- METHOD OF PRODUCING HALOGEN COMPOUND
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PROBLEM TO BE SOLVED: To provide a method of efficiently producing an aromatic compound including a halogen group of interest. SOLUTION: A method of producing a halogen compound represented by the specified general formula (1) comprises reacting a compound represented by the specified general formula (2) with a compound represented by the specified general formula (3) in the presence of a transition metal compound, a phosphine compound being 1,1'-bis(diphenylphosphino)ferrocene or 4,5'-bis(diphenylphosphino)-9,9'-dimethylxanthene, and a base. (In the formula, Ar1 and Ar2 represent organic groups; X represents a halogen group; Z represents a halogen group different than X; m represents an integer greater than or equal to 0; p represents an integer greater than or equal to 1; and each R represents a hydrogen atom, alkyl group or phenyl group, where the two R's may be linked together to form a ring.) SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
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Paragraph 0052-0060; 0088-0090
(2021/05/07)
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- Impregnated palladium on magnetite as catalyst for direct arylation of heterocycles
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Palladium impregnated on magnetite is an efficient, cheap and easy to prepare catalyst for the direct arylation of heterocycles. Good yields are afforded under relatively mild conditions and a broad substrate scope is evident. The catalyst is regioselective in many cases, affording arylated products, at the C2- or C3-position (depending of the heterocycle used). The methodology can be extended to prepare chromenes through an intramolecular direct arylation reaction. Some evidence is provided for two catalyst deactivation pathways, which prevents efficient recycling.
- Cano, Rafael,Pérez, Juana M.,Ramón, Diego J.,McGlacken, Gerard P.
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p. 1043 - 1050
(2016/07/06)
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- Modular synthesis of phenanthro[9,10-c]thiophenes by a sequence of C-H activation, suzuki cross-coupling and photocyclization reactions
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A total number of 15 different 3,4-diarylthiophenes were synthesized, which bear a chlorine atom in ortho-position of one of the aryl substituents. One aryl group was introduced by an oxidative cross-coupling reaction, involving a C-H activation at C4(3) of the thiophene core. The other aryl group was in most cases introduced by a Suzuki cross-coupling reaction, which succeeded the oxidative cross-coupling step. Photocyclization reactions of the 3,4-diarylthiophenes were performed in a solvent mixture of benzene and acetonitrile (50:50 v/v) at λ=254 nm and proceeded to the title compounds in yields of 60-82%. The selectivity of the photocyclization was determined at the ortho-chloro-substituted aryl ring by the position of the chlorine substituent. At the other ring, a single regioisomer was observed for phenyl and para-substituted phenyl groups. For 2-naphthyl and ortho-substituted phenyl rings a clear preference was observed in favor of a major regioisomer, while meta-substitution in the phenyl ring led to a about 1:1 mixture of 5- and 7-substituted phenanthro[9,10-c]thiophenes. Mechanistically, the photocyclization is likely to occur as a photochemically allowed, conrotatory [(4n+2)π] process accompanied by elimination of HCl. It was shown for two phenanthro[9,10-c]thiophene products that they can be readily brominated in positions C1 and C3 (74-77%), which in turn allows for further functionalization at these positions, for example, in the course of halogen-metal exchange and polymerization reactions. Three C-C bond formation reactions are successively coupled in a convergent synthesis of phenanthro[9,10-c]thiophenes A. The key reaction is an unprecedented photocyclization of precursors B, which proceeds cleanly at λ=254 nm (60-82% yield). Diarylthiophenes B are conveniently assembled employing a sequence of oxidative and regular Suzuki cross-coupling reactions.
- Schnapperelle, Ingo,Bach, Thorsten
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supporting information
p. 9725 - 9732
(2014/08/18)
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- Pd/C as a catalyst for completely regioselective c=h functionalization of thiophenes under mild conditions
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The completely C3-selective arylation of thiophenes and benzo[b]thiophenes was achieved by using Pd/C as a heterogeneous catalyst without ligands or additives under mild reaction conditions. The practicability of this transformation is demonstrated by notable functional group tolerance and the insensitivity of the reaction to H2O and air. This method is also applicable to nitrogen- and oxygen-containing heterocycles, yielding the corresponding C2-arylated products. Three-phase tests along with Hg-poisoning and hot-filtration tests suggest that the catalytically active species is heterogeneous in nature. I+ can do better! Pd/C can be used without ligands or additives to catalyze the completely C3-selective arylation of diversely substituted thiophenes and benzo[b]thiophenes under mild reaction conditions. The physical nature of the catalytic species was investigated and the mechanism was studied. Relative rate data generated in a "robustness screen" were used to design a complex substrate that undergoes highly chemoselective sequential functionalization. Copyright
- Tang, Dan-Tam D.,Collins, Karl D.,Ernst, Johannes B.,Glorius, Frank
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supporting information
p. 1809 - 1813
(2014/03/21)
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- Identification and structure-activity relationships of a novel series of estrogen receptor ligands based on 7-thiabicyclo[2.2.1]hept-2-ene-7-oxide
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To develop estrogen receptor (ER) ligands having novel structures and activities, we have explored compounds in which the central hydrophobic core has a more three-dimensional topology than typically found in estrogen ligands and thus exploits the unfilled space in the ligand-binding pocket. Here, we build upon our previous investigations of 7-oxabicyclo[2.2.1]heptene core ligands, by replacing the oxygen bridge with a sulfoxide. These new 7-thiabicyclo[2.2.1] hept-2-ene-7-oxides were conveniently prepared by a Diels-Alder reaction of 3,4-diarylthiophenes with dienophiles in the presence of an oxidant and give cycloadducts with endo stereochemistry. Several new compounds demonstrated high binding affinities with excellent ERα selectivity, but unlike oxabicyclic compounds, which are transcriptional antagonists, most thiabicyclic compounds are potent, ERα-selective agonists. Modeling suggests that the gain in activity of the thiabicyclic compounds arises from their endo stereochemistry that stabilizes an active ER conformation. Further, the disposition of methyl substituents in the phenyl groups attached to the bicyclic core unit contributes to their binding affinity and subtype selectivity.
- Wang, Pengcheng,Min, Jian,Nwachukwu, Jerome C.,Cavett, Valerie,Carlson, Kathryn E.,Guo, Pu,Zhu, Manghong,Zheng, Yangfan,Dong, Chune,Katzenellenbogen, John A.,Nettles, Kendall W.,Zhou, Hai-Bing
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experimental part
p. 2324 - 2341
(2012/05/20)
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- Photochemical generation of thiophene analogs of 9-fluorenyl cations
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The 9-fluorenyl cation is a member of the 4N Hueckel antiaromatic series of intermediates, first observed by time-resolved spectroscopy on UV photo-excitation of 9-fluorenol. Thiophene analogs of 9-fluorenol in which one of the annelated benzene rings is
- Bancerz, Mathew,Huck, Lawrence A.,Leigh, William J.,Mladenova, Gabriela,Najafian, Katayoun,Zeng, Xiaofeng,Lee-Ruff, Edward
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experimental part
p. 1202 - 1213
(2011/09/12)
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- Rigid-core fluorescent oligothiophene-S,S-dioxide isothiocyanates. Synthesis, optical characterization, and conjugation to monoclonal antibodies
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In this paper we report the synthesis of a new class of fluorescent thiophene-based isothiocyanates containing a 3,5-disubstituted dithieno [3,2-b:2′,3′-d] thiophene-4,4-dioxide moiety as the rigid core, using the palladium-catalyzed cross-coupling reaction of aryl stannanes with aryl bromides (Stille coupling). By changing the molecular structure through the progressive addition of thienylene or phenylene units, light emission from blue to orange was obtained. Photoluminescence quantum yields ranged from 0.65 to 0.90 for blue and green light emitters to 0.10-0.35 for yellow and orange ones. Optically and chemically stable fluorescent bioconjugates were prepared by spontaneous reaction of the isothiocyanates with monoclonal antibodies anti-CD3 and anti-CD8 in slightly basic solutions.
- Sotgiu, Giovanna,Zambianchi, Massimo,Barbarella, Giovanna,Aruffo, Fabio,Cipriani, Franco,Ventola, Alfredo
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p. 1512 - 1520
(2007/10/03)
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- Preparation and coupling reaction of thienylmanganese bromides
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3-Thienylmanganese bromide, 3-bromo-4-thienylmanganese bromide and 4-substituted 3-thienylmanganese bromides were prepared from the reactions of Rieke manganese with 3-bromothiophene, 3,4-dibromothiophene and 4-substituted 3-bromothiophenes, respectively. The resulting thienylmanganese bromides underwent cross-coupling reactions under mild reaction conditions.
- Kim, Seung-Hoi,Rieke, Reuben D.
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p. 993 - 996
(2007/10/03)
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- Direct Preparation of 3-Thienyl Organometallic Reagents: 3-Thienylzinc and 3-Thienylmagnesium Iodides and 3-Thienylmanganese Bromides and Their Coupling Reactions
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3-Thienylzinc and 3-thienylmagnesium iodides can be generated from the direct oxidative addition of Rieke zinc and magnesium to 3-iodothiophene, respectively. The direct preparation of 3-thienylmanganese bromides from the reaction of Rieke manganese with 3-bromothiophene and 3,4-dibromothiophene is also performed. These 3-thienyl organometallic reagents have been found to be regiostable intermediates and undergo coupling reactions with a variety of versatile electrophiles such as acid chlorides, aryl iodides, aldehydes, and disulfide.
- Rieke, Reuben D.,Kim, Seung-Hoi,Wu, Xiaoming
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p. 6921 - 6927
(2007/10/03)
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