- Electro-optic properties of a side chain poly(norbornene-dicarboximide) system with an appended phenyl vinylene thiophene chromophore
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A side chain EO copolymer series has been synthesized by ROMP using the Grubbs 3rd generation initiator and quenched with ethyl vinyl ether. The copolymers were prepared by combining two norbornene-dicarboximide monomers, one with a cyclohexyl substituent and another substituted with an FTC chromophore. The mol% of the chromophore-substituted monomer was varied from 0.00?mol% to 22.92?mol%, all polymers were obtained in a yield of between 83 and 92% and a purity of between 97 and 98%. The cis:trans vinylene ratio remained constant at 1:1, confirming the polymers were amorphous. Peak molecular weights increased from 29,541?g/mol to 142,113?g/mol and the PDI increased from 1.36 to 4.01 respectively. Glass transition and thermal decomposition temperatures decreased from 206?°C to 168?°C and 433?°C to 382?°C as the mol% of the chromophore-substituted monomer was increased. UV–vis absorbance spectroscopy was used to quantify the chromophore content. A close correlation (68–95%) between the measured and calculated absorbance was found. The polymer containing 22.92?mol% of the chromophore-substituted monomer had a maximum r33 of 70?pm/V when polled at an optimum field of 60?V/μm at a polling temperature of 200?°C. This equates to a high polling efficiency of 1.16. High current flow in this polymer film at elevated field strength caused a breakdown of the electrode, preventing access to an elevated electro-optic coefficient. This polymer was found to have an excellent stability of 76% when aged at 85?°C for 1000?h in air.
- Spring, Andrew M.,Qiu, Feng,Hong, Jianxun,Bannaron, Alisa,Yokoyama, Shiyoshi
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Read Online
- Online analysis of flowing streams using microflow HPLC
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The application of a recently developed online HPLC reaction sampling instrument for monitoring flow chemistry reactions is described. The system was found to work well for online analysis of flowing streams at or near atmospheric pressure, allowing for convenient time-based withdrawal, dilution, and HPLC analysis of the output of flow reactors. A general study of the capability of the instrument to sample from flowing streams is presented, along with a detailed study in which the instrument is used to characterize a thermal isomerization reaction carried out using a hot-zone flow reactor.
- Welch, Christopher J.,Gong, Xiaoyi,Cuff, James,Dolman, Sarah,Nyrop, Jason,Lin, Fiona,Rogers, Hallena
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Read Online
- Preparation method of exo-Dickson anhydride
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The preparation method comprises the following steps: (1) adding a solvent in a reaction container, maleic anhydride, a chiral catalyst D and nitrogen to replace air in a reaction container. (2) At -5 - 5 °C, cyclopentadiene is added dropwise, and the dropping is carried out at a certain temperature. (3) After the completion of the reaction, water was added and quenched. Concentration, crystallization in ethanol and filtration gave exo. The preparation method has the characteristics of high reaction stereoselectivity, high yield, good product quality, simple and convenient process operation, high stability and high safety, and is suitable for industrial mass production.
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Paragraph 0017-0018; 0042-0043; 0046-0049
(2021/10/16)
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- Near-Infrared Fluorescent Micelles from Poly(norbornene) Brush Triblock Copolymers for Nanotheranostics
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This contribution describes the design and synthesis of multifunctional micelles based on amphiphilic brush block copolymers (BBCPs) for imaging and selective drug delivery of natural anticancer compounds. Well-defined BBCPs were synthesized via one-pot multi-step sequential grafting-through ring-opening metathesis polymerization (ROMP) of norbornene-based macroinitiators. The norbornenes employed contain a poly(ethylene glycol) methyl ether chain, an alkyl bromide chain, and/or a near-infrared (NIR) fluorescent cyanine dye. After block copolymerization, post-polymerization transformations using bromide-azide substitution, followed by the strain-promoted azide-alkyne cycloaddition (SPAAC) allowed for the functionalization of the BBCPs with the piplartine (PPT) moiety, a natural product with well-documented cytotoxicity against cancer cell lines, via an ester linker between the drug and the polymer side chain. The amphiphilic BBCPs self-assembled in aqueous media into nano-sized spherical micelles with neutral surface charges, as confirmed by dynamic light scattering analysis and transmission electron microscopy. During self-assembly, paclitaxel (PTX) could be effectively encapsulated into the hydrophobic core to form stable PTX-loaded micelles with high loading capacities and encapsulation efficiencies. The NIR fluorescent dye-containing micelles exhibited remarkable photophysical properties, excellent colloidal stability under physiological conditions, and a pH-induced disassembly under slightly acidic conditions, allowing for the release of the drug in a controlled manner. The in vitro studies demonstrated that the micelles without the drug (blank micelles) are biocompatible at concentrations of up to 1 mg mL-1 and present a high cellular internalization capacity toward MCF-7 cancer cells. The drug-functionalized micelles showed in vitro cytotoxicity comparable to free PPT and PTX against MCF-7 and PC3 cancer cells, confirming efficient drug release into the tumor environment upon cellular internalization. Furthermore, the drug-functionalized micelles exhibited higher selectivity than the pristine drugs and preferential cellular uptake in human cancer cell lines (MCF-7 and PC3) when compared to the normal breast cell line (MCF10A). This study provides an efficient strategy for the development of versatile polymeric nanosystems for drug delivery and image-guided diagnostics. Notably, the easy functionalization of BBCP side chains via SPAAC opens up the possibility for the preparation of a library of multifunctional systems containing other drugs or functionalities, such as target groups for recognition.
- Braga, Carolyne B.,Pilli, Ronaldo A.,Ornelas, Catia,Weck, Marcus
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p. 5290 - 5306
(2021/11/30)
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- ROMP polymer supported manganese porphyrins: Influence of C[dbnd]C bonds along polymer chains on catalytic behavior in oxidation of low concentration Fe2+
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One unsaturated polymer support was prepared through ring opening metathesis polymerization (ROMP) of norbornene-2,3-dip-toluene sulfonate initiated by Grubbs 2nd initiator and manganese porphyrins were immobilized on polymer through transesterification reaction. To investigate the effect of C[dbnd]C bonds along polymer chains on the catalytic behavior, the obtained polymer supported catalyst (P-PPIXMnCl) was applied in oxidation of low concentration Fe2+ to mimic catalytic behavior of Ceruloplasmin. In the presence of P-PPIXMnCl, the conversion of Fe2+ reaches to 91.92% and 96.46% at 10 °C and 37.5 °C (body temperature), respectively. Compared to manganese porphyrins, P-PPIXMnCl can dramatically increase oxidation rate of Fe2+ and the catalytic kinetic shows that the oxidation reaction changes from second-order to third-order. Upon hydrogenation of ROMP polymer, the oxidation reaction still conforms to the second-order kinetics. Density functional theory (DFT) calculation shows that the C[dbnd]C bonds along polymer chains play an important role in the coordination with Fe2+ in the catalytic microenvironment. The real time morphology of supported catalysts in aqueous environment characterized by Cryo-TEM indicates that hydrogenation can shrink the morphology of polymer-water skeleton. The catalyst could be recycled six times without any significant loss in activity. The liner heterogeneous catalyst is expected to be used as drugs for treating excessive iron accumulation in the human body.
- Li, Fanfan,Wang, Xuan,Zhang, Yanwu,Zhao, Huanhuan
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- Catalytic Living Ring Opening Metathesis Polymerisation: The Importance of Ring Strain in Chain Transfer Agents
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A recently developed catalytic living ring opening metathesis polymerisation (ROMP) was investigated using a series of reversible chain transfer agents (CTA) carrying either cyclopentene or cyclohexene rings, differing only in ring strain. All cyclopentene derivatives examined showed significantly faster reaction rates than the corresponding cyclohexene derivatives. This resulted in lower molecular weight dispersities and better control of the molecular weight for the cyclopentene compared to the cyclohexene CTAs. Both Grubbs’ second and third generation catalysts could be employed in catalytic living ROMP using cyclopentene CTA derivatives. The kinetics of different CTAs were studied, block copolymers were synthesised and residual ruthenium quantified by ICP-OES. All polymers were fully characterised by NMR, GPC and MALDI-ToF mass spectrometry. The new cyclopentene CTAs are readily synthesised in a few straightforward steps and provide faster reaction kinetics than all previously reported reversible CTAs.
- Liu, Peng,Yasir, Mohammad,Kilbinger, Andreas F. M.
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supporting information
p. 15278 - 15282
(2019/09/17)
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- Facile Synthesis of a New Chiral BINOL–Silica Hybrid Catalyst for Asymmetric Diels–Alder and Aza Michael Reactions
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Abstract: A novel chiral BINOL–silica hybrid has been successfully prepared by the reaction of (S)-BINOL and SiCl4 following by gel polymerization under atmosphere condition. The synthesized catalyst was characterized by elemental analysis, Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Catalytic activity of the chiral BINOL–silica hybrid for diastereo- and enantioselective Diels–Alder and aza Michael reactions has been investigated. Mild reaction conditions, high yields, excellent diastereo- and enantiomeric excess make this powerful and effective catalyst as an attractive option for the synthesis of chiral organic compounds. Graphical Abstract: [Figure not available: see fulltext.]
- Saeidian, Hamid,Paghandeh, Hossein,Parvin, Zahra,Mirjafary, Zohreh,Ghaffarzadeh, Mohammad
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p. 1366 - 1374
(2018/05/03)
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- METHOD FOR PRODUCING NORBORNANE DICARBOXYLIC ACID
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The present invention relates to a method for producing norbornane carboxylic acid, and more specifically, to a method for producing norbornane carboxylic acid, which comprises a step for reacting cyclopentadiene obtained by thermal decomposition of dicyclopentadiene with maleic anhydride. The production method according to the present invention utilizes dicyclopentadiene, has excellent reaction efficiency, and has an industrially useful whole reaction process, and thus it is possible to mass-produce the norbornane dicarboxylic acid with high yield and the norbornane dicarboxylic acid can be applied to various industrial fields.COPYRIGHT KIPO 2018
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- METHOD FOR PRODUCING BICYCLO[2.2.1]HEPTANE-2,3-DIYLDIMETHANOL
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The present invention refers to bicyclo [2. 2. 1] Heptane - 2, 3 - manufacturing method relates to the d methanol which will be a d, more particularly claw pen hit diene between d and reacting maleic anhydride with pen hit diene obtained by pyrolysis cycles including a number bath is formed on the bicyclo [2. 2. 1] Heptane - 2, 3 - to the d methanol which will be a d manufacturing method are disclosed. The present invention according to manufacturing method is that by the claw pen hit diene between d, reaction efficiency is superior, since the whole reaction process industrially useful bicyclo [2. 2. 1] Heptane - 2, 3 - [...] high yield can be mass produced, industrially nephrophathy intensity applications. (by machine translation)
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- Target Specific Tactics in Olefin Metathesis: Synthetic Approach to cis-syn-cis-Triquinanes and -Propellanes
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A concise and simple synthetic approach to cis-syn-cis-triquinanes and -propellanes has been demonstrated via olefin metathesis starting with exo-nadic anhydride. This approach involves a ring-opening and ring-closing metathesis sequence of norbornene derivatives using Grubb's catalyst. Early-stage diallylation of norbornene derivatives is demonstrated followed by ring-closing metathesis that delivers propellanes exclusively. Surprisingly, ring-opening metathesis, late-stage diallylation, followed by ring-closing metathesis delivers triquinane as well as propellane derivatives.
- Kotha, Sambasivarao,Aswar, Vikas R.
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p. 1808 - 1811
(2016/05/19)
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- A microwave reaction preparing high-purity cis-5-norbornene-exo -2,3-dicarboxylic anhydride method
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The invention relates to a method for preparing high-purity cis-5-norbornene-exo-2,3-dicarboxylic anhydride through microwave reaction. According to the invention, cis-5-norbornene-endo-2,3-dicarboxylic anhydride is well mixed with a solvent, and the mixture is placed into a mirowave reaction kettle; temperature and time are set, and a microwave reaction is carried out; oil bath and stirring are carried out, such that crystallization is allowed; the obtained material is cooled to room temperature, and is filtered and dried, such that the product cis-5-norbornene-exo-2,3-dicarboxylic anhydride is obtained. With the method, product yield is up to 80% and purity is up to 98%. Compared to prior arts, the method provided by the invention does not pollute the environment, has clean process, and is environment-friendly. The method is suitable for large-scale productions.
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Paragraph 0038-0040
(2017/02/09)
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- A Robust, Recyclable Resin for Decagram Scale Resolution of (±)-Mefloquine and Other Chiral N-Heterocycles
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Decagram quantities of enantiopure (+)-mefloquine have been produced via kinetic resolution of racemic mefloquine using a ROMP-gel supported chiral acyl hydroxamic acid resolving agent. The requisite monomer was prepared in a few synthetic steps without chromatography and polymerization was safely performed on a >30 gram scale under ambient conditions. The reagent was readily regenerated and reused multiple times for the resolution of 150 grams of (±)-mefloquine and other chiral N-heterocylces.
- Kreituss, Imants,Chen, Kuang-Yen,Eitel, Simon H.,Adam, Jean-Michel,Wuitschik, Georg,Fettes, Alec,Bode, Jeffrey W.
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p. 1553 - 1556
(2016/02/12)
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- An analysis of the structural, thermal and optical characteristics as well as the electrical resistivity of tert-butyldiphenylsilyl substituted poly(norbornene-dicarboximide)s
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A sequence of well controlled tert -butyldiphenylsilyl substituted poly(norbornene-dicarboximide)s with ascending molecular weights have been prepared using the Grubbs 1st generation catalyst in anhydrous chloroform. The kinetics of the polymerization was examined using nuclear magnetic resonance spectroscopy and gel permeation chromatography. By decreasing the Grubbs catalyst concentration, the polymer molecular weights increased linearly. The glass transition temperatures and thermal decomposition temperatures initially increased with polymer molecular weight, then reached a plateau. Regardless of molecular weight the polydispersities remained narrow. The polymers exhibited a predominantly trans microstructure and matrix-assisted laser desorption/ionization mass spectrometry was utilized to determine polymer end groups and to calculate the absolute molecular weights. The residual ruthenium content of the polymers was quantified using inductively coupled plasma mass spectrometry and the influence on the resistivity, refractive indices and thin film optical transmittance was evaluated.
- Spring, Andrew M.,Maeda, Daisuke,Ozawa, Masaaki,Odoi, Keisuke,Qiu, Feng,Yamamoto, Kazuhiro,Yokoyama, Shiyoshi
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p. 189 - 198
(2015/03/03)
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- Synthesis and structural characterization of N-Phenyl-5-norbornene-2,3-dicarboximide
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The compound N-phenyl-5-norbornene-2,3-dicarboximide (C15H13NO2, Mr = 239.26) was synthesized and characterized by single crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c, with a = 9.7534(13), b = 21.395(2), c = 12.0647(14) ?, β = 108.7020(10)°, V = 2384.6(5) ?3, Z = 8, Dc = 1.333 g/cm3, λ = 0.71073 ?, μ(MoKα) = 0.089 mm-1, F(000) = 1008. The final refinement gave R = 0.0741, wR (F2) = 0.1676 for 4,199 observed reflections with I > 2α(I). The structure of the title compound comprises a racemic mixture of chiral molecules containing four stereogenic centres. X-ray diffraction analysis reveals that the cyclohexane ring tends towards a boat conformation, the tetrahydrofuran ring and the dihydrofuran ring adopt envelope conformations. The dihedral angles between the pyrrolidine-2,5-dione plane and the aromatic ring are 65.5 (2)° and 54.9 (2)°, respectively in the two molecules.
- Liang, Zu Pei,Li, Jian,Pan, Xiao Ru
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p. 2806 - 2808
(2015/12/11)
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- NORBORNENE MONOMER, POLYNORBORNENE DERIVATIVE, LIQUID CRYSTAL PHOTOALIGNMENT FILM CONTAINING THE SAME AND LIQUID CRYSTAL DISPLAY CONTAINING THE SAME
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The present invention relates to a norbornene monomer, a polynorbornene derivative, a liquid crystal alignment film including the same, and a liquid crystal display device including the same. More particularly, the present invention relates to a norbornene monomer, a polynorbornene derivative, a liquid crystal alignment film including the same, and a liquid crystal display device including the same, which have an alignment property by photoreaction, excellent thermal stability and photoreactivity, the increased photo-reaction rate and reliability of the alignment film, thereby showing high manufacturing process efficiency.
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Paragraph 0081-0085
(2014/08/07)
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- PROCESS FOR PREPARING BENZISOTHIAZOL-3-YL-PEPERAZIN-L-YL-METHYL-CYCLO HEXYL-METHANISOINDOL-1,3-DIONE AND ITS INTERMEDIATES
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The present invention discloses process for preparing benzisothiazol-3-yl- piperazin-l-yl-methyl-cyclo hexyl-methanisoindol-l,3-dione and intermediates thereof.
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Page/Page column 28; 29
(2013/08/28)
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- Water-soluble and water-insoluble, ring opening metathesis polymerization products, monomers and related methods
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The invention provides certain novel water-soluble and water-insoluble monomers for ring opening metathesis polymerization and novel polymers, compositions and products, and related methods thereof.
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Page/Page column 28-29
(2013/02/27)
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- Synthesis and structure-property comparisons of hydrogenated poly(oxanorbornene-imide)s and poly(norbornene-imide)s prepared by ring-opening metathesis polymerization
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Various structures of poly(norbornene-imide)s and poly(oxanorbornene-imide) s were synthesized and an optimal hydrogenation method was established. The thermal, thermomechanical, mechanical, and optical properties of thus prepared polymers were investigated, together with the structural characteristics shown by wide-angle X-ray scattering patterns. Poly(oxanorbornene-imide)s exhibit local nanostructure caused by intermolecular interactions between the imide and backbone oxygen moiety, which appears to prevent a significant decrease in Tg when compared with poly(norbornene-imide)s. Overall, hydrogenated poly(oxanorbornene-imide)s, obtained with more readily prepared exo-monomer, exhibit similar physical properties when compared with the corresponding hydrogenated poly(norbornene-imide)s. Copyright
- Yoon, Kyung-Hwan,Kim, Kyung Oh,Wang, Chengqing,Park, Insook,Yoon, Do Y.
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experimental part
p. 3914 - 3921
(2012/10/08)
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- Synthesis and characterization of substituted polynorbornene derivatives
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This paper describes palladium (II) catalyst based synthesis and detailed characterization of vinyl-type polynorbornenes (PNBs) with bulky phenyl, adamantane, or norbornane substituents linked by ester, ether, or alkyl bridges. The structure-property relationships of the substituted PNBs were investigated concerning the thermal stability, glass transition temperature, wide-angle X-ray scattering (WAXS) patterns, mechanical properties, and dielectric characteristics. PNBs with phenyl substituted pendant groups improved the solubility and film forming properties due to aromatic-aromatic interactions. The substituted PNBs exhibited good thermal and thermo-mechanical properties with thermal decomposition temperature (Td,5%) above 300 °C and glass transition temperature in the range of 134-325 °C.WAXS studies revealed the presence of local nano-scale order in the noncrystalline state, especially in ester bridged adamantane and norbornane substituted polymers, probably due to the steric packing requirements of bulky side groups coupled with dipolar interactions. Nanoindentation results showed high modulus (6.5-7.9 GPa) and hardness (0.11-0.38 GPa) for PNBs with diester adamantane and norbornane substituted polymers. Excellent dielectric properties with a dielectric constant (ε) of 2.5 and a dielectric loss tangent (tan δ) of 0.0005 were measured for poly [2-(4-phenylbutyl)-5-norbornene] at 1 GHz, rendering it very attractive for interconnect dielectric films in high-frequency electronic devices.
- Mulpuri, Syamkumar V.,Shin, Jinbok,Shin, Boo-Gyo,Yoon, Do Y.,Greiner, Andreas
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p. 4377 - 4386,10
(2012/12/12)
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- NOVEL LIQUID TETRACARBOXYLIC DIANHYDRIDES AND PROCESS FOR THE PREPARATION THEREOF
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The invention relates to a tetracarboxylic dianhydride represented by the following formula (1). [In formula (1) R1, R2, R3 and R4 each independently represent an alkyl group having from 1 to 5 carbon atoms, m represents a number from 1 to 30, all of the silicon atoms bonding to the norbornane rings are in an exo-configuration with respect to the norbornane rings, and all of the dicarboxylic anhydride groups bonding to the norbornane rings are in an exo-configuration with respect to the norbornane rings.]
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Page/Page column 6
(2011/12/14)
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- THERMOSETTING RING-OPENING METATHESIS POLYMERIZATION MATERIALS WITH THERMALLY DEGRADABLE LINKAGES
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The present invention provides a new class of thermosetting ring-opening metathesis polymerization materials based on norbornene and oxanorbornene dicarboximide moieties containing at least one acetal ester group linkage. The acetal ester group is degradable when subjected to heat or acidic aqueous hydrolysis. The polymerization materials can be used in reworkable thermosetting compositions. R1-Rs, X, and n are defined herein.
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Page/Page column 15
(2010/09/18)
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- ROMP-derived oligomeric phosphates for application in facile benzylation
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The development of new ROMP-based oligomeric benzyl phosphates (OBP n) is reported for use as soluble, stable benzylating reagents. These oligomeric reagents are readily synthesized from commercially available materials and conveniently polymerized and purified in a one-pot process, affording bench-stable, pure white, free-flowing solids on multigram scale. Utilization in benzylation reactions with a variety of nucleophiles is reported.
- Long, Toby R.,Maity, Pradip K.,Samarakoon, Thiwanka B.,Hanson, Paul R.
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supporting information; experimental part
p. 2904 - 2907
(2010/09/30)
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- Features of reactions between (3,5-dioxo-4-azatricyclo-[5.2.1.0 2-endo,6-endo ]dec-8-en-4-yl)carboxylic acids and p-nitrophenyl azide
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Reactions were performed of (3,5-dioxo-4-azatricyclo[5.2.1.0 2-endo,6-endo ]dec-8-en-4-yl)carboxylic acids and their derivatives with p-nitrophenyl azide. A significant fact of the involvement of the carboxy group into the formation of aziridine ring was established and the intermolecular character of this process was confirmed. The structure of compounds synthesized was proved by IR and 1H NMR spectra.
- Tarabara,Bondarenko,Kas'Yan
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scheme or table
p. 234 - 241
(2009/09/25)
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- Solvent-free Diels-Alder reactions of in situ generated cyclopentadiene
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A solvent-free Diels-Alder reaction was carried out by heating a mixture of dicyclopentadiene and a dienophile. Cyclopentadiene, formed in situ, reacted with the dienophile in a thermodynamically controlled reaction. Besides being solvent-free, the descri
- Huertas, David,Florscher, Melinda,Dragojlovic, Veljko
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experimental part
p. 91 - 95
(2010/04/22)
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- Synthesis of fluorine-18 functionalized nanoparticles for use as in vivo molecular imaging agents
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Nanoparticles containing fluorine-18 were prepared from block copolymers made by ring opening metathesis polymerization (ROMP). Using the fast initiating ruthenium metathesis catalyst (H2IMes)(pyr)2(Cl)2Ru=CHPh, low polydispersity amphiphilic block copolymers were prepared from a cinnamoyl-containing hydrophobic norbornene monomer and a mesyl-terminated PEG-containing hydrophilic norbornene monomer. Self-assembly into micelles and subsequent cross-linking of the micelle cores by light-activated dimerization of the cinnamoyl groups yielded stable nanoparticles. Incorporation of fluorine-18 was achieved by nucleophilic displacement of the mesylates by the radioactive fluoride ion with 31% incorporation of radioactivity. The resulting positron-emitting nanoparticles are to be used as in vivo molecular imaging agents for use in tumor imaging. Copyright
- Matson, John B.,Grubbs, Robert H.
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p. 6731 - 6733
(2008/12/22)
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- Catalyst-free one-pot synthesis of 2,4,6-triaryl-1,4-dihydropyridines in ionic liquid and their catalyzed activity on two simple Diels-Alder reactions
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A series of 2,4,6-triaryl-1,4-dihydropyridines bearing a hydroxyl group was synthesized greenly by the cascade aldol/Michael/addition reaction of aromatic aldehyde, acetophenone, and NH4OAc (1:2:excessive) in ionic liquid [BmIm][BF4] without any catalyst. The results of their catalyzed activity on two simple Diels-Alder reactions indicated that this kind of compound containing a poly aryl ring can be used as an effective catalyst on the Diels-Alder reaction. This method, because of its environmental friendliness, simplicity, mild conditions, effectiveness, and lower costs, is suitable for the synthesis of arrays of compounds. Copyright Taylor & Francis Group, LLC.
- Wu, Hui,Wan, Yu,Lu,Shen, Yang,Ye,Zhang
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p. 666 - 673
(2008/09/16)
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- METHOD OF SEPARATING STEREOISOMERS OF NORBORNENE, DICARBOXYLIC ACID HAVING NORBORNANE STRUCTURE, OR DERIVATIVE THEREOF
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A method of efficiently extracting a high-purity stereoisomer from a mixture comprising the endo isomer and the exo isomer of a dicarboxylic acid having a norbomene or norbomane structure, or a derivative thereof. The present invention relates to a method of separating the endo isomer and the exo isomer of a dicarboxylic acid represented by a general formula (1) or (2) or a derivative thereof, and includes the step of stirring and mixing a mixture comprising mainly the endo isomer of the dicarboxylic acid represented by the general formula (1) or (2) or a derivative thereof, and the exo isomer of the dicarboxylic acid represented by the general formula (1) or (2) or a derivative thereof, with a basic compound and a solvent. (wherein, R1 to R8 represent a hydrogen atom, methyl group, ethyl group, or butyl group), (wherein, R'1 to R'10 represent a hydrogen atom, methyl group, ethyl group, or butyl group)
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Page/Page column 21
(2008/06/13)
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- Catalyst economy. Part 2: Sequential metathesis - Kharasch sequences using the Grubbs metathesis catalysts
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Sequential ring-closing metathesis (RCM)-Kharasch cyclizations are promoted by the Grubbs metathesis catalysts and provide rapid access to bicyclic lactones and lactams.
- Edlin, Chris D.,Faulkner, James,Quayle, Peter
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p. 1145 - 1151
(2007/10/03)
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- NONIONIC LIQUID SURFACTANTS AS GREEN SOLVENTS
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A method for preparing a product of a chemical reaction includes conducting the chemical reaction in a solvent medium of one or more liquid nonionic surfactant(s). The liquid nonionic surfactants preferably are CmEn type poly(alkylene oxide) alcohols and are preferably separated from the product without the use of a volatile organic compound.
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Page/Page column 6-7
(2008/06/13)
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- Gas sorption in new fluorine containing polynorbornenes with imide side chain groups
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The synthesis of (N-3,5-bis(trifluoromethyl)phenyl-exo-endo-norbornene-5,6-dicarboximide) as well as the ring opening methatesis polymerization (ROMP) of this monomer to yield poly(N-3,5-bis-(trifluoromethyl)phenyl-exo-encdo-norbornene-5,6-dicarboximide) are reported. The glass transition of the polymer is 162°C. Solubility coefficients of different gases (nitrogen, oxygen, carbon monoxide, carbon dioxide, methane, ethane, ethylene, propane, and propylene) in membranes prepared by casting from poly(N-3,5-bis(trifluoromethyl)phenyl-exo-endo-norbornene-5,6-dicarboximide) solutions were measured at several temperatures and pressures. The interpretation of the sorption results by the dual-mode model gives the Henry and Langmuir contributions to the solubility. As usual in glassy membranes, sorption processes are exothermic and the activation energies associated with the Henry and Langmuir parameters are also negative. Gas sorption in the continuous amorphous phase was interpreted in terms of the Flory-Huggins theory obtaining reasonable values for the enthalpic parameter x that accounts for the gas (in liquid form)-polymer interactions. The use of this approach to simulate gas sorption in polymers is discussed.
- Tlenkopatchev, Mikhail,Vargas, Joel,Almaraz-Giron, Marco A.,Lopez-Gonzalez, Mar,Riande, Evaristo
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p. 2696 - 2703
(2007/10/03)
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- An in-depth look at the effect of Lewis acid catalysts on Diels-Alder cycloadditions in ionic liquids
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The present work explores in detail the Diels-Alder reaction between cyclopentadiene and a series of dienophiles, performed in an innovative medium such as an ionic liquid. The potential activation of different Lewis acid catalysts and their load effect when used in combination with this solvent have been explored, in order to settle the improvement on rates and selectivities.
- Silvero, Guadalupe,Arévalo, María José,Bravo, José Luis,ávalos, Martín,Jiménez, José Luis,López, Ignacio
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p. 7105 - 7111
(2007/10/03)
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- Protein phosphatase 2A inhibition and circumvention of cisplatin cross-resistance by novel TCM-platinum anticancer agents containing demethylcantharidin
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The structurea€"activity requirement of the PP2A-inhibiting demethylcantharidin for the circumvention of cisplatin cross-resistance demonstrated by the novel TCMa€"Pt compounds is discussed. Novel TCM-platinum compounds [Pt(C8H8O5)(NH 2R)2] 1-5, derived from integrating demethylcantharidin, a modified component from a traditional Chinese medicine (TCM) with a platinum moiety, possess anticancer and protein phosphatase 2A inhibition properties. The compounds are able to circumvent cisplatin resistance by apparently targeting the DNA repair mechanism. Novel isosteric analogues [Pt(C9H 10O4)(NH2R)2] A and B, devoid of PP2A-inhibitory activity, were found to suffer from an enhanced DNA repair and were cross-resistant to cisplatin. The results advocate a well-defined structure-activity requirement associating the PP2A-inhibiting demethylcantharidin with the circumvention of cisplatin cross-resistance demonstrated by TCM-Pt compounds 1-5.
- To, Kenneth K.W.,Wang, Xinning,Yu, Chun Wing,Ho, Yee-Ping,Au-Yeung, Steve C.F.
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p. 4565 - 4573
(2007/10/03)
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- Synthesis and gas transport properties of new high glass transition temperature ring-opened polynorbornenes
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The synthesis and polymerization of the new monomers N-(1-adamantyl)-exo-norbornene-5,6-dicarboximide (AdNDI), N-cyclohexyl-exo-norbornene-5,6-dicarboximide (ChNDI), and N-phenyl-exo-norbornene-5,6-dicarboximide (PnNDI) are reported. Copolymers of N-(1-adamantyl)-exo-norbornene-5,6-dicarboximide/norbornene, with molar compositions 50/50, 70/30, and 30/70, were also obtained. The transport of hydrogen, oxygen, nitrogen, carbon monoxide, carbon dioxide, methane, ethylene, and ethane across membranes prepared from these homopolymers and copolymers was determined at 30°C using permeation techniques. Diffusion coefficients correlate rather well with the diameter of diffusant molecules except in the case of carbon dioxide. The values of the permselectivity coefficient for different gases depend on the type of membranes. For example, the permselectivity of oxygen with respect to nitrogen, α(O2/N2), is ca. 5.50 for membranes prepared from N-(1-adamantyl)-exo-norbornene-5,6-dicarboximide/norbornene (50/50) copolymers, which compares favorably with the values reported for this parameter in membranes with imide groups located in the backbone. The values of α(H2/C2H6) in membranes of poly(N-(1-adamantyl-exo-norbornene-5,6-dicarboximide), poly(N-cyclohexyl-exo-norbornene-5,6-dicarboximide), and poly(N-phenyl-exo-norbornene-5,6-dicarboximide) are 183, 124, and 122, respectively, whereas the values of α(C2H4/C2H6) amount to 6.9, 7.6, and 6.4, respectively. For most membranes used in this study, diffusion rather than solubility is responsible for the discrimination of gas transport. However, solubility is mainly responsible for the high permselectivity of ethylene with respect to ethane displayed by the membranes.
- Pineda Contreras, Armando,Tlenkopatchev, Mikhail A.,Del Mar Lopez-Gonzalez, Maria,Riande, Evaristo
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p. 4677 - 4684
(2007/10/03)
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- Application of arylboron difluoride Lewis acid catalysts to the Diels- Alder reaction: Convenient, non-volatile alternatives to boron trifluoride
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Comparative studies were carded out on boron trifluoride etherate, phenylboron difluoride and meta-nitrophenylboron difluoride for the Lewis acid catalysed Diels-Alder reaction of cyclopentadiene and a range of standard dienophiles in tetrahydrofuran solution. Phenylboron difluoride showed remarkably similar reactivity in terms of yield and endo to exo selectivity to boron trifluoride, whereas meta-nitrophenylboron difluoride was more reactive than either boron trifluoride or phenylboron difluoride and showed more marked differences in endo: exo ratios. These results contrast to some extent with gas-phase semi-empirical calculations (PM3), which suggest that boron trifluoride and meta-nitrophenylboron difluoride should have similar reactivity; phenylboron difluoride being less reactive. However, since arylboron difluorides are easily prepared, these Lewis acids represent a group of potentially highly tuneable catalysts for Diels-Alder reactions.
- De La Torre, Maria Fe,Caballero, M. Cruz,Whiting, Andrew
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p. 8547 - 8554
(2007/10/03)
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- Cycloadditions with clays and alumina without solvents
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The utilization of unactivated K-10 montmorillonite or alumina for Diels-Alder reactions in the absence of solvents, either with symmetrically- or unsymmetrically-substituted carbonyl dienophiles, constitutes an environmentally-friendly alternative providing excellent selectivities under mild conditions.
- Avalos, Martin,Babiano, Reyes,Bravo, Jose L.,Cintas, Pedro,Jimenez, Jose L.,Palacios, Juan C.,Ranu, Brindaban C.
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p. 2013 - 2016
(2007/10/03)
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- Indium trichloride (InCl3) catalysed Diels-Alder reaction in water
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Indium trichloride (InCl3) is found to catalyse the Diels-Alder reaction in water; the catalyst can be easily recovered from water after the reaction is completed and can be reused.
- Loh, Teck-Peng,Pei, Jian,Lin, Mei
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p. 2315 - 2316
(2007/10/03)
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- Stereospecificity and concertedness of Retro-Diels-Alder fragmentation in some diester systems upon chemical ionization
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Retro-Diels-Alder (RDA) fragmentation of cis- and trans-2,3-diethoxycarbonyl-5,6,7,8-dibenzobicyclo[2.2.2] octanes under isobutane and methane chemical ionization conditions is highly stereospecific, giving rise to protonated diethyl maleate and fumarate, respectively. This behaviour indicates a single-step concerted mechanism, analogous to the ground-state RDA process that occurs in neutral molecules in the condensed phase. The analogous dissociation is partially stereospecific in stereoisomeric endo-, exo- and trans-2,3-diethoxycarbonylbicyclo [2.2.1]heptanes and non-stereospecific in endo-, exo- and trans-2,3-diethoxycarbonyl-5,6-benzobicyclo [2.2.2]octanes, indicating the involvement of a stepwise mechanism in the latter two systems. The different behaviour of the above systems is explained in terms of the energy of the RDA fragmentation. The differentiation and quantitative estimates of protonated diethyl maleate and fumarate were obtained from collision-induced dissociation measurements.
- Denekamp,Weisz,Mandelbaum
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p. 1028 - 1032
(2007/10/03)
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- Clay catalysis: A convenient and rapid formation of anhydride from carboxylic acid and isopropenyl acetate under microwave irradiation
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The Montmorillonite KSF catalyses the synthesis of anhydrides from carboxylic acids in the presence of isopropenyl acetate under microwave irradiations.
- Villemin,Labiad,Loupy
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p. 419 - 424
(2007/10/02)
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- A Remarkably Efficient Photochemical Methodology for Endo to Exo Isomerization of Diels-Alder Cycloadducts
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Irradiation of a solution of ethanol containing Diels-Alder cycloadducts and 10-20 percent (by volume) triethylamine at 300 nm furnishes quantitative yield (>90percent) of corresponding exo isomers.A probable mechanism based on photo-induced electron transfer (PET) has been described.
- Pandey, Bipin,Athawale, Asawari A.,Reddy, Ravinder S.,Dalvi, Pramod V.,Kumar, Pradeep
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p. 1173 - 1176
(2007/10/02)
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- Enzymatic optical resolution of norbornanecarboxylic esters using Pig Liver Esterase
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The hydrolysis of a series of norbornane-type carboxylic esters catalyzed by pig liver esterase (PLE) has been investigated.It was found that an exo-ester function (syn to the C7 methylene group) is hydrolyzed with high preference.Enantioselective hydrolysis can be accomplished when a vicinal carbonyl-containing function (ester, formyl, acetyl) is present in a trans position with respect to the exo ester.The regiospecifity of the enzymatic hydrolysis has been used for the separation of exo/endo mixtures of the cycloadducts derived from cyclopentadiene and alkene esters.The regiospecifity and enantioselectivity of the enzymatic hydrolysis of norbornane-type esters were analyzed in terms of Tamm's substrate model and also by Griengl's method.
- Gastel, F. J. C. van,Klunder, A. J. H.,Zwanenburg, B.
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p. 175 - 184
(2007/10/02)
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- 6-(3-Carbamoylbicyclohept-2-yl)hexanoic Acids, a New Class of TxA2 Antagonists
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The synthesis of prostanoids 20-27, 40a, b, and 45a, b starting from the educts 1a, b, and 31 is described.Configurational changes concerning to the positions 2 and 3 of the bicyclic system were proofed by 13C-NMR spectroscopy and were also used for the preparation of the four exo/endo derivatives. 25 and 26 are potent TxA2 antagonists.
- Lieb, Folker,Niewoehner, Ulrich,Wendisch, Detlef
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p. 607 - 616
(2007/10/02)
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- Novel Synthesis of Five- and Six-Membered Spiro γ-Lactones in Rigid Bicyclic Systems
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The reaction of bis(bromomagnesio)alkanes with bridged tricyclic endo- and exo-dicarboxylic anhydrides and their dihydro derivatives provides a general and versatile route to corresponding tricyclic spiro γ-butanolides.Futher extension of this methodology to the dianhydride of bicyclooctene showed appreciable regioselectivity.The subsequent transformation of spiro γ-lactones into 4-spiro-2-butenolides by retro-Diels-Alder reaction has provided a simple and convenient synthesis of these molecules.Proton and 13C NMR spectra are reported for most of the compounds.
- Cannone, Persephone,Belanger, Denis,Lemay, Gilles
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p. 3953 - 3959
(2007/10/02)
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