- STEREOREGULAR FLUOROPOLYMERS: 6. THE RING-OPENING POLYMERIZATION OF N-PENTAFLUOROPHENYLBICYCLOHEPT-5-ENE-2,3-DICARBOXIMIDE
-
Exo-N-pentafluorophenylbicyclohept-5-ene-2,3-dicarboximide (I) readily undergoes metathesis ring-opening polymerization when exposed to conventional metathesis catalysts such as WCl6/Me4Sn and MoCl5/Me4Sn; by contrast, its endo isomer (II) is not homopolymerized but can be copolymerized with (I).The microstructures of the resulting polymers are established and discussed.
- Blackmore, P. M.,Feast, W. J.
-
-
Read Online
- Synthesis and ionic transport of sulfonated ring-opened polynorbornene based copolymers
-
The N-pentafluorophenyl-exo-endo-norbornene-5,6-dicarboximide (1a) and N-phenyl-exo-endo-norbornene- 5,6-dicarboximide (1b)monomers were synthesized and copolymerized via ring opening metathesis polymerization (ROMP) using bis(tricyclohexylphosphine)benzylidene ruthenium(IV) dichloride (I) and tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2- ylidene][benzylidene] rutheniumdichloride (II). Experiments, at distinct monomer molar ratios, were carried out using catalyst I in order to determine the copolymerization reactivity constants by applying theMayo-Lewis and Fineman- Ross methods. Moreover, both catalysts were used to produce random and block high molecular weight copolymers of 1a with 1b and 1a with norbornene (NB) which were further hydrogenated using a Wilkinson's catalyst. Then, the saturated copolymers underwent a nucleophilic aromatic substitution by reacting with sodium 4-hydroxybenzenesulfonate dihydrate to generate new polynorbornene ionomers bearing fluorinated pendant benzenesulfonate groups. A thorough study on the electrochemical characteristics involving electromotive forces of concentration cells and proton conductivity of cation-exchange membranes based on a block copolymer of norbornene dicarboximides containing structural units with phenyl and fluorinated pendant benzenesulfonate moieties is reported. The study of electromotive forces (emf) of concentration cells with the sulfonated membrane of copolymer 8 separating electrolyte solutions of different concentration indicate that the membranes exhibit high permselectivity to protons and sodium ions at moderately low concentrations. In principle, these results suggest that the membranes can be considered candidates for ionic separation applications.
- Santiago, Arlette A.,Vargas, Joel,Cruz-Gomez, Javier,Tlenkopatchev, Mikhail A.,Gavino, Ruben,Lopez-Gonzalez, Mar,Riande, Evaristo
-
-
Read Online
- Lewis acid catalyst system for Diels–Alder reaction
-
Abstract: Ca(OTf)2/Bu4NPF6 catalytic system has been illustrated for the synthesis of Diels–Alder adduct for the first time. This procedure tolerates substrate diversity and delivers high yield. Use of environmentally benign catalyst, high yields and substrate diversity are the highlight of the existing method. Graphic Abstract: Ca(OTf)2, along with n-Bu4NPF6 as the co-catalyst, is shown to be an effective Lewis acidic catalyst system for the Diels–Alder reaction. Apart from being sustainable and efficient, this procedure is robust and products are obtained in near-quantitative yields.[Figure not available: see fulltext.].
- Kalepu, Rishir,Mishra, Satyendra
-
-
- Synthetic method of aliphatic pentacyclic dianhydride
-
The invention discloses a synthetic method of aliphatic pentacyclic dianhydride, and particularly relates to a synthetic method of pentacyclic [8.2. 1.14, 702, 903, 8] tetradecane-5, 6, 11, 12-tetracarboxylic dianhydride. The invention belongs to the field of preparation methods of fine chemicals. Maleic anhydride and cyclopentadiene are used as initial raw materials, an intermediate product norbornene dianhydride is synthesized through a 1, 4-addition reaction at a low temperature, then a solvent and a photocatalyst are added, the reaction process is monitored through HPLC under the illumination condition of a single-wavelength light source, and after the reaction is finished, a white solid is obtained through aftertreatment. The method disclosed by the invention is simple to operate, high in synthesis yield and few in byproducts.
- -
-
Page/Page column 6-11
(2020/03/12)
-
- ROMP polymer supported manganese porphyrins: Influence of C[dbnd]C bonds along polymer chains on catalytic behavior in oxidation of low concentration Fe2+
-
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
-
-
- A 1, 2, 3, 4 - cyclopentane tetracarboxylic dianhydride of the preparation method (by machine translation)
-
The invention discloses a 1, 2, 3, 4 - cyclopentane tetracarboxylic dianhydride of the preparation method, the invention belongs to the field of fine chemicals preparation method. The main technical proposal is to maleic anhydride and the cyclopentadiene as the starting material, the low temperature by 1, 4 - addition reaction intermediate of synthesis of 5 - norbornene - 2, 3 - dicarboxylic acid anhydride; through the ozone oxidation, hydrolysis, hydrogen peroxide oxidation reaction to obtain the cyclopentane tetracarboxylic acid; finally to acetic anhydride as the dehydrating agent, the dehydration ring-closure of the synthesized target product 1, 2, 3, 4 - cyclopentane tetracarboxylic dianhydride. The proposal to the traditional process, mild reaction conditions, the product has high purity, high yield, pollution-free and the like, and is suitable for large-scale industrial production. (by machine translation)
- -
-
Paragraph 0005; 0020-0021; 0025-0026; 0030-0031; 0035-0036
(2019/05/04)
-
- A Crystalline Ready-to-Use Form of Cyclopentadiene
-
Cyclopentadiene (Cpd) is widely used as a starting material in organic and inorganic chemistry. In neat form, Cpd dimerizes, making it necessary to distill it prior to use to obtain fully reactive material. We have screened three different tetraphenyladamantane octaethers for their ability to act as encapsulating organic crystal (EnOC) hosts for Cpd. To this end, we also synthesized 1,3,5,7-tetrakis(3,5-dimethoxyphenyl)adamantane, a new octaether, dubbed iso -TDA. Only one of the octaethers was found to produce inclusion complexes with Cpd in the crystalline state. The encapsulated diene was stable for one month and showed full reactivity in a series of different synthetic transformations.
- Krupp, Felix,He, Shiliang,Frey, Wolfgang,Richert, Clemens
-
supporting information
p. 1707 - 1710
(2018/07/03)
-
- Cyclopentadienyl binuclear chair-shaped cobalt-nitrogen complex as well as preparation method and application thereof
-
The invention discloses a cyclopentadienyl binuclear chair-shaped cobalt-nitrogen complex as well as a preparation method and an application thereof. The complex utilizes bicyclo[2.2.1]-2-heptene-5,6-dicarboxylic acid as a main ligand, utilizes 1,10-phenanthroline as an auxiliary ligand and has a special cyclopentadienyl binuclear chair-shaped structure. The preparation method of the complex comprises steps as follows: the complex is synthesized from bicyclo[2.2.1]-2-heptene-5,6-dicarboxylic acid, cobalt salt and 1,10-phenanthroline as raw materials through one step, and [Co2[C7H8(COO)2]2(C12H8N2)2].5H2O crystals are obtained through self-volatilized crystallization. The preparation method is simple to operate, reaction conditions are mild, yield is high, product crystal phase is uniform, purity is high, and besides, the cobalt-nitrogen complex is stable in structure, shows better catalytic activity when applied to an esterification reaction as a catalyst, and is particularly suitable for catalyzing a reaction for synthesizing polyester from dibasic acid and dihydric alcohol.
- -
-
Paragraph 0038; 0039; 0040
(2017/07/21)
-
- An analysis of the structural, thermal and optical characteristics as well as the electrical resistivity of tert-butyldiphenylsilyl substituted poly(norbornene-dicarboximide)s
-
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
-
p. 189 - 198
(2015/03/03)
-
- Functional norbornanyl ester derivatives, polymers and process for preparing same
-
This invention relates to the new functional norbornanyl ester derivative and/or polymer compositions which are easily obtainable by reacting the Diels-Alder adduct of appropriate dienes and dienophiles with carboxylic acids. In particular, this invention relates to a new process for making cyclic chemical raw materials suitable for production coating, ink, adhesive, plasticizer, thermoplastic or thermosetting plastic and functional polymers.
- -
-
Paragraph 0225
(2013/12/04)
-
- ENDO-METHYLENE HEXAHYDROPHTHALIC ANHYDRIDE AND PRODUCTION METHOD THEREOF
-
The present invention belongs to the field of organic chemical synthesis, and discloses hexahydro-3,6-methanophthalic anhydride and a method of producing the same. The method uses maleic anhydride and mixed C5s as raw materials, generates Nadic anhydride by absorbing cyclopentadiene with maleic anhydride directly at a temperature of 0-5°C, and crystallizes to obtain a pure product; and a Cu-Ni/ZnO-ZrO2 or Co-Ni/ZnO-ZrO2 catalyst is added to the generated Nadic anhydride, carrying out a catalytic hydrogenation reaction in a high-pressure autoclave for 4-6 hours at a temperature of 100-140°C and under a hydrogen pressure of 1-4 MPa, the catalyst is filtered after cooling, and reduced pressure distilling to obtain the hexahydro-3,6-methanophthalic anhydride. Compared with the prior art, the present invention prepares the Nadic anhydride by using mixed C5s, an inexpensive by-product of ethylene, as a raw material, and further synthesizes hexahydro-3,6-methanophthalic anhydride while obtaining a chemical raw material de-cyclized C5s at the same time, enhances the in-depth processing of mixed C5s, and can be used widely in industrial production.
- -
-
Page/Page column 4
(2012/09/21)
-
- (Meth)acrylate compound, photosensitive polymer, and resist composition
-
Disclosed are a (meth)acrylate compound, a photosensitive polymer, and a resist composition, and the (meth)acrylate compound includes a lactone-group-containing (meth)acrylate compound represented by the following Chemical Formula 1.
- -
-
-
- Polyimide aerogels by ring-opening metathesis polymerization (ROMP)
-
Polyimide aerogel monoliths are prepared by ring-opening metathesis polymerization (ROMP) of a norbornene end-capped diimide, bis-NAD, obtained as the condensation product of nadic anhydride with 4,4′-methylenedianiline. The density of the material was varied in the range of 0.13-0.66 g cm -3 by varying the concentration of bis-NAD in the sol. Wet gels experience significant shrinkage, relative to their molds (28%-39% in linear dimensions), but the final aerogels retain high porosities (50%-90% v/v), high surface areas (210-632 m2 g-1, of which up to 25% is traced to micropores), and pore size distributions in the mesoporous range (20-33 nm). The skeletal framework consists of primary particles 16-17 nm in diameter, assembling to form secondary aggregates (by SANS and SEM) 60-85 nm in diameter. At lower densities (e.g., 0.26 g cm-3), secondary particles are mass fractals (Dm = 2.34 ± 0.03) turning to closed-packed surface fractal objects (DS = 3.0) as the bulk density increases (≥0.34 g cm-3), suggesting a change in the network-forming mechanism from diffusion-limited aggregation of primary particles to a space-filling bond percolation model. The new materials combine facile one-step synthesis with heat resistance up to 200 °C, high mechanical compressive strength and specific energy absorption (168 MPa and 50 J g-1, respectively, at 0.39 g cm-3 and 88% ultimate strain), low speed of sound (351 m s-1 at 0.39 g cm-3) and styrofoam-like thermal conductivity (0.031 W m-1 K-1 at 0.34 g cm -3 and 25 °C); hence, they are reasonable multifunctional candidate materials for further exploration as thermal/acoustic insulation at elevated temperatures.
- Leventis, Nicholas,Sotiriou-Leventis, Chariklia,Mohite, Dhairyashil P.,Larimore, Zachary J.,Mang, Joseph T.,Churu, Gitogo,Lu, Hongbing
-
experimental part
p. 2250 - 2261
(2012/02/15)
-
- Retro-diels-alder reactions of masked cyclopentadienones catalyzed by heterogeneous Bronsted acids
-
The zeolite H-Beta catalyzes the retro-Diels-Alder reaction of a range of cyclopentadiene cyclo-adducts at moderate temperatures and ambient pressure, in the presence of an active dienophile. The active catalyst was identified and optimum reaction conditions established after screening a range of zeolites in the retro-Diels-Alder reaction of the cyclopentadiene adduct of cyclopentenone. Our results suggest that retro-Diels-Alder reactions of tricyclodecadienones are catalyzed by Bronsted acids and the high catalytic performance of H-Beta catalysts can be ascribed to the optimal balance between the number of acid sites and their strength as well as to the accessibility of these sites. The methodology was then applied to a series of alkyl derivatives of cyclopentadienylcyclopentenones to provide a viable alternative synthetic route to 4-alkylcyclopentenones and the versatility of the approach was demonstrated by the successful cycloreversion of N-cyclohexyl-2-azanorborn-5-ene. Copyright
- Demuynck, Anneleen L. W.,Levecque, Pieter,Kidane, Aklilu,Gammon, David W.,Sickle, Eugene,Jacobs, Pierre A.,De Vos, Dirk E.,Sels, Bert F.
-
p. 3419 - 3430
(2011/02/23)
-
- Solvent-free Diels-Alder reactions of in situ generated cyclopentadiene
-
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
-
experimental part
p. 91 - 95
(2010/04/22)
-
- 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
-
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
-
p. 666 - 673
(2008/09/16)
-
- Gas sorption in new fluorine containing polynorbornenes with imide side chain groups
-
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
-
p. 2696 - 2703
(2007/10/03)
-
- DEODORANTS
-
The present invention provides a liquid deodorant suitable for deodorization of spaces and fiber products, and a hair cosmetic and skin cosmetic having a high deodorization effect. Here, any of the hair cosmetic and skin cosmetic may be that referred to as a body deodorant. Namely, the present invention provides a deodorant comprising a deodorant organic dibasic acid composed of an organic dibasic acid and/or salt thereof having a difference between the first acid dissociation index (hereinafter, abbreviated as first acid dissociation index) and the second acid dissociation index (hereinafter, abbreviated as second acid dissociation index or pK2) of 1.7 or more at 25°C.
- -
-
-
- The nature of lithium perchlorate and gallium chloride salt effect in cycloaddition reactions
-
Comparing the acceleration effects of (4 + 2)-, (3 + 2)- and (2 + 2)-cycloaddition reactions in the presence of the salts of two types: gallium chloride in inert solvents and lithium perchlorate (LP) in diethyl ether (DE) it was observed that in the presence of GaCl3 the acceleration effect is approximately the same (104 times) for the studied reactions, while in LPDE medium for the same reactions strong increase (up to 104 times), weak increase or even decrease of the rate and equilibrium constants take place even with the common dienophile depending on the nature of the second reagent. it was suggested that the acceleration effect of cycloaddition reactions in the presence of such Lewis acids as aluminum, gallium or boron halides is due to the sharp increase of Π-acceptor properties of dienophiles and therefore increasing energy of orbital interaction, whereas LPDE medium demonstrates strong stabilization of static and/or dynamic polar forms and favors reactions with charge control.
- Shtyrlin, Yury G.,Murzin, Dmitry G.,Luzanova, Natalia A.,Iskhakova, Gulnara G.,Kiselev, Vladimir D.,Konovalov, Alexandr I.
-
p. 2631 - 2646
(2007/10/03)
-
- Borole derivatives. 20. Three-center Fe-H-B bonding in (borole) (cyclopentadienyl)hydridoiron derivatives
-
(Borole)tricarbonyliron complexes Fe(CO)3(3,4-R12C4H2BPh) (3a, R1 = H; 3b, R1 = Me) react with cyclopentadiene under irradiation to give the hydrides CpFeH(3,4-R12C4H2BPh) (1a,b). Deprotonation by NaH in THF produces the borataferrocene anions [CpFe(3,4-R12C4H2BPh)]-(5a -, 5b-). These can be alkylated in the 2-/5-position by alkyl iodides in the presence of NaH to give 2,5-dialkyl hydride derivatives: e.g. CpFeH(2,5-R22C4H2BPh) (1c, R2 = Me; 1g, R2 = CH2=CH(CH2)4; 1h, R2 = (CH2)2CHCH2). The structures of CpFeH(2,3,4,5-Me4C4BPh) (1d; Fe-B = 215.1(4) pm, Fe-H = 147(3) pm, B-H = 151(3) pm) and (C5H4Me)FeH(2,5-Me2C4H 2-BPh) (1f; Fe-B = 215.5(2) pm, Fe-H = 147.5(23) pm, B-H = 146.1(26) pm) as determined by low-temperature X-ray diffraction show the presence of an Fe-H-B three-center bond with a weak B-H interaction. In solution 1a establishes a mobile equilibrium between the ground state 1a-G with Fe-H-B three-center bonding and the agostic isomer 1a-A with Fe-H-C-2(C4H4B) three-center bonding with an estimated ΔG = 1.4 kcal/mol. The hydridic proton and the 2-/5-protons of the borole ring undergo fast intramolecular exchange (Tc = 333 K at 80 MHz and ΔG?333 = 17.0 ± 0.7 kcal/mol for 1a). A merry-go-round of the three H atoms involved with one hydrogen crossing the exo face of the borole ligand is proposed as an exchange mechanism. The bonding in CpFeH(C4H4BH) is analyzed by means of extended Hu?ckel calculations, which confirm the Fe-H-B three-center bonding. Exploratory extended Hu?ckel calculations also support the existence of agostic isomers as well as the proposed exchange mechanism. Cyclic voltammetry revealed the existence of the 17e complex CpFe(C4H4BPh) (5a), which is characterized by its EPR and paramagnetic 1H NMR spectra. 1a reacts with CNBut to give the boracyclopentenyl complex CpFe(CNBut)(C4H5BPh) (9a) and, probably via the intermediate Fe(CNBUt)(C4H4BPh)(C5H6) (10), the borole complex Fe(CNBUt)3(C4H4BPh) (11a) and 1 equiv of cyclopentadiene. Labeling experiments show that the shift of the hydridic hydrogen to the borole and Cp ligands, respectively, is an intramolecular process. 1c reacts analogously.
- Herberich, Gerhard E.,Carstensen, Tobias,K?ffer, Dieter P. J.,Klaff, Norbert,Boese, Roland,Hyla-Kryspin, Isabella,Gleiter, Rolf,Stephan, Martin,Meth, Helmut,Zenneck, Ulrich
-
p. 619 - 630
(2008/10/08)
-
- BISREAGENTS IN THE DIELS-ALDER REACTION. VII. PRODUCTION OF POLYADDUCTS FROM THE REACTION OF BISPOLYMETHYLCYCLOPENTADIENES AND BISMALEIMIDES AND THEIR PROPERTIES
-
Polymethylcyclopentadienes and bisdienes exhibit high reactivity with mono- and bisdienophiles in the Diels-Alder reaction.By reaction calorimetry in solution, differential scanning calorimetry, and derivatography it was found that the mono-, bis-, and polyadducts have high thermal stability.The ionization potentials, determined for a series of dienes by photoelectron spectroscopy and spectrophotometry of charge-transfer complexes, lie in the range of 7.15-8.5 eV.The coefficients of the Kuhn-Houwink equation were calculated from data on the characteristic viscosity of the solutions of the polyadducts.They agree with the spherical shape of the polyadducts.The molecular mass of the new polyadducts is greater than 100000.
- Kiselev, V. D.,Sakhabutdinov, A. G.,Shakirov, I. M.,Zverev, V. V.,Konovalov, A. I.
-
p. 1806 - 1813
(2007/10/02)
-
- KINETIC AND THERMODYNAMIC STUDY OF THE DIELS-ALDER REACTION WITH 1,2,3,4,5-PENTAMETHYLCYCLOPENTADIENE
-
A kinetic and thermochemical study of the Diels-Alder reaction between 1,2,3,4,5-pentamethylcyclopentadiene and a series of dienophiles was undertaken.The ionization potential of the diene (7.08 eV) was calculated from the spectrum of the charge-transfer complex with p-chloranil.Pentamethylcyclopentadiene was more reactive than cyclopentadiene, 9,10-dimethylanthracene, and even 2,5-diphenylisobenzofuran.The exothermicity of the reactions of the dienophiles with pentamethylcyclopentadiene in benzene is appreciably higher than in the reactions with other dienes.An important feature of the investigated diene is the favorable combination of its enhanced reactivity in the Diels-Alder reaction with the enhanced stability of its adducts.
- Kiselev, V. D.,Sakhabutdinov, A. G.,Shakirov, I. M.,Konovalov, A. I.
-
p. 2276 - 2278
(2007/10/02)
-
- Pylcyclic Aromatic Compounds: Part VII - Synthesis of 1,3-Di-p-tolylcyclopentaceanthrylen-2(H)-one and Its Transformation with Ethylenic and Acetylenic Compounds to Polycyclics Containing Benzofluoranthene Nucleus
-
Aceanthraquinone (I) undergoes condensation with 4,4'-dimethyldibenzyl ketone (II) to form a reactive diene, 1,3-di-p-tolylcyclopentaceanthrylen-2(H)-one (III) from which a number of polycyclic aromatic compounds (IV-X) containing a benzofluoranthene nucleus have been prepared by diene synthesis with dienophiles containing a reactive ethylenic or acetylenic bond.The dienophiles used are maleic anhydride, chloromaleic anhydride, acenaphthylene, 1-chloroacenaphthylene, indene, 3-chloroindene, bicyclohepta-2,5-diene, diphenylacetylene and benzyne.
- Bandyopadhyay, T. K.,Bhattacharya, A. J.
-
-
