- A Pd-catalyzed optional approach for the synthesis of dibenzothiophenes
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A direct and practical approach for the construction of DBTs was developed via a Pd-catalyzed tandem reaction, in which commercially available o-bromo-iodobenzenes combined with benzene thiols or iodobenzenes combined with o-bromo-benzene thiols were applied. These two approaches will provide an alternative for the synthesis of DBT derivatives.
- Song, Juan,Wu, Hao,Sun, Wei,Wang, Songjiang,Sun, Haisen,Xiao, Kang,Qian, Yan,Liu, Chao
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- Thiolate-Initiated Synthesis of Dibenzothiophenes from 2,2′-Bis(methylthio)-1,1′-Biaryl Derivatives through Cleavage of Two Carbon-Sulfur Bonds
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A catalytic reaction involving the cleavage of two carbon-sulfur bonds in 2,2′-bis(methylthio)-1,1′-biaryl derivatives is reported. This reaction does not require a transition-metal catalyst and is promoted by a thiolate anion. Notably, based on DFT calculations, the product-forming cyclization step is shown to proceed through a concerted nucleophilic aromatic substitution (CS N Ar) mechanism.
- Chatani, Naoto,Kawashima, Yuki,Kodama, Takuya,Masuya, Yoshihiro,Tobisu, Mamoru
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- Hydrodesulfurization of Alkyldibenzothiophenes over a NiMo/Al2O3 Catalyst: Kinetics and Mechanism
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The transformation mechanism of dibenzothiophene, 4-methyldibenzothiophene, 4,6-dimethyldibenzothiophene, and 2,8-dimethyldibenzothiophene has been studied in a batch reactor over an industrial NiMo/Al2O3 hydrotreating catalyst at 573 K under 5 MPa of hydrogen pressure. A detailed mechanistic study including competitive catalytic experiments proved that the adsorption of the most refractory molecules at the catalyst surface was not the rate-determining step for their transformation. Our results imply that the hydrodesulfurization of these compounds occurs on one single type of sites by a flat adsorption, leading to a preliminary partial hydrogenation of one aromatic ring. Variations in reactivities of the dibenzothiophene derivatives were thus explained by different reaction rates for the C-S bond scission due to steric hindrance generated by the methyl substitution near the sulfur atom.
- Meille, Valerie,Schulz, Emmanuelle,Lemaire, Marc,Vrinat, Michel
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- Facile Synthesis of Thienoacenes via Transition-Metal-Free Ladderization
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Herein, we report a facile transition-metal-free approach to sulfur-containing heteroacenes from fluorinated oligophenylenes. Unlike most existing methods, the presented approach is not restricted to simple dibenzothiophene derivatives and thus appears to
- Akhmetov, Vladimir,Amsharov, Konstantin Yu,Feofanov, Mikhail,Takayama, Ryo
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p. 14759 - 14766
(2021/11/12)
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- Palladium catalysis based one-pot synthesis method for DBTs (dibenzothiophenes)
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The invention discloses a palladium catalysis based one-pot synthesis method for DBTs (dibenzothiophenes). An inorganic base is added to an N,N-dimethylacetamide solution, with a palladium catalyst/ligand as a catalysis system, o-bromoiodobenzene derivatives or iodobenzene derivatives and thiophenol derivatives taken as raw materials are subjected to a reaction in nitrogen atmosphere, and DBTs areobtained through separation. The simple, economical and easily available raw materials are taken as substrates, all-position-substituted DBTs are synthesized on the basis of palladium catalyzed cascade reaction, and DBTs have great application prospect in medical synthesis intermediates and organic optoelectronic material science.
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Paragraph 0025-0030
(2020/05/12)
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- Rhodium-Catalyzed Sequential Dehydrogenation/Deoxygenation in One-Pot: Efficient Synthesis of Dibenzothiophene Derivatives from Diaryl Sulfoxides
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A novel strategy for the synthesis of dibenzothiophene derivatives is established through a one-pot intramolecular cross-dehydrogenative-coupling reaction of diaryl sulfoxides followed by deoxygenation with a Rh/Ag catalytic system. The yields obtained were good to excellent (up to 96 %), therefore making the described protocol an attractive option for building dibenzothiophene compounds. A novel strategy for the synthesis of dibenzothiophene derivatives was established through a one-pot intramolecular cross-dehydrogenative-coupling reaction of diaryl sulfoxides followed by deoxygenation with a Rh/Ag catalytic system.
- Huang, Qiufeng,Fu, Shurong,Ke, Shaojia,Xiao, Hanbing,Zhang, Xiaofeng,Lin, Shen
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supporting information
p. 6602 - 6605
(2015/10/29)
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- Synthesis of dibenzothiophenes by pd-catalyzed dual C-H activation from diaryl sulfides
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Palladium-catalyzed dual C-H functionalization of diaryl sulfides to form dibenzothiophenes (DBTs) by oxidative dehydrogenative cyclization is reported. This protocol afforded various DBTs in moderate to good yields with tolerance of a wide variety of substrates. Benzo[1,2-b:4,5-b]bis[b]benzothiophene was successfully synthesized by this method, which was used as an organic semiconductor for field-effect transistors.
- Che, Rui,Wu, Zhiqing,Li, Zhengkai,Xiang, Haifeng,Zhou, Xiangge
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supporting information
p. 7258 - 7261
(2014/06/23)
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- Active-alkali metal promoted reductive desulfurization of dibenzothiophene and its hindered analogues
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Dibenzothiophene and some related organosulfur compounds are efficiently reductively desulfurized under mild reaction conditions, with Na and/or Li metal in the presence of a catalytic amount of tetraphenylethylene in THF at room temperature. This simple methodology was applied to the synthesis of several substituted biphenyls, thus realizing a connection between the directing properties of the sulfur atom of dibenzothiophene and the efficiency of 1,2-dianions of tetraphenylethane as homogenous electron transfer reagents.
- Pittalis, Mario,Azzena, Ugo,Pisano, Luisa
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p. 207 - 211
(2013/01/15)
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- Redox and EPR spectral behaviour of radical cations of dibenzothiophene and some of its derivatives
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The radical cations of dibenzothiophene 1 and its 2,8-[2H2]-isotopomer (2), a series of methylated dibenzothiophenes, viz. 2,8- (3), 3,7- (4) and 4,6-dimethyldibenzothiophene (5), and 2,4,6,8-tetramethyldibenzothiophene (6), as well as 2,2′- (7) and 4,4′-bidibenzothiophene (8) have been generated in 1,1,1,3,3,3-hexafluoropropan-2-ol, mostly by TlIII trifluoroacetate or 4-tolyl-TlIII trifluoroacetate oxidation. From the hyperfine coupling constants obtained, it is concluded that the 2- and 4-positions of 1.+ are the carbon atoms possessing the highest spin density. This assignment agrees with results of high-level quantum-chemical calculations, placing the 2B1 state as the lowest energy level of 1.+. Acta Chemica Scandinavica 1997.
- Eberson, Lennart,Hartshorn, Michael P.,Persson, Ola,Radner, Finn
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p. 492 - 500
(2007/10/03)
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- Hydrodesulfurization of Organosulfur Heterocycles by Metal Hydride-Nickel(0) Complexes: Accelerated Single-Electron Transfer in Carbon-Sulfur Bond Cleavage
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The novel nickel complex, LiAlH2(THF)n.C10H8N2.Ni (2), which result from the interaction in a THF solution of (2,2'-bipyridyl)(1,5-cyclooctadiene)nickel (1) with LiAlH4 in a 1:1 molar ration is powerful desulfurizing agent in homogeneous solution for such aromatic sulfur heterocycles as dibenzothiophene (3), phenoxathiin (11), phenothiazine (12), and thianthrene(13).When employed in a 2:1 molar ratio with the heterocyclic substrate, 2 produces the corresponding ring-opened desulfurization products (biphenyl, diphenyl ether, diphenylamine, and benzene, respectively) in high yields.In contrast, 1 effects predominantly ring contraction during desulfurization and yields dibenzofuran, carbazole, and dibenzothiophene from 11, 12, and 13, respectively.From consideration of relative desulfurization rates for substituted dibenzothiophenes, deuterium labeling experiments, and the chemical reactivity differences for 1 and 2, it is concluded that these reagents desulfurize via single-electron-transfer mechanism and that radical anoins are crucial reactive intermediates.The greater reactivity of 2 is ascribed to its anionic nickel character.
- Eisch, John J.,Hallenbeck, Lawrence E.,Han, Kyoung Im
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p. 7763 - 7767
(2007/10/02)
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- The Synthesis of All of the Dimethyldibenzothiophenes and Monoethyldibenzothiophenes
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The synthesis of all four isomers of the monoethyldibenzothiophenes and all of the sixteen isomers of the dimethyldibenzothiophenes has been accomplished.
- Tedjamulia, Marvin L.,Tominaga, Yoshinori,Castle, Raymond N.
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p. 1485 - 1495
(2007/10/02)
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