- De novo synthesis of benzofurans via trifluoroacetic acid catalyzed cyclization/oxidative aromatization cascade reaction of 2-hydroxy-1,4-diones
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A facile, one-pot method for the de novo synthesis of benzofurans from 2-hydroxy-1,4-diones is described. Using trifluoroacetic acid (TFA) as the catalyst and N-bromobutanimide (NBS) as the oxidant, 2-hydroxy-1,4-diones underwent a cyclization/oxidative a
- Sha, Qiang,Liu, Haixuan
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p. 7547 - 7551
(2019/08/20)
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- Lewis Acid-Catalyzed Synthesis of Benzofurans and 4,5,6,7-Tetrahydrobenzofurans from Acrolein Dimer and 1,3-Dicarbonyl Compounds
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2,3-Disubstituted benzofurans were synthesized from acrolein dimer and 1,3-dicarbonyl compounds by using N-bromosuccinimide as an oxidizing agent. The method was used to synthesize two commercial drug molecules, benzbromarone and amiodarone. The proposed mechanism of the reaction involves a N-bromosuccinimide (NBS)-assisted autotandem catalysis with Lewis acid catalyst. To proof the proposed mechanism, an intermediate was isolated successfully, which can be converted to 4,5,6,7-tetrahydrobenzofurans.
- Huang, Wenbo,Xu, Jing,Liu, Changhui,Chen, Zhiyan,Gu, Yanlong
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p. 2941 - 2950
(2019/02/26)
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- Synthesis of oxacalothrixin B and its analogues involving iodine/TBHP-mediated electrocyclization
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The total synthesis of oxacalothrixins, an isostere of biologically important carbazoloquinone alkaloid, calothrixin B was achieved from 2-acetyl-3-methylbenzofuran. An iodine/TBHP-mediated oxidative cyclization of benzofuranyl-enamine has been employed as a key step to synthesize, the crucial intermediate 1-hydroxy dibenzofurancarbaldehyde. The latter upon reductive cyclization followed by PIDA-mediated oxidation furnished oxacalothrixin B and its analogues.
- Ramalingam, Bose Muthu,Mohanakrishnan, Arasambattu K.
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p. 2919 - 2922
(2017/07/11)
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- Palladium-Catalyzed Oxidative Cycloisomerization of 2-Cinnamyl-1,3-Dicarbonyls: Synthesis of Functionalized 2-Benzyl Furans
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A new palladium-catalyzed intramolecular oxidative cycloisomerization of readily available starting materials, 2-cinnamyl-1,3-dicarbonyls, has been demonstrated for the creation of structurally diverse 2-benzyl furans. The cycloisomerization occurs by a regioselective 5-exo-trig pathway. The reaction shows a broad substrate scope with good to excellent yields. Furthermore, a one-pot procedure has been executed by using readily available cinnamyl alcohols and 1,3-diketones. Cinnamyl verit: Palladium-catalyzed intramolecular oxidative cycloisomerization of readily available 2-cinnamyl-1,3-dicarbonyls affords structurally diverse 2-benzyl furans. The cycloisomerization occurs by a regioselective 5-exo-trig pathway, with a broad substrate scope in good to excellent yields. Furthermore, a one-pot procedure is executed by using readily available cinnamyl alcohols and 1,3-diketones
- Nallagonda, Rajender,Reddy, Reddy Rajasekhar,Ghorai, Prasanta
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supporting information
p. 14732 - 14736
(2015/10/19)
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- Cu-catalyzed reaction of 1,2-dihalobenzenes with 1,3-cyclohexanediones for the synthesis of 3,4-dihydrodibenzo[b,d]furan-1(2H)-ones
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The Cu(I)-catalyzed reaction of 1-bromo-2- iodobenzenes and other 1,2-dihalobenzenes with 1,3-cyclohexanediones in DMF at 130 °C using Cs 2CO3 as a base and pivalic acid as an additive selectively delivers 3,4- dihydrodibenzo[b,d]fur
- Aljaar, Nayyef,Malakar, Chandi C.,Conrad, Juergen,Strobel, Sabine,Schleid, Thomas,Beifuss, Uwe
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p. 7793 - 7803
(2013/01/15)
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- Reporting the release of caged species by a combination of two sequential photoreactions, a molecular switch, and one color of light
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In the right light: UV light triggers bond breaking, liberates a caged carboxylic acid, and generates the central C=C double bond in the photoresponsive hexatriene molecule of a dithienylethene molecular switch. Light of the same wavelength converts the colorless isomer into its colored counterpart (see picture) in a visually convenient method to report on the success of the release event. Copyright
- Wu, Tuoqi,Tang, Hao,Bohne, Cornelia,Branda, Neil R.
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p. 2741 - 2744
(2012/05/04)
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- Gold(III)-catalyzed tandem reaction of O-arylhydroxylamines with 1,3-dicarbonyl compounds: Highly selective synthesis of 3-carbonylated benzofuran derivatives
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Figure presented. A highly regioselective protocol for the synthesis of 3-carbonylated benzofuran derivatives has been developed involving the gold(III)-catalyzed tandem condensation/rearrangement/cyclization reaction of O-arylhydroxylamines with 1,3-dicarbonyl compounds.
- Liu, Yunkui,Qian, Jianqiang,Lou, Shaojie,Xu, Zhenyuan
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supporting information; experimental part
p. 6300 - 6303
(2010/11/18)
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- Cycloaddition of arynes with lodonium ylides: A mild and general route for the synthesis of benzofuran derivatives
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A mild and general cycloaddition of arynes with iodonium ylides protocol has been developed for the synthesis of benzofurans. In the presence of CsF, ortho-silyl aryltriflates were reacted with iodonium ylides smoothly at room temperature in moderate to good yields.
- Huang, Xiao-Cheng,Liu, Yi-Lin,Liang, Yun,Pi, Shao-Feng,Wang, Feng,Li, Jin-Heng
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supporting information; experimental part
p. 1525 - 1528
(2009/04/07)
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- Naturally Occurring Dibenzofurans. Part 4. Synthesis of Dibenzofurandiols by Annelation of Benzofurans
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Methyl 3-acetylbenzofuran-2-ylacetate (8) undergoes C-methylation affording methyl 2-(3-acetylbenzofuran-2-yl)propionate (13).These compounds and similar oxo esters undergo ready cyclization to dibenzofurandiols on treatment with sodium methoxide in boiling methanol.A convenient synthesis of dimethyl furan-2,5-diylacetate (30) is described, as are attempts to synthesize 1,3,7,9-tetramethoxy-2,8-dimethyldibenzofuran (3).
- Carvalho, Christopher F.,Sargent, Melvyn V.
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p. 1605 - 1612
(2007/10/02)
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