methods of use thereof.
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Page/Page column 14
(2010/06/13)
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- Novel perfluoroalkylated oligo(oxyethylene) methyl ethers with high hemocompatibility and excellent co-emulsifying properties for potential biomedical uses
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Two series of novel perfluoroalkylated amphiphilic compounds were synthesized from monomethyl ethers of mono-, di- and tri-(oxyethylene) glycols. The first series CH3(OCH2CH2)nOCH2CH(OH)CH2-CF2(CF2CF2)nCF3 (n = 1-3) bearing the hydroxy group at the spacer between hydrophilic and hydrophobic parts was prepared by the reactions of the monomethyl ethers with 2-(perfluoroalkylmethyl)oxiranes in 76-97% yields. The second series CH3(OCH2CH2)nOCH2CH2CH2-CF2(CF2CF2)nCF3 (n = 1-3) possessing the non-hydroxylated spacer was synthesized from allyl methyl ethers of oligo(oxyethylene) glycols using radical additions of perfluoroalkyl iodides and subsequent selective reductions of the C-I bond in the adducts in overall yields of 23-69%. Some of the novel amphiphilic compounds displayed very low hemolytic activity to erythrocytes and excellent co-emulsifying properties on testing on perfluorodecalin/Pluronic F-68 microemulsions. 1-O-(2-Hydroxy-4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluorononyl)-d-xylitol was prepared by a novelized synthesis and employed as a standard compound in the testing.
- Kaplánek, Robert,Paleta, Old?ich,Ferjentsiková, Ivana,Kodí?ek, Milan
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experimental part
p. 308 - 316
(2009/12/03)
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- NEW TETRACYCLIC COMPOUNDS
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This disclosure relates to new tetracyclic compounds that may be used to modulate a histamine receptor in an individual. The compounds in one embodiment are tetracyclic [4,3- b]indoles. Pharmaceutical compositions comprising the compounds are also provided, as are methods of using the compounds in a variety of therapeutic applications, including the treatment of a cognitive disorder, psychotic disorder, neurotransmitter-mediated disorder and/or a neuronal disorder.
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Page/Page column 250
(2009/05/30)
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- METHODS FOR PREPARING PYRIDYLETHYL-SUBSTITUTED CARBOLINES
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Methods of preparing pyridylethyl-substituted carbolines under reaction conditions that use fewer molar equivalents of MVP to produce the pyridylethyl-substituted carboline as compared to reported methods of preparing pyridylethyl-substituted carbolines using MVP are provided. Also provided are methods of preparing a pyridylethyl-substituted carboline using non-commercial MVP.
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Page/Page column 26
(2009/10/22)
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- Allyl sulfides are privileged substrates in aqueous cross-metathesis: Application to site-selective protein modification
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Allyl sulfides undergo efficient cross-metathesis in aqueous media with Hoveyda-Grubbs second generation catalyst 1. The high reactivity of allyl sulfides in cross-metathesis was exploited in the first examples of cross-metathesis on a protein surface. S-Allylcysteine was incorporated chemically into the protein, providing the requisite allyl sulfide handle. Preliminary efforts to genetically incorporate S-allylcysteine into proteins are also reported. Copyright
- Lin, Yuya A.,Chalker, Justin M.,Floyd, Nicola,Bernardes, Goncalo J. L.,Davis, Benjamin G.
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supporting information; experimental part
p. 9642 - 9643
(2009/02/04)
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- Methods and compositions for treating Huntington's disease
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The invention provides method for treating Huntington's disease, slowing the onset and/or development and/or progression of Huntington's disease or preventing the development of Huntington's disease using hydrogenated pyrido[4,3-b]indoles, including dimebon.
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- Network-type ionic conductors based on oligoethyleneoxy-functionalized pentamethylcyclopentasiloxanes
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Network-type solid polymer electrolytes (NSPEs) were synthesized containing oligoethylene oxide chains, CH3(OCH2CH2) 3(CH2)3-, within the network structures. Hydrosilylation reactions of precursors 1 and 2 (oligoethyleneoxy partially substituted pentamethylccyclopentasiloxanes (D5H)) with an α,ω-diallyloligo(ethylene glycol) were employed for the formation of the cross-linked networks. The conductivities of the network polymer/LiX complexes with variable EO/Li ratios were measured by impedance experiments. NSPE-2, with 36.0% cross-linking density, exhibited higher conductivity than NSPE-1, with 43.8%. The optimum conductivity (σ = 9.24 × 10 -5 S/cm at 25°C, 2.11 × 10-4 S/cm at 37°C) was found for NSPE-2 with lithium bis(oxalato)borate (LiBOB). LiBOB-doped polymers exhibited higher conductivity than those doped with LiTFSI at the same salt concentration.
- Zhang, Zhengcheng,Lyons, Leslie J.,Amine, Khalil,West, Robert
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p. 5714 - 5720
(2008/02/02)
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- Cross-Linked Network Polymer Electrolytes Based on a Polysiloxane Backbone with Oligo(oxyethylene) Side Chains: Synthesis and Conductivity
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A novel cross-linked siloxane-based solid polymer network has been synthesized by the hydrosilylation of polymethylhydrosiloxane (PMHS) partly substituted with oligo(ethylene glycol) methyl ether side groups and a α,ω-diallyl poly(ethylene glycol) cross-linking reagent. The ionic conductivities of the networks doped with LiTFSI are high at ambient temperature (σ = 1.33 × 10-4 S cm-1 at the optimum LiTFSI concentration EO/Li+ = 20:1). The temperature dependence of the conductivity followed the VTF form, indicating that polymer segmental motion assists the ion transport in the solid networks.
- Zhang, Zhengcheng,Sherlock, David,West, Ryan,West, Robert,Amine, Khalil,Lyons, Leslie J.
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p. 9176 - 9180
(2007/10/03)
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- Quantification of grafted poly(ethylene glycol)-silanes on silicon by time-of-flight secondary ion mass spectrometry
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Silicon grafted monodisperse poly(ethylene glycol) (PEG) silanes with various PEG chain lengths and mixtures of these were systematically analyzed with static time-of-flight secondary ion mass spectrometry (TOF-SIMS). The mass spectra show differences in the various relative signal intensities, an observation that was used to elucidate important aspects of the grafting process. The relationship between PEG-silane fragment ion abundances and Si+ ion abundances were used to (i) qualitatively describe layer thicknesses of grafted mixtures of PEG-silanes on silicon, (ii) construct a calibration curve from which PEG chain length (or molecular mass) can be determined and (iii) quantitatively determine surface mixture compositions of grafted monodisperse PEG-silanes of different chain lengths (3, 7 and 11 PEG units). The results suggest that discrimination does take place in the adsorption process. The PEG-silane with the shorter PEG chain is discriminated for mixtures containing PEG3-silane, whereas the PEG-silane with the longer PEG chain is discriminated in PEG7/PEG11-silane mixtures. The origin of this difference in adsorption behavior is not well understood. Aspects of the grafting process and the TOF-SIMS analyses are discussed. Copyrigh
- Norrman,Papra,Kamounah,Gadegaard,Larsen
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p. 699 - 708
(2007/10/03)
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- Thermochromism and solvatochromism of non-ionic polar polysilanes
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Polar polysilanes bearing ethereal side groups [{CH3-Si-(CH2)m-O-(CH2CH 2O)n-CH3}x, m = 3-5 and n = 0-3}] were prepared and were found to be soluble in a wide range of polar solvents. UV spectroscopic behavior is highly dependent on the nature of the solvents used but no simple relationship between λmax and specific solvent parameter is found. Small molar absorbance (ε 3)2CHOH (HFIP) in non-polar solvent (benzene, CH2Cl2) or even in (CH3)2CHOH solution, where higher HFIP concentration brings about longer wavelength absorption. This type of solvatochromism is originated by strong hydrogen bond formation between the ethereal side groups and HFIP. Because non-dissociative nature of HFIP-concerned hydrogen bonding, increased bulkiness of the side moieties brings about disentanglement. Polysilanes 1-5, though having long side chains, show thermochromism of continuous spectral shift on cooling. The same λmax value in thermochromism and solvatochromism indicates that nearly the same degree of disentanglement is caused by HFIP and thermally.
- Oka, Kunio,Fujiue, Naofumi,Nakanishi, Saburo,Takata, Toshikazu,West, Robert,Dohmaru, Takaaki
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- New inorganic-organic hybrid Li+ ion conducting polymer electrolytes
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A new series of inorganic-organic hybrid polymer electrolytes containing the aluminate structure were prepared. Incorporation of stronger Lewis acid sites into the polymer in the region of the aluminate bond was effective for enhancing ionic conductivity. The materials were shown to be single Li+ ion conductors.
- Fujinami, Tatsuo,Sugie, Kazuhiro,Mori, Kenji,Mehta, Mary Anne
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p. 619 - 620
(2007/10/03)
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- Pictet-Spengier Reaction in Trifluoroacetic Acid. Large Scale Synthesis of Pyridoindolobenzodiazepine as an Atypical Antipsychotic Agent
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Traditional syntheses of benzodiazepines involve a Bischler-Napieralski reaction which is a three step process and gives low overall yields.An attractive alternative is to construct the diazepine ring under Pictet-Spengler conditions.This paper reports the synthesis of a novel pyridoindolobenzodiazepine as a potent atypical antipsychotic agent.The key step in the synthesis is the ring formation of the diazepine ring in neat trifluoroacetic acid.
- Zhang, Lin-hua,Meier, W.,Wats, E.,Costello, T. D.,Ma, P.,et al.
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p. 8387 - 8390
(2007/10/02)
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- Stable silica-based ether bonded phases for biopolymer separations
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Fast high resolution separations of biopolymers with retention of biological activity have been achieved by hydrophobic interaction chromatography using trialkoxy silyl ethers of the general formula chemically bonded to silica-based chromatographic supports. In the formula R is alkyl of from one to five carbons, m is an integer from two to five, n is an integer from one to five, p is an integer from zero of ten, and R' is methyl, phenyl, or substituted phenyl. Stable and reproducible bonded phases are prepared in a novel solventless procedure by a bonding process which uses a defined and controlled amount of water on the silica surface and a gaseous or volatile basic catalyst such as ammonia to produce a controlled amount of silane polymerization and cross-linking in addition to extensive bonding between silane and silica. High performance liquid chromatography on such weakly hydrophobic stationary phases using aqueous eluents and decreasing salt gradients under mild conditions permits high speed, high resolution separations of biopolymers such as proteins without destruction of their biological activity and without column degradation. Size exclusion chromatography can also be performed on these phases using low ionic strength eluents.
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