- Copper-catalysed benzofuran synthesis: developing aryl bromide-alkenyl triflates as general heterocycle precursors
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A range of conjugated aryl bromide-alkenyl triflates, previously described as indole precursors, are efficiently converted to the corresponding benzofurans when treated with CuI/TMEDA and potassium hydroxide.
- Tadd, Andrew C.,Fielding, Mark R.,Willis, Michael C.
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Read Online
- Efficient [3,3]-sigmatropic rearrangement accelerated by a trifluoroacetyl group: Synthesis of benzofurans under mild conditions
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The [3,3]-sigmatropic rearrangement took place smoothly during the course of trifluoroacetylation of O-phenyl-oxime at below room temperature to give the dihydrobenzofuran or benzofuran as a result of concomitant cyclization.
- Miyata, Okiko,Takeda, Norihiko,Morikami, Yoshiaki,Naito, Takeaki
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Read Online
- Supported Pt-Ni bimetallic nanoparticles catalyzed hydrodeoxygenation of dibenzofuran with high selectivity to bicyclohexane
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Catalytic hydrodeoxygenation (HDO) is one of the most effective methods to upgrade the oxygen-containing compounds derived from coal tar to valuable hydrocarbons. Herein, an efficient bimetallic catalyst Pt1Ni4/MgO was prepared and applied in the HDO of dibenzofuran (DBF). High yield (95%) of the desired product bicyclohexane (BCH) was achieved at 240 °C and 1.2 MPa of H2. Superior catalytic performance could be ascribed to the “relay catalysis” of Pt sites and Ni sites, and the reaction pathway is proposed as well. Scale-up experiment and recyclability test were also performed, which demonstrated the recyclability and promising potential application of Pt1Ni4/MgO.
- Cai, Chun,Wu, Pengyu
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supporting information
(2021/07/10)
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- Synthesis of benzofurans from the cyclodehydration of α-phenoxy ketones mediated by Eaton’s reagent
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Cyclodehydration of α-phenoxy ketones promoted by Eaton’s reagent (phosphorus pentoxide–methanesulfonic acid) is used to prepare 3-substituted or 2,3-disubstituted benzofurans with moderate to excellent yields under mild conditions. The method provides a facile access to benzofurans from readily available starting materials such as phenols and α-bromo ketones. The reaction is highly efficient, which is attributed to the good reactivity and fluidity of Eaton’s reagent. The reaction can be applied to prepare naphthofurans, furanocoumarins, benzothiophenes, and benzopyrans.
- Ma, Lin,Ma, Zhanwei,Zhang, Min,Zhou, Min
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p. 426 - 436
(2020/03/23)
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- Direct C-H α-Arylation of Enones with ArI(O2CR)2 Reagents
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α-Arylation of α,β-unsaturated ketones constitutes a powerful synthetic transformation. It is most commonly achieved via cross-coupling of α-haloenones, but this stepwise strategy requires prefunctionalized substrates and expensive catalysts. Direct enone C-H α-arylation would offer an atom- and step-economical alternative, but such reports are scarce. Herein we report the metal-free direct C-H arylation of enones mediated by hypervalent iodine reagents. The reaction proceeds via a reductive iodonium Claisen rearrangement of in situ-generated β-pyridinium silyl enol ethers. The aryl groups are derived from ArI(O2CCF3)2 reagents, which are readily accessed from the parent iodoarenes. The reaction is tolerant of a wide range of substitution patterns, and the incorporated arenes maintain the valuable iodine functional handle. Mechanistic investigations implicate arylation via an umpoled "enolonium" species and show that the presence of a β-pyridinium moiety is critical for the desired C-C bond formation.
- Sousa E Silva, Felipe Cesar,Van, Nguyen T.,Wengryniuk, Sarah E.
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- Method for synthesizing benzofuran derivative by taking alpha-phenoxy-ketone as raw material
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The invention discloses a method for synthesizing a benzofuran derivative by taking alpha-phenoxy-ketone as a raw material. Under shielding of inert gas, the alpha-phenoxy-ketone is dissolved in dry dichloromethane, then a mixed solution of TiCl4 and dichloromethane is dropwise added slowly, and after the indoor temperature reaction, the benzofuran derivative after separation and purification is obtained. The method for synthesizing the benzofuran derivative has the advantages that raw materials are easy to obtain, the cost is low, and reaction conditions are mild; operation is simple and easyto control, there are fewer side reactions, and the after-processing is simple; the yield of the derivative is higher, the production cost is greatly reduced, better economic benefits are achieved, and the method is suitable for industrial production.
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Paragraph 0041; 0042; 0043; 0044
(2019/04/26)
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- Titanium tetrachloride promoted cyclodehydration of aryloxyketones: Facile synthesis of benzofurans and naphthofurans with high regioselectivity
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An efficient and facile method for the synthesis of a broad series of benzofurans and naphthofurans is described. The direct intramolecular cyclodehydration of aryloxyketones in the presence of titanium tetrachloride affords the corresponding benzofurans and naphthofurans with good regioselectivity and yields.
- Zhang, Qiu,Luo, Juan,Wang, Bingqiao,Xiao, Xiaoqin,Gan, Zongjie,Tang, Qiang
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supporting information
p. 1337 - 1340
(2019/04/16)
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- In order to phenol and α - halo as raw material synthetic benzofuran derivatives (by machine translation)
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The present invention to provide a phenol and α - halo as raw materials, the role of titanium tetrachloride in the reaction of the next step high-efficient method for preparing benzofuran derivative, namely under protection of inert gas, adding phenol to and [...], then heating and stirring to reflux then adding titanium tetrachloride, finally dropping into the α - halo and [...] mixed solution, after the reaction is completed after the separation and purification to obtain the benzofuran derivatives. The synthesizing method of the invention, raw materials are easy, low cost, mild reaction conditions, the operation is simple and easy to control, less side reaction, after treatment is simple, and the product yield is high, production cost is greatly reduced, with better economic benefits, is suitable for the industrial large-scale production. (by machine translation)
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Paragraph 0028; 0029; 0030; 0031
(2019/04/14)
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- One-step regioselective synthesis of benzofurans from phenols and α-Haloketones
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Reported here is the direct synthesis of naphthofurans and benzofurans from readily available phenols and α-haloketones promoted by titanium tetrachloride which combines Friedel-Crafts-like alkylation and intramolecular cyclodehydration into one step. This simple protocol allows for the formation of a variety of high value naphthofurans and benzofurans within which a series of cyclic and acyclic groups are readily incorporated. This process demonstrates the advantages of high levels of regioselectivity, broad substrate scope, and moderate to excellent yields.
- Wang, Bingqiao,Zhang, Qiu,Luo, Juan,Gan, Zongjie,Jiang, Wengao,Tang, Qiang
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- Pd-Nb binfunctional catalysts supported on silica and zirconium phosphate heterostructures for O-removal of dibenzofurane
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Bifunctional PdNb catalysts were studied in the hydrodesoxygenation (HDO) reaction of dibenzofuran (DBF) at 275?°C and 15?bar of H2 pressure. The influence of both the support employed (silica and zirconium phosphate heterostructure (PPH)) and the catalyst preparation procedure were evaluated in the catalytic response in the HDO reaction. The catalysts were prepared by incipient wetness impregnation by using two synthetic routes. The catalysts were characterized by means of X-ray diffraction (XRD), N2 adsorption-desorption, thermoprogrammed desorption of NH3 (TPD-NH3), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and elemental analysis. The results show that silica supported catalysts are much more active than those supported on PPH. While the characterization results point to a higher dispersion of the supported catalysts on PPH and better textural and acidic properties, the PdCl2 precursor salt remains on these catalysts even after calcination and catalytic tests, explaining the lower catalytic performance presented by these systems: fewer active centers and more residues of carbon. With respect to the preparation method, regardless the support employed, the catalysts synthesized by incorporating Pd after Nb incorporation and calcination, are more active, most probably due to a better phase dispersion and therefore to a higher amount of active centers.
- Infantes-Molina,Moretti,Segovia,Lenarda,Rodríguez-Castellón
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p. 143 - 151
(2016/09/28)
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- Rearrangements of Cycloalkenyl Aryl Ethers
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Rearrangement reactions of cycloalkenyl phenol and naphthyl ethers and the acid-catalyzed cyclization of the resulting product were investigated. Claisen rearrangement afforded 2-substituted phenol and naphthol derivatives. Combined Claisen and Cope rearrangement resulted in the formation of 4-substituted phenol and naphthol derivatives. In the case of cycloocthylphenyl ether the consecutive Claisen and Cope rearrangements were followed by an alkyl migration. The mechanism of this novel rearrangement reaction is also discussed.
- T?rincsi, Mercedesz,Nagy, Melinda,Bihari, Tamás,Stirling, András,Kolonits, Pál,Novak, Lajos
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- Promising Ni/Al-SBA-15 catalysts for hydrodeoxygenation of dibenzofuran into fuel grade hydrocarbons: Synergetic effect of Ni and Al-SBA-15 support
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This work has been undertaken with the aim of designing promising noble-metal-free catalysts for efficient hydrodeoxygenation (HDO) of dibenzofuran (DBF) into fuel grade hydrocarbons. For this, various Ni/Al-SBA-15 catalysts with different Si/Al (50, 60, 70 and 80) mole ratios were synthesized and their catalytic performance was tested for HDO of DBF in a batch reactor. The catalysts were systematically characterized using XRD, N2-adsorption-desorption, Raman, H2-TPR, NH3-TPD, XRF, and FESEM techniques. The activity results showed that the HDO of DBF proceeds via hydrogenation of benzene on the Ni sites followed by cleavage of C-O bonds on the acidic sites of the catalyst to yield unsaturated hydrocarbons. Further hydrogenation of unsaturated hydrocarbons on the Ni sites gives bicyclohexane as the major product. Remarkably, a 100% DBF conversion was found for all the catalysts except for Ni/SBA-15 and Ni/Al-SBA-15(80) (Si/Al mole ratio = 80) catalysts, which showed 97.97 and 99.31%, respectively. A significant observation noticed in this study is that the incorporation of Al into Ni/SBA-15 results in an outstanding improvement in the selectivity of the bicyclohexane product. Among the catalysts tested, the Ni/Al-SBA-15(50) (Si/Al mole ratio = 50) catalyst showed the highest efficiency, with superior selectivity of ~87% for bicyclohexane and ~96% degree of deoxygenation at 10 MPa, 260 °C and 5 h. The obtained structure-activity results reveal the synergetic effect of Ni and support in HDO of DBF reaction: the concentration of acidic sites has a significant effect on the selectivity of the desired products.
- Gbadamasi, Sharafadeen,Ali, Tammar Hussein,Voon, Lee Hwei,Atta, Abdulazeez Yusuf,Sudarsanam, Putla,Bhargava, Suresh K.,Abd Hamid, Sharifah Bee
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p. 25992 - 26002
(2016/03/25)
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- Effective hydrodeoxygenation of dibenzofuran by a bimetallic catalyst in water
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Effective hydrodeoxygenation (HDO) of dibenzofuran (DBF) catalyzed by a bimetallic nickel/platinum (Ni/Pt) catalyst in water was demonstrated at 200 °C and 1.2 MPa hydrogen (H2) pressure. The bimetallic catalysts prepared by a wet chemical method exhibit prominent activity that overcomes the limitations of use of a single Ni or Pt metal catalyst. The yield of HDO products can be up to 90%. Reaction results indicate that the conversion of DBF was affected by the reaction temperature and H2 pressure. The deoxygenation selectivity was strongly dependent on reaction temperature. The reaction pathway is also proposed.
- Dong, Peng,Lu, Guo-Ping,Cai, Chun
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p. 1605 - 1609
(2016/02/19)
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- Nickel and cobalt phosphides as effective catalysts for oxygen removal of dibenzofuran: Role of contact time, hydrogen pressure and hydrogen/feed molar ratio
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The catalytic activity of nickel and cobalt phosphides, with a metal loading of 5 wt.%, supported on silica was investigated in the hydrodeoxygenation reaction (HDO) of dibenzofuran (DBF) as a model oxygenated compound at different contact times, H2 pressures and H2/DBF molar ratios. The aim of the study was to understand the mechanism of the reaction and to study the impact of H2 pressure and H2/DBF molar ratio on the reaction. The catalysts were characterized by N2 adsorption-desorption isotherm measurement at -196°C, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), CO chemisorption, NH3 Temperature-Programmed Desorption (NH3-TPD), IR spectroscopy and H2 Temperature-Programmed Desorption (H2-TPD). The prepared catalysts were tested in the HDO reaction of DBF in a continuous-flow fixed-bed stainless steel catalytic reactor at pressures ranging from 1-30 bar at 275°C. The results obtained indicate that the Ni2P catalyst is more active than the CoP catalyst, converting more than 90% of DBF at the highest contact time into oxygen-free products. The activity of both catalysts increases with increased contact time. At low contact times, the intermediates tetrahydrodibenzofuran (THDBF) and hexahydrodibenzofuran (HHDBF) are observed as products, while an increment in the contact time led to the transformation of THDBF and HHDBF into O-free compounds, mainly bicyclohexane (BCH), indicating that the HDO of DBF follows the path: DBF → HHDBF → THDBF → 2-CHP → BCH. Further, both Ni2P and CoP catalysts are active at medium pressures with HDO degrees similar to those obtained at 30 bar. Ni2P is less affected by the changes in H2/DBF ratio than CoP and the catalysts are more active at high H2/DBF molar ratios.
- Infantes-Molina,Gralberg,Cecilia,Finocchio, Elisabetta,Rodríguez-Castellón
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p. 3403 - 3415
(2015/06/08)
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- Scalable, transition-metal-free direct oxime o-arylation: Rapid access to o-arylhydroxylamines and substituted benzo[b]furans
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O-Aryloximes, generated from readily available and inexpensive oximes through transition-metal-free O-arylation, can either be hydrolyzed to O-arylhydroxylamines or conveniently converted to structurally diverse benzo[b]furans through an environmentally benign, one-pot [3,3]-sigmatropic rearrangement/cyclization sequence. A scalable, transition-metal-free (TM-free) direct O-arylation of ketone oximes with a wide range of diaryliodonium salts has been developed. More than two dozen O-arylated oximes have been prepared in good to excellent yields at ambient temperature and were converted to the corresponding substituted benzo[b]furans through a [3,3]-sigmatropic rearrangement/cyclization sequence. Overall, this operationally simple, environmentally benign, and protecting-group-free approach, including a one-pot variant, allows rapid and convenient synthetic access to substituted benzo[b]furans (see scheme).
- Gao, Hongyin,Xu, Qing-Long,Keene, Craig,Kuerti, Laszlo
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p. 8883 - 8887
(2014/07/22)
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- Metal-free one-pot synthesis of benzofurans
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Ethyl acetohydroxamate was efficiently arylated with diaryliodonium salts at room temperature under transition-metal-free conditions. The obtained O-arylated products were reacted in situ with ketones under acidic conditions to yield substituted benzo[b]furans through oxime formation, [3,3]-rearrangement, and cyclization in a fast and operationally simple one-pot fashion without using excess reagents. Alternatively, the O-arylated products could be isolated or transformed in situ to aryloxyamines or O-arylaldoximes. The methodology was applied to the synthesis of Stemofuran A and the formal syntheses of Coumestan, Eupomatenoid 6, and (+)-machaeriol B. Just add salt! A metal-free, room temperature arylation of ethyl acetohydroxamate, followed by an in situ reaction with ketones under acidic conditions yielded substituted benzo[b]furans in a fast and operationally simple one-pot fashion without using excess reagents (see scheme). Alternatively, the O-arylated products could be isolated, hydrolyzed in situ to aryloxyamines, or transformed to O-arylaldoximes. The efficiency of the methodology was demonstrated by the formal synthesis of several biologically active benzofurans.
- Ghosh, Raju,Stridfeldt, Elin,Olofsson, Berit
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p. 8888 - 8892
(2014/07/22)
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- Dehydrative C-H alkylation and alkenylation of phenols with alcohols: Expedient synthesis for substituted phenols and benzofurans
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A well-defined cationic Ru-H complex catalyzes the dehydrative C-H alkylation reaction of phenols with alcohols to form ortho-substituted phenol products. Benzofuran derivatives are efficiently synthesized from the dehydrative C-H alkenylation and annulation reaction of phenols with 1,2-diols. The catalytic C-H coupling method employs cheaply available phenols and alcohols, exhibits a broad substrate scope, tolerates carbonyl and amine functional groups, and liberates water as the only byproduct.
- Lee, Dong-Hwan,Kwon, Ki-Hyeok,Yi, Chae S.
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supporting information; experimental part
p. 7325 - 7328
(2012/06/16)
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- Cationic palladium-catalyzed [5 + 2] annulation of 2-acylmethoxyarylboronic acids and allenoates: Synthesis of 1-benzoxepine derivatives
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The 1-benzoxepine derivatives were synthesized conveniently by cationic palladium-catalyzed [5 + 2] annulation reaction of 2-acylmethoxyarylboronic acids with allenoates in high yields. This annulation involves the intramolecular nucleophilic addition to ketones without the formation of π-allylpalladium species.
- Yu, Xufen,Lu, Xiyan
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experimental part
p. 6350 - 6355
(2011/10/02)
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- Cascade palladium-catalyzed direct intramolecular arylation/alkene isomerization sequences: Synthesis of indoles and benzofurans
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One route, two cycles: A palladium-catalyzed intramolecular direct arylation reaction combined with an isomerization step provided a straightforward synthetic route to both indoles and benzofurans (see scheme). Isolation and functionalization of intermedi
- Yagoubi, Myriam,Cruz, Ana C. F.,Nichols, Paula L.,Elliott, Richard L.,Willis, Michael C.
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supporting information; experimental part
p. 7958 - 7962
(2011/01/11)
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- Iron and copper salts in the synthesis of benzo[b]furans
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Intramolecular C-O bond forming reactions of aryl 2-bromobenzyl ketones lead to benzo[b]furans. The cyclizations can be catalyzed by 10 mol% of iron trichloride (of 98% or of 99.995% purity) or sub-mol% quantities of copper(II) chloride (of 99.995% purity
- Bonnamour, Julien,Piedrafita, Maria,Bolm, Carsten
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supporting information; experimental part
p. 1577 - 1581
(2010/09/05)
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- Direct preparation of benzofurans from O-arylhydroxylamines
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Reaction of O-arylhydroxylamine hydrochlorides with either cyclic or acyclic ketones in the presence of methanesulfonic acid leads directly to the benzofuran derivative via a proposed one-pot condensation-rearrangement- cyclisation reaction sequence in good to excellent yields. Georg Thieme Verlag Stuttgart.
- Contiero, Fanny,Jones, Kevin M.,Matts, Edward A.,Porzelle, Achim,Tomkinson, Nicholas C.O.
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experimental part
p. 3003 - 3006
(2010/03/03)
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- Palladium(II)-catalyzed intramolecular addition of arylboronic acids to ketones
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A palladium(II)-catalyzed intramolecular addition of arylboronic acids to ketones was developed. Compared to Pd(OAc)2 catalysis system, cationic palladium complex with dppp as the ligand has higher catalytic activity and efficiency for wider sc
- Liu, Guixia,Lu, Xiyan
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p. 7324 - 7330
(2008/12/20)
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- One-pot synthesis of benzofurans via palladium-catalyzed enolate arylation with o-bromophenols
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(Chemical Equation Presented) A one-pot synthesis of benzofurans which utilizes a palladium-catalyzed enolate arylation is described. The process demonstrates broad substrate scope and provides differentially substituted benzofurans in moderate to excelle
- Eidamshaus, Christian,Burch, Jason D.
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supporting information; experimental part
p. 4211 - 4214
(2009/06/06)
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- Efficient synthesis of benzofurans utilizing [3,3]-sigmatropic rearrangement triggered by N-trifluoroacetylation of oxime ethers: Short synthesis of natural 2-arylbenzofurans
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A new synthetic method for the preparation of benzofurans has been developed. The key step of this method is the [3,3]-sigmatropic rearrangement of N-trifluoroacetyl-ene-hydroxylamines, which was triggered by acylation of oxime ethers. TFAA has been proved to be the best reagent to induce [3,3]-sigmatropic rearrangement for the synthesis of cyclic or acyclic dihydrobenzofurans. On the other hand, the TFAT-DMAP system is found to be the most effective for constructing various benzofurans. Synthetic utility of this reaction is demonstrated by the short synthesis of natural benzofurans without protection of the hydroxy group. The synthesis of Stemofuran A was accomplished via condensation of ketones with aryloxyamine and subsequent reaction with TFAT-DMAP in a four-step synthesis with 72% overall yield. Similarly, Eupomatenoid 6 and Coumestan were synthesized through the reaction of oxime ether with TFAT-DMAP. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Takeda, Norihiko,Miyata, Okiko,Naito, Takeaki
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p. 1491 - 1509
(2008/09/19)
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- Palladium-catalysed intramolecular enolate O-arylation and thio-enolate S-arylation: synthesis of benzo[b]furans and benzo[b]thiophenes
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Enolates derived from α-(ortho-haloaryl)-substituted ketones undergo palladium-catalysed C-O bond formation to deliver benzofuran products in good yield. A catalyst generated from Pd2(dba)3 and the ligand DPEphos effects the key bond
- Willis, Michael C.,Taylor, Dawn,Gillmore, Adam T.
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p. 11513 - 11520
(2007/10/03)
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- On-water chemistry: Copper-catalyzed straightforward synthesis of benzo[b]furan derivatives in neat water
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A more sustainable protocol leading to 2-alkyl- or 2-aryl-substituted benzo[b]furans is reported, involving a copper-TMEDA complex which catalyzes the transformation of readily available ketone derivatives into the corresponding benzofurans in good to excellent yields. The reaction is accomplished using water as the solvent without organic cosolvents, and one example of catalyst reutilization is also presented.
- Carril, Monica,SanMartin, Raul,Tellitu, Imanol,Dominguez, Esther
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p. 1467 - 1470
(2007/10/03)
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- CuI/N,N-dimethylglycine-catalyzed cross-coupling reaction of vinyl halides with phenols and its application to the assembly of substituted benzofurans
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CuI-catalyzed coupling reaction of vinyl halides and phenols occurs at 60-90 °C with N,N-dimethylglycine hydrochloride as the additive, giving vinyl aryl ethers in good yields. The cross-coupling products formed from o-iodophenols and vinyl iodides are co
- Ma, Dawei,Cai, Qian,Xie, Xiaoan
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p. 1767 - 1770
(2007/10/03)
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- Deuterium-Labeling Studies Establishing Stereochemistry at the Oxypalladation Step in Wacker-Type Oxidative Cyclization of an o-Allylphenol
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The stereochemical pathway (syn or anti) of the oxypalladation step was studied in the palladium(II)-catalyzed Wacker-type cyclization of stereospecifically deuterated 6-(2-hydroxyphenyl)-3-deuteriocyclohexenes, cis-3-d-1 and trans-3-d-1, giving dihydrobe
- Hayashi, Tamio,Yamasaki, Kaori,Mimura, Michihiro,Uozumi, Yasuhiro
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p. 3036 - 3037
(2007/10/03)
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- Hydroxamic acid compounds useful as matrix metalloproteinase inhibitors
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Compounds of the formula; are useful for inhibiting matrix metalloproteinase enzymes in animals, and as such, prevent and treat diseases resulting from the breakdown of connective tissues. Also disclosed are methods for the preparation of such compounds,
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Page column 22
(2008/06/13)
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- Palladium-catalyzed intramolecular O-arylation of enolates: Application to benzo[6]furan synthesis
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(Chemical Equation Presented) A catalyst generated from Pd 2(dba)3 and the ligand DPEphos effects intramolecular C-O bond formation between enolates and aryl halides in the conversion of 1-(2-haloaryl)ketones directly into the corres
- Willis, Michael C.,Taylor, Dawn,Gillmore, Adam T.
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p. 4755 - 4757
(2007/10/03)
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- Tricyclic biphenyl sulfonamide matrix metalloproteinase inhibitors
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Matrix metalloproteinase inhibitors are tricyclic sulfonamides of the Formula I 1 or a pharmaceutically acceptable salt thereof,wherein R1 and R2 include hydrogen, alkyl, and substituted alkyl; R3 is OH or NHOH; X is O or S(O)n; n is 0, 1, or 2; p is 0, 1, 2, or 3;— is absent or a bond; and the sulfur atom bearing (O)q is bonded to the benzo ring at position a or position b.[From equivalent US6555535] Matrix metalloproteinase inhibitors are tricyclic sulfonamides of the Formula I STR1or a pharmaceutically acceptable salt thereof,wherein R 1 and R 2 include hydrogen, alkyl, and substituted alkyl; R 3 is OH or NHOH; X is O or S(O) n ; n is 0, 1, or 2; p is 0, 1, 2, or 3; -- is absent or a bond; and the sulfur atom bearing (O) q is bonded to the benzo ring at position a or position b.
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- Tricyclic biphenyl sulfonamide matrix metalloproteinase inhibitors
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Matrix metalloproteinase inhibitors are tricyclicsulfonamides of the Formula I or a pharmaceutically acceptable salt thereof, wherein R1 and R2 include hydrogen, alkyl, and substituted alkyl; R3 is OH or NHOH; X is O or S(
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- α-Oxidation of ketones using n-cation radicals
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Six-membered ring ketones and acyclic ketones were oxidized by stable triarylamminium radical cations in moist acetonitrile at room temperature in the presence of a base to α-hydroxy ketones in good yield. Five-membered ring ketones gave the corresponding αβ-unsaturated compounds.
- Schulz, Manfred,Kluge, Ralph,Sivilai, Li,Kamm, Birgit
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p. 2371 - 2380
(2007/10/02)
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- Synthetic Applications of Heteroatom-Directed Photoarylation. Benzofuran Ring Construction
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The preparation of several α-phenoxy-α,β-unsaturated carboxylic acid esters via condensation of phosphonate 3c with ketones and an aldehyde is described.The resulting aryl vinyl ethers undergo photocyclization to give 2,3-dihydrobenzofuran-2-carboxylic
- Schultz, Arthur G.,Napier, James J.,Ravichandran, Ramanathan
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p. 3408 - 3412
(2007/10/02)
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- Aryne and SNAr Reactions of Polyhalogenobenzenes. 6. Synthesis of Benzofurans
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The scope and limitations of the one-pot synthesis of benzofurans by aryne condensations of the cyclic ketone enolates with dihalogenobenzenes in the presence of the complex base NaNH2-t-BuONa were studied.It is shown that this method is of interest for t
- Bachelet, Jean-Pierre,Caubere, Paul
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p. 234 - 238
(2007/10/02)
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