492-97-7Relevant articles and documents
Desorption/ionization on self-assembled monolayer surfaces (DIAMS)
Sanguinet,Aleveque,Blanchard,Dias,Levillain,Rondeau
, p. 830 - 833 (2006)
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Receptor- And ligand-based study on novel 2,2′-bithienyl derivatives as non-peptidic AANAT inhibitors
Lepailleur, Alban,Lemaitre, Stephane,Feng, Xiao,Santos, Jana Sopkova-De Oliveira,Delagrange, Philippe,Boutin, Jean,Renard, Pierre,Bureau, Ronard,Rault, Sylvain
, p. 446 - 460 (2010)
Arylalkylamine N-acetyl transferase (serotonin N-acetyl transferase, AANAT) is a critical enzyme in the light-mediated regulation of melatonin production and circadian rythm. With the objective of discovering new chemical entities with inhibitory potencies against AANAT, a medium-throughput screening campaign was performed on a chemolibrary. We found a class of molecules based on a 2,2′-bithienyl scaffold, and compound 1 emerged as a first hit. Herein, we describe our progress from hit discovery and to optimization of this new class of compounds. To complete the study, computational approaches were carried out: a docking study which provided insights into the plausible binding modes of these new AANAT inhibitors and a three-dimensional quantitative structure-activity relationship study that applied comparative molecular field analysis (CoMFA) methodology. Several CoMFA models were developed (variable alignments and options), and the best predictive one yields good statistical results (q2 = 0.744, r2 = 0.891, and s = 0.273). The resulting CoMFA contour maps were used to illustrate the pharmacomodulations relevant to the biological activities in this series of analogs and to design new active inhibitors. This novel series of 2,2′-bithienyl derivatives gives new insights into the design of AANAT inhibitors.
Laser flash photolysis study on the photoinduccd reactions of 3,3′-bridged bithiophenes
Fujitsuka, Mamoru,Sato, Tadatake,Sezaki, Fumiyasu,Tanaka, Kazuyoshi,Watanabe, Akira,Ito, Osamu
, p. 3331 - 3337 (1998)
Photophysical properties and photoinduced reactions of 3,3′-bridged-2,2′-bithiophenes {dithieno[3,2-b:2′,3′-d]-thiophene, 4H-cyclopenta[2,1-b:3,4-b′]dithiophene, and 4H-dithieno[3,2-b;2′,3′-d]pyrrole (DTP)} and 2,2′-bithiophene (BT) were investigated by observing the transient absorption spectra in the visible and near-IR regions using nanosecond laser flash photolysis. Fluorescence quantum yields for the bridged bithiophenes were low compared with that for BT. An especially low quantum yield for DTP in acetonitrile was attributed to an addition reaction with the solvent. The triplet energy of BT was the lowest amongst the examined bithiophenes, indicating some conformational change in the triplet state. Triplet-energy-transfer reactions at diffusion limited rates were confirmed between bithiophenes and triplet-energy donors or acceptors. Photochemical generation of the radical cations of the bithiophenes was confirmed by the transient absorption spectra, which show good correspondence with those observed in γ-ray radiolysis. It was found that the triplet quenching rates of the electron-transfer reactions were small when the Gibbs energy change for the reaction was ≥ -25 kJ mol-1. The observed tendency agreed with the semi-empirical equation of Rehm-Weller. The generated radical cations decay according to a second-order function, indicating deactivation by a back electron-transfer reaction.
Preparation and Reactions of Dichlorodithienogermoles
Ohshita, Joji,Nakamura, Masashi,Ooyama, Yousuke
, p. 5609 - 5614 (2015)
The reaction of 3,3′-dilithiobithiophenes with tetrachlorogermane afforded 4,4-dichlorodithienogermoles, which readily underwent substitution on the central germanium atom. Reactions of a dichlorodithienogermole with LiAlH4, MeLi, Me2NC6H4Li, and C6F5MgBr gave the corresponding Ge-substituted products. Dihydrodithienogermole obtained from the reaction with LiAlH4 was further treated with LDA to give a dimer whose structure was verified by a single-crystal X-ray diffraction (XRD) study. Hydrolysis of dichlorodithienogermoles provided cyclotetragermoxanes. Their optical properties were examined with respect to the UV absorption and fluorescence spectra. It was found that one of the cyclotetragermoxanes responded to a nitorobenzene vapor in the solid state, decreasing the PL intensity.
A novel approach to a one-pot synthesis of unsubstituted oligo(α-thiophenes)
Buzhansky, Ludmila,Feit, Ben-Ami
, p. 7523 - 7525 (2002)
Oligo(α-thiophenes) α-4T and α-8T were prepared by the following one-pot sequential conversions: thiophene (T) → α-2T → α-4T → α-8T. PdCl2-induced coupling of a mono-α-mercuration derivative of each of the n-mers T, α-2T, and α-4T was applied in these conversions.
Copper(I)-catalysed homocoupling of organosilicon compounds: Synthesis of biaryls, dienes and diynes
Kang, Suk-Ku,Kim, Tae-Hyun,Pyun, Sung-Jae
, p. 797 - 798 (1997)
Copper(I) iodide catalyses the homocoupling of aryl-, alkenyl- and alkynyl-substituted chloro- or fluorodimethylsilanes under mild conditions to afford biaryls, dienes and diynes, respectively.
Pd-catalyzed oxidative homocoupling of arylboronic acids in WEPA: A sustainable access to symmetrical biaryls under added base and ligand-free ambient conditions
Appa, Rama Moorthy,Lakshmidevi, Jangam,Naidu, Bandameeda Ramesh,Venkateswarlu, Katta
, (2021/01/11)
Symmetrical and unsymmetrical biaryls comprises a diverse class of biologically eloquent organic compounds. We herein report, a quick and eco-friendly protocol for the synthesis of biaryls by an oxidative (aerobic) homocoupling of arylboronic acids (ABAs) using Pd(OAc)2 in water extract of pomogranate ash (WEPA) as an efficient agro-waste(bio)-derived aqueous (basic) media. The reactions were executed at ambient aerobic conditions in the absence of external base and ligand to result symmetrical biaryls in excellent yields. The use of renewable media with an effective exploitation of waste, short reaction times, excellent yields of products, easy separation of the products, unnecessating the external base, oxidant, ligand or volatile organic solvents and ambient reaction conditions are the vital insights of the present protocol.
Zirconium-redox-shuttled cross-electrophile coupling of aromatic and heteroaromatic halides
Fu, Yue,Liu, Fang-Jie,Liu, Peng,Tang, Jian-Tao,Toste, F. Dean,Wu, Ting-Feng,Ye, Baihua,Zhang, Yue-Jiao
supporting information, p. 1963 - 1974 (2021/07/07)
Transition metal-catalyzed cross-electrophile coupling (XEC) is a powerful tool for forging C(sp2)–C(sp2) bonds in biaryl molecules from abundant aromatic halides. While the synthesis of unsymmetrical biaryl compounds through multimetallic XEC is of high synthetic value, the selective XEC of two heteroaromatic halides remains elusive and challenging. Herein, we report a homogeneous XEC method, which relies on a zirconaaziridine complex as a shuttle for dual palladium-catalyzed processes. The zirconaaziridine-mediated palladium (ZAPd)-catalyzed reaction shows excellent compatibility with various functional groups and diverse heteroaromatic scaffolds. In accord with density functional theory (DFT) calculations, a redox transmetallation between the oxidative addition product and the zirconaaziridine is proposed as the crucial elementary step. Thus, cross-coupling selectivity using a single transition metal catalyst is controlled by the relative rate of oxidative addition of Pd(0) into the aromatic halide. Overall, the concept of a combined reducing and transmetallating agent offers opportunities for the development of transition metal reductive coupling catalysis.
Electrochromic properties of pyrene conductive polymers modified by chemical polymerization
Chang, Lijing,Hou, Yanjun,Li, Rui,Ma, Yang,Miao, Shoulei,Wang, Cheng,Xu, Haoran,Zhang, Yuhang
, p. 39291 - 39305 (2021/12/27)
Pyrene is composed of four benzene rings and has a unique planar melting ring structure. Pyrene is the smallest condensed polycyclic aromatic hydrocarbon, and its unique structural properties have been extensively studied. Pyrene has excellent properties such as thermal stability, high fluorescence quantum efficiency and high carrier mobility. This paper mainly used thiophene, EDOT and triphenylamine groups to enhance the pyrene based π-conjugated system and control the molecular accumulation of organic semiconductors, and improve their charge transport performances. Five kinds of polymer were synthesized and correspondingly characterized. The five kinds of pyrene conductive polymer had outstanding properties in terms of solubility, fluorescence intensity and thermal stability, good film-forming properties, stable electrochromic properties and high coloring efficiency. The coloration efficiency (CE) of PPYTP was as high as 277 cm2C?1, and the switching response time was short. The coloring time of PPYEDOT was 1.3 s and the bleaching time was 3.2 s. The lower impedance will also provide the possibility of such polymers being incorporated into electrochromic devices in the future. In short, the synthesized new pyrene conductive polymers will have wide application prospects in the field of electrochromic materials.
