- Evidence for the Formation of ?-Dianions of 9-Fluorenone and 10,11-Dihydro-5H-dibenzocyclohepten-5-one from 1H NMR and CNDO Charge Distributions
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It was demonstrated on the basis of reactivity, 1H NMR and CNDO charge distributions that the ?-dianions of 9-fluorenone and 10,11-dihydro-5H-dibenzocyclohepten-5-one were formed from the corresponding neutral precursors in contact with sodium or potassium in dimethoxyethane or tetrahydrofuran at low temperature in vacuo.
- Hirayama, Masatoshi,Suzuki, Hideto,Ohhata, Hiroshi
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Read Online
- Self-promoted post-synthetic modification of metal-ligand M 2L3 mesocates
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Reactive alcohol functionality has been incorporated into a self-assembled M2L3 mesocate. Post-synthetic modification of this complex with suitable isocyanates is not only possible, but is self-catalyzed by multiple internal hydrogen bonds from the self-assembly. As the metal-ligand coordination is reversible at elevated temperature, the isomeric distribution of product changes upon reaction, due to the different steric bulk conferred on the assembly after the modification. The Royal Society of Chemistry.
- Young, Michael C.,Johnson, Amber M.,Hooley, Richard J.
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Read Online
- Acidities of Hydrocarbons and Sulfur-Containing Hydrocarbons in Dimethyl Sulfoxide Solution
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The relative pKa values in Me2SO solution of 13 hydrocarbons that form carbanions with highly dispersed negative charges on deprotonation were found to differ from literature relative ion-pair acidities in cyclohexylamine (CHA) by only +/-0.7 unit, or less, when the ion-pair pKa's were anchored to the pKa of 17.9 for 9-phenylfluorene in Me2SO.The relative pKa's for phenylacetylene, cyclopentadiene, and indene were found to be 2.4, 2.7, and 0.9 units higher, respectively, in Me2SO than in CHA.Higher relative pKa's were also observed for PhCH2SO2Ph, PhSO2CH3 and PhSO2CH2Me, by 1.9, 2.7, and 2.8 units, respectively, and for 2-phenyl-1,3-dithiane, 2-(p-phenylphenyl)-1,3-dithiane, 4-methyl-2,6,7-trithiabicyclooctane, and 1,3-dithiane, by 0.4, 0.65, 0.8, and 1.9 units respectively.The apparent higher relative acidities for these compounds in CHA is probably caused by stronger ion pairing or aggregation of the ions derived therefrom than for the hydrocarbon indicator ions with which they are being compared.These perturbations of the equilibria probably arise because of differences in the extent of charge dispersion in the acid and indicator ions.The pKa of 1,3-dithiane itself is estimated from an average of three extrapolations to be 39 +/- 2 in Me2SO.Acidities in Me2SO for 1,3-dithianes with electron-withdrawing groups in the 2-position were observed to increase in the following order: 2-C6H5 2-CO2Me 2-CN.The order of acidities of 3 alkylthio alkyl sulfoxides was found to be MeSCH2S(O)Me EtCH2S(O)Et t-BuSCH2S(O)t-Bu.
- Bordwell, Frederick G.,Drucker, George E.,Andersen, Niels H.,Denniston, Alan D.
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- Efficient preparation and application of monodisperse palladium loaded graphene oxide as a reusable and effective heterogeneous catalyst for suzuki cross-coupling reaction
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A homogeneously dispersed graphene oxide supported palladium nanomaterial (Pd?GO) has been successfully synthesized and used as a catalyst in cross-coupling reactions at room temperature. Various analytical techniques such as X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM) were used to characterize the monodisperse Pd?GO. Monodisperse Pd?GO nanomaterials were used for the cross-coupling reactions which brought together organic molecules with functional significance. This catalyst showed superior catalytic activity and stability for these coupling reactions. High product yields, short reaction times and mild reaction conditions, obtained by the using of developed catalysts. Importantly, the catalyst can be used at least five experiments successfully without losing its efficiency.
- Diler, Fatma,Burhan, Hakan,Genc, Hayriye,Kuyuldar, Esra,Zengin, Mustafa,Cellat, Kemal,Sen, Fatih
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- COMPOSITIONS AND METHODS FOR REDUCTION OF KETONES, ALDEHYDES AND IMINIUMS, AND PRODUCTS PRODUCED THEREBY
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A method of producing an alcohol, comprises reducing an aldehyde or a ketone with a hydridosilatrane. The reducing is carried out with an activator.
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Paragraph 0091-0092
(2018/01/20)
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- 1-Hydrosilatrane: A Locomotive for Efficient Ketone Reductions
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An efficient method for the reduction of ketones with 1-hydrosilatrane is described. In the presence of a Lewis base activator, the resulting secondary alcohols are rapidly formed in good to excellent yields (20 examples, 71–99 % yields). The relative bulkiness of 1-hydrosilatrane also enables the diastereoselective reduction of (–)-menthone to (+)-neomenthol, and the use of a chiral alkoxide activator can lead to the enantioselective reduction of prochiral ketones.
- Varjosaari, Sami E.,Skrypai, Vladislav,Suating, Paolo,Hurley, Joseph J. M.,Gilbert, Thomas M.,Adler, Marc J.
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supporting information
p. 229 - 232
(2017/01/24)
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- Neutral Dinuclear Copper(I)-NHC Complexes: Synthesis and Application in the Hydrosilylation of Ketones
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The synthesis of a class of highly stable neutral dinuclear Cu(I)-NHC complexes using 1,2,4-triazole as a bridging ligand is described. Various NHCs were used to generate a library of [Cu(μ-trz)(NHC)]2 complexes. Interestingly, [Cu(μ-trz)(IPr)]2 was found to be highly active in the hydrosilylation of ketones, without the need for an external base or any other additive. A wide range of aryl and alkyl ketones, as well as sterically hindered ketones, was successfully reduced to alcohols using the lowest catalyst loading reported to date.
- Trose, Michael,Lazreg, Fa?ma,Chang, Tao,Nahra, Fady,Cordes, David B.,Slawin, Alexandra M. Z.,Cazin, Catherine S. J.
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p. 238 - 242
(2017/06/07)
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- The second aryl piperazine compounds and their pharmaceutical use (by machine translation)
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The invention relates to the general formula I indicated by the two aryl piperazine compound, solvate, stereoisomer or a pharmaceutically acceptable salt thereof, pharmaceutical compositions containing them, and the compounds for the preparation for preventing or treating post-surgical pain, migraine, visceral pain, neuropathic pain such as the pain and analgesics such as by analgesic drug addiction and tolerance caused by the use of disease. (by machine translation)
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Paragraph 0231; 0232; 0233
(2017/07/26)
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- Dibenzo[b,f][1,4]oxazepines and dibenzo[b,e]oxepines: Influence of the chlorine substitution pattern on the pharmacology at the H1R, H4R, 5-HT2AR and other selected GPCRs
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Inspired by VUF6884 (7-Chloro-11-(4-methylpiperazin-1-yl)dibenzo[b,f][1,4]oxazepine), reported as a dual H1/H4 receptor ligand (pKi: 8.11 (human H1R (hH1R)), 7.55 (human H4R (hH4R))), four known and 28 new oxazepine and related oxepine derivatives were synthesised and pharmacologically characterized at histamine receptors and selected aminergic GPCRs. In contrast to the oxazepine series, within the oxepine series, the new compounds showed high affinity to the hH1R (pKi: 6.8–8.7), but no or moderate affinity to the hH4R (pKi: ≤ 5.3). For one oxepine derivative (1-(2-Chloro-6,11-dihydrodibenzo[b,e]oxepin-11-yl)-4-methylpiperazine), the enantiomers were separated and the R-enantiomer was identified as the eutomer at the hH1R (pKi: 8.83 (R), 7.63 (S)) and the guinea-pig H1R (gpH1R) (pKi: 8.82 (R), 7.41 (S)). Molecular dynamic studies suggest that the tricyclic core of the compounds is bound in a similar mode into the binding pocket, as described for doxepine in the hH1R crystal structure. Moreover, docking studies of all oxepine derivatives at the hH1R indicate that the oxygen and the position of the chlorine in the tricyclic core determines, if the R- or the S-enantiomer is the eutomer. For some of the oxazepines and oxepines the affinity to other aminergic GPCRs is in the same range as to hH1R or hH4R, thus, those compounds have to be classified as dirty drugs. However, one oxazepine derivative (3,7-Dichloro-11-(4-methylpiperazin-1-yl)dibenzo[b,f][1,4]oxazepine was identified as dual hH1/h5-HT2A receptor ligand (pKi: 9.23 (hH1R), 8.74 (h5-HT2AR), ≤7 at other analysed GPCRs), whereas one oxepine derivative (1-(3,8-Dichloro-6,11-dihydrodibenzo[b,e]oxepin-11-yl)-4-methylpiperazine) was identified as selective hH1R antagonist (pKi: 8.44 (hH1R), ≤6.7 at other analyzed GPCRs). Thus, the pharmacological results suggest that the oxazepine/oxepine moiety and additionally the chlorine substitution pattern toggles receptor selectivity and specificity.
- Naporra, Franziska,Gobleder, Susanne,Wittmann, Hans-Joachim,Spindler, Julia,Bodensteiner, Michael,Bernhardt, Günther,Hübner, Harald,Gmeiner, Peter,Elz, Sigurd,Strasser, Andrea
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p. 610 - 625
(2016/10/12)
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- Direct trifluoromethylthiolation of alcohols under mild reaction conditions: Conversion of R-OH into R-SCF3
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A direct process for the trifluoromethylthiolation of allylic and benzylic alcohols under mild conditions has been developed. A wide range of free alcohols underwent nucleophilic substitution in the presence of stable CuSCF3 and BF3·Et2O to give the corresponding products in good to excellent yields.
- Nikolaienko, Pavlo,Pluta, Roman,Rueping, Magnus
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supporting information
p. 9867 - 9870
(2014/08/18)
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- Regiospecific rearrangement of hydroxylamines to secondary amines using diisobutylaluminum hydride
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A systematic investigation of a reductive ring-expansion reaction of N-monosubstituted hydroxylamines with diisobutylaluminum hydride (DIBALH) was carried out. The reaction regiospecifically provided a variety of bicyclic or tricyclic heterocycles or linear secondary amines containing nitrogen attached to an aromatic ring. The Japan Institute of Heterocyclic Chemistry.
- Cho, Hidetsura,Sugimoto, Kenji,Iwama, Yusuke,Mitsuhashi, Nakako,Okano, Kentaro,Tokuyama, Hidetoshi
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experimental part
p. 1633 - 1644
(2011/05/05)
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- Flow-vacuum pyrolysis of dibenzocycloheptane derivatives on zeolites catalysts. IV
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The pyrolysis of 10,11-dihydro-5H-dibenzo[a,d]cicloheptadien-5-ol (4) and of 5H-dibenzo[a,d]cycloheptatrien-5-ol (5) in flowvacuum conditions (advanced vacuum, inert atmosphere) on zeolites at 300°C is presented. The reaction products were identified by GC/MS using authentic samples and a reaction mechanisms involving cationic species as intermediates were proposed. A comparison with the pyrolysis of the same compounds performed in FVP conditions on quartz is presented.
- Istrati, Daniela,Parvulescu, Luminitza,Popescu, Angela,Mihaiescu, Dan,Badea, Florin
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scheme or table
p. 711 - 714
(2011/10/02)
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- Synthesis of conformationally constrained spirohydantoins with a dibenzo[a,d]heptadiene ring
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Conformationally constrained dibenzo[a,d]cycloheptadiene-based spirohydantoins were prepared from dibenzosuberone via the transformation of the α-hydroxy ester to the azido ester, followed by its reduction to the amino ester, and cyclization of the carbomethoxy N,N'-asymmetric ureas, derived from the amino ester with triphosgene and a variety of amines. A novel ring expansion reaction was also observed in the process.
- Tao,Timberlake
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p. 1449 - 1453
(2007/10/03)
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- Benzylphosphonic acid inhibitors of human prostatic acid phosphatase
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A series of α-substituted benzylphosphonic acids is described as inhibitors of human prostatic acid phosphatase, an enzyme has been used as a model to study aryl phosphatases. The most potent inhibitors in this series are 2-trifluoromethylbenzhydrylphosphonic acid (9 μM), and α-(2-phenylethyl)benzylphosphonic acid (14 μM). The structure-activity studies suggest that bulk tolerance beyond the phosphate binding area limits the steric or hydrophobic contribution to inhibitor potency achieved through α-carbon substitution.
- Schwender,Beers,Malloy,Cinicola,Wustrow,Demarest,Jordan
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p. 311 - 314
(2007/10/03)
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- CYCLOHEPTENE DERIVATIVES
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1-2-(4,5,10,11-Tetrahydro-1H-dibenzo a,d!cyclohepten-5-yl) ethyl!pyrrolidine of the formula STR1 and its pharmaceutically acceptable acid addition salts, prepared through various intermediates, are described. The compounds have valuable histamine-H 1 antagonistic properties and are suitable for the control or prevention of allergic reactions, such as, urticaria, hay fever, anaphylaxis and over-sensitivity to medicaments.
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