78648-59-6Relevant articles and documents
Donor-Acceptor-Donor Thienopyrazine-Based Dyes as NIR-Emitting AIEgens
Calamante, Massimo,Coppola, Carmen,Dessì, Alessio,Franchi, Daniele,Goti, Giulio,Mordini, Alessandro,Reginato, Gianna,Sinicropi, Adalgisa,Zani, Lorenzo
, p. 2655 - 2664 (2021/06/26)
Organic Near-Infrared luminophores have found broad application as functional materials, but the development of efficient NIR emitters is still a challenging goal. Here we report on a new class of thieno[3,4-b]pyrazine-based NIR emitting materials with Aggregation Induced Emission (AIE) properties. The dyes feature a donor–acceptor–donor (D?A?D) structure, with a thienopyrazine acceptor core connected to two triarylamine donor groups bearing a tetraphenylethylene (TPE) moiety. Fast and efficient synthesis allowed the modular preparation of three dyes of tunable absorption and emission profiles. These constructs were extensively characterized by spectroscopic studies in different solvents, which revealed intense light-harvesting ability and emissions in the deep-red and NIR region with large Stokes shift values. Remarkably, the dyes exhibited AIE properties, retaining emissive ability in the aggregate state, thus emerging as attractive materials for their potential application in the development of luminescent devices.
Palladium-catalyzed direct C-H arylation of thieno[3,4-b]pyrazines: Synthesis of advanced oligomeric and polymeric materials
Abdo, Nabiha I.,El-Shehawy, Ashraf A.,El-Barbary, Ahmed A.,Lee, Jae-Suk
, p. 5540 - 5551 (2012/10/30)
The first examples are reported of an efficient regioselective direct C-H arylation of thieno[3,4-b]pyrazine (TP) and its 2,3-dimethyl derivative with bromoalkylthiophenes (BATs), under Heck experimental conditions using Pd(OAc)2/Bu4NBr as the catalytic system, giving rise to a variety of valuable aryl-substituted thienopyrazines. The obtained results suggested that the 2-position of the TP moiety is less reactive towards C-H arylation than the 5-and 7-positions. Moreover, the 3-position of the TP moiety showed almost no significant reactivity when all other positions were arylated. The C-H arylation of 2,3-dimethyl-TP with an excess amount of BATs proceeded smoothly, affording the corresponding diarylated thienopyrazine derivatives in excellent yields, without any additional products. Compared to usual cross-coupling reactions, the present synthetic methodology has been used to prepare interesting donor-acceptor π-conjugated polymeric materials in a facial manner in a simple way. Microwave-assisted polymerization proved to be efficient for obtaining reasonable molecular weight copolymers ranging from 18.8 to 24.3 kg mol-1. Incorporating the thienopyrazine unit into polyhexylthiophene chains affected the photophysical and electrochemical properties. The optical band gaps were estimated to be in the range of 1.63-1.06 eV. All copolymers exhibited a diffraction peak at around 2θ = 5.72° corresponding to a d spacing of 15.43 A, which was assigned to an interchain spacing between polymer main chains similar to that found in P3HT. Moreover, a peak around 2θ = 23.09 (3.84 A) was also observed and is believed to be related to π-π stacking of the polymer backbones.
Thieno[3,4-b]pyrazines: Synthesis, structure, and reactivity
Kenning, Don D.,Mitchell, Kari A.,Calhoun, Tessa R.,Funfar, Melanie R.,Sattler, Daniel J.,Rasmussen, Seth C.
, p. 9073 - 9076 (2007/10/03)
A general synthetic route has been developed for the efficient preparation of 2,3-disubstituted thieno[3,4-b]-pyrazines. These methods eliminate problems in the preparation of the precursor 3,4-diaminothiophene and utilize α-diones prepared through the reaction of the appropriate organocuprates with oxalyl chloride. This combination allows the convenient preparation of thieno[3,4-b]pyrazine and its 2,3-disubstituted analogues (where substituent = methyl, hexyl, octyl, decyl, dodecyl, and phenyl) in high yield. Characterization of the structure and reactivity of this class of compounds is also described, including the results of structural, electrochemical, and pKa studies.
Synthese de nouveaux systemes heterocycliques thiopheniques azotes a partir du diamino-3,4 thiophene
Outurquin, Francis,Paulmier, Claude
, p. 159 - 163 (2007/10/02)
The synthesis of thiophenic bicyclic and tricyclic heterocycles are described. 3,4-Diaminothiophene reacted with carbondisulfide in alkaline medium to yield the tautomeric form of 2-mercaptothienoimidazole.Thienopyrazines and thieno1,
