542-92-7Relevant articles and documents
Photoinduced Isomerization of Radical Ions. 3. Radical Cations of Cyclopentadiene, Dicyclopentadienes, and 1,3-Bishomocubane Produced in γ-Irradiated Freon Matrices
Shida, Tadamasa,Momose, Takamasa,Ono, Noboru
, p. 815 - 820 (1985)
The radical cations of cyclopentadiene and the three C10H12 systems in the title have been produced in γ-irradiated Freon matrices at 77 K.Electronic and ESR spectroscopy were used to determine the interrelationships among the cations and their photoproducts.The three C10H12+.'s yielded different photoproducts depending upon the wavelength used for photoexcitation.The photoproduct obtained from endo-dicyclopentadiene cation excited to its first excited state was also obtained by a thermal reaction between the neutral molecule of cyclopentadiene and its radical cation.The product is inferred to be the radical cation of a new dicyclopentadiene.Possible mechanisms of obtaining this new C10H12+. isomer are discussed.
Time-Resolved Kinetic Energy Releases for Metastable Phenol Ions
Lifshitz, C.,Gefen, S.,Arakawa, R.
, p. 4242 - 4246 (1984)
Time-resolved kinetic energy releases (KERs) were determined from metastable ion peak shapes for the reaction C6H5OH+ -> c-C5H6+ + CO in phenol.Ion beam pulsing was combined with an ion trapping device and with an MS/MS technique of
Gas-phase identification of (Z)-1,2-ethenediol, a key prebiotic intermediate in the formose reaction
Alessandrini, Silvia,Barone, Vincenzo,Bizzocchi, Luca,Dore, Luca,Gazzeh, Houda,Guillemin, Jean-Claude,Melosso, Mattia,Puzzarini, Cristina,Rivilla, Víctor M.,Tonolo, Francesca
supporting information, p. 2750 - 2753 (2022/03/07)
Prebiotic sugars are thought to be formed on primitive Earth by the formose reaction. However, their formation is not fully understood and it is plausible that key intermediates could have formed in extraterrestrial environments and subsequently delivered
Diastereoselective Diboration of Cyclic Alkenes: Application to the Synthesis of Aristeromycin
Vendola, Alex J.,Allais, Christophe,Dechert-Schmitt, Anne-Marie R.,Lee, James T.,Singer, Robert A.,Morken, James P.
supporting information, p. 2863 - 2867 (2021/05/05)
The Pt-catalyzed diboration of cyclic alkenes is extended to unsaturated heterocycles and bicyclic compounds and can be accomplished in a diastereoselective fashion. The optimal procedures, substrate scope, and diastereoselectivity were investigated, and examples employing both homogeneous and heterogeneous catalysis were examined. Lastly, application to the construction of the nucleoside analog (±)-aristeromycin was conducted.
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.
Cyclohexanedicarboxylic acid derivative with bridge ring and pharmaceutical composition and application thereof
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Paragraph 0081-0083; 0109-0110, (2021/11/10)
The invention discloses a cyclohexane dicarboxylic acid derivative with a bridged ring represented by general formula (I). The application of the stereoisomers and the pharmaceutically acceptable salts in the preparation of antitumor drugs has obvious inhibition effects on leukemia, liver cancer, lung cancer, gastric cancer and ovarian cancer. The compound disclosed by the invention has high anti-tumor activity, wide anti-tumor spectrum and low toxicity, and is suitable for preparing anti-cancer drugs.
Oxathiaborolium-Catalyzed Enantioselective [4 + 2] Cycloaddition and Its Application in Lewis Acid Coordinated and Chiral Lewis Acid Catalyzed [4 + 2] Cycloaddition
Boobalan, Ramalingam,Chein, Rong-Jie
supporting information, p. 6760 - 6764 (2021/09/11)
The nascency of second-generation sulfur-stabilized borenium cations by halophilic Lewis acid SnCl4 leads to highly active chiral Lewis acids that are very effective catalysts for [4 + 2] cycloaddition. Oxathiaborolium pentachlorostannate (5-10 mol %) successfully catalyzed cycloaddition of various dienes and dienophiles to afford cycloadducts with excellent enantioselectivity (20 examples, up to 99% ee). This super Lewis acid also exhibited good enantioselectivity for the first Lewis acid coordinated and chiral Lewis acid catalyzed [4 + 2] cycloaddition to α,β-unsaturated mixed ester amide.
Application of hierarchical pore molecular sieve in preparation process of cyclopentadiene and JP-10 aviation fuel
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, (2021/07/01)
The invention relates to an application of a hierarchical pore molecular sieve in a the preparation process of cyclopentadiene and JP-10 aviation fuel. The hierarchical pore molecular sieve is one or two or more of an H-ZSM-5 molecular sieve, an H-beta molecular sieve, an H-Y molecular sieve, an H-USY molecular sieve, a La-Y molecular sieve and an H-MOR molecular sieve with a hierarchical pore structure, a sulfonated SBA-15 molecular sieve, a sulfonated MCM-41 molecular sieve, a sulfonated Ti-SBA-15 molecular sieve, a sulfonated MCM-41 molecular sieve, a sulfonated Zr-MCM-41 molecular sieve and a sulfonated Zr-SBA-15 molecular sieve; and the hierarchical pore structure comprises micropores and mesopores. The catalyst and the raw materials used in the method are cheap and easy to obtain, the preparation process is simple, and the hierarchical pore molecular sieve has high activity and selectivity for rearrangement reaction of furfuryl alcohol, hydrogenation reaction of hydroxyl cyclopentenone and dehydration reaction. The invention provides a cheap and efficient synthesis method for synthesizing the JP-10 aviation fuel from a lignocellulose-based platform compound furfuryl alcohol.
Production Of Cyclopentadiene From Furfural
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Paragraph 0040; 0081-0085, (2021/06/26)
The application relates to processes and systems that use a furfural compound for producing five-membered carbocyclic rings that are unsaturated, such as cyclopentene and cyclopentadiene. Examples methods for conversion of furfural compounds may include converting a furfural compound to at least a five-membered, saturated carbocyclic ring, and converting the five-membered, saturated carbocyclic ring in a presence of a catalyst to at least a five-membered, unsaturated carbocyclic ring.
Direct Evidence on the Mechanism of Methane Conversion under Non-oxidative Conditions over Iron-modified Silica: The Role of Propargyl Radicals Unveiled
?ot, Petr,Hemberger, Patrick,Pan, Zeyou,Paunovi?, Vladimir,Puente-Urbina, Allen,van Bokhoven, Jeroen Anton
supporting information, p. 24002 - 24007 (2021/10/01)
Radical-mediated gas-phase reactions play an important role in the conversion of methane under non-oxidative conditions into olefins and aromatics over iron-modified silica catalysts. Herein, we use operando photoelectron photoion coincidence spectroscopy to disentangle the elusive C2+ radical intermediates participating in the complex gas-phase reaction network. Our experiments pinpoint different C2-C5 radical species that allow for a stepwise growth of the hydrocarbon chains. Propargyl radicals (H2C?C≡C?H) are identified as essential precursors for the formation of aromatics, which then contribute to the formation of heavier hydrocarbon products via hydrogen abstraction–acetylene addition routes (HACA mechanism). These results provide comprehensive mechanistic insights that are relevant for the development of methane valorization processes.
