- Formation of [2]- and [3]Rotaxanes through Bridging under Kinetic and Thermodynamic Control
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An efficient synthesis of a doubly stranded [3]rotaxane has been developed through bridging of a pseudo[3]rotaxane featuring two axle components. Reversible azine formation was effective as the bridging reaction. Kinetic and thermodynamic conditions provided the [2]- and [3]rotaxanes, respectively.
- Fujino, Takaaki,Naitoh, Hirotake,Miyagawa, Shinobu,Kimura, Masaki,Kawasaki, Tsuneomi,Yoshida, Kazuyuki,Inoue, Hajime,Takagawa, Hiroaki,Tokunaga, Yuji
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Read Online
- PROTAC compound for targeted degradation of IDO1, and preparation method and application thereof
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The invention provides a PROTAC compound represented by formula I and used for targeted degradation of IDO1, and a pharmaceutically acceptable salt, a hydrate or a solvate thereof. In the formula I, Xrepresents -CH2 or -C = O, Y represents -CH2 or -C= O, and n is a natural number from 2 to 9. The PROTAC compound for targeted degradation of the IDO1 has efficient activity of targeted degradation of the IDO1 protein.
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Paragraph 0024-0026; 0036-0037
(2020/06/17)
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- Amino-polystyrene supported hexaethylene glycol-bridged ionic liquid as an efficient heterogeneous catalyst for water-mediated nucleophilic hydroxylation
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We report a simple and eco-friendly method for producing an amino-polystyrene supported hexaethylene glycol-bridged ionic liquid (APS-HEGBIL) based on the copolymerization of amino-styrene with 1-vinyl imidazolium ionic liquid bearing hexaethylene glycol moieties, and its characterization by several analytical techniques. The resulting APS-HEGBIL catalyst was found to be remarkably efficient at catalyzing the selective nucleophilic hydroxylation of alkyl halides to produce the corresponding alcohols in water, which acted as a solvent and a nucleophilic hydroxide source. The catalyst was easily recycled and maintained its catalytic activity and stability after ten cycles with excellent yields. The main attributes of the catalyst were that it significantly enhanced the nucleophilicity of water during reactions and promoted the rapid conversions of polar and base-sensitive alkyl halide reactants to alcohols in excellent yields. The combination of ionic liquids and polymeric materials afforded quasi-homogeneous catalysts that were recycled by simple filtration and provided environmentally benign means for conducted catalytic procedures.
- Reddy, Mudumala Veeranarayana,Kang, Seok Min,Yoo, Suah,Woo, Sang Sik,Kim, Dong Wook
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p. 9435 - 9442
(2019/04/01)
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- Preparation method of organic intermediate hexaethylene glycol
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The invention provides a preparation method of organic intermediate hexaethylene glycol. The preparation method comprises the following steps of: dissolving tetraglycol in tetrahydrofuran, and adding sodium hydride for reaction; after no hydrogen is released, cooling, dropwise adding tert-butyl bromoacetate for reacting overnight; after reaction is finished, adding water, quenching residual sodium hydride, and extracting with ethyl acetate so as to obtain an intermidate compound A; drying the compound A, mixing with silica gel powder, packing column, performing chromatographic purification, dissolving the purified compound A into tetrahydrofuran, cooling, adding lithium aluminium hydride for reacting overnight; after reaction is finished, adding water, quenching residual lithium aluminium hydride, extracting with small polar impurities with dichloromethane, reserving a water phase, adding ion exchange resin until the pH is neutral, filtering out resin, and performing vacuum concentration on the water phase, thereby obtaining organic intermediate hexaethylene glycol. The preparation method is capable of producing a large amount of hexaethylene glycol, not only is convenient to extract and purify and high in final hexaethylene glycol, but also can be applied to series of high polyethylene glycol products with single synthesis.
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Paragraph 0014; 0015
(2017/06/02)
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- Nucleophilic Hydroxylation in Water Media Promoted by a Hexa-Ethylene Glycol-Bridged Dicationic Ionic Liquid
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Hexaethylene glycol bis(3-hexaethylene glycol imidazolium) dimesylate ionic liquid (hexaEG-DHIM) was designed and prepared as a highly efficient promoter for the nucleophilic hydroxylation of alkyl halides to the corresponding alcohol products in neat water media. It was observed that hexaEG-DHIM promoter enhanced the nucleophilicity of water significantly in the reaction. In addition, the hexaEG-DHIM could be reused several times without loss of activity. Moreover, the hydroxylation reactions of base-sensitive and/or polar alkyl halide substrates proceeded highly chemoselectively in excellent yields.
- Jadhav, Vinod H.,Kim, Jin Gwan,Jeong, Hyeon Jin,Kim, Dong Wook
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p. 7275 - 7280
(2015/07/28)
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- Highly efficient synthesis of monodisperse poly(ethylene glycols) and derivatives through macrocyclization of oligo(ethylene glycols)
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A macrocyclic sulfate (MCS)-based approach to monodisperse poly(ethylene glycols) (M-PEGs) and their monofunctionalized derivatives has been developed. Macrocyclization of oligo(ethylene glycols) (OEGs) provides MCS (up to a 62-membered macrocycle) as versatile precursors for a range of monofunctionalized M-PEGs. Through iterative nucleophilic ring-opening reactions of MCS without performing group protection and activation, a series of M-PEGs, including the unprecedented 64-mer (2850Da), can be readily prepared. Synthetic simplicity coupled with versatility of this new strategy may pave the way for broader applications of M-PEGs. Macrocycles make synthesis easier: Convenient macrocyclization of the OEGs provides versatile macrocyclic sulfates. These compounds are cornerstones for both monofunctionalization of OEGs and highly efficient synthesis of monodisperse PEGs and derivatives, including an unprecedented 64-mer.
- Zhang, Hua,Li, Xuefei,Shi, Qiuyan,Li, Yu,Xia, Guiquan,Chen, Long,Yang, Zhigang,Jiang, Zhong-Xing
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p. 3763 - 3767
(2015/03/18)
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- Controlled-length efficient synthesis of heterobifunctionalized oligo ethylene glycols
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A set of heterobifunctional oligo ethylene glycols have been synthesized in a straightforward and stepwise manner starting from inexpensive, commercially available, tetraethylene glycol. Introduction of terminal allyl moieties followed by reductive ozonolysis allowed controlled elongation. Mono-allyl derivatives were used for the elongation with a functionalized moiety and for successive introduction of different functional groups on the chain terminal. Georg Thieme Verlag Stuttgart - New York.
- Zona, Cristiano,D'Orazio, Giuseppe,La Ferla, Barbara
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supporting information
p. 709 - 712
(2013/05/09)
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- A cost-effective, column-free route to ethylene glycol oligomers EG 6, EG10, and EG12
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Although monodisperse ethylene glycol (EG) oligomers are important in a wide range of applications (ranging from drug therapeutics to materials science and engineering), their cost - especially for longer EG oligomers is often prohibitive. For example, decaethylene, EG10, and dodecaethylene, EG12, glycols cost hundreds of dollars per gram, and are only available from most vendors, including Sigma-Aldrich, in the polydispersed form. This high-cost is, in large part, due to laborious nature of synthesis and, above all, purification steps involved. Therefore, the motivation of our work was to design a cost-effective route to the EG oligomers that would altogether avoid the column-chromatography purification. This was achieved by a simple synthetic strategy, which combines bidirectional growth of the EG chains with the protection scheme using easy-to-remove trityl groups. Georg Thieme Verlag Stuttgart · New York.
- Gothard, Chris M.,Grzybowski, Bartosz A.
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experimental part
p. 717 - 722
(2012/04/04)
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- Convenient multigram synthesis of monodisperse oligo(ethylene glycols): Effective reaction monitoring by infrared spectroscopy using an attenuated total reflection fibre optic probe
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A convenient approach for the synthesis of monodisperse oligo(ethylene glycols) up to 12 units is described. A novel cleavage protocol replacing laborious hydrogenolysis is introduced to achieve a fast, inexpensive and widely applicable procedure. In addition to the synthetic part, Fourier transform infrared (FTIR) spectroscopy using a fibre optic attenuated total reflection (ATR) sensor was applied to monitor the formation of sensitive key intermediates, resulting in optimized reaction times. By applying this in-line technique, the possibility of real-time analysis under inert conditions was impressively demonstrated.
- Lumpi, Daniel,Braunshier, Christian,Hametner, Christian,Horkel, Ernst,Zachhuber, Bernhard,Lendl, Bernhard,Fr?hlich, Johannes
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supporting information; experimental part
p. 6469 - 6471
(2011/02/23)
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- An expedient synthesis of monodispersed oligo(ethylene glycols)
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A convenient approach to the synthesis of oligo(ethylene glycols) under phase transfer conditions is described. Oligo(ethylene glycols) (x = 7-12) are obtained in excellent yields and high purity via modular, bi-directional elongation of readily available ethylene glycol bis-tosylates.
- Burkett, Brendan A.,Chan, Tak Hang
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p. 1007 - 1010
(2007/10/03)
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- Multiple drug resistance reversal agent
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The present invention relates to a MDR reversal agent. The agent is polyvalent possessing two or more binding domains spaced to effectively inhibit the multiple drug resistance activity of Pgp. The MDR reversal agent is based upon the naturally occurring compound (?)-stipiamide. The multiple drug resistence reversal agent of the present invention can be a homodimer based on napthyl-DHS. The homodimer incorporates two napthyl-DHS domains joined by a series of joined ethylene glycol spacers. The invention also relates to method of reversing MDR in a human cell by administering the reversal agent of the invention. When Pgp is contacted with the reversal agent, the ATPase activity of Pgp is significantly reduced as well as the binding affinity of Pgp for its known substrates.
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- Therapeutic and diagnostic ligand systems comprising transport molecule binding properties and medicaments containing the same
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The invention relates to transport molecule binding ligand compounds which comprise a therapeutically and/or diagnostically active substance and a carrier molecule-affine substance with a high association constant to the carrier molecule. The invention also relates to medicaments containing these ligand compounds and to diagnostic kits.
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- Composition for film formation and material for insulating film formation
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A composition for film formation capable of forming a coating film excellent in low dielectric constant characteristics, cracking resistance, modulus of elasticity, and adhesion to substrates and useful as an interlayer insulating film material in semiconductor devices, etc. The composition for film formation contains (A) at least one member selected from an aromatic polyarylene and an aromatic poly (arylene ether), (B) a polyvinylsiloxane, and (C) an organic solvent.
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- Permeable, non-irritating prodrugs of nonsteroidal and steroidal agents
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Prodrugs containing an active drug molecule linked to a polyethylene glycol group, and a method of use thereof are described. Exemplary soluble ester prodrugs contain naproxen, triamcinolone acetonide, gancyclovir, taxol, cyclosporin, dideoxyinosine, trihydroxy steroids, and flurbiprofen molecules linked to polyethylene glycol (PEG) groups. Pharmaceutical compositions containing these prodrugs, and a method of using these esters for treating disease states or symptoms are also described.
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- Preparation and crystallinity of a large unsubstituted crown ether, cyclic heptacosa(oxyethylene) (cyclo-E27, 81-crown-27), studied by Raman spectroscopy, X-ray scattering and differential scanning calorimetry
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Cyclic heptacosa(oxyethyelene) (cyclo-E27, 81-crown-27) was prepared from linear α-hydro, ω-hydroxy-heptacosa(oxyethylene) by reaction with tosyl chloride under alkaline conditions, purified by preparative-scale gel permeation chromatography, and studied by laser-Raman spectroscopy, wide-angle and small-angle X-ray scattering, and differential scanning calorimetry. Comparison was made with the properties of linear oligo(oxyethylene) dimethyl ethers (including C1E27C1). The sub-cell of the crystalline cyclic oligomer was the same as that of its linear counterparts, i.e. the same as that of high-molar-mass poly(oxyethylene). However, the cyclic oligomer crystallised as a twice-folded ring, as confirmed by its long spacing and the frequency of its single-node longitudinal acoustic mode (LAM-1). Enthalpies of fusion and melting temperatures were analysed to provide estimates of the enthalpy and entropy of formation of a fold in an oligo(oxyethylene) layer crystal.
- Yang, Zhuo,Yu, Ga-Er,Cooke, Jennifer,Ali-Adib, Ziad,Viras, Kyriakos,Matsuura, Hiroatsu,Ryan, Anthony J.,Booth, Colin
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p. 3173 - 3182
(2007/10/03)
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- Synthesis and Characterization of Large (30-60-Membered) Aliphatic Crown Ethers
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We report a new synthetic approach to large (30-72 membered) crown ethers based on isolation of the small and large cyclic polyethers made by combination of 1 mol or 2 mol each, respectively, of oligo(ethylene glycol)s and oligo(ethylene glycol) ditosylates.The advantages of this approach are the use of readily available glycols as starting materials and the ability to optimize the procedure for selective production of either macrocycle, producing yields superior or comparable to previous methods.At higher reaction temperatures the large crown ether is preferentially formed.This approach has been used to produce the crown ethers on 100-g scales.Purification was achieved by a combination of filtration through silica gel, treatment with a polymeric acid chloride, and recrystallization techniques, avoiding standard column chromatography.The pure crown ethers, 60-crown-20, 48-crown-16, 42-crown-14, 36-crown-12, and 30-crown-10, were characterized by melting points, 1H- and 13C-NMR, elemental analysis, and/or MS, GC-MS, and TGA-MS.Melting points were as much as 26 deg C higher than previously reported for these crown ethers.All the aliphatic crown ethers larger than 18-crown-6 decompose upon heating in air at ca. 200 deg C.
- Gibson, Harry W.,Bheda, Mukesh C.,Engen, Paul,Shen, Ya Xi,Sze, Jean,et al.
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p. 2186 - 2196
(2007/10/02)
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- Production of polyalkylene glycol ethers
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Mono-alkyl or alkylene ethers of polyalkylene glycols are produced by reacting them with an aldehyde to form an adduct and hydrogenating the adduct.
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- Cation-controlled Emission of Crowned Acetophenone
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Effects of alkali- and alkaline-earth-metal cations on the emission properties of 4'-acetylbenzo-15-crown-5 (1a), 4'-acetylbenzo-18-crown-6 (1b), 4'-acetylbenzo-21-crown-7 (1c), and 3,4-dimethoxyacetophenone (2) has been studied in degassed EtOH-MeOH (4:1 v/v) glasses at 77 K.The fluorescence quantum yields (φf) for (1a-c) were negligibly small (0.009-0.014).The phosphorescence quantum yields (φp) for (1a), (1b), (1c), and (2) were 0.26, 0.47, 0.51, and 0.52, respectively, being dependent on the ring size of the crown ether moiety.Binding of alkaline-earth-metal cations decreased the phosphorescence peak at 470 nm concomitant with an appearance of the fluorescence peak at 365 nm.The φf/φp values increased with an increase in the binding ability of alkaline-earth-metal cations to (1a-c).Although φp values of (1a-c) slightly decreased on addition of alkali-metal cations, the exception being a slight enhancement of φp for (1a)-Cs+, (1b)-Cs+, and (1b)-Rb+ systems, no fluorescence peak appeared.
- Shirai, Masamitsu,Morimoto, Satoru,Tanaka, Makoto
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p. 1187 - 1190
(2007/10/02)
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- Phase-Transfer-Catalyzed Synthesis of Oligoethylene Glycols and Derivatives
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An efficient, two-step synthetic method for the addition of ethyleneoxy units to diols is reported.Reaction of HOROH with Cl(CH2CH2O)nTHP and 50percent aqueous NaOH in the presence of a phase-transfer catalyst gives THP(OCH2CH2)nORO(CH2CH2O)nTHP from which the protecting groups are readily removed to provide H(OCH2CH2)nORO(CH2CH2O)n in good-to-excellent yields.The influence of reactant diol structure upon yield has been determined.
- Bartsch, Richard A.,Cason, Victor C.,Czech, Bronislaw P.
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p. 857 - 860
(2007/10/02)
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- Intramolecular End-to-End Reactions of Photoactive Terminal Groups Linked by Poly(oxyethylene) Chains
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The triplet-sensitized photochemical reaction using a series of poly(oxyethylene) chains with a pair of photoactive terminal groups, dibenzazepine (DBA) chromophores (DBA-COCH2CH2(OCH2CH2)nOCH2CH2CO-DBA, n=0-10) was examined.The photoirradiation of bichromophoric compounds caused either intra- or intermolecular reactions.These reactions were kinetically analyzed by two different methods: the measurement of deactivation processes of the reaction intermediates (excited triplet state of DBA) by nanosecond laser photolysis and the quantitative analysis of the reaction products by GPC.The intramolecular deactivation rate constant, kintra, showed a remarkable chain-length dependence; the maximum kintra value appeared at n=5 and it was found to be 5.9X104 s-1.On the other hand, the intramolecular cyclization rate also depends on the chain length; the maximum quantum yield, φintrad, was given at n=7 (φintrad=0.51).The chain length for the maximum cyclization yield shifted slightly to the longer region than that for the maximum kintra value due to the restriction of the terminal structure (anti-configuration).The results obtained for this reaction system are compared with those obtained for the previously reported polymethylene system and the effect of chain flexibility on the intramolecular ring-closure reaction is discussed.
- Ashikaga, Kazuo,Ito, Shinzaburo,Yamamoto, Masahide,Nishijima, Yasunori
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p. 2443 - 2450
(2007/10/02)
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- A Facile Synthesis of Hexa- and Octaethylene Glycols
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One-pot syntheses of hexa- and octaethylene glycol are achieved by the reaction of tri- or tetraethylene glycol with tosyl chloride in the presence of an appropriate base followed by a Williamson-type condensation reaction.
- Nakatsuji, Yohji,Kameda, Nobuko,Okahara, Mitsuo
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p. 280 - 281
(2007/10/02)
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- A NOVEL, UNEQUIVOCAL SYNTHESIS OF POLYETHYLENE GLYCOLS
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Unequivocal synthesis of polyethyleneglycols is presented.The key step for this synthesis is the selective monobenzylation of oligoethyleneglycols by the phase transfer catalysis technique.
- Coudert, Gerard,Mpassi, Michel,Guillaumet, Gerald,Selve, Claude
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- SYNTHESES AND PROPERTIES OF ARENEDIAZONIUM AND ANILINIUM CATION LARIAT ETHER COMPLEXES: AN "OSTRICH MOLECULE" COMPLEX AND EVIDENCE FOR INTRAMOLECULAR SIDEARM - MACRORING INTERACTION
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The preparation of several novel lariat ethers (macrocyclic crown polyethers having sidearms bearing pendant donor groups) is reported.These compounds are ethers derived from known 2-hydroxymethyl-15-crown-5 or -21-crown-7.The sidearms include 2-aminophenyl, 2,4-diaminophenyl, 2-nitrophenyl, 2-(3'-nitrobiphenyl), and 2-(3'-aminobiphenyl).In several cases, the amino groups were converted into ammonium salts which showed substantial stabilization by intramolecular hydrogen bonding.Likewise, an -NH2(1+)*BF3(1-) complex showed evidence of intramolecular hydrogen bonding.Diazotization of the aminobiphenyl residue produced an arenediazonium cation which underwent intramolecular crown complexation, as judged by infrared spectroscopic studies to form what we call an "ostrich molecule" complex.Addition of N,N-dimethylaniline to the intramolecular arenediazonium cation complex afforded an azo compound, but europium shift reagent studies showed clearly that the diazonium cation reacted outside the macroring.
- Beadle, James R.,Dishong, Dennis M.,Khanna, Raj K.,Gokel, George W.
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p. 3935 - 3944
(2007/10/02)
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- The Influence of Cation Binding on the Kinetics of the Hydrolysis of Crown Ether Acetals
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The rate of hydrogen ion-catalysed hydrolysis of crown ether acetals in 60:40 (v/v) dioxan-water is found to be strongly decreased by the addition of alkali and alkaline earth metal chlorides having cations of appropriate size to be complexed by the substrate ring.The compounds studied are the monoacetals CH3CH(OCH2CH2)xO with x=1-8.The dependence of the initial rate of formation of acetaldehyde on metal-ion concentration is expressed in terms of (i) the equilibrium constant for complex formation, (ii) the influence of the bound cation on the rate constant, and (iii) an electrolyte effect.A curve-fitting procedure is used to derive the parameters governing the first two of these effects.The equilibrium constants are large and cannot be evaluated with any precision, but a fair estimate of the influence of the guest cation on the rate can be obtained.This effect is explicable by the electrostatic repulsion between the cationic charges of the metal ion and the proton added to the acetal in the first step of the hydrolysis.The size of the effect requires the values of the effective relative permittivity of the space between the charges to be close to that of the bulk solvent.
- Baker, David S.,Gold, Victor,Sghibartz, Cristian M.
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p. 1121 - 1128
(2007/10/02)
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- MACROHETEROCYCLES. VIII. SYNTHESIS AND COMPLEXING ABILITY OF TRICARBONYL ANALOGS OF CROWN ETHERS
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The respective dicarboxylic acids were obtained by the reaction of glycolic, β-phenyllactic, and thioglycolic acids with diglycolic anhydride.Thirteen new macrocyclic esters were obtained by the reaction of the chlorides of these acids with polyethylene glycols under the conditions of high dilution.The stability constants of the complexes of these compounds with potassium and sodium cations in alcohol were determined by a polarographic method.It was established that certain crown ether triones exhibit appresiable sodium/potassium selectivity.
- Bogat-skii, A. V.,Luk'yanenko, N. G.,Popkov, Yu. A.,Zakharov, K. S.,Varava, V. M.
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p. 938 - 943
(2007/10/02)
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- Complexes of macrocyclic compounds
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Novel macrocyclic (monocyclic and bicyclic) compounds having nitrogen bridgehead atoms and having in the hydrocarbon bridging chains at least two additional hetero atoms selected from the group consisting of sulfur, oxygen, and nitrogen, when admixed with a compatible cation-donor compound form stable cation-containing macrocyclic complexes which, in turn, can be conveniently dissociated by addition of acid or a quaternizing agent. The novel macrocyclics are valuable for use in the same way and for the same purposes as chelating agents.
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- Monocyclic macrocyclic compounds and complexes thereof
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Novel monocyclic macrocyclic compounds having nitrogen bridgehead atoms and having in the hydrocarbon bridging chains at least two additional hetero atoms selected from the group consisting of sulfur, oxygen, and nitrogen, when admixed with a compatible cation-donor compound form stable cation-containing macrocyclic complexes which, in turn, can be conveniently dissociated by addition of acid or a quaternizing agent. The novel macrocyclics are valuable for use in the same way and for the same purposes as chelating agents.
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