- Quinoline Ligands Improve the Classic Direct C?H Functionalisation/Intramolecular Cyclisation of Diaryl Ethers to Dibenzofurans
-
The C?H functionalisation approach to the synthesis of dibenzofurans is hampered by a number of problems. Herein we describe the evolution of a cheap, bench stable quinoline ligand, which obviates most of the current limitations and allows for a high yielding synthesis of a range of valuable dibenzofurans. Dibenzofurans are important motifs in natural products and compounds with wide biological activity.
- Mackey, Katrina,Jones, David J.,Pardo, Leticia M.,McGlacken, Gerard P.
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supporting information
p. 495 - 498
(2021/01/12)
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- Fluorinations of unsymmetrical diaryliodonium salts containing: Ortho -sidearms; Influence of sidearm on selectivity
-
Activated aromatics were reacted with two different fluoroidoane reagents 1 and 2 in the presence of triflic acid to prepare only the para-substituted diaryliodonium salts. With fluoroiodane 1 the unsymmetrical diaryliodonium salts contained an ortho-propan-2-ol sidearm, whereas the alcohol sidearm was eliminated to form an ortho-styrene sidearm in the reaction with fluoroiodane 2. Only the diaryliodonium salts containing a styrene sidearm were fluorinated successfully to deliver para-fluorinated aromatics in good yields.
- Abudken, Ahmed M. H.,Hope, Eric G.,Singh, Kuldip,Stuart, Alison M.
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p. 6140 - 6146
(2020/10/30)
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- Recyclable synthesis of mesityl iodonium(III) salts
-
An efficient protocol for C–H condensation of hypervalent iodine compounds toward arenes in fluoroalcohols has been applied to the recyclable preparation of mesityl iodonium(III) salts. The electrophilicities of [hydroxy(tosyloxy)iodo]mesitylene (MesI(OH)OTs) and iodomesitylene diacetate (MesI(OAc)2) are suitably enhanced in 2,2,2-trifluoroethanol. A series of nucleophilic aromatic compounds react smoothly with MesI(OH)OTs and MesI(OAc)2 or in situ hypervalent iodine(III) species, generated from iodomesitylene, to provide the target mesityl iodonium(III) salts in good yields at room temperature with broad functional group tolerance. This C–H condensation strategy merits high para-regioselectivities during the diaryliodonium(III) salt formation, but the major limitation in the case of low-reactive aromatic substrates is byproduct formation resulting from the self-condensation of the nucleophilic mesitylene ring in MesI(OH)OTs and MesI(OAc)2.
- Dohi, Toshifumi,Hayashi, Takumi,Ueda, Shohei,Shoji, Toshitaka,Komiyama, Keina,Takeuchi, Hitoshi,Kita, Yasuyuki
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p. 3617 - 3627
(2019/05/27)
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- Reactions of Arylsulfonate Electrophiles with NMe4F: Mechanistic Insight, Reactivity, and Scope
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This paper describes a detailed study of the deoxyfluorination of aryl fluorosulfonates with tetramethylammonium fluoride (NMe4F) and ultimately identifies other sulfonate electrophiles that participate in this transformation. 19F NMR spectroscopic monitoring of the deoxyfluorination of aryl fluorosulfonates revealed the rapid formation of diaryl sulfates under the reaction conditions. These intermediates can proceed to fluorinated products; however, diaryl sulfate derivatives bearing electron-donating substituents react very slowly with NMe4F. Based on these findings, aryl triflate and aryl nonaflate derivatives were explored, since these cannot react to form diaryl sulfates. Aryl triflates were found to be particularly effective electrophiles for deoxyfluorination with NMe4F, and certain derivatives (i.e., those bearing electron-neutral/donating substituents) afforded higher yields than their aryl fluorosulfonate counterparts. Computational studies implicate a similar mechanism for deoxyfluorination of all the sulfonate electrophiles.
- Schimler, Sydonie D.,Froese, Robert D. J.,Bland, Douglas C.,Sanford, Melanie S.
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p. 11178 - 11190
(2018/09/12)
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- METHOD FOR AROMATIC FLUORINATION
-
Disclosed is a fluorination method comprising providing an aryl fluorosuifonate and a fluorinating reagent to a reaction mixture; and reacting the aryl fluorosuifonate and the fluorinating reagent to provide a fluorinated aryl species. Also disclosed is a fluorination method comprising providing, a salt comprising a cation and an aryloxyiate, and SO2F2 to a reaction mixture; reacting the SO2F2 and the ammonium salt to provide a fluorinated aryl species. Further disclosed a fluorination method comprising providing a compound having the structure Ar-OH to a reaction mixture; where A is an aryl or heteroaryl; providing SO2F2 to the reaction mixture; providing a fluorinating reagent to the reaction mixture; reacting the SO2F2, the fluorinating reagent and the compound having the structure Ar-OH to provide a fluorinated aryl species having the structure Ar-F.
- -
-
Paragraph 0051; 0052
(2017/12/18)
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- Nucleophilic deoxyfluorination of phenols via aryl fluorosulfonate intermediates
-
This report describes a method for the deoxyfluorination of phenols with sulfuryl fluoride (SO2F2) and tetramethylammonium fluoride (NMe4F) via aryl fluorosulfonate (ArOFs) intermediates. We first demonstrate that the reaction of ArOFs with NMe4F proceeds under mild conditions (often at room temperature) to afford a broad range of electronically diverse and functional group-rich aryl fluoride products. This transformation was then translated to a one-pot conversion of phenols to aryl fluorides using the combination of SO2F2 and NMe4F. Ab initio calculations suggest that carbon-fluorine bond formation proceeds via a concerted transition state rather than a discrete Meisenheimer intermediate.
- Schimler, Sydonie D.,Cismesia, Megan A.,Hanley, Patrick S.,Froese, Robert D.J.,Jansma, Matthew J.,Bland, Douglas C.,Sanford, Melanie S.
-
supporting information
p. 1452 - 1455
(2017/02/10)
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- CATALYTIC SYSTEM FOR CROSS-COUPLING REACTIONS
-
The present invention concerns a process for creating a Carbon-Carbon bond (C—C) or a Carbon-Heteroatom bond (C—HE) by reacting a compound carrying a leaving group with a nucleophilic compound carrying a carbon atom or a heteroatom (HE) that can substitute for the leaving group, creating a C—C or C—HE bond, wherein the reaction takes place in the presence of an effective quantity of a. a catalytic system comprising a ligand and at least a metal-based catalyst, such a metal catalyst being chosen among iron or copper compounds proviso that only a single metal is present.
- -
-
Paragraph 0305; 0306
(2016/06/06)
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- Modular Synthesis of Arylacetic Acid Esters, Thioesters, and Amides from Aryl Ethers via Rh(II)-Catalyzed Diazo Arylation
-
One-pot formation of arylacetic acid esters, thioesters, and amides via Rh(II)-catalyzed arylation of a Meldrum's acid-derived diazo reagent with electron-rich arenes is described. The methodology was used to efficiently synthesize an anticancer compound.
- Best, Daniel,Jean, Micka?l,Van De Weghe, Pierre
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p. 7760 - 7770
(2016/09/12)
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- Visible-light-mediated synthesis of diaryl ethers from arylboronic acids and diaryliodonium salts
-
With visible-light irradiation, a simple and metal-free photocatalytic system for the synthesis of diaryl ethers from arylboronic acids and diaryliodonium salts has been developed. The reaction proceeded in high yield for a range of different substrates in the presence of eosin Y under mild reaction conditions.
- Liu, Li,Tang, Jiaqi,Qiang, Jian,Li, Jian,He, Mingyang
-
p. 261 - 264
(2016/07/06)
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- Synthesis of copper nanoparticles supported on a microporous covalent triazine polymer: An efficient and reusable catalyst for O-arylation reaction
-
Copper nanoparticles were supported on a microporous covalent triazine polymer prepared by the Friedel-Crafts reaction (Cu@MCTP-1). The resulting material was characterized by powder X-ray diffraction, thermogravimetric analysis, N2 adsorption-desorption isotherms at 77 K, transmission electron microscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma optical emission spectroscopy, and Cu particles with an average size of 3.0 nm and a BET total surface area of ca. 1002 m2 g-1 were obtained. Cu@MCTP-1 was evaluated as a heterogeneous catalyst for the Ullmann coupling of O-arylation over a series of aryl halides and phenols without employing expensive ligands or inert atmosphere, which produced an excellent yield of the corresponding diaryl ethers. The catalyst could be recovered by simple centrifugation and was reusable at least five times with only a slight decrease in catalytic activity.
- Puthiaraj, Pillaiyar,Ahn, Wha-Seung
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p. 1701 - 1709
(2016/04/05)
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- PHOTOREDOX-CATALYZED DIRECT C-H FUNCTIONALIZATION OF ARENES
-
The invention generally relates to methods of making substituted arenes via direct C-H amination. More specifically, methods of making para- and ortho-substituted arenes via direct C-H amination are disclosed. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.
- -
-
Paragraph 00388
(2017/01/31)
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- Air-stable palladium(0) phosphine sulfide catalysts for Ullmann-type C-N and C-O coupling reactions
-
This paper describes an efficient procedure for palladium(0)-catalyzed N-arylation and O-arylation of aryl halides by Ullmann-type cross coupling reaction under mild reaction conditions in a short reaction time. Two phosphine sulphide ligands and their corresponding Pd(0) complexes namely [Pd(p2S2)(dba)] and [Pd(pp3S4)(dba)], were synthesized, where p2S2 is 1,2-bis(diphenylphosphino)ethane disulfide, pp3S4 is tris[2-(diphenylphosphino)ethyl]phosphine tetrasulfide and dba is dibenzylideneacetone. Optimal reaction conditions were determined for the arylation reactions using iodobenzene and benzimidazole by varying temperature, solvent, base and catalyst loading. The cross coupling reactions were carried out taking iodobenzenes/bromobenzenes and a wide variety of substituted aryl amines/phenols/alcohols with different steric and electronic properties to afford the desired N-aryl amines/diaryl ethers/alkyl aryl ethers in good to excellent yield (70-94%).
- Majumder, Arpi,Gupta, Ragini,Mandal, Mrinmay,Babu, Madhu,Chakraborty, Debashis
-
-
- Barberry fruit extract assisted in situ green synthesis of Cu nanoparticles supported on a reduced graphene oxide-Fe3O4 nanocomposite as a magnetically separable and reusable catalyst for the O-arylation of phenols with aryl halides under ligand-free conditions
-
In situ synthesis of copper nanoparticles (NPs) supported on a reduced graphene oxide (RGO)-Fe3O4 nanocomposite was carried out with barberry fruit extract as a reducing and stabilizing agent. The morphology and structure of the Cu/RGO-Fe3O4 nanocomposite was fully characterized by means of X-ray diffraction (XRD), Fourier transformed infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FE-SEM), Raman, energy dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). Cu/RGO-Fe3O4 was a promising catalyst for the O-arylation of phenols with aryl halides under ligand-free conditions. A diverse range of diaryl ethers were obtained in a good to high yield. Furthermore, due to the magnetic separability and high stability of the composite the catalyst could be separated conveniently from the reaction mixtures by an external permanent magnet and recycled multiple times without loss of catalytic activity.
- Nasrollahzadeh, Mahmoud,Maham, Mehdi,Rostami-Vartooni, Akbar,Bagherzadeh, Mojtaba,Sajadi, S. Mohammad
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p. 64769 - 64780
(2015/08/18)
-
- Anchoring of Pd(ii) complex in functionalized MCM-41 as an efficient and recoverable novel nano catalyst in C-C, C-O and C-N coupling reactions using Ph3SnCl
-
Anchored palladium(ii) in functionalized MCM-41 mesoporous silica was prepared and used as an efficient, recoverable and thermally stable heterogeneous nano catalyst for C-C, C-O and C-N bond formation in cross-coupling reactions in the presence of Ph3SnCl. MCM-41 was prepared trough hydrothermal synthesis using tetraethyl orthosilicate (Si(OC2H5)4) as silica source and cetyltrimethylammonium bromide (CTAB) as a template. The structure of functionalized MCM-41 was studied by FT-IR, XRD, SEM, TEM, TGA, EDS, ICP and BET techniques.
- Ghorbani-Choghamarani, Arash,Nikpour, Farzad,Ghorbani, Farshid,Havasi, Forugh
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p. 33212 - 33220
(2015/04/27)
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- A counteranion triggered arylation strategy using diaryliodonium fluorides
-
A mild and transition metal-free counteranion triggered arylation strategy has been developed using diaryliodonium fluorides. The fluoride counteranion within the hypervalent iodonium species displays unusual reactivity that activates a phenolic O-H bond leading to electrophilic O-arylation. A wide range of phenols and diaryliodonium salts are compatible with this transformation under remarkably mild conditions. Furthermore, we pre-empt the wider implications of this strategy by demonstrating the compatibility of the arylation tactic with latent carbon nucleophiles.
- Chan,McNally,Toh,Mendoza,Gaunt
-
p. 1277 - 1281
(2015/02/05)
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- PhenoFluorMix: Practical chemoselective deoxyfluorination of phenols
-
A practical deoxyfluorination with novel deoxyfluorinating reagent PhenoFluorMix, a mixture of N,N'-1,3-bis(2,6-diisopropylphenyl)chloroimidazolium chloride and CsF, is presented. PhenoFluorMix overcomes the challenges associated with hydrolysis of PhenoFluor. PhenoFluorMix does not hydrolyze, is readily available on decagram scale, and is storable in air. In this paper, we demonstrate the practicality of the reagent and exhibit the deoxyfluorination of a variety of phenols and heterocycles.
- Fujimoto, Teppei,Ritter, Tobias
-
supporting information
p. 544 - 547
(2015/03/05)
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- The coupling reactions of aryl halides and phenols catalyzed by palladium and MOP-type ligands
-
Palladium-catalyzed coupling reactions of aryl halides and phenols are described employing the bulky and electron-rich MOP-type ligands. When K3PO4 was used as base and toluene as solvent, the catalyst system exhibited high efficiency for the coupling reaction of the activated aryl halides. When NaH was used as base and o-xylene as solvent, unactivated aryl halides can be used as substrates.
- Zhang, Yi,Ni, Gang,Li, Chengjun,Xu, Sheng,Zhang, Zhaoguo,Xie, Xiaomin
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p. 4927 - 4932
(2015/06/23)
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- KF/Clinoptilolite, an effective solid base in Ullmann ether synthesis catalyzed by CuO nanoparticles
-
Employing KF/Clinoptilolite as an efficient base the cross-coupling reactions of various phenols with aryl iodides could be successfully carried out in the presence of copper oxide nanoparticles. The C-O coupling products were obtained in moderate to good yields (62-87%) for a variety of substrates. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2014.
- Khalilzadeh, Mohammad A.,Keipour, Hoda,Hosseini, Abolfazl,Zareyee, Daryoush
-
-
- Synthesis of highly functionalized diaryl ethers by copper-mediated O-arylation of phenols using trivalent arylbismuth reagents
-
Highly functionalized diaryl ethers were prepared by copper(II) acetate mediated O-arylation reaction of phenols using trivalent organobismuthanes. The reaction is performed under simple conditions and tolerates a wide diversity of functional groups on the phenol and on the organobismuth reagent. Substoichiometric amounts of catalyst can be used by performing the reaction under an oxygen atmosphere. The N-arylation of pyridones is also reported. Highly functionalized diaryl ethers were prepared by a copper(II) acetate mediated O-arylation reaction of phenols using trivalent organobismuthanes (see scheme). The reaction is performed under simple conditions and tolerates a wide diversity of functional groups on the phenol and on the organobismuth reagent. Substoichiometric amounts of catalyst can be used by performing the reaction under an oxygen atmosphere. The N-arylation of pyridones is also reported. FG=functional group.
- Crifar, Cynthia,Petiot, Pauline,Ahmad, Tabinda,Gagnon, Alexandre
-
supporting information
p. 2755 - 2760
(2014/03/21)
-
- Potassium tert-butoxide-mediated synthesis of unsymmetrical diaryl ethers, sulfides and selenides from aryl bromides
-
Potassium tert-butoxide mediated carbon-chalcogen C-E (E=O, S and Se) coupling reaction has been studied from aryl bromide and phenol/aryl disulfide/diselenide substrates. A series of unsymmetrical diaryl chalcogenides were accessed from aryl bromide and diaryl dichalcogenide precursors by using 2.5 equiv of potassium tert-butoxide in DMSO at 80 C. Unsymmetrical diaryl ethers were also obtained by using phenol precursors at 40-45 C. Aryl bromides with methyl, trifluoromethyl, methoxy and nitro substituents showed compatibility in the carbon-chalcogen bond forming reaction. 4-Methoxy, methyl, trifluoromethyl substituted bromobenzene substrates gave two regioisomers: 3-substituted and 4-substituted diaryl chalcogenides when reacted with phenols/diaryl disulfides/diselenides. Formation of two regioisomeric diaryl chalcogenides in the reaction mixture suggests that potassium tert-butoxide reacts with bromobenzene to produce benzyne intermediate, which subsequently reacts with diaryl dichalcogenides and finally give a regioisomeric mixture of 4-substituted and 3-substituted diaryl chalcogenides.
- Kumar, Amit,Bhakuni, Bhagat Singh,Prasad, Ch. Durga,Kumar, Shailesh,Kumar, Sangit
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p. 5383 - 5392
(2013/07/04)
-
- Cu-catalyzed fluorination of diaryliodonium salts with KF
-
A mild Cu-catalyzed nucleophilic fluorination of unsymmetrical diaryliodonium salts with KF is described. This protocol preferentially fluorinates the smaller aromatic ligand on iodine(III). The reaction exhibits a broad substrate scope and proceeds with high chemoselectivity and functional group tolerance. DFT calculations implicate a CuI/CuIII catalytic cycle.
- Ichiishi, Naoko,Canty, Allan J.,Yates, Brian F.,Sanford, Melanie S.
-
supporting information
p. 5134 - 5137
(2013/10/22)
-
- Palladium(III)-catalyzed fluorination of arylboronic acid derivatives
-
A practical, palladium-catalyzed synthesis of aryl fluorides from arylboronic acid derivatives is presented. The reaction is operationally simple and amenable to multigram-scale synthesis. Evaluation of the reaction mechanism suggests a single-electron-transfer pathway, involving a Pd(III) intermediate that has been isolated and characterized.
- Mazzotti, Anthony R.,Campbell, Michael G.,Tang, Pingping,Murphy, Jennifer M.,Ritter, Tobias
-
supporting information
p. 14012 - 14015
(2013/10/21)
-
- Microwave-assisted synthesis of nonsymmetrical aryl ethers using nitro-arenes
-
An efficient, microwave-assisted ligand-free, catalyst-free synthetic method for nonsymmetrical diaryl ethers has been developed by using nitroarenes. A variety of phenols and nitroarenes was scanned by using this method to produce nonsymmetrical aryl ethers. The newly developed method is an ecofriendly and cost-effective approach to synthesize nonsymmetrical aryl ethers.
- Sarkate, Aniket P.,Bahekar, Sushilkumar S.,Wadhai, Vijay M.,Ghandge, Ganesh N.,Wakte, Pravin S.,Shinde, Devanand B.
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p. 1513 - 1516
(2013/08/23)
-
- Nickel-catalyzed intramolecular C-H arylation using aryl pivalates as electrophiles
-
This paper describes a method for nickel catalyzed intramolecular C-H arylation using aryl pivalates as electrophiles. The transformation is efficient for the synthesis of diverse electronically and sterically differentiated dibenzofurans. Additionally, the method could be expanded toward the synthesis of carbazoles. Preliminary mechanistic studies of the transformation are also described.
- Wang, Jiayi,Ferguson, Devin M.,Kalyani, Dipannita
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p. 5780 - 5790
(2013/07/19)
-
- Mild copper-mediated fluorination of aryl stannanes and aryl trifluoroborates
-
This communication describes a mild copper-mediated fluorination of aryl stannanes and aryl trifluoroborates with N-fluoro-2,4,6-trimethylpyridinium triflate. This protocol demonstrates broad substrate scope and functional group tolerance, and does not require the use of any noble metal additives. The reaction is proposed to proceed via an arylcopper(III) fluoride intermediate.
- Ye, Yingda,Sanford, Melanie S.
-
supporting information
p. 4648 - 4651
(2013/05/09)
-
- Cu(OTf)2-mediated fluorination of aryltrifluoroborates with potassium fluoride
-
This Communication describes the Cu(OTf)2-mediated fluorination of aryltrifluoroborates with KF. The reaction proceeds under mild conditions (at 60 C over 20 h) and shows a broad substrate scope and functional group tolerance. The Cu is proposed to play two separate roles in this transformation: (1) as a mediator for the aryl-F coupling and (2) as an oxidant for accessing a proposed CuIII(aryl)(F) intermediate.
- Ye, Yingda,Schimler, Sydonie D.,Hanley, Patrick S.,Sanford, Melanie S.
-
supporting information
p. 16292 - 16295
(2013/12/04)
-
- Low catalyst loadings for copper-catalyzed O-arylation of phenols with aryl and heteroaryl halides under mild conditions
-
A practical and mild strategy has been developed for the cross-coupling of O-arylation of phenol with differently substituted aryl halides and heteroaryl iodides using low catalyst loading of copper iodide under low operating temperature in DMF with TMHD as the ligand and Cs2CO3 as the base. This method tolerates a variety of functional groups including sterically hindered phenols and heteroaryl iodides to afford products in good to excellent yields (up to 95%). Georg Thieme Verlag Stuttgart. New York.
- Yong, Fui-Fong,Teo, Yong-Chua,Yan, Yaw-Kai,Chua, Guan-Leong
-
supporting information; experimental part
p. 101 - 106
(2012/02/03)
-
- Copper-mediated fluorination of aryl iodides
-
The synthesis of aryl fluorides has been studied intensively because of the importance of aryl fluorides in pharmaceuticals, agrochemicals, and materials. The stability, reactivity, and biological properties of aryl fluorides can be distinct from those of the corresponding arenes. Methods for the synthesis of aryl fluorides, however, are limited. We report the conversion of a diverse set of aryl iodides to the corresponding aryl fluorides. This reaction occurs with a cationic copper reagent and silver fluoride. Preliminary results suggest this reaction is enabled by a facile reductive elimination from a cationic arylcopper(III) fluoride.
- Fier, Patrick S.,Hartwig, John F.
-
supporting information; experimental part
p. 10795 - 10798
(2012/08/07)
-
- Highly efficient copper catalytic system for the O-arylation of phenol with iodoarene
-
An efficient Cu-catalyzed O-arylation was carried out by involving phenols with iodoarenes to afford various substituted diarylether derivatives with tiny loading of Cu2O and 1H-imidazole-4-carboxylic acid as catalytic system under mild conditions, which provided good to excellent yields with good tolerance of functional groups.
- Cheng, An-Yi,Hsieh, Jen-Chieh
-
supporting information; experimental part
p. 71 - 75
(2012/01/31)
-
- Rhodium(NHC)-catalyzed O -arylation of aryl bromides
-
Chemical equations presented. The first example of the rhodium-catalyzed O-arylation of aryl bromides is reported. While the right combination of rhodium species and N-heterocyclic carbene (NHC) offered an effective catalytic system enabling the arylation to proceed, the choice of NHC was determined to be most important. The developed O-arylation protocol has a wide range of substrate scope, high functional group tolerance, and flexibility allowing a complementary route to either N- or O-arylation depending on the choice of NHC.
- Kim, Hyun Jin,Kim, Min,Chang, Sukbok
-
supporting information; experimental part
p. 2368 - 2371
(2011/06/24)
-
- New Catalytic System for Cross-Coupling Reactions
-
The present invention concerns a process for creating a Carbon-Carbon bond (C—C) or a Carbon-Heteroatom bond (C-HE) by reacting a compound carrying a leaving group with a nucleophilic compound carrying a carbon atom or a heteroatom (HE) that can substitute for the leaving group, creating a C—C or C-HE bond, wherein the reaction takes place in the presence of an effective quantity of a. a catalytic system comprising a ligand and at least a metal-based catalyst, such a metal catalyst being chosen among iron or copper compounds proviso that only a single metal is present.
- -
-
Page/Page column 13
(2012/01/03)
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- Fe3O4@mesoporouspolyaniline: A highly efficient and magnetically separable catalyst for cross-coupling of aryl chlorides and phenols
-
A high surface, magnetic Fe3O4@mesoporouspolyaniline core-shell nanocomposite was synthesized from magnetic iron oxide (Fe 3O4) nanoparticles and mesoporouspolyaniline (mPANI). The novel porous magnetic Fe3O4 was obtained by solvothermal method under sealed pressure reactor at high temperature to achieve high surface area. The mesoporouspolyaniline shell was synthesized by in situ surface polymerization onto porous magnetic Fe3O4 in the presence of polyvinylpyrrolidone (PVP) and sodium dodecylbenzenesulfonate (SDBS), as a linker and structure-directing agent, through 'blackberry nanostructures' assembly. The material composition, stoichiometric ratio and reaction conditions play vital roles in the synthesis of these nanostructures as confirmed by variety of characterization techniques. The role of the mesoporouspolyaniline shell is to stabilize the porous magnetic Fe3O4 nanoparticles, and provide direct access to the core Fe3O4 nanoparticles. The catalytic activity of magnetic Fe3O 4@mesoporousPANI nanocomposite was evaluated in the cross-coupling of aryl chlorides and phenols. Copyright
- Arundhathi,Damodara,Likhar, Pravin R.,Kantam, M. Lakshmi,Saravanan,Magdaleno, Travis,Kwon, Sun Hee
-
supporting information; experimental part
p. 1591 - 1600
(2011/08/03)
-
- A PEG1000-DAIL[CdCl3]-toluene temperature-dependent biphasic system that regulates homogeneously catalyzed C-O coupling of organic halides with phenols and alcohols under ligand-free conditions
-
An efficient, experimentally simple, and convenient procedure for the C-O coupling of organic halides with phenols and alcohols in a PEG 1000-DAIL[CdCl3]-toluene temperature-dependent biphasic system has been developed. The product can be easily isolated by a simple decantation, and the catalytic system can be recycled and reused without loss of catalytic activity.
- Hu, Yu Lin,Ma, Xiao Yun,Lu, Ming
-
experimental part
p. 471 - 480
(2011/06/22)
-
- Recyclable heterogeneous copper oxide on alumina catalyzed coupling of phenols and alcohols with aryl halides under ligand-free conditions
-
An efficient alumina-supported CuO-catalyzed O-arylation of phenols and aliphatic alcohols with various aryl as well as heteroaryl halides under ligand-free conditions are reported. This protocol provides a variety of diaryl ether and bis-diaryl ether motifs by reacting different aryl/aliphatic halides with differently substituted phenols and saturated alcohols in the presence of a catalytic amount of CuO on alumina and KOH as a base at moderate temperature under nitrogen atmosphere. The described methodology is simple, straightforward and efficient to afford the cross-coupled products in high yields under ligand-free conditions. The explored catalyst is inexpensive, air-stable and recyclable up to three cycles.
- Swapna, Kokkirala,Murthy, Sabbavarapu Narayana,Jyothi, Mocharla Tarani,Nageswar, Yadavalli Venkata Durga
-
supporting information; experimental part
p. 5978 - 5988
(2011/10/05)
-
- Copper(I) Phenoxide complexes in the etherification of aryl halides
-
"Chemical Equation Presented" No copping out! Copper(I) phenoxide complexes containing chelating ligands (see picture), proposed intermediates in copper-catalyzed etherification of aryl halides, have been synthesized and fully characterized. The kinetic and chemical competence of the isolated complexes are demonstrated for the synthesis of aryl phenyl ethers, and experiments provide evidence against mechanistic pathways involving the formation of either free or caged radicals.
- Tye, Jesse W.,Weng, Zhiqiang,Giri, Ramesh,Hartwig, John F.
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supporting information; experimental part
p. 2185 - 2189
(2010/06/19)
-
- Efficient catalytic activity of copper/aluminum hydrotalcite in diaryl ether synthesis
-
A simple copper/aluminum hydrotalcite (Cu/Al-HT) catalyzed arylation of phenols with aryl iodides afforded the corresponding diaryl ethers in moderate to excellent yields. This ligand- free Cu/Al-HT catalyzed coupling of aryl iodides with phenols resulted in high yields of diaryl ethers in the absence of an additive. The catalyst was quantitatively recovered from the reaction by simple filtration and reused for a number of cycles. Georg Thieme Verlag Stuttgart New York.
- Sreedhar,Arundhathi,Reddy, M. Amarnath,Kantam, M. Lakshmi
-
experimental part
p. 483 - 487
(2009/07/11)
-
- Iron-catalyzed C-O cross-couplings of phenols with aryl iodides
-
(Chemical Equation Presented) Low-price coupling: A versatile, practical, and cost-efficient iron-catalyzed O-arylation protocol is applied to the synthesis of a variety of diaryl ethers, which are formed in high yields. Best results were obtained by using FeCl3 and a β-diketo ligand.
- Bistri, Olivia,Correa, Arkaitz,Bolm, Carsten
-
p. 586 - 588
(2008/09/20)
-
- Copper- or iron-catalyzed arylation of phenols from respectively aryl chlorides and aryl iodides
-
The utility of diketone-1 was checked, which was first introduced for bimetallic Fe-Cu catalysts, in copper-catalyzed arylation of phenols from aryl chlorides. A systematic study was first undertaken by choosing 3,5-dimethylphenol as a model substrate. The first blank test was undertaken with PhCl and the dieketone-1/[Cu(acac)2] system. The second blank test was performed without copper and showed as expected that the arylation from PhCl did not proceed at all with a catalytic system only based on iron. A protocol permitting the arylation of 3,5-dimethylphenol with chlorobenzene in excellent yield. The system diketone-1//[Cu(acac)2] efficiently promotes cross-coupling reactions between phenols and chlorobenzene or aryl chlorides, which are deactivated by electron-donating substituents. The results indicate that an efficient global method for arylation of phenols from aromatic chlorides can be discovered.
- Xia, Ning,Taillefer, Marc
-
supporting information; experimental part
p. 6037 - 6039
(2009/05/27)
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- Copper-catalyzed Ullmann coupling under ligand- and additive- free conditions. Part 1: O-Arylation of phenols with aryl halides
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O-Arylation of a wide variety of substituted phenols and aliphatic alcohols with aryl halides catalyzed by copper iodide under mild ligand and additive free conditions (nBu4NBr, DMF, K3PO4, reflux, 22 h) is accomplished in good to excellent product yields (up to 95%).
- Chang, Joyce Wei Wei,Chee, Sheena,Mak, Shiya,Buranaprasertsuk, Pongchart,Chavasiri, Warinthorn,Chan, Philip Wai Hong
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p. 2018 - 2022
(2008/09/19)
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- Fluorination of fluorene, dibenzofuran and their open analogues with caesium fluoroxysulfate and related fluorinating reagents
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Fluorination of fluorene (1) with caesium fluoroxysulfate (CFS), 2,6-dichloro-l-fluoropyridinium tetrafluoroborate (FP-B800) and 1-fluoro-4-hydroxy-1,4-diazoniabicyclo[2.2.2]-octane bis(tetrafluoroborate) (Accufluor NFTh) occurred only on the aromatic ring in the position ortho and para to the biphenyl central bond with the ratio 2-fluoro- (2a) vs 4-fluorofluorene (2b) 1.7-2.4:1. Regioselectivity of fluorination of both open-chain analogues - diphenylmethane (3a) and biphenyl (3b) was different and more ortho-fluorinated product was formed. Furthermore, the reaction of diphenylmethane (3a) with CFS occurred also on central carbon forming benzophenone (6) and fluorodiphenylmethane (7), while fluorination with FP-B800 and Accufluor NFTh occurred only at the aromatic ring. Similar effect of the structure of fluorinating reagent on the regioselectivity was also observed with dibenzofuran (8) and its open-chain analogues diphenyl ether (10) and biphenyl (3b), where the regioselectivity of fluorination with CFS (1- (9a):2- (9b):3- (9c) = 27:46:27) was similar to fluorination with Selectfluor. Product distribution of fluorination of fluorene (1) and dibenzofuran (8) with CFS is similar to nitration and is in accordance with the calculated HOMO electron density, which indicates the presence of the electron transfer pathway.
- Iskra, Jernej,Stavber, Stojan,Zupan, Marko
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experimental part
p. 1671 - 1680
(2009/05/27)
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- Ullmann diaryl ether synthesis in ionic liquids
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Copper-catalyzed Ullmann diaryl ether synthesis has been successfully demonstrated in ionic liquids as reaction media. The copper catalysts immobilized in ionic liquid media can be reused. Product isolation can be achieved via simple extraction using organic solvents.
- Luo, Yunting,Wu, Jeff Xin,Ren, Rex X.
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p. 1734 - 1736
(2007/10/03)
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- Aryl substituted pyrazoles, and pyrroles, and the use thereof
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This invention relates to compounds having the Formula I: or a pharmaceutically acceptable salt, prodrug or solvate thereof, wherein Het and R5-R13are set in the specification. The invention also is directed to the use of compounds of Formula I for the treatment of neuronal damage following global and focal ischemia, for the treatment or prevention of neurodegenerative conditions such as amyotrophic lateral sclerosis (ALS), and for the treatment, prevention or amelioration of both acute or chronic pain, as antitinnitus agents, as anticonvulsants, and as antimanic depressants, as local anesthetics, as antiarrhythmics and for the treatment or prevention of diabetic neuropathy.
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- Preparation process of fluorine substituted aromatic compound
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A preparation process of a fluorine substituted aromatic compound comprising reacting an alkali metal or alkali earth metal salt of an aromatic compound having a hydroxy group with an organic fluorinating agent is disclosed. As a representative fluorinating agent, a bis-dialkylamino-difluoromethane compound, for example, 2,2′-difluoro-1,3-dimethylimidazolidine, is exemplified. According to the process, an industrially useful fluorinated aromatic compound, for example, a fluorobenzene, a fluorine substituted benzophenone, a fluorine substituted diarylsulfone can be prepared with ease in economy without specific equipment.
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- Mechanisms of the photochemical rearrangement of diphenyl ethers
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The mechanism of the photochemical rearrangement of diphenyl ether (1a) was studied. Irradiation of 1a in ethanol gave 2-phenylphenol (2, 42%) and 4-phenylphenol (3, 11%) as rearrangement products, in addition to phenol (4, 30%) and benzene (5, 25%) as diffusion products. Cross-coupling experiments employing [2H10]1a demonstrated that the formation of 2- and 4-phenylphenol was an intramolecular process. Irradiation of 1a in benzene or in toluene gave biphenyls in good yields. The combined yields of rearrangement products (2 and 3) increased with increase of solvent viscosity, with a concomitant decrease in the formation of 4. All the results can be rationalized in terms of excitation of 1a to the singlet state and dissociation to a radical pair intermediate involving phenoxy and phenyl radicals. Intramolecular recombination of these radicals gives rearrangement products, and escape followed by hydrogen abstraction from the solvent gives diffusion products. When position 4 of 1a was occupied by an electron-donating substituent (1b-e), aryloxy-phenyl bond cleavage to give the corresponding rearrangement products prevailed over phenoxy-aryl bond cleavage. The opposite was the case for substrates with an electron-withdrawing substituent at position 4 (1h,i).
- Haga, Naoki,Takayanagi, Hiroaki
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p. 735 - 745
(2007/10/03)
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- The regioselectivity in the fluorination of dibenzofuran, diphenylether and biphenyl with N-F type of reagents
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Dibenzofuran, diphenylether and biphenyl were used as target molecules in an investigation of the effect of N-F type of reagent structure and reaction conditions on the fluorination process. The yields of fluorinated products formed and the regioselectivity depend on the reagent used, and in the reactions with dibenzofuran three products were formed. The ratios of 2-fluorodibenzofuran (4) and 3-fluorodibenzofuran (5) formed were: 1.3 for 1-fluoro-4-hydroxy-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (NFTh, 1b), 1.4 for 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (F-TEDA, 1a), and 1.8 for N-fluoro-2,6-dichloropyridinium tetrafluoroborate (FPD-B, 1c). Ortho regioselectivity predominated for all reagents in the fluorination of biphenyl (ortho: para ratio varied from 4.8 to 1.2), while para attack prevailed for diphenylether (ortho: para = 0.9-0.7); however substitution of a phenyl ring by a methyl group enhanced the amount of 2-fluoroanisole. Second order rate constants for the fluorination of aromatic molecules with F-TEDA in acetonitrile at 65°C were established: anisole 4.8 x 10-3 Lmol-1s-1, dibenzofuran 2.5 x 10-4 Lmol-1s-1 an biphenyl 1.0 x 10-4 Lmol-1s-1.
- Zupan, Marko,Iskra, Jernej,Stavber, Stojan
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p. 11341 - 11348
(2007/10/03)
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- Remarks on the internal motion in diphenyl ether. Fluorophenyl ethers
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The 13C nuclear agnetic resonance chemical shifts and the 13C,19F spin-spin coupling constants are reported for 4,4'-difluorophenyl ether and 4-fluorophenyl phenyl ether in CS2 and in acetone-d6 solutions.An estimate of 6J90, the extremum in the ?-? coupling constant between the 19F nucleus on one ring and the ipso 13C nucleus on the other, is obtained from measurements on 2,6-dibromo-4-fluorophenyl phenyl ether.The ensuing estimates of 2θ>, the expectation values of sin2Θ as obtained from 6J(13C,19F), are compared with those obtained from STO-3G MO computations for diphenyl ether and its 4-fluoro derivatives.These computations give conformational energies at 30 deg intervals of the angles of twist about the two C-O bonds.In rough agreement with C-INDO computations, interconvesion of the helical forms is calculated to occur most easily by the so-called one-ring flip mechanism; the barrier to interconversion is less than 1 kJ/mol in the ether and its 4-fluoro derivatives, It appears that the conformational behaviour of these derivatives is unaltered by passage from CS2 to acetone solutions at 300 K.Furthermore, 2θ> values from 6J(13C,19F) in solution are very similar to those obtained from the computations on free molecules.If this agreement is not accidental, then it may arise from a high degree of flexibility of the molecules in which, by a disrotatory or one-ring flip mechanism requiring a very low energy of activation, one helical or C2 conformation can be converted to another.The other conformations have considerably hogher energies and the solvents do not appear to lower these energies enough to favor their populations significantly at 300 K.
- Schaefer, Ted,Penner, Glenn H.,Takeuchi, Craig,Tseki, Potlaki
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p. 1647 - 1650
(2007/10/02)
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