- Synthetic approaches to phomactins: Novel oxidation of homoallylic alcohols using tetra-n-propylammonium perruthenate
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Previous studies of a synthesis of phomactin A had resulted in the synthesis of a 15-methylenebicyclo[9.3.1]pentadecadiene. The next step in the synthesis was to be the epoxidation of this methylenecyclohexane that was hoped would lead to a 1-(hydroxymethyl)cyclohexene by rearrangement of the exocyclic epoxide, but the epoxidation was difficult to carry out regioselectively on advanced intermediates. However, oxidation of a 15-methylenebicyclo[9.3.1]pentadeca-3,7-dien-14-ol using tetra-n-propylammonium perruthenate and N-methylmorpholine-N-oxide led to conversion of this homoallylic alcohol into the corresponding 14-oxobicyclo[9.3.1]pentadeca-1(15),3,7-triene-15-carboxaldehyde in one step. Reduction of this using DIBAL-H gave a promising intermediate for a synthesis of a phomactin. The scope of this oxidation of homoallylic alcohols was briefly investigated.
- Blackburn, Timothy J.,Thomas, Eric J.
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- A convenient preparation of (E)-3-penten-2-one
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A convenient large-scale synthesis of (E)-3-penten-2-one has been described based on the synthesis of the corresponding β,γ-unsaturated ketone and its subsequent base-catalyzed olefin isomerization.
- Chiu, Pauline,Wong, Sun Ting
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- PROCESS FOR PREPARING PLATINUM ORGANOSILOXANE COMPLEXES USING AN ENONE ADDITIVE
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A platinum organosiloxane complex is prepared by a process including combining A) a platinous halide; B) a ketone; C) an enone additive distinct from any other starting materials or rearrangement products thereof; and D) a polyorganosiloxane having, per molecule, 2 to 4 silicon bonded terminally unsaturated hydrocarbon groups having from 2 to 6 carbon. The platinum organosiloxane complex prepared by the process is useful as a hydrosilylation catalyst.
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Paragraph 0023
(2019/02/06)
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- Investigation of hollow bimetal oxide nanomaterial and their catalytic activity for selective oxidation of alcohol
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The aerobic oxidation procedure utilized sustainable non-noble-metal catalysts has been a long-standing objective in laboratory and industrial research. The synthesized hollow bimetal oxide nanoparticles catalysts (HNPs) as a stable and efficient catalyst, which was applied to the selective oxidation of alcohols with molecular oxygen as oxidant, is reported. The catalytic performance of Co3O4/Fe3O4@C HNPs was tested via selective aerobic oxidation catalytic reaction of cinnamyl alcohol in the liquid phase. The results prove that the Co3O4/Fe3O4@C HNPs exhibit ~ 90% yield for alcohol oxidation, which can be conveniently separated and recycled from reaction system by an external magnetism. Forthrmore, the catalyst can be reutilized for at least 5 runs without a distinct activity reduction. A feasible reaction mechnism over the bimetal catalyst for the alcohol oxidation was proposed. The surface effect between metal oxide nanoparticle and carbon support, and relatively high and easy reducibility grant favorable catalytic activity of Co3O4/Fe3O4@C HNPs. This make the Co3O4/Fe3O4@C HNPs a very significant catalyst for aerobic catalytic oxidation reaction of alcohols in the liquid phase for industrial manufacture.
- Gao, Wenbin,Li, Feng,Huo, Hongfei,Yang, Yuanyuan,Wang, Xiang,Tang, Yu,Jiang, Pengbo,Li, Shuwen,Li, Rong
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- INHIBITION OF MACROPHAGE MIGRATION INHIBITORY FACTOR IN MELANOMA AND COLON CANCER
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Compounds and compositions are provided which inhibit MIF. Methods of treatment of melanoma and colon cancers are also provided.
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Paragraph 0070
(2015/12/30)
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- Catalytic aerobic oxidation of allylic alcohols to carbonyl compounds under mild conditions
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A new catalytic aerobic oxidation of alcohols to aldehydes under green conditions was developed (room temperature and pressure, water solution, open vials). The water-soluble platinum(II) tetrasulfophthalocyanine (PtPcS) catalyst showed the best selectivity for carbonyl derivatives, and in particular for α,β-unsaturated alcohols; the reactions are slow.
- Tonucci, Lucia,Nicastro, Marco,D'Alessandro, Nicola,Bressan, Mario,D'Ambrosio, Primiano,Morvillo, Antonino
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experimental part
p. 816 - 820
(2010/04/23)
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- Facile photochemical transformation of alkyl aryl selenides to the corresponding carbonyl compounds by molecular oxygen: Use of selenides as masked carbonyl groups
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(Chemical Equation Presented) Alkyl aryl selenides with and without functional groups on the alkyl group were transformed efficiently into the corresponding carbonyl compounds, particulary primary alkyl aryl selenides in good yields, by a simple photolysis in the presence of air or oxygen. This transformation can be conducted without protection of functional groups. The yield of carbonyl compounds was much affected by the solvent viscosity, reaction temperature, concentration of dissolved oxygen in the solvents, wavelength of light, and structure of the aryl substituents. The present study indicates that aryl selenides can be considered as a masked carbonyl group that can be easily converted to a carbonyl group by very mild reaction conditions even in the presence of various unprotected functional groups. Therefore, this functional group transformation can be used as an important tool in organic synthesis due to its simplicity and mild reaction condition.
- Hyugano, Takeshi,Liu, Suyou,Ouchi, Akihiko
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supporting information; scheme or table
p. 8861 - 8866
(2009/04/05)
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- Compounds capable of activating cholinergic receptors
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The present invention generally relates to nicotinic compounds, in the form of aryl substituted olefinic compounds, as well as pro-drug, N-oxide, metabolite and pharmaceutically acceptable salt forms thereof. Methods of modulating neurotransmitter release via administration of the compounds, pro-drugs, N-oxides and/or pharmaceutically acceptable salts are also disclosed.
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- Compounds capable of activating cholinergic receptors
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The present invention generally relates to nicotinic compounds, in the form of aryl substituted olefinic compounds, as well as pro-drug, N-oxide, metabolite and pharmaceutically acceptable salt forms thereof. Methods of modulating neurotransmitter release via administration of the compounds, pro-drugs, N-oxides and/or pharmaceutically acceptable salts are also disclosed.
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- Biocatalytic oxidative kinetic resolution of sec-alcohols: Stereocontrol through substrate-modification
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Whole lyophilised cells of Rhodococcus ruber DSM 44541 were employed for the oxidative kinetic resolution of sec-alcohols using acetone as hydrogen acceptor. The enantioselectivity of this process could be controlled effectively by introducing C-C multiple bonds into substrates, which were inefficiently recognised, in particular short-chain (ω-1)-alcohols and (ω-2)-analogs. Thus, the enantioselectivities of rac-2-pentanol (E=16.8) and rac-3-octanol (E=13.3) were significantly improved by introducing a C=C bond adjacent to the alcohol moiety to give racemic (E)-pent-3-en-2-ol and 4-(E)-octen-3-ol, which were resolved with excellent selectivities (E >100 and 50, respectively). In addition, it was found that high stereodifferentiation between the E- and Z-configured double bonds occurred, as the corresponding (Z)-isomers were not converted. Similar selectivity-enhancing effects were observed with acetylenic analogs.
- Stampfer, Wolfgang,Kosjek, Birgit,Faber, Kurt,Kroutil, Wolfgang
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p. 275 - 280
(2007/10/03)
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- Liquid-phase isomerization of saturated and unsaturated epoxides
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The liquid-phase isomerization of a variety of epoxides was studied using a complex catalyst system based on magnesium bromide and dimethylformamide. The data obtained elucidate the mechanism of the liquid-phase isomerization and show the range of oxygen-containing compounds which can be prepared through this reaction.
- Mel'nik,Khvatova,Moskvichev,Srednev,Egorova
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p. 167 - 169
(2007/10/03)
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- Chromium catalyzed oxidation of (homo-)allylic and (homo-)propargylic alcohols with sodium periodate to ketones or carboxylic acids
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Primary and secondary (homo-)allylic and (homo-)propargylic alcohols can be oxidized under slightly acidic conditions at or below room- temperature with sodium periodate in the presence of sodium dichromate as the catalyst to the corresponding carboxylic acids and ketones, respectively.
- De Vondervoort, Lizette Schmieder-Van,Bouttemy, Sabine,Padrón, José M.,Le Bras, Jean,Muzart, Jacques,Alsters, Paul L.
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p. 243 - 246
(2007/10/03)
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- Synthesis of oxygen-containing compounds from 1,4-pentadiene
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1,4-Pentadiene oxidation with pinane and cumene hydroperoxides was examined. The application of crude cumene hydroperoxide was shown to yield 90% 1,2-epoxypentene-4 at an oxidant conversion of over 95%. The isomerization of 1,2-epoxypentene-4 in the vapor phase at 290-330°C on lithium phosphate was studied. The rearrangement yielded 2,4-pentadiene-1-ol and unsaturated carbonyl compounds in a nearly 1:1 ratio at an epoxide conversion of 50%. Carbonyl compounds consisted mainly of pentenals with a different double-bond position. The results of the rearrangement show that the epoxide C-O bond heterolysis takes place mainly on the allyl group side.
- Srednev,Yas'Kina,Moskvichev,Egorova,Shutova,Kozlova
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- Allylation of Acid Chlorides by Allyltributyltin in the Presence of Catalytic Amounts of Dibutyltin Dichloride
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Redistribution of allyltributyltin and dibutyltin dichloride into allyldibutyltin chloride and tributyltin chloride is enhanced by coordinative compounds such as phosphine oxide and ammonium chloride.This redistribution is applied to the reaction of allyl
- Yano, Katsunori,Baba, Akio,Matsuda, Haruo
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p. 1181 - 1184
(2007/10/02)
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- Photolysis of Alkyl 4-Nitrobenzenesulfenates. A New and Versatile Method for the Generation of Free Radicals
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The irradiation of alkyl 4-nitrobenzenesulfenates with >300-nm wavelength light in benzene solution results in the homolytic cleavage of the O-S bond.The tertiary alkoxy radicals thus formed undergo β scission to produce carbon-centered free radicals in e
- Pasto, Daniel J.,L'Hermine, Gael
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p. 5815 - 5816
(2007/10/02)
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- (α-Ethoxyvinyl)tributyltin; An Efficient Reagent for the Nucleophilic Acetylation of Organic Halides via Palladium Catalysis
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(α-Ethoxyvinyl)tributyltin acts as a masked acetylating agent in the palladium catalyzed reaction with various organic halides, such as aryl bromides, vinyl bromides, benzyl chloride, and allyl chloride, giving, after hydrolysis of the resulting reaction mixture, good yields of the corresponding ketone product.
- Kosugi, Masanori,Sumiya, Takashi,Obara, Yukimasa,Suzuki, Motohiro,Sano, Hiroshi,Migita, Toshihiko
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p. 767 - 768
(2007/10/02)
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- A Simple and Effective Electrocatalytic Deprotection of the 4-Phenyl-1,3-dioxolane Protecting Group
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Anodic deprotection of ketone acetals under very mild conditions may be achieved by a combination of 1-phenylethane-1,2-diol as a protecting reagent and N-hydroxyphthalimide as a mediator.
- Masui, Masaichiro,Kawaguchi, Tetsuo,Ozaki, Shigeko
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p. 1484 - 1485
(2007/10/02)
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- ELECTROPHILIC REACTION OF ALLYLTRIMETHYLSILANE WITH NITRILES IN THE PRESENCE OF BORON TRICHLORIDE
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Allyltrimethylsilane reacted with various nitriles in the presence of boron trichloride, giving after hydrolysis β,γ-unsaturated ketones in high yields.The reactions of substituted allyltrimethylsilanes and intramolecular reaction of allylic trimethylsilane with nitrile were also studied.
- Hamana, Hiroshi,Sugasawa, Tsutomu
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p. 921 - 924
(2007/10/02)
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- Gas-Phase Elimination Kinetics of (Dimethylamino)alkyl Acetates. The Ion-Pair Mechanism through Neighboring Group Participation.
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The gas-phase elimination kinetics of some amino esters and a keto acetate have been studied in the temperature region of 260.0-411.5 deg C and in the pressure range of 21.5-170.0 torr.These eliminations, in vessels seasoned with allyl bromide, are predominantly unimolecular and homogenous and obey a first order rate law.The rate coefficients for the reactions are expressible by the following Arrhenius equations: for 3-(dimethylamino)-1-propyl acetate (1), log k1 (s-1) = (12.97 +/- 0.20) - (202.1 +/- 2.5) kJ mol-1 (2.303RT)-1; for 4-(dimethylamino)-1-butyl acetate (4), log k1 (s-1) = (11.91 +/- 0.43) - (163.5 +/- 4.8) kJ mol-1 (2.303 RT)-1; for 4-oxo-1-pentyl acetate (7), log k1 (s-1) = (12.77 +/- 0.36) - (202.8 +/- 4.6) kJ mol-1 (2.303RT)-1.The presence of the (CH3)2N group in these acetates appears to provide anchimeric assistance in the elimination; methyl acetate and the corresponding heterocyclic products arise from an intimate ion-pair mechanism.The CH3CO substituent is believed to influence the pyrolysis rate of 5-acetoxy-2-pentanone by a weak steric acceleration.
- Chuchani, Gabriel,Rotinov, Alexandra,Dominguez, Rosa M.,Gonzalez, Neil
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p. 4157 - 4160
(2007/10/02)
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- Titanium-promoted Allyl Transfer to Carbon Monoxide and Other Unsaturated Molecules
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Carbonylation of Cp2Ti-(?-allyl) yields Cp2Ti(CO)2 and triallylmethanol; reactions of Cp2Ti-(?-allyl) and Cp2Ti-(?-1-methylallyl) with other ligands proceed via insertion or allyl-elimination pathways.
- Klei, Bert,Teuben, Jan H.,Meijer, Henk J. de Liefde
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p. 342 - 344
(2007/10/02)
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- IMPROVED SYNTHESIS OF β,γ-UNSATURATED KETONES BY THE REACTION OF ALLYLIC ZINC BROMIDES WITH NITRILES.
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The reaction of allylic bromides with nitriles in the presence of Zn-Ag couple leads, after hydrolysis, to β,γ-unsaturated ketones in high yield.
- Rousseau, G.,Conia, J. M.
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p. 649 - 652
(2007/10/02)
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- RADICAL REACTIONS OF CARBONYL COMPOUNDS INITIATED BY METAL SALTS AND OXIDES. XIV. RADICAL OXIDATIVE TELOMERIZATION OF ETHYLENE WITH ACETONE
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The radical telomerization of ethylene with acetone was investigated.The telomeric radicals CH3COCH2(CH2CH2)n-1C.H2CH2 (n=1-5) are oxidized by the metal ions with the formation of unsaturated and acetoxy-substituted ketones.The effect of the nature of metal ion and the solvent (acetic acid, ethyl acetate, ethanol, acetonitrile) on the direction of oxidation of the radicals was studied.It was shown that oxidative telomerization takes place most selectively in the presence of divalent copper ions; here the main products are γ-acetopropyl and γ-acetopropenyl acetates or ω-unsaturated ketones, depending on the reaction conditions.
- Vinogradov, M. G.,Petrenko, O. N.,Verenchikov, S. P.,Nikishin, G. I.
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p. 626 - 631
(2007/10/02)
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