- Copper-Catalyzed One-Pot Synthesis of Dibenzofurans, Xanthenes, and Xanthones from Cyclic Diphenyl Iodoniums
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Oxygenation of cyclic diphenyl iodoniums (CDPIs) with varied medium-ring sizes has been fully investigated. This practical copper-catalyzed tandem reaction of CDPIs with water as the oxygen source enables the construction of derivatised dibenzofurans and xanthenes at moderate to good yields. Moreover, structurally important xanthones are also successfully accessed under the oxygenation conditions with additional TEMPO.
- Zhu, Daqian,Li, Min,Wu, Zhouming,Du, Yongliang,Luo, Bingling,Huang, Peng,Wen, Shijun
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supporting information
p. 4566 - 4571
(2019/07/09)
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- Synthesis process of dibenzofuran derivatives
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The invention relates to a synthesis process of dibenzofuran derivatives, and relates to the fields of natural products with biological activity, medicaments and material chemistry. The used raw material is a cyclic diphenyliodonium trifluoromethanesulfonate derivative, a reaction is carried out in a water phase at 100 DEG C under the catalysis of a 1,10-phenanthroline ligand and cuprous iodide, and a series of dibenzofuran derivatives are obtained. With the adoption of the method provided by the invention, the dibenzofuran derivatives can be obtained by carrying out the reaction at the temperature of 100 DEG C for 24 hours, and the yield is 60-96%. In the reaction, water is taken as a reagent as well as a solvent for participating in the reaction, and the simple, convenient, green, economic, and novel method is provided for synthesizing the derivatives.
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Paragraph 0020; 0021
(2018/09/26)
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- Microwave-Promoted Pd-Catalyzed Synthesis of Dibenzofurans from Ortho-Arylphenols
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ortho-Aryl phenols, synthesized via protecting group free Suzuki–Miyaura coupling of ortho-halophenols and arene boronic acids, undergo a cyclization to dibenzofurans via oxidative C–H activation. The reaction proceeds under microwave irradiation in short reaction times using catalytic amounts of Pd(OAc)2 without additional ligands.
- Schmidt, Bernd,Riemer, Martin
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p. 1287 - 1297
(2017/03/27)
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- A One-Pot Synthesis of Dibenzofurans from 6-Diazo-2-cyclohexenones
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A novel and efficient protocol for the rapid construction of dibenzofuran motifs from 6-diazo-2-cyclohexenone and ortho-haloiodobenzene has been developed. The process involves one-pot Pd-catalyzed cross-coupling/aromatization and Cu-catalyzed Ullmann coupling.
- Zhao, Hua,Yang, Ke,Zheng, Hongyan,Ding, Ruichao,Yin, Fangjie,Wang, Ning,Li, Yun,Cheng, Bin,Wang, Huifei,Zhai, Hongbin
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p. 5744 - 5747
(2015/12/11)
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- Chemoselective arylation of phenols with bromo-nitroarenes: Synthesis of nitro-biaryl-ols and their conversion into benzofurans and carbazoles
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A series of electron withdrawing or donating group substituted phenols were chemoselectively arylated with various substituted bromo-nitroarenes using KOtBu at room temperature via an SNAr pathway. The synthesis of natural alkaloids (carbazoles), dibenzofurans, and a biaryl-indole was achieved from the synthesized nitro-biaryl-ols. This journal is the Partner Organisations 2014.
- Kumar, Sangit,Kumar, Amit,Yadav, Abhimanyu,Verma, Ajay,Jana, Sadhan,Sattar, Moh.,Kumar, Shailesh,Prasad, Ch. Durga
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supporting information
p. 9481 - 9484
(2014/08/18)
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- Efficient synthesis of dibenzoxaborininols from diaryl ethers and their application to dibenzofuran synthesis
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A convenient and efficient method for the borylation of diaryl ethers leading to dibenzoxaborininols and the synthesis of dibenzofuran derivatives has been developed. The borylation involves the sequential three-step process: lithiation, borylation and hydrolysis. The synthesized dibenzoxaborininols could be readily transformed into dibenzofuran derivatives in good to excellent yields under palladium catalysis in the presence of iodine, and this is the first example for the formation of an aryl C-C bond from diarylborinic acids. Copyright
- Niu, Liting,Yang, Haijun,Jiang, Yuyang,Fu, Hua
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p. 3625 - 3632
(2014/01/06)
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- Rhodium-catalyzed decarbonylative C-H arylation of 2-aryloxybenzoic acids leading to dibenzofuran derivatives
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Rhodium-catalyzed intramolecular C-H arylation of 2-aryloxybenzoic acids proceeded accompanied by decarbonylation to give dibenzofuran derivatives in high yields. The present reaction is widely applicable to substrates bearing various functionalities.
- Maetani, Shinji,Fukuyama, Takahide,Ryu, Ilhyong
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supporting information
p. 2754 - 2757
(2013/07/19)
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- Oxidative cyclization of 2-arylphenols to dibenzofurans under Pd(II)/peroxybenzoate catalysis
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2-Arylphenols undergo intramolecular C-H bond activation/C-O bond formation to afford dibenzofuran derivatives under palladium catalysis in the presence of tert-butyl peroxybenzoate as an oxidant. Kinetic isotope effect experiments indicated that C-H bond cleavage is the rate-limiting step of the reaction.
- Wei, Ye,Yoshikai, Naohiko
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supporting information; experimental part
p. 5504 - 5507
(2011/12/05)
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- Diels-Alder reactions of nitrobenzofurans: A simple dibenzofuran Synthesis. Theoretical studies using DFT methods
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2- and 3-nitrobenzofurans are studied in polar thermal Diels-Alder reactions with normal electron demand using several structurally different dienes. A very strong electron-acceptor group, such as the nitro group, pushes the dienophilic character of these heterocyclic compounds. Since this substituent is easily extruded under thermal conditions, this reaction sequence becomes a simple method for the preparation of families of organic compounds with heteroatom rings. Part of this work is specifically concerned with theoretical studies using DFT methods. The global and local electrophilicity and nucleophilicity indices were calculated for the dienophiles and dienes used in this study. When 2-nitrobenzofuran and 3-nitrobenzofuran were reacted with isoprene, 1-trimethylsilyloxy-1,3-butadiene and Danishesfky's diene, under different thermal reaction conditions they showed their dienophilic character taking part in normal-demand polar DA cycloaddition reactions.
- Della Rosa, Claudia D.,Sanchez, Juan P.,Kneeteman, María N.,Mancini, Pedro M.E.
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scheme or table
p. 2316 - 2319
(2011/05/09)
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- Formation of dibenzofurans by flash vacuum pyrolysis of aryl 2-(allyloxy)benzoates and related reactions
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Flash vacuum pyrolysis (FVP) of aryl 2-(allyloxy)benzoates 5 and of the corresponding aryl 2-(allylthio)benzoates 6 at 650°C, gives dibenzofurans 19 and dibenzothiophenes 20, respectively. The mechanism involves generation of phenoxyl (or thiophenoxyl) radicals by homolysis of the O-allyl (or S-allyl) bond, followed by ipso attack at the ester group, loss of CO2 and cyclisation of the resulting aryl radical. Synthetically, the procedure works well for p-substituted substrates, which lead to 2-substituted dibenzofurans 19b-f (73-90%) and dibenzothiophenes 20b-c (90-94%). Little selectivity is shown in the cyclisation of m-substituted substrates and competing interactions of the radical with the substituent - and ipso-attack - complicate the pyrolyses of o-substituted substrates. FVP of related radical precursors including 2-(allyloxy)phenyl benzoates 43 gave no dibenzofurans, whereas 2-(allyloxy-5-methyl)azobenzene 44 gave a much reduced yield. No carbazoles were obtained by FVP of 4-methylphenyl 2-(allylamino)benzoate 42.
- Black, Michael,Cadogan,McNab, Hamish
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experimental part
p. 2961 - 2967
(2010/09/06)
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- Gas phase generation and cyclisation reactions of some o-substituted phenyl radicals
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Flash vacuum pyrolysis of the allyl esters 2 (X=O, S, CH2, CO) at 900°C (10-2 Torr) gives dibenzofurans, dibenzothiophenes, fluorenes, and fluorenones respectively as the major products. The mechanism involves the phenyl radical intermediates 1 which equilibrate by intramolecular hydrogen transfer via six-membered transition states, prior to cyclisation.
- Cadogan,Hutchison,McNab
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p. 7747 - 7762
(2007/10/02)
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- A Short Synthesis of Dibenzofurans and Dibenzothiophenes
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An afficient synthesis of dibenzofurans and dibenzothiophenes from aryl salicylates is described, which involves a novel rearrangement-extrusion-cyclisation sequence of o-substituted phenoxyl and thiophenoxyl radicals.
- Black, Michael,Cadogan, J. I. G.,McNab, Hamish
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p. 395 - 396
(2007/10/02)
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- EFFECT OF RING SIZE ON PHOTOREACTIVITY OF MEDIUM AND LARGE RING ESTERS.
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Photochemical studies on 7,8,12,14,16 and 20 membered cyclic esters have been carried out in benzene and methanol.Decarboxylation and solvolysis ascribable to β- and α-scission respectively are observed in case of seven and eight membered cyclic esters.Larger rings do not undergo these photoreactions thus demonsrating effect of ring size on photoreactivity.
- Kulkarni, V. S.,Kulkarni, N. N.,Lele, S. R.,Hosangadi, B. D.
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p. 6169 - 6174
(2007/10/02)
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