نتایج جستجو برای: thiophenes
تعداد نتایج: 426 فیلتر نتایج به سال:
Annulation of thiophenes directly into the bay regions of rylene dyes through effective Stille coupling and subsequent ring-fusion under Scholl conditions leads to core-extended rylene tetracarboxylic diimides with interesting electro-optical properties.
Three-component Process for the Synthesis of Some Thiophene Derivatives Using Water as a Green Media
A convenient and efficient three-component reaction to a one-pot synthesis of thiophene derivatives from activated acetylenic compounds and ethyl 2chloroacetoacetate in the presence of tetramethyl thiourea in water lead to the formation of thiophenes in good yields.
Lutein is a health promoting xanthophyll that may be extracted from marigold flowers. But the plant is known also for biosynthesis of phototoxic polythiophenes. Extracts of flowers of some Tagetes species grown in Belgorod (RF) T. erecta L. (cv. Gavaii) , T. patula L. (cv. Petit orange), T. tenuifolia Cav. (unknown cv.), and T. lucida Cav. were investigated by thin layer chromatography (TLC) an...
Herein, we describe a novel approach for the practical synthesis of tetrasubstituted thiophenes 8. The developed method was particularly used for the facile preparation of thienyl heterocycles 8. The mechanism for this reaction is based on the formation of a sulfur ylide-like intermediate. It was clearly suggested by (i) the intramolecular cyclization of ketene N,S-acetals 7 to the correspondin...
Possible applications of thiophenes in radiopharmaceutical chemistry have been explored. Thiophene for benzene ring substitution was applied to the synthesis of thienyl-[18F]GBR 13119, an analog of the potent and selective dopamine uptake inhibitor [18F]GBR 13119. In vivo regional brain distribution in mice shows essentially identical results for the thienyl and phenyl compounds (striatum/cereb...
The palladium catalysed 5-arylation of 2-(trimethylsilyl)thiophene with aryl bromides via C-H bond functionalisation allows the synthesis of arylated silylthiophenes in only one step.
With a view to combining the desirable electronic and photochemical properties of hexabenzocoronene (HBC) and the C-C bond forming capabilities of thiophenes, 1-(3-thienyl)-2,3,4,5,6-penta(4-tert-butyl-phenyl)benzene (1) was oxidised using FeCl(3). The resulting products, superaromatic thiophene (2) and its 5,5'-dimer (3), are S-HBC systems and provide a new pair of spectral comparators.
The synthesis of unsymmetrical 2,5-disubstituted thiophenes by selective and sequential palladium-catalyzed cross-coupling reactions of indium organometallics with 2,5-dibromothiophene is reported. Following an iterative coupling sequence, α-oligothiophenes were synthesized in good yields and with high atom economy.
The occurrence of thiophenic compounds in diverse plant organs and in in vitro root-, callus- and cell suspension cultures of Tagetes patula cv. Carmen was investigated using capillary GLC and GLC-MS. The separation of thiophenes by capillary GLC and the group specific MS fragmentation with the typical sulfur isotope peaks allowed the unequivocal assignment of individual thiophenes in complex m...
In this study we designed a new class of symmetrical facial oligothiophene amphiphiles, which could be obtained in fewer steps than for previously reported analogues, but still possess the specific substituent sequence to control their backbone curvature. This novel design allows the late-stage introduction of hydrophilic groups, aiding both purification and ease of structure variation. Followi...
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