- Chromium(VI) supported and entrapped on silica and zirconia as recyclable materials for oxidation of alcohols
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Oxidation of alcohols have been realized with Cr(VI) oxide supported or entrapped, via sol-gel methodology, on silica and zirconia. These materials were easily recovered from the reaction mixture without leaching of chromium in solution. Moreover, recycling studies have indicated that they can be regenerated by calcinations at 400-600°C or by treatment with ozone at room temperature. In the case of Cr(VI) entrapped into silica matrix up to 18 oxidation cycles have been realized without loss in activity.
- Gruttadauria, Michelangelo,Liotta, Leonarda F.,Deganello, Giulio,Noto, Renato
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Read Online
- Cooperative Catalysis for Selective Alcohol Oxidation with Molecular Oxygen
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The activation of dioxygen for selective oxidation of organic molecules is a major catalytic challenge. Inspired by the activity of nitrogen-doped carbons in electrocatalytic oxygen reduction, we combined such a carbon with metal-oxide catalysts to yield
- Slot, Thierry K.,Eisenberg, David,van Noordenne, Dylan,Jungbacker, Peter,Rothenberg, Gadi
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Read Online
- Radical induced disproportionation of alcohols assisted by iodide under acidic conditions
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The disproportionation of alcohols without an additional reductant and oxidant to simultaneously form alkanes and aldehydes/ketones represents an atom-economical transformation. However, only limited methodologies have been reported, and they suffer from a narrow substrate scope or harsh reaction conditions. Herein, we report that alcohol disproportionation can proceed with high efficiency catalyzed by iodide under acidic conditions. This method exhibits high functional group tolerance including aryl alcohol derivatives with both electron-withdrawing and electron-donating groups, furan ring alcohol derivatives, allyl alcohol derivatives, and dihydric alcohols. Under the optimized reaction conditions, a 49% yield of 5-methyl furfural and a 49% yield of 2,5-diformylfuran were obtained simultaneously from 5-hydroxymethylfurfural. An initial mechanistic study suggested that the hydrogen transfer during this redox disproportionation occurred through the inter-transformation of HI and I2. Radical intermediates were involved during this reaction.
- Huang, Yang,Jiang, Haiwei,Li, Teng,Peng, Yang,Rong, Nianxin,Shi, Hexian,Yang, Weiran
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supporting information
p. 8108 - 8115
(2021/10/29)
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- 6,7-DIHYDRO-4H-PYRAZOLO[1,5-A]PYRAZINE INDOLE-2-CARBOXAMIDES ACTIVE AGAINST THE HEPATITIS B VIRUS (HBV)
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The present invention relates generally to antiviral agents. Specifically, the present invention relates to compounds of formula I which can inhibit the protein(s) encoded by hepatitis B virus (HBV) or interfere with the function of the HBV replication cycle, compositions comprising such compounds, methods for inhibiting HBV viral replication, methods for treating or preventing HBV infection, and processes and intermediates for making the compounds.
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Page/Page column 52-53
(2020/05/29)
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- NOVEL 6,7-DIHYDRO-4H-PYRAZOLO[1,5-A]PYRAZINE INDOLE-2-CARBOXAMIDES ACTIVE AGAINST THE HEPATITIS B VIRUS (HBV)
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The present invention relates generally to novel antiviral agents. Specifically, the present invention relates to compounds which can inhibit the protein(s) encoded by hepatitis B virus (HBV) or interfere with the function of the HBV replication cycle, compositions comprising such compounds, methods for inhibiting HBV viral replication, methods for treating or preventing HBV infection, and processes and intermediates for mating the compounds.
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Page/Page column 55
(2020/05/29)
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- NOVEL OXALYL PIPERAZINES ACTIVE AGAINST THE HEPATITIS B VIRUS (HBV)
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The present invention relates generally to novel antiviral agents. Specifically, the present invention relates to compounds which can inhibit the protein(s) encoded by hepatitis B virus (HBV) or interfere with the function of the HBV replication cycle, compositions comprising such compounds, methods for inhibiting HBV viral replication, methods for treating or preventing HBV infection, and processes and intermediates for making the compounds.
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Page/Page column 69; 70
(2020/11/12)
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- NOVEL INDOLE-2-CARBOXAMIDES ACTIVE AGAINST THE HEPATITIS B VIRUS (HBV)
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The present invention relates generally to novel antiviral agents. Specifically, the present invention relates to compounds which can inhibit the protein(s) encoded by hepatitis B virus (HBV) or interfere with the function of the HBV replication cycle, compositions comprising such compounds, methods for inhibiting HBV viral replication, methods for treating or preventing HBV infection, and processes and intermediates for making the compounds.
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Page/Page column 89
(2020/11/13)
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- NOVEL, HIGHLY ACTIVE PYRAZOLO-PIPERIDINE SUBSTITUTED INDOLE-2-CARBOXAMIDES ACTIVE AGAINST THE HEPATITIS B VIRUS (HBV)
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The present invention relates generally to novel antiviral agents. Specifically, the present invention relates to compounds which can inhibit the protein(s) encoded by hepatitis B virus (HBV) or interfere with the function of the HBV replication cycle, compositions comprising such compounds, methods for inhibiting HBV viral replication, methods for treating or preventing HBV infection, and processes and intermediates for making the compounds.
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Page/Page column 76
(2019/05/22)
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- NOVEL, HIGHLY ACTIVE AMINO-THIAZOLE SUBSTITUTED INDOLE-2-CARBOXAMIDES ACTIVE AGAINST THE HEPATITIS B VIRUS (HBV)
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The present invention relates generally to novel antiviral agents. Specifically, the present invention relates to compounds which can inhibit the protein(s) encoded by hepatitis B virus (HBV) or interfere with the function of the HBV replication cycle, compositions comprising such compounds, methods for inhibiting HBV viral replication, methods for treating or preventing HBV infection, and processes and intermediates for making the compounds.
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Page/Page column 105
(2019/05/22)
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- Synthesis of Tetrahydroisoquinolines by Visible-Light-Mediated 6- exo -trig Cyclization of α-Aminoalkyl Radicals
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Starting from the respective tertiary α-silylmethyl amines, the intramolecular cyclization of α-aminoalkyl radicals to Michael acceptors produced tetrahydroisoquinolines. The reaction conditions included the use of 5 molpercent of an iridium photoredox catalyst, dimethylformamide as the solvent, and equimolar amounts of water and cesium carbonate as the additives. 13 substrates were synthesized from ortho -alkylbenzaldehydes in a three-step procedure involving a carbonyl condensation, a radical bromination, and a substitution by a secondary α-silylmethyl amine. After optimization of the photocyclization, the reaction delivered tetrahydroisoquinolines in moderate to high yields (41-83percent). A facial diastereoselectivity (dr ? 80:20) was observed with chiral substrates and a crystal structure provided evidence for the relative configuration of the major diastereoisomer. A catalytic cycle with direct electron transfer to the photoexcited metal catalyst is proposed.
- Bach, Thorsten,Grübel, Michael,Jandl, Christian
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supporting information
p. 1825 - 1829
(2019/09/09)
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- Selective aerobic oxidation of alkyl aromatics on Bi2MoO6 nanoplates decorated with Pt nanoparticles under visible light irradiation
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Pt/Bi2MoO6 nanoplates are efficient photocatalysts for the selective oxidation of saturated C-H bonds in alkyl aromatics under visible light illumination using O2 as an oxidant. This study opens a new window for direct C-H functionalization through the photocatalytic method based on cheap Bi2MoO6 semiconductor materials.
- Zhang, Bao,Yang, Xiaojing,Li, Jun,Cheng, Gang
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supporting information
p. 12194 - 12197
(2018/11/21)
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- Process for synthesizing 2-ethyl styrene
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The invention discloses a process for synthesizing 2-ethyl styrene. The process comprises the following specific steps of: (1) dissolving 2-ethyl bromobenzene in a dry polar organic solvent, adding n-butyl lithium dropwise at a low temperature for 1-4 hours, maintaining the temperature for a reaction at the low temperature for 1-6 hours after addition is completed dropwise, then adding anhydrous N,N-dimethylformamide, maintaining the temperature for 1-6 hours after addition is completed, adding a quenching solvent for quenching, performing washing by using water, keeping the obtained mixture standing for stratification, concentrating an organic phase without additional purification so as to obtain an intermediate with a yield of 95-100%; and (2) mixing the intermediate, an inorganic base,triphenyl methyl phosphine and the dry solvent, maintaining the temperature for a reaction for 2-10 hours under an inert atmosphere and a reflux condition after mixing is completed, and performing post-treatment to obtain the pure target product with a yield of 80-90%. The product produced by the process has the advantages of good quality, stable operation, high yield, less three-waste and low production cost.
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Paragraph 0023; 0024; 0025; 0028; 0029; 0030; 0033; 0034
(2018/07/06)
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- The Oxidation of Hydrophobic Aromatic Substrates by Using a Variant of the P450 Monooxygenase CYP101B1
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The cytochrome P450 monooxygenase CYP101B1, from a Novosphingobium bacterium is able to bind and oxidise aromatic substrates but at a lower activity and efficiency than norisoprenoids and monoterpenoid esters. Histidine 85 of CYP101B1 aligns with tyrosine 96 of CYP101A1, which, in the latter enzyme forms the only hydrophilic interaction with its substrate, camphor. The histidine residue of CYP101B1 was mutated to phenylalanine with the aim of improving the activity of the enzyme for hydrophobic substrates. The H85F mutant lowered the binding affinity and activity of the enzyme for β-ionone and altered the oxidation selectivity. This variant also showed enhanced affinity and activity towards alkylbenzenes, styrenes and methylnaphthalenes. For example the rate of product formation for acenaphthene oxidation was improved sixfold to 245 nmol per nmol CYP per min. Certain disubstituted naphthalenes and substrates, such as phenylcyclohexane and biphenyls, were oxidised with lower activity by the H85F variant. Variants at H85 (A and G) designed to introduce additional space into the active site so as to accommodate these larger substrates did not improve the oxidation activity. As the H85F mutant of CYP101B1 improved the oxidation of hydrophobic substrates, this residue is likely to be in the substrate binding pocket or the access channel of the enzyme. The side chain of the histidine might interact with the carbonyl groups of the favoured norisoprenoid substrates of CYP101B1.
- Sarkar, Md. Raihan,Lee, Joel H. Z.,Bell, Stephen G.
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p. 2119 - 2128
(2017/10/12)
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- Chemoselective hydrogenation using molecular sieves-supported Pd catalysts: Pd/MS3A and Pd/MS5A
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Palladium catalysts embedded on molecular sieves (MS3A and MS5A) were prepared by the adsorption of Pd(OAc)2 onto molecular sieves with its in situ reduction to Pd0 by MeOH as a reducing agent and solvent. 0.5% Pd/MS3A and 0.5% Pd/MS5A catalyzed the hydrogenation of alkynes, alkenes, and azides with a variety of coexisting reducible functionalities, such as nitro group, intact. It is noteworthy that terminal alkenes of styrene derivatives possessing electron-donating functionalities on the benzene nucleus were never hydrogenated under 0.5% Pd/MS5A-catalyzed conditions, while internal alkenes of 1-propenylbenzene derivatives were readily reduced to the corresponding alkanes.
- Takahashi, Tohru,Yoshimura, Masatoshi,Suzuka, Hiroyasu,Maegawa, Tomohiro,Sawama, Yoshinari,Monguchi, Yasunari,Sajiki, Hironao
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experimental part
p. 8293 - 8299
(2012/09/21)
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- A general and efficient suzuki-miyaura cross-coupling protocol using weak base and no water: The essential mole of acetate
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A weak base, CsOAc, promotes Suzuki-Miyaura cross-coupling and related Pd-catalyzed reactions under anhydrous conditions as effectively as stronger bases. Aryl triflates exhibit unusual reaction rates, which are comparable to that: of bromoarenes. A negle
- Wang, Bing,Sun, Hui-Xia,Sun, Zhi-Hua
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experimental part
p. 3688 - 3692
(2009/12/03)
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- THERAPEUTIC FLUOROETHYLCYANO GUANIDINES
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Disclosed herein is compound having a formula as described herein. Therapeutic methods, compositions, and medicaments related thereto are also disclosed.
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- SUBSTITUTED FLUOROETHYL UREAS AS ALPHA 2 ADRENERGIC AGENTS
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Therapeutic compounds, and methods, compositions, and medicaments related thereto are disclosed herein.
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Page/Page column 21; 22; 37
(2008/12/04)
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- Reductive carbonylation - An efficient and practical catalytic route for the conversion of aryl halides to aldehydes
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Alternative routes for the introduction of aldehyde functionality are particularly desirable for fine chemical and pharmaceutical intermediates because of the wide range of further transformations that are possible. Catalytic processes are of particular interest for minimising waste, and therefore the reductive carbonylation of aryl halides has been explored. We have shown that high yields of aldehydes may be obtained for a wide selection of aryl iodides and bromides using mild conditions (3 bar of CO, temperatures 60-120°C) and silanes as hydride source. A choice of conditions (catalyst, base, solvent) is required to cover the range of aryl substituents varying in electron donation and steric influence. This is related to the competing needs of the several steps of this reaction, including oxidative addition, CO substitution, CO insertion, hydride transfer, and reductive elimination.
- Ashfield, Laura,Barnard, Christopher F. J.
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- Tetraphosphine/palladium catalysed Suzuki cross-coupling reactions of aryl halides with alkylboronic acids
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Through the use of [PdCl(C3H5)]2/cis,cis, cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as a catalyst, a range of aryl bromides and chlorides undergoes Suzuki cross-coupling with alkylboronic acids in good yields. Several alkyl substituents such as ethyl, n-butyl, n-octyl, isobutyl or 2,2-dimethylpropyl on the alkylboronic acids have been successfully used. The functional group tolerance on the aryl halide is remarkable; substituents such as fluoro, methyl, methoxy, acetyl, formyl, benzoyl, nitro or nitrile are tolerated. Furthermore, this catalyst can be used at low loading, even for reactions of sterically hindered aryl bromides.
- Kondolff, Isabelle,Doucet, Henri,Santelli, Maurice
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p. 3813 - 3818
(2007/10/03)
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- Indole derivatives for the treatment of depression and anxiety
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The present invention provides compounds of formula (I): which are useful for treating depression, anxiety, and alleviating the symptoms caused by withdrawal or partial withdrawal from the use of tobacco or of nicotine.
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Page/Page column 91
(2010/02/05)
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- Oxidation of benzyl alcohol by pyridinium dichromate in acetonitrile. Using the paralmeta ratio of substituent effects for mechanism elucidation
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Rate constants were measured for the oxidation reaction of benzyl alcohol and twenty-five ortho-, recta- and para-monosubstituted derivatives in the temperature range 293-323 K at intervals of 10 K. The kinetics were followed spectrophotometrically in dry acetonitrile acidified with trichloroacetic acid (TCA) using pyridinium dichromate (PDC) as oxidising agent under pseudo-first-order conditions with respect to PDC. Benzaldehyde is the only oxidation product and no reaction takes place without TCA. From good linear Eyring plots activation enthalpies Δ?H° and entropies Δ?S° are calculated. For ortho-substituted benzyl alcohols high Δ?H° values and small negative Δ?S° values point to an ortho effect on the rate-determining step. Using the tetralinear approach to substituent effects, the average value λ = 1.09 ± 0.05 for the para/meta ratio of inductive or Electra effects is obtained and negative Hammett reaction constants decreasing in magnitude with increasing temperature are found. A mechanism implicating the prior acid-catalysed formation of neutral benzyl hydrogen dichromate ester followed by intramolecular proton transfer is proposed. Modelling of parameter λ in terms of the electrostatic theory showed its experimental value to be consistent with the ratio of electric potentials generated in the immediate vicinity of the nearest chromium atom by dipolar substituents introduced in the aromatic ring on para and meta positions. At a molecular level the oxidative, rate-determining step is suggested to be triggered by the retraction or shrinkage of electron pairs from sigma bonds in Cr2VI species to non-bonding orbitals in unstable CrIV-O-CrVI species. In contrast with past interpretations, an electrochemical approach is used to explain negative values for the Hammett reaction constant.
- Kabilan,Girija,Reis, Joao Carlos R.,Segurado, Manuel A.P.,De Oliveira, Jaime D. Gomes
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p. 1151 - 1157
(2007/10/03)
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- Photochemical synthesis, conformational analysis, and transformation of [60]fullerene-o-quinodimethane adducts bearing a hydroxy group
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The photochemical reactions of [60]fullerene with various aromatic aldehydes or ketones 1a-n carrying an alkyl group at the ortho position were examined. Some of them afforded stable o-quinodimethane adducts 2 with a hydroxy group attached to the cyclohexene ring. The adducts 2 were found to adopt one or both of two conformers A and E, which possess pseudoaxial and pseudoequatorial hydroxy groups, respectively. The conformer ratios depended remarkably on the substituents attached to the aromatic nucleus and the cyclohexene ring. The dynamic behavior of 2 was also investigated by the VT-NMR technique.
- Nakamura, Yosuke,O-kawa, Kyoji,Minami, Satoshi,Ogawa, Toshio,Tobita, Seiji,Nishimura, Jun
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p. 1247 - 1252
(2007/10/03)
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- Benzylic oxidation of aromatics with cerium(IV) triflate; Synthetic scope and mechanistic insight
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The synthetic utility of cerium(IV) triflate Ce(OTf)4 as a reagent for benzylic oxidation has been tested for a variety of aromatic compounds. Insight is provided into various factors that govern these oxidations and their progress. It has been shown that the mode of preparation of Ce(OTf)4 and the % H2O present in the sample have a marked influence on oxidation ability. A variety of mono- and dialkylbenzenes, haloalkylbenzenes, bicyclic and tricyclic ring systems, and alkoxybenzenes have been surveyed. The method offers an easy to perform one-pot reaction for the room temperature synthesis of aromatic ketones and aldehydes from aromatics and has the potential to find wider application.
- Laali, Kenneth K.,Herbert, Mark,Cushnyr, Brad,Bhatt, Anand,Terrano, David
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p. 578 - 583
(2007/10/03)
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- Directed Metalation of Aromatic Aldimines with Lithium 2,2,6,6-Tetramethylpiperidide
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N-Cyclohexyl aromatic aldimines are ortho-lithiated or o-methyl-lithiated with 2 equiv of lithium 2,2,6,6-tetramethylpiperidide (LTMP) in THF solution at -15 deg C.The lithiated intermediates generally reacted with alkyl halides or CO2 to provide ortho-functionalized aldimine products which could be readily converted to the corresponding aldehydes by hydrolysis with aqueous 4 M HCl.Aromatic aldimines derived from (+/-)-trans-2-methylcyclohexylamine or 3-amino-2,4-dimethylpentane are resistant toward C=N addition with 1 equiv of n-BuLi at 0 deg C in THF solution; however, they are also surprisingly resistant toward directed metalation reactions with either LTMP or n-BuLi.Exceptions to the ortho-directing and o-methyl-directing effects of the aldimine group were observed in a reaction of 3-methylthiophene-2-carboxaldehyde cyclohexylimine (7) with LTMP, followed by CH3I, which gave a 9:1 mixture of 3,5-dimethylthiophene-2-carboxaldehyde cyclohexylimine (22) and 5-ethyl-3-methylthiophene-2-carboxaldehyde cyclohexylimine (23), and a reaction of p-tolualdehyde 2,4-dimethylpent-3-ylimine (11) with either n-BuLi or LTMP, followed by CH3I, which gave p-ethylbenzaldehyde 2,4-dimethylpent-3-ylimine (25).
- Flippin, Lee A.,Muchowski, Joseph M.,Carter, David S.
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p. 2463 - 2467
(2007/10/02)
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- PALLADIUM-MEDIATED 2,6-DIALKYLATION OF N-BENZILIDINE IMINES: PREPARATION OF 2,6-DIALKYLBENZALDEHYDES
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Treatment of di-μ-trifluoroacetatobisdipalladium with two equivalents of primary alkyl iodides and subsequent hydrolysis provides an efficient route to 2,6-disubstituted benzaldehydes.
- McCallum, J. Stuart,Gasdaska, John R.,Liebeskind, Lanny S.
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p. 4085 - 4088
(2007/10/02)
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- Intramolecular Generation of Oxonium Ylides from Functionalized Arylcarbenes
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Arylcarbenes carrying alkoxyalkyl groups in the ortho position have been generated by flash pyrolysis and photolysis of appropriate tosylhydrazone sodium salts.In the gas phase and in a aprotic solvents, interaction of the carbenes with the lone electron pairs of oxygen competes efficiently with insertion into C-H bonds.Both five- and six-membered cyclic oxonium ylides have been generated.The ylides 23, 37, 61b, and 74 undergo 1,2 shifts of benzyl groups with ease, even if ring contraction to highly strained benzocyclobutenes is involved (23, 74).The oxonium ylides37 and 61b strongly prefer the nonconcerted Stevens rearrangement to the sigmatropic Sommelet rearrangement, in contrast to analogous ammonium ylides.Alkyl shifts occur to a very minor extent, if at all.Evidence is presented that alcohols intercept both the carbenes and the oxonium ylides.Protonation of the ylides leads to cyclic oxonium ions, which undergo nucleophilic cleavage of the C-O bonds.Acid catalyzed decomposition of the appropriate diazo compounds gives rise to six-membered, but not to five-membered, cyclic oxonium ions, thus confirming the different intramolecular reactivities of arylcarbenes and benzyl cations.The efficiency of carbene interception increases with increasing acidity of the medium, suggesting nucleophilic behavior (protonation) of the arylcarbenes.
- Kirmse, Wolfgang,Kund, Klaus
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p. 1465 - 1473
(2007/10/02)
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- Antihypertensive Activity of 6-Arylpyridopyrimidin-7-amine Derivatives
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A series of 51 6-arylpyridopyrimidin-7-amine derivatives was prepared and evaluated for antihypertensive activity in the conscious spontaneously hypertensive rat.A number of these compounds, notably 6-(2,6-dichlorophenyl)-2-methylpyridopyrimidin-7-amine (36), lowered blood pressure in these rats in a gradual and sustained manner to normotensive levels at oral doses of 10-50 mg/kg.Normalized blood pressure levels could then be maintained by single daily oral doses.The effect of structural variation in the 6-aryl group and in the 2 and 4 positions of the pyridopyrimidine ring on activity is reported and discussed.
- Bennett, Lawrence R.,Blankley, C. John,Fleming, Robert W.,Smith, Ronald D.,Tessman, Deirdre K.
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p. 382 - 389
(2007/10/02)
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- SINGLET OXYGENATION OF CYCLOHEPTATRIENE: ISOLATION AND CHARACTERIZATION OF THE 1,2-DIOXETANE.
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Tetraphenylporphyrin-sensitized photooxygenation of cycloheptatriene afforded the 1,2-dioxetane in 9percent yield, thus completing the set of possible cycloaddition products; the 1,2-dioxetane is the precursor to the benzaldehyde product, but not the (2+6)-cycloadduct.
- Adam, Waldemar,Rebollo, Hector
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p. 3049 - 3052
(2007/10/02)
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- PHOTOOXYGENATION OF 7-SUBSTITUTED CYCLOHEPTATRIENES
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Photooxygenation of 7-substituted cycloheptatrienes, including the Me, Et, iPr, Ph, CN, COOMe, COOEt, and CONH2 groups was studied, and several products among the tropilidene-type (1 and 2) and norcaradiene-type (3 and 4) endoperoxides, o-substituted benzaldehydes (5), diepoxides (6 and 7), and ketoalcohols (8) were obtained.Mechanism of the formations of the products was discussed.Thermal isomerization of the endoperoxides (1, 3 and 4) to the corresponding diepoxides (10, 6 and 7), and the reaction of the endoperoxides (1 and 3) with triethylamine were examined.
- Asao, Toyonobu,Yagihara, Morio,Kitahara, Yoshio
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p. 985 - 991
(2007/10/02)
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