16939-13-2Relevant academic research and scientific papers
Diselenide-assisted sulfuration of dienes
Rys, Andrzej Z.,Hou, Yihua,Abu-Yousef, Imad A.,Harpp, David N.
, p. 9181 - 9184 (2004)
Various diselenides assist in the sulfuration of dienes giving cyclic di- and tetrasulfides as main products. The reaction requires a 2-fold excess of diselenides to be efficient. Catalytic amounts of diselenides result in lower yields. This is likely due to secondary reactions (polymerization, aromatization) occurring during extended reaction times under catalytic conditions. It was verified that the sulfur-transferring properties of diselenatetrasulfides are virtually identical to those of diselenides combined with sulfur. Contrary to previous claims, not only the cyclic diselenatetrasulfide but also linear diselenatetrasulfides (RSeSnSeR) transfer sulfur to dienes. A mechanism is proposed and its implications to the nature of diatomic sulfur are discussed.
TBAI-assisted direct C-H activation of indoles with β-E -styrene sulfonyl hydrazides: A stereoselective access to 3-styryl thioindoles
Hafeez, Saira,Saeed, Aamer
, p. 15608 - 15616 (2021)
The current work describes the challenging introduction of a vinyl sulfide group by simple C-H activation on a variety of substrates. The direct C-H activation of indoles with β-(E)-styrene sulfonyl hydrazides under the sulfenylation conditions, assisted by the iodic catalyst tert-butyl ammonium iodide (TBAI), afforded a series of (E)-styrylthioindoles. Accordingly, β-(E)-styrene sulfonyl hydrazides undergo radical cross-coupling reactions with a variety of substituted indoles to afford structurally diverse indole vinyl thioethers in moderate to high yields with E-stereoselectivity. This method is metal-catalyst-free and is valuable not only because of its novelty, but also for providing a convenient synthetic pathway to a variety of (E)-styrylthioindoles with retention of the configuration. The current study paves the way for the use of β-(E)-styrene sulfonyl hydrazides as a unique styryl mercaptan source in chemical synthesis.
Accessing π-expanded heterocyclics beyond dibenzothiophene: Syntheses and properties of phenanthrothiophenes
Venkateswarlu, Samala,Prakoso, Suhendro Purbo,Kumar, Sushil,Tao, Yu-Tai
, p. 437 - 445 (2020/02/13)
A series of phenanthrothiophenes are designed and synthesized from polyarylthiophenes through regioselective Scholl reactions in one step using iron chloride as catalyst. The molecular structures of these heteroarenes displayed multiple twisted fjords, which perturb the shapes of the polycyclic frameworks to pack in slipped to near-perfect face-to-face styles in parallel or antiparallel packings. Field-effect transistor devices using single crystals of 6,12-difluorodiphenanthro[9, 10-b:9′, 10′]thiophene gave a hole mobility of 0.22 cm2 V?1 s?1.
Synthesis of Phenanthro[9,10-c]thiophenes by 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-Promoted Cyclo-Oxidation
Gao, Han,Connors, David M.,Goroff, Nancy S.
, p. 630 - 633 (2019/05/21)
A new method to prepare phenanthro[9,10-c]thiophenes has been developed. In the presence of triflic acid, 3,4-diaryl thiophenes undergo 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-promoted cyclo-oxidation. NMR and computational studies indicate that p
H-type acceptor material and preparation method thereof
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Paragraph 0074-0076, (2019/01/14)
The invention discloses an H-type acceptor material and a preparation thereof, and belongs to the field of organic photoelectric material preparation. The acceptor material cannot rotate as both two arms of the acceptor material are connected with a core
Impregnated palladium on magnetite as catalyst for direct arylation of heterocycles
Cano, Rafael,Pérez, Juana M.,Ramón, Diego J.,McGlacken, Gerard P.
, p. 1043 - 1050 (2016/07/06)
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.
Palladacycle-catalyzed Suzuki-Miyaura reaction of aryl/heteroaryl halides with MIDA boronates in EtOH/H2O or H2O
Li, Yabo,Wang, Jingran,Wang, Zhiwei,Huang, Mengmeng,Yan, Beiqi,Cui, Xiuling,Wu, Yusheng,Wu, Yangjie
, p. 36262 - 36266 (2014/11/08)
With good to excellent yields, a series of mono- or diheteroaryl compounds were synthesized via the palladacycle-catalyzed Suzuki-Miyaura reaction of various N-methyliminodiacetic acid (MIDA) boronates with aryl/heteroaryl halides in EtOH/H2O or H2O. This journal is the Partner Organisations 2014.
Pd/C as a catalyst for completely regioselective c=h functionalization of thiophenes under mild conditions
Tang, Dan-Tam D.,Collins, Karl D.,Ernst, Johannes B.,Glorius, Frank
, p. 1809 - 1813 (2014/03/21)
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
Direct C-H arylation of thiophenes at low catalyst loading of a phosphine-free bis(alkoxo)palladium complex
Li, Yabo,Wang, Jingran,Huang, Mengmeng,Wang, Zhiwei,Wu, Yusheng,Wu, Yangjie
, p. 2890 - 2897 (2014/05/06)
An efficient phosphine-free direct C-H arylation of thiophenes at the α-position has been developed at low catalyst loading of bis(alkoxo)palladium complex (Cat.I, 0.1-0.2 mol %). The developed synthetic method can be applied to the synthesis of α-aryl/heteroaryl thiophenes from aryl or heteroaryl bromides in good to excellent yields and is compatible with the substrates bearing electron-donating or electron-withdrawing groups. The reactivities of the 2- and 5-positions of thiophenes are equivalent and not dependent on steric hindrance under optimal conditions. This condition can also be applied to other heterocyclic moieties such as benzothiophene, benzofuran, and pyrrole with high conversion yields.
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
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
experimental part, p. 2324 - 2341 (2012/05/20)
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.
