- UV PhotoVap: Demonstrating How a Simple and Versatile Reactor Based on a Conventional Rotary Evaporator Can Be Used for UV Photochemistry
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We report the use of a simple rotary evaporator as a semi-continuous UV photochemical reactor. By generation of a thin film from the rotation of a flask, better light penetration is achieved, and in this work we used high-power Hg lamps to enable the direct irradiation of molecules with UV light. The intramolecular [2 + 2] photocycloaddition of Cookson's dione and the intermolecular [2 + 2] photocycloaddition of maleimide with 1-hexyne were used as test reactions to examine the effectiveness of this reactor. High productivities, equivalent to 210 g h-1, were obtained for the simple intramolecular reaction, demonstrating the scalability of the reactor. The effects of flask size, reaction mixture volume, and use of borosilicate or quartz glassware were also investigated.
- Clark, Charlotte A.,Lee, Darren S.,Pickering, Stephen J.,Poliakoff, Martyn,George, Michael W.
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- First synthesis of 9,10-dimethoxy-2-methyl-1,4-anthraquinone: A naturally occurring unusual anthraquinone
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The synthesis of 9,10-dimethoxy-2-methyl-1,4-anthraquinone, an unusual quinone, was achieved in five steps from p-benzoquinone. A Kochi-Anderson radical methylation features as the key step in the synthesis. The chemistry of a cyclopropa-1,4-anthracenedio
- Mal, Dipakranjan,Ray, Sutapa
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- A Crystalline Ready-to-Use Form of Cyclopentadiene
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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
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- Unexpected regioselectivity observed in the bromination and epoxidation reactions of p-benzoquinone-fused norbornadiene: An experimental and computational study
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The bromination reaction of p-benzoquinone-fused norbornadiene was studied at various temperatures (?78,??50, 0, 25, and 77?°C). At room temperature, the double bonds of the p-benzoquinone units were mainly brominated. The double bond of the norbornene unit also underwent a bromination reaction in a yield of only 2%. However, the reaction at??78?°C resulted in the formation of products derived from the attack of bromine on the norbornene double bond with higher charge density. In contrast to the bromination reaction, the epoxidation reaction of the same compound with m-chloroperbenzoic acid and dimethyldioxirane exclusively resulted in the formation of products derived from the addition to the double bond of norbornadiene. The regioselectivity observed was investigated and the results were supported by theoretical calculations.
- Essiz, Selcuk,Dalkilic, Erdin,Sari, Ozlem,Dastan, Arif,Balci, Metin
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- Soluble cycloannulated tetroxa[8]circulane derivatives: Synthesis, optical and electrochemical properties, and generation of their robust cation-radical salts
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Syntheses of soluble bicycloalkane-annulated tetraoxa[8]circulane derivatives via Lewis acid-catalyzed tetramerization of readily available cycloannulated benzoquinons is described. The ready availability of the soluble circulane derivatives allows the evaluation of their optical and electrochemical properties. These circulanes form stable (isolable) cation-radical salts upon 1-electron oxidation using antimony pentachloride and various aromatic oxidants.
- Rathore, Rajendra,Abdelwahed, Sameh H.
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- Lewis acid catalyst system for Diels–Alder reaction
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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
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- Triquinane scaffolds: Shape and geometry as a function of saturation and bridgehead groups
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Polycyclic hydrocarbon compounds, also known as "cage compounds", are of interest in drug discovery due to their versatility as scaffolds. Derivatives of both pentacycloundecane-dione and triquinane-dione have been the focus of numerous investigations as multifunctional neuroprotective drugs where these compounds were used as novel drug scaffolds with the ability to cross the blood brain barrier. Here we present the synthesis, characterization and single crystal X-ray analysis for two triquinane synthons; tricyclo[6.3.0.0 2,6]undecane-4,9-diene-3,11-dione (compound 5 crystallizes in the monoclinic system, unit cell parameters are: a = 6.5876 (12) ?, b = 10.4204 (19) ?, c = 12.074 (2) ?; V = 825.4 (3) ?3 and Z = 4) and tricyclo[6.3.0.02,6]undecane-3,11-dione (compound 6 crystallizes in monoclinic system, unit cell parameters are: a = 7.5992 (7) ?, b = 10.7294 (10) ?, c = 10.8664 (10) ?; V = 884.04 (14) ?3 and Z = 4); as well as a triquinane derivative, N-(3-methoxybenzyl)-3,11-azatricyclo[6.3.0.02,6]undecane (compound 11 crystallizes in triclinic system, unit cell parameters are: a = 7.6714 (7) ?, b = 9.0100 (9) ?, c = 11.2539 (11) ?; V = 745.78 (12) ?3 and Z = 2). The size and geometrical conformation of the triquinane scaffolds were compared to tetra and pentacycloundecanes, revealing that tricyclo[6.3.0.02,6]undecane-3,11-dione experiences strain relief resulting in greater flexibility, a more asymmetric molecular shape and larger surface area. However, with the introduction of the aza-bridge in N-(3-methoxybenzyl)-3,11-azatricyclo[6.3.0.02,6]undecane, much of the flexibility and asymmetry is lost again. We also discuss the rearrangement mechanism for the observed retro cycloaddition and reversion, and utilized density functional theory calculations to discuss the photocyclization mechanism of this unique [2 + 2] Diels-Alder system.
- Young, Lois-May,Zeller, Matthias,Geldenhuys, Werner J.,Malan, Sarel F.,Van Der Schyf, Cornelis J.
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- The Rates of a Diels-Alder Reaction in Liquid and Supercritical Carbon Dioxide
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Kinetic measurements on the Diels-Alder reaction between p-benzoquinone and cyclopenta-1,3-diene have been carried out in carbon dioxide as a medium between 25 and 40 deg C; the reaction effectively occurs throughout liquid and supercritical ranges with no discontinuity and rates are about 20percent greater than those in diethyl ether.
- Isaacs, Neil S.,Keating, Nicholas
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- Design, synthesis and evaluation of pentacycloundecane and hexacycloundecane propargylamine derivatives as multifunctional neuroprotective agents
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The multifactorial pathophysiology of neurodegenerative disorders remains one of the main challenges in the design of a single molecule that may ultimately prevent the progression of these disorders in affected patients. In this article, we report on twelve novel polycyclic amine cage derivatives, synthesized with or without a propargylamine function, designed to possess inherent multifunctional neuroprotective activity. The MTT cytotoxicity assay results showed the SH-SY5Y human neuroblastoma cells to be viable with the twelve compounds, particularly at concentrations less than 10 μM. The compounds also showed significant neuroprotective activity, ranging from 31% to 61% at 1 μM, when assayed on SH-SY5Y human neuroblastoma cells in which neurodegeneration was induced by MPP+. Calcium regulation assays conducted on the same cell line showed the compounds to be significant VGCC blockers with activity ranging from 26.6% to 51.3% at 10 μM; as well as significant NMDAr antagonists with compound 5 showing the best activity of 88.3% at 10 μM. When assayed on human MAO isoenzymes, most of the compounds showed significant inhibitory activity, with compound 5 showing the best activity (MAO-B: IC50 = 1.70 μM). Generally, the compounds were about 3–52 times more selective to the MAO-B isoenzyme than the MAO-A isoenzyme. Based on the time-dependency studies conducted, the compounds can be defined as reversible MAO inhibitors. Several structure activity relationships were derived from the various assays conducted, and the compounds’ possible putative binding modes within the MAO-B enzyme cavity were assessed in silico.
- Zindo, Frank T.,Malan, Sarel F.,Omoruyi, Sylvester I.,Enogieru, Adaze B.,Ekpo, Okobi E.,Joubert, Jacques
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supporting information
p. 83 - 94
(2018/12/04)
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- Underwater diene addition reaction synthesizing method and application thereof in synthesizing of double-cage spiro hydrocarbon PCUD
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The invention provides an underwater diene addition reaction synthesizing method and application thereof in synthesizing of double-cage spiro hydrocarbon PCUD. The synthesizing method is characterizedin that p-benzoquinone and cyclic conjugate diolefins are treated as raw materials, and water is treated as a dispersant, and on that basis, Diels-Alder addition reaction is carried out. According tothe method, pure water is treated as a medium in the reaction; and the reaction post-treatment is simple, and easy to carry out; the energy consumption is low; and the yield is high.
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Paragraph 0047; 0052-0055
(2019/09/17)
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- Bridged Ring compounds As Hepatitis C Virus (HCV) Inhibitors And Pharmaceutical Applications Thereof
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Provided herein is a compound having Formula (I), or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a hydrate, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof, which can be used for treating HCV infection or a HCV disorder. Also provided herein are pharmaceutical compositions comprising the compounds disclosed herein, which can be used for treating HCV infection or a HCV disorder.
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Paragraph 0679; 0725; 0726; 0727; 0728
(2015/03/28)
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- BRIDGED RING COMPOUNDS AS HEPATITIS C VIRUS INHIBITORS, PHARMACEUTICAL COMPOSITIONS AND USES THEREOF
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Provided herein is a bridged bring compound of formula (I) or a stereoisomer, a tautomer, an N-oxide, a hydrate, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof, which can be used for treating treat hepatitis C virus (HCV) infection or hepatitis C disease. Furthermore provided herein are pharmaceutical compositions containing the compounds and the method of using the compounds or harmaceutical com ositions thereof in the treatment of HCV infection or he atitis C.
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Paragraph 00172
(2015/08/06)
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- BRIDGED RING COMPOUNDS AS HEPATITIS C VIRUS INHIBITORS, PHARMACEUTICAL COMPOSITIONS AND USES THEREOF
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Provided herein is a compound of formula (I) or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a hydrate, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof, which can be used for treating HCV infection or a HCV disorder. Also provided herein are a pharmaceutical composition comprising the compound and the use of the compound and the pharmaceutical composition thereof, which can also be used for treating HCV infection or a HCV disorder.
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Page/Page column 181
(2014/09/16)
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- BRIDGED RING COMPOUNDS AS HEPATITIS C VIRUS (HCV) INHIBITORS AND PHARMACEUTICAL APPLICATIONS THEREOF
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Provided herein is a compound having Formula (I), or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a hydrate, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof, which can be used for treating HCV infection or a HCV disorder. Also provided herein are pharmaceutical compositions comprising the compounds disclosed herein, which can be used for treating HCV infection or a HCV disorder.
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Paragraph 00339
(2014/02/16)
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- Solar driven uphill conversion of dicyclopentadiene to cyclopentadiene: An important synthon for energy systems and fine chemicals
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The retro Diels-Alder conversion of endo-dicyclopentadiene to cyclopentadiene (Cp)-which is thermodynamically uphill under ambient conditions (ΔG = +9.7 kcal mol-1; values based on computation at 273 K following CBS-QB3 methodology)-was carried out at 175-190 °C in neat state using solar energy. The reaction is thermodynamically favorable at elevated temperature. Considering heat release from the reverse reaction (ΔH = -23.4 kcal mol-1), the energy storage efficiency was computed to be ca. 5.5% with respect to the IR component in concentrated solar radiation. Solar energy was further utilized for preparation of a model 2,5-norbornadiene derivative (75% isolated yield) through the cycloaddition reaction of Cp with 4-phenylbut-3-yn-2-one at 150-185 °C. The norbornadiene-quadricyclane system has been proposed for solar energy storage, and its solar assisted synthesis would help reduce its carbon footprint over its life cycle. Norbornadiene synthesis using solar energy may also be of interest for greener processing of fuels derived from this compound. Cookson's cage ketone, which too has been proposed as an energy storage medium, was additionally synthesized from the Diels-Alder adduct of Cp and p-benzoquinone employing concentrated solar photo-thermochemical conditions. The reaction proceeded rapidly (15 min) and gave the desired product in 96% isolated yield. Besides the above applications, Cp is an important synthon in the preparation of fine chemicals.
- Dinda, Milan,Chakraborty, Supratim,Kanti Si, Mrinal,Samanta, Supravat,Ganguly, Bishwajit,Maiti, Subarna,Ghosh, Pushpito K.
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p. 54558 - 54564
(2015/02/05)
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- Design, synthesis and evaluation of small molecule reactive oxygen species generators as selective Mycobacterium tuberculosis inhibitors
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Here, we report 5-hydroxy-1,2,3,4,4a,9a-hexahydro-1,4-ethano-9,10- anthraquinone (13), a small molecule generating reactive oxygen species (ROS) in pH 7.4 buffer under ambient aerobic conditions that has selective and potent Mycobacterium tuberculosis gro
- Dharmaraja, Allimuthu T.,Alvala, Mallika,Sriram, Dharmarajan,Yogeeswari, Perumal,Chakrapani, Harinath
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supporting information
p. 10325 - 10327
(2012/11/13)
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- The importance of hydrogen bonding to stereoselectivity and catalyst turnover in gold-catalyzed cyclization of monoallylic diols
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Density functional calculations and experiment were used to examine the mechanism, reactivity, and origin of chirality transfer in monophosphine Au-catalyzed monoallylic diol cyclization reactions. The lowest energy pathway for cyclization involves a two-
- Ghebreghiorgis, Thomas,Biannic, Berenger,Aponick, Aaron,Kirk, Brian H.,Ess, Daniel H.
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supporting information
p. 16307 - 16318,12
(2020/09/09)
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- Promotion of organic reactions by interfacial hydrogen bonds on hydroxyl group rich nano-solids
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Surface hydroxyl group rich nano-structured solids dramatically increase the rate of several organic reactions; such effect is attributed to the formation of interfacial hydrogen bonds between the surface hydroxyl groups and the reactants; this catalytic
- Niu, Fang,Liu, Chang-Chang,Cui, Zhi-Min,Zhai, Jin,Jiang, Lei,Song, Wei-Guo
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supporting information; body text
p. 2803 - 2805
(2009/02/05)
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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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- Enhanced Diels-Alder reactions: on the role of mineral catalysts and microwave irradiation in ionic liquids as recyclable media
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This manuscript explores in detail the combined effect of solid supports or microwave irradiation in ionic liquids on a series of Diels-Alder reactions involving 1,3-cyclopentadiene and numerous dienophiles.
- López, Ignacio,Silvero, Guadalupe,Arévalo, María José,Babiano, Reyes,Palacios, Juan?Carlos,Bravo, José Luis
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p. 2901 - 2906
(2007/10/03)
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- Polymeric Phosphine Ligand from Ring-Opening Metathesis Polymerization of a Norbornene Derivative. Applications in the Heck, Sonogashira, and Negishi Reactions
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The phosphine-containing polymer 1 is obtained by ruthenium-catalyzed ring-opening metathesis polymerization of the norbornene derivative 2. Polymer 1 is employed as the polymer support in the palladium-catalyzed Heck, Sonogashira, and Negishi reactions,
- Yang, Yun-Chin,Luh, Tien-Yau
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p. 9870 - 9873
(2007/10/03)
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- The synthesis of epi-epoxydon utilising the Baylis-Hillman reaction
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(±)-epi-Epoxydon was synthesised by means of a triethylaluminium/tri-n-butylphosphine-catalysed Baylis-Hillman reaction between an O-protected epoxidised hydroxyquinol core and paraformaldehyde, constituting the first application of the Baylis-Hillman reaction to a highly functionalised β-substituted enone.
- Genski, Thorsten,Taylor, Richard J.K.
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p. 3573 - 3576
(2007/10/03)
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- A novel, versatile synthetic approach to linearly fused tricyclopentanoids via photo-thermal olefin metathesis
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Fifteen examples of a new, speedy and general approach to linearly fused tricyclopentanoids bearing the tricyclo[6.3.0.02,6]undecane (triquinane) frame of high contemporary interest is delineated. The key concept in our synthetic sequence to triquinanes is the novel photo-thermal olefin metathesis of cheap, abundantly available Diels-Alder adducts of 1,3-cyclopentadienes and p-benzoquinones. Thus, photolysis of endo-tricyclo[6.2.1.02,7]undeca-4,9-dien-3,6-dliones (9a-j, 13a,b)furnished pentacyclo[5.4.0.02,6.03,10.05,9]undecan-8,11-diones (10a-j, 14a, b), which on thermal fragmentation of the cyclobutane ring gave cis, syn, cis-tricyclo [6.3.0.02,6]undeca-4,9-dien-3, ll-diones (lla-j, 15a,b) in just three steps and in exceptionally good yields. A few interesting transformations of the readily available parent bis-enone 11a which indicates its wider uses in syntheses, are described. Finally, a smooth thermal isomerisation of cis, syn, cis-bis-enones to cis, anti, cis-bis-enones is reported, which further enhances the scope and versatility of our synthetic theme.
- Mehta, Goverdhan,Srikrishna,Reddy, A. Veera,Nair, Mangalam S.
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p. 4543 - 4559
(2015/01/09)
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