2746-19-2Relevant articles and documents
Electro-optic properties of a side chain poly(norbornene-dicarboximide) system with an appended phenyl vinylene thiophene chromophore
Spring, Andrew M.,Qiu, Feng,Hong, Jianxun,Bannaron, Alisa,Yokoyama, Shiyoshi
, p. 13 - 27 (2017)
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.
Online analysis of flowing streams using microflow HPLC
Welch, Christopher J.,Gong, Xiaoyi,Cuff, James,Dolman, Sarah,Nyrop, Jason,Lin, Fiona,Rogers, Hallena
, p. 1022 - 1025 (2009)
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.
Preparation method of exo-Dickson anhydride
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Paragraph 0017-0018; 0042-0043; 0046-0049, (2021/10/16)
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.
Near-Infrared Fluorescent Micelles from Poly(norbornene) Brush Triblock Copolymers for Nanotheranostics
Braga, Carolyne B.,Pilli, Ronaldo A.,Ornelas, Catia,Weck, Marcus
, p. 5290 - 5306 (2021/11/30)
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.
ROMP polymer supported manganese porphyrins: Influence of C[dbnd]C bonds along polymer chains on catalytic behavior in oxidation of low concentration Fe2+
Li, Fanfan,Wang, Xuan,Zhang, Yanwu,Zhao, Huanhuan
, (2020/02/22)
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.
Catalytic Living Ring Opening Metathesis Polymerisation: The Importance of Ring Strain in Chain Transfer Agents
Liu, Peng,Yasir, Mohammad,Kilbinger, Andreas F. M.
supporting information, p. 15278 - 15282 (2019/09/17)
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.
Facile Synthesis of a New Chiral BINOL–Silica Hybrid Catalyst for Asymmetric Diels–Alder and Aza Michael Reactions
Saeidian, Hamid,Paghandeh, Hossein,Parvin, Zahra,Mirjafary, Zohreh,Ghaffarzadeh, Mohammad
, p. 1366 - 1374 (2018/05/03)
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.]
METHOD FOR PRODUCING NORBORNANE DICARBOXYLIC ACID
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Paragraph 0092; 0097; 0098, (2018/07/28)
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
METHOD FOR PRODUCING BICYCLO[2.2.1]HEPTANE-2,3-DIYLDIMETHANOL
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Paragraph 0105-0106, (2018/07/28)
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)
Target Specific Tactics in Olefin Metathesis: Synthetic Approach to cis-syn-cis-Triquinanes and -Propellanes
Kotha, Sambasivarao,Aswar, Vikas R.
, p. 1808 - 1811 (2016/05/19)
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.
