- Solution processable alternating oligothiophene-PEO-block-copolymers: Synthesis and evidence for solvent dependent aggregation
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A new route to oligothiophene-PEO-block-copolymers has been developed, in which well-defined α-oligothiophene blocks (from bithiophene to sexithiophene) alternate with poly(ethylene oxide) blocks. These materials show high solubility in common organic solvents. UV/visible and fluorescence studies in solution indicate that the oligothiophene segments are molecularly dissolved in good solvents like chloroform. Aggregation of the oligothiophenes occurs in dioxane-water mixtures, which is manifest by shifts of the UV/ visible absorption maxima towards the blue and quenching of the fluorescence. An oligothiophene length of three thiophenes (terthiophene) is necessary to observe this aggregation phenomenon.
- Kilbinger,Feast
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- Receptor- And ligand-based study on novel 2,2′-bithienyl derivatives as non-peptidic AANAT inhibitors
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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.
- Lepailleur, Alban,Lemaitre, Stephane,Feng, Xiao,Santos, Jana Sopkova-De Oliveira,Delagrange, Philippe,Boutin, Jean,Renard, Pierre,Bureau, Ronard,Rault, Sylvain
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- Reactions of lithiated aromatic heterocycles with carbon monoxide
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The reaction of lithium derivatives of aromatic heterocycles with carbon monoxide was studied under several reaction conditions: 2-furyllithium afforded only one product, the tetrahydro-2-furaldehyde (25% yield). On the other hand, 2-thienyllithium and 5-methyl-2-furyllithium gave two and five products, respectively. Although in relatively low yields, formation of highly functionalized compounds takes place in a fast process under mild conditions. For 1,4-dihydroxy-1,4-bis(5-methyl-2-furanyl)butane-2,3-dione, reaction conditions were achieved to obtain this difficult to prepare derivative in 50% yield. To the best of our knowledge, this is the first report on the reaction of lithiated aromatic heterocycles with CO: evidence is given on the involvement of proton transfers in the reactions of 2-furyllithium and 2-thienyllithium, while the reaction of 5-methyl-2-furyllithium seems to proceed through an electron transfer as the first step. Copyright
- Garcia Linares, Guadalupe E.,Nudelman, Norma S.
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- Laser flash photolysis study on the photoinduccd reactions of 3,3′-bridged bithiophenes
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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.
- Fujitsuka, Mamoru,Sato, Tadatake,Sezaki, Fumiyasu,Tanaka, Kazuyoshi,Watanabe, Akira,Ito, Osamu
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- Influence of donor–acceptor conjugation between thiophene-phthalazinone structures containing Sp3 C?N bond on the frontier orbital levels and optic–electronic properties
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Herein, an electron-deficient phthalazinone unit containing a unique Sp3 hybrid nitrogen atom as an acceptor to cut off the ether bond was presented and three Donor–Acceptor (D–A) conjugated fluoropolymers via Classical Aromatic Nucleophilic Displacement Polymerization (CANDP) method were successfully synthesized. These polymers exhibit excellent thermostability. The 5% weight loss temperature of PDT2TF under nitrogen atmosphere is high, up to 470 °C. This is due to that the D–A conjugation between thiophene-phthalazinone units affects its resonance energy and stabilizes the thiophene-phthalazinone structures. These three fluoropolymers show strong absorptions and fluorescence in visible light region both in solution and thin film states. The band gaps (Eg) of these polymers are narrower than that of their corresponding di-NH capped monomers, owing to the good electronic communication properties of the Sp3 nitrogen atom in the phthalazinone unit. The Eg value of PDT3TF is decreased to 2.03 eV. These results indicate that phthalazinone unit is an efficient acceptor and could exhibit strong D–A effect with thiophene unit. Also, the Sp3 nitrogen atom in the phthalazinone shows good electronic wave function and charge transport properties. This facile CANDP synthetic method combined with Sp3 C?N bond linked electron-deficient phthalazinone unit affords polymers with controllable photoelectric properties.
- Han, Jianhua,Cheng, ShengLi,Liu, Cheng,Wang, Jinyan,Jian, Xigao
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- Preparation and Reactions of Dichlorodithienogermoles
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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.
- Ohshita, Joji,Nakamura, Masashi,Ooyama, Yousuke
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- Far- and mid-infrared of crystalline 2,2′-bithiophene: Ab initio analysis and comparison with infrared response
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Infrared intramolecular vibrations and lattice modes in the crystalline phase of 2,2′-bithiophene (2T) are investigated using the direct method combined with density functional theory (DFT)-based total energy calculations. For the first time, the far- and mid-infrared responses have been calculated from the Γ-point modes and the Born effective charge tensors of the 2T crystalline phase. The relative good agreement between the calculated and experimental infrared spectra allows us to assign the origin of the main features of the experimental spectra, which is of particular interest in the far-infrared domain. These assignments are useful for understanding all the properties of the 2T crystalline phase in which phonon-phonon and electron-phonon interactions play an important role.
- Hermet,Bantignies,Rahmani,Sauvajol,Johnson,Serein
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- A novel approach to a one-pot synthesis of unsubstituted oligo(α-thiophenes)
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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.
- Buzhansky, Ludmila,Feit, Ben-Ami
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- Bithienylsilanes: Unexpected structure and reactivity
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5-(2,2′-Bithienyl)hydrosilanes were prepared by reaction of bithienyl lithium with chlorodimethylsilane, dichloromethylsilane and trichlorosilane. It was shown that 5-(2,2′-bithienyl)dimethylsilane possesses higher reactivity in the hydrosilylation reaction of monosubstituted acetylene derivatives compared with (2-thienyl)dimethylsilane. The elongation of the π-conjugated chain leads to increasing selectivity of the hydrosilylation reaction. An unusual structure for bis[5-(2,2′-bithienyl)]methylsilane has been established by X-ray analysis.
- Lukevics, Edmunds,Ryabova, Victoria,Arsenyan, Pavel,Belyakov, Sergey,Popelis, Juris,Pudova, Olga
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- Copper(I)-catalysed homocoupling of organosilicon compounds: Synthesis of biaryls, dienes and diynes
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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.
- Kang, Suk-Ku,Kim, Tae-Hyun,Pyun, Sung-Jae
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- Facile preparation of SERS-active nanogap-rich Au nanoleaves
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To simply reduce HAuCl4 using 2-thiophenemethanol in an aqueous solution at room temperature, a novel metallic Au nanostructure with a high SERS activity was obtained. Flat sheet-like Au nanoleaves possessing many nanogap hotspots bound with a large percentage of high-index facets were obtained.
- Hong, Jin-Hyung,Hwang, Yong-Kyung,Hong, Jin-Yeon,Kim, Hee-Jin,Kim, Sung-Jin,Won, Yong Sun,Huh, Seong
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- SYNTHESIS OF 5-(3-PYRIDYL)-2,2'-BITHIOPHENE(SENSITIZER)
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Disclosed herein is a novel simple, short process for synthesis of the photosensitizer, 5-(3-pyridyl)-2,2'-bithiophene.
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(2021/02/05)
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- Zirconium-redox-shuttled cross-electrophile coupling of aromatic and heteroaromatic halides
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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.
- Fu, Yue,Liu, Fang-Jie,Liu, Peng,Tang, Jian-Tao,Toste, F. Dean,Wu, Ting-Feng,Ye, Baihua,Zhang, Yue-Jiao
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supporting information
p. 1963 - 1974
(2021/07/07)
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- Electrochromic properties of pyrene conductive polymers modified by chemical polymerization
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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.
- Chang, Lijing,Hou, Yanjun,Li, Rui,Ma, Yang,Miao, Shoulei,Wang, Cheng,Xu, Haoran,Zhang, Yuhang
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p. 39291 - 39305
(2021/12/27)
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- Pd-catalyzed oxidative homocoupling of arylboronic acids in WEPA: A sustainable access to symmetrical biaryls under added base and ligand-free ambient conditions
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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.
- Appa, Rama Moorthy,Lakshmidevi, Jangam,Naidu, Bandameeda Ramesh,Venkateswarlu, Katta
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- Recyclable Pd2dba3/XPhos/PEG-2000 System for Efficient Borylation of Aryl Chlorides: Practical Access to Aryl Boronates
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Pd2dba3/XPhos in poly(ethylene glycol) (PEG-2000) is shown to be a highly stable and efficient catalyst for the borylation of aryl chlorides with bis(pinacolato)diboron. The borylation reaction proceeds smoothly at 110 °C, delivering a wide variety of aryl boronates in good to excellent yields with high functional group tolerance. The crude products were easily isolated via simple extraction of the reaction mixture with cyclohexane. Moreover, both expensive Pd2dba3 and XPhos in PEG-2000 system could be readily recycled and reused more than six times without loss of catalytic efficiency.
- Cai, Mingzhong,Huang, Bin,Luo, Chengkai,Xu, Caifeng
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- Porphyrin n-pincer pd(Ii)-complexes in water: A base-free and nature-inspired protocol for the oxidative self-coupling of potassium aryltrifluoroborates in open-air
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Metalloporphyrins (and porphyrins) are well known as pigments of life in nature, since representatives of this group include chlorophylls (Mg-porphyrins) and heme (Fe-porphyrins). Hence, the construction of chemistry based on these substances can be based on the imitation of biological systems. Inspired by nature, in this article we present the preparation of five different porphyrin, meso-tetraphenylporphyrin (TPP), meso-tetra(p-anisyl)porphyrin (TpAP), tetra-sodium meso-tetra(p-sulfonatophenyl)porphyrin (TSTpSPP), meso-tetra(m-hydroxyphenyl)porphyrin (TmHPP), and meso-tetra(m-carboxyphenyl)porphyrin (TmCPP) as well as their N-pincer Pd(II)-complexes such as Pd(II)-meso-tetraphenylporphyrin (PdTPP), Pd(II)-meso-tetra(p-anisyl)porphyrin (PdTpAP), Pd(II)-tetrasodium meso-tetra(p-sulfonatophenyl)porphyrin (PdTSTpSPP), Pd(II)-meso-tetra(m-hydroxyphenyl)porphyrin (PdTmHPP), and Pd(II)-meso-tetra(m-carboxyphenyl)porphyrin (PdTmCPP). These porphyrin N-pincer Pd(II)-complexes were studied and found to be effective in the base-free self-coupling reactions of potassium aryltrifluoroborates (PATFBs) in water at ambient conditions. The catalysts and the products (symmetrical biaryls) were characterized using their spectral data. The high yields of the biaryls, the bio-mimicking conditions, good substrate feasibility, evading the use of base, easy preparation and handling of catalysts, and the application of aqueous media, all make this protocol very attractive from a sustainability and cost-effective standpoint.
- Hanafiah, Marlia M.,Lakkaboyana, Sivarama Krishna,Lakshmidevi, Jangam,Marella, Ravi Kumar,Naidu, Bandameeda Ramesh,Prasad, Sana Siva,Venkateswarlu, Katta
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- Exploring the coordination confinement effect of divalent palladium/zero palladium doped polyaniline-networking: As an excellent-performance nanocomposite catalyst for C-C coupling reactions
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A pre-formed catalyst Pd2+/PANI composite for C-C coupling reaction was synthesized by combining the self-stabilized dispersion polymerization method with the in-situ composite material. Experiments have confirmed that the relatively high reduced structure (75%) in the polyaniline carrier is more favorable for the coupling reaction. Raman spectroscopy, solid nuclear magnetic, and X-ray photoelectron spectroscopy were performed to characterize the structures. The pre-formed catalyst has uniform coordination of divalent palladium and nitrogen in different valence states of the carrier polyaniline, which shows a good synergistic effect in the catalytic Ullmann reaction, and greatly reduces the use of reducing agents such as hydrazine hydrate. Compared with other studies, we analyzed the catalytic reaction mechanism in detail through real-time online infrared and XPS characterization. The results show that the divalent palladium in the catalyst and the zero-valent palladium generated by the in-situ reaction synergistically promote the reaction, while the polyaniline support acts as a stabilizer and dispersant, which prevents the agglomeration of the metal particles and prolongs increased catalyst life. The prepared Pd2+/PANI composites will become the most attractive alternative to traditional organic materials due to their wide applicability, high catalytic activity, stable recycling and relatively low price. This work provides a new theoretical basis for the understanding of the essential driving force of PANI catalytic activity and the cognition of the micro mechanism of action.
- Liang, Yanping,Liu, Wanyi,Song, Manrong,Sun, Yanyan,Wang, Gang,Wu, Zhiqiang,Zhan, Haijuan
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p. 177 - 188
(2020/03/17)
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- Palladium/Sensory Component-Catalyzed Homocoupling Reactions of Aryl Halides
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A novel and efficient catalyst system was developed for homocoupling reactions of aryl halides. The catalyst system consists of Pd(OAc) 2and the peppery sensory component of tobacco leaves. This is the first time that a sensory component has been used in an organic reaction. Experiments using the catalyst system showed that the reactions proceeded smoothly under air in the absence of both an additional ligand and a reductant. Furthermore, the catalyst system can be applied to the coupling reactions of hetaryl iodides. Many functional groups (including a hydroxy group) are tolerated.
- Bai, Haixin,Bao, Fengyu,Chai, Guobi,Liu, Pengfei,Liu, Zhikai,Zhang, Haiyan,Zhang, Qidong
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supporting information
(2020/09/09)
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- Non-covalent bridging of bithiophenes through chalcogen bonding grips
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In this work, chalcogen functionalized dithiophenes, equipped on both extremities with chalcogen-bonding recognition heterocycles, have been prepared following two synthetic pathways. The insertion of the chalcogenazolo[5,4-β]pyridine allows the control of the organization at the solid state. X-Ray diffraction analysis of the single crystals, showed that the Te-doped derivatives give the most persistant assemblies, with the molecules arranging at solid-state in wire-like polymeric structures through Te?N interactions. As expected, the introduction of the Se and Te atoms, dramatically decreases the emission properties, with the Te-bearing congeners being virtually non emissive.
- Babudri, Francesco,Biot, Nicolas,Bonifazi, Davide,Romito, Deborah
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supporting information
p. 6732 - 6738
(2020/05/16)
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- A novel dual-function bithiophene-Meldrum's acid based chemosensor for highly sensitive, colorimetric and fluorimetric detection of cyanide and hypochlorite and its applications
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A dual-function bithiophene-Meldrum's acid based chemosensor 2TM was developed, which displayed ultrafast, colorimetric and fluorescence turn-on responses for CN? and ClO? with specific selectivity and high sensitivity. The sensor 2TM for CN? detection in DMSO/H2O (1/3, V/V) solution was based on the nucleophilic addition of CN? to sensor, which resulted in remarkable spectral and discernible color changes. Meanwhile, 2TM showed specific selectivity for ClO? in 100percent aqueous solution based on the sensing mechanism of oxidative cleavage of C[dbnd]C bond. The detection limits were obtained to be 0.96 μM for CN? and 48 nM for ClO?. The sensing mechanism of 2TM toward CN? and ClO? was investigated by job'plot, FTIR, 1H NMR, HRMS and optical spectra. The sensor 2TM loaded colorimetric test strips/supported silica measurements demonstrated to be a portable, eco-friendly and ultrafast device for real-time and on-site visual detection of CN? and ClO? in water by the naked eye. More importantly, sensor 2TM with excellent photophysical properties and low biotoxicity was successfully applied to detect CN? and ClO? in live cells and environmental water samples, as well as capable of monitoring CN? in the natural food samples, illustrating its practical utility in biological and environmental systems.
- Chen, Jianbin,Hu, Tingting,Li, Chunpeng,Li, Tianduo,Niu, Qingfen,Qin, Xuyang,Wei, Tao,Yang, Lan
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- Rapid and sensitive detection of hypochlorite in ~100% aqueous solution using a bithiophene-based fluorescent sensor: Application to water analysis and live-cell imaging
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A new bithiophene-based biocompatible fluorescent and colorimetric sensor 2TD capable of detecting hypochlorite (ClO?) in enviro/biosystem was successfully synthesized. This sensor 2TD underwent a highly specific and sensitive oxidation reaction with ClO? and produced a bithiophene aldehyde (2T-CHO) emitting strong blue fluorescence, which was strongly confirmed by 1H NMR, HRMS, FTIR and DFT calculation. The 2TD for detecting ClO? displays an ultra-fast response (25 s), great water-solubility (~100% aqueous solution), wide pH working range (7–11), excellent anti-interference capability, and ultra-sensitivity with low detection limit of 8.3 nM. Colorimetric test strips demonstrate that 2TD can be utilized as a cost-effective and efficient solid-state sensor for rapidly and conveniently sensing ClO? with great sensitivity in practical applications. With the robust applicability, the 2TD was successfully utilized to determine/image ClO? in environmental water and live-cells. More interestingly, this developed sensor 2TD could be used as an efficient test tool for ClO? sensing.
- Chen, Jianbin,Hu, Tingting,Li, Chunpeng,Li, Tianduo,Niu, Qingfen,Qin, Xuyang,Wei, Tao,Yin, Pengcheng
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- Copper quinolate: A simple and efficient catalytic complex for coupling reactions
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We describe an effective and novel method to prepare N-aryl imidazoles via the copper quinolate-catalyzed N-arylation of aryl halides and imidazoles. A wide range of products were obtained in moderate to excellent yields under the optimal reaction conditions. Applying standard conditions, the model reaction could be performed on a gram scale. This method also presents a new avenue to the “click” reaction of terminal alkynes, benzyl bromide, and sodium azide and to the construction of C–C bonds by homocoupling of phenylboronic acid or phenylacetylene derivatives with the aid of copper quinolate.
- Wu, Fengtian,Li, Huiqin,Xie, Jianwei
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- Efficient Pd-catalyzed oxidative homocoupling of arylboronic acids in aqueous NaClO
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An efficient, mild and practical method was developed for the synthesis of biaryls via the Pd-catalyzed oxidative homocoupling of aromatic/heteroaromatic boronic acids in aqueous NaClO.
- Li, Min-Xin,Tang, Yan-Ling,Gao, Hui,Mao, Ze-Wei
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supporting information
(2020/03/04)
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- Transition-Metal-Free Oxidative Cross-Coupling of Tetraarylborates to Biaryls Using Organic Oxidants
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Readily prepared tetraarylborates undergo selective (cross)-coupling through oxidation with Bobbitt's salt to give symmetric and unsymmetric biaryls. The organic oxoammonium salt can be used either as a stoichiometric oxidant or as a catalyst in combination with in situ generated NO2 and molecular oxygen as the terminal oxidant. For selected cases, oxidative coupling is also possible with NO2/O2 without any additional nitroxide-based cocatalyst. Transition-metal-free catalytic oxidative ligand cross-coupling of tetraarylborates is unprecedented and the introduced method provides access to various biaryl and heterobiaryl systems.
- Gerleve, Carolin,Studer, Armido
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supporting information
p. 15468 - 15473
(2020/05/06)
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- Polythiophene Doping of the Cu-Based Metal-Organic Framework (MOF) HKUST-1 Using Innate MOF-Initiated Oxidative Polymerization
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The copper-based metal-organic framework (MOF) HKUST-1 adsorbs organic molecules into its pores. When loaded with electron-rich oligothiophenes, the resulting system reacts under heat to initiate oxidative polymerization without the use of any other oxidant or catalyst. This reaction is not observed in the non-redox-active MOF MIL-100(Al). We have characterized the composites by optical and nanoscale microscopy, vibrational and UV-vis spectroscopy, X-ray photoelectron spectroscopy, N2 sorption analysis, and thermogravimetric analysis/residual gas analysis. Unsubstituted oligothiophenes polymerize within MOF pores, while 3,4-ethylenedioxythiophene forms a coating on the MOF surface. MOF composites with conjugated polymer dopants trapped inside their pores undergo profound shifts in the composite electronic structure. Reasoning from time-dependent density functional theory calculations of an HKUST-1 model system bound to monomers, we rationalize the observed reactivity and propose an initiation mechanism based on a ligand-to-metal charge-transfer state.
- Marshall, Nicholas,James, William,Fulmer, Jeremy,Crittenden, Scott,Thompson, Anthony B.,Ward, Patrick A.,Rowe, Gerard T.
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supporting information
p. 5561 - 5575
(2019/04/25)
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- Self-assembly of catalytically active supramolecular coordination compounds within metal?organic frameworks
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Supramolecular coordination compounds (SCCs) represent the power of coordination chemistry methodologies to self-assemble discrete architectures with targeted properties. SCCs are generally synthesized in solution, with isolated fully coordinated metal atoms as structural nodes, thus severely limited as metal-based catalysts. Metal?organic frameworks (MOFs) show unique features to act as chemical nanoreactors for the in situ synthesis and stabilization of otherwise not accessible functional species. Here, we present the self-assembly of PdII SCCs within the confined space of a pre-formed MOF (SCCs@MOF) and its post-assembly metalation to give a PdII?AuIII supramolecular assembly, crystallography underpinned. These SCCs@MOFs catalyze the coupling of boronic acids and/or alkynes, representative multi-site metal-catalyzed reactions in which traditional SCCs tend to decompose, and retain their structural integrity as a consequence of the synergetic hybridization between SCCs and MOFs. These results open new avenues in both the synthesis of novel SCCs and their use in heterogeneous metal-based supramolecular catalysis.
- Adam, Rosa,Mon, Marta,Greco, Rossella,Kalinke, Lucas H.G.,Vidal-Moya, Alejandro,Fernandez, Antonio,Winpenny, Richard E.P.,Domenech-Carbo, Antonio,Leyva-Perez, Antonio,Armentano, Donatella,Pardo, Emilio,Ferrando-Soria, Jesus
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supporting information
p. 10350 - 10360
(2019/08/20)
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- Self-Assembly of Catalytically Active Supramolecular Coordination Compounds within Metal-Organic Frameworks
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Supramolecular coordination compounds (SCCs) represent the power of coordination chemistry methodologies to self-assemble discrete architectures with targeted properties. SCCs are generally synthesized in solution, with isolated fully coordinated metal atoms as structural nodes, thus severely limited as metal-based catalysts. Metal-organic frameworks (MOFs) show unique features to act as chemical nanoreactors for the in situ synthesis and stabilization of otherwise not accessible functional species. Here, we present the self-assembly of PdII SCCs within the confined space of a pre-formed MOF (SCCs?MOF) and its post-assembly metalation to give a PdII-AuIII supramolecular assembly, crystallography underpinned. These SCCs?MOFs catalyze the coupling of boronic acids and/or alkynes, representative multi-site metal-catalyzed reactions in which traditional SCCs tend to decompose, and retain their structural integrity as a consequence of the synergetic hybridization between SCCs and MOFs. These results open new avenues in both the synthesis of novel SCCs and their use in heterogeneous metal-based supramolecular catalysis.
- Adam, Rosa,Mon, Marta,Greco, Rossella,Kalinke, Lucas H. G.,Vidal-Moya, Alejandro,Fernandez, Antonio,Winpenny, Richard E. P.,Doménech-Carbó, Antonio,Leyva-Pérez, Antonio,Armentano, Donatella,Pardo, Emilio,Ferrando-Soria, Jesús
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supporting information
p. 10350 - 10360
(2019/08/27)
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- N-Heterocarbene Palladium Complexes with Dianisole Backbones: Synthesis, Structure, and Catalysis
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A series of palladium N-heterocyclic carbenes (NHCs), complexes C1-C5, bearing dianisole backbones and substituted N-aryl moieties have been synthesized and characterized. The electronic effect as well as the steric environment of the NHC ligands has been assessed. The synthesized palladium complexes were applied for Suzuki-Miyaura cross-coupling reactions under aerobic conditions. The relationship between the catalytic structure and catalytic performance was then extensively investigated. Upon optimizing the reaction conditions, the C4 was found to be highly efficient to catalyze the cross-coupling of (hetero)aryl chlorides with (hetero)arylboronic acids at a 0.1 mol % palladium loading.
- Li, Dong-Hui,He, Xu-Xian,Xu, Chang,Huang, Fei-Dong,Liu, Ning,Shen, Dong-Sheng,Liu, Feng-Shou
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p. 2539 - 2552
(2019/06/17)
-
- Oligothienyl catenated germanes and silanes: Synthesis, structure, and properties
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The synthesis of two new groups of oligothienyl catenated silanes and germanes, Me5M2Thn (1a-b), Me5M2ThnM2Me5 (2a-c) (terminal), and ThnM2Me4Thn (3a-d) (internal) (M = Si, Ge; n = 2, 3; Th = 2- or 2,5-thienyl), is reported. The study of their structural parameters as well as of their spectral (NMR), electrochemical (CV) and optical (UV/vis absorbance, luminescence) properties has been performed in detail; in addition, the unexpected compound [Th2Si2Me4Th]2 (3a′) is also studied. Theoretical investigations have been performed for model compounds in order to establish structure-property relationships. The molecular structures of 2a (Me5Si2Th2Si2Me5), 2b (Me5Ge2Th2Ge2Me5), 3a (Th2Si2Me4Th2) and 3b (Th2Ge2Me4Th2) have been investigated by X-ray diffraction analysis. An effective conjugation with flattening of both Th planes in terminal 2a and 2b was observed. The main trends in the dependence of the optical and electrochemical properties on the structural parameters have been established. All of the compounds studied exhibit a strong emission within the 378-563 nm range, and the maximal quantum yield (up to 77%) is observed for the Si derivative 3a′. For the majority of the compounds, the quantum yields (20-30%) are significantly larger than for 2,2′-bi- and 2,2′:5′,5′′-terthiophenes. Due to their good emission properties, these compounds could be used to develop new materials with specific spectral properties.
- Zaitsev, Kirill V.,Lam, Kevin,Poleshchuk, Oleg Kh.,Kuz'Mina, Lyudmila G.,Churakov, Andrei V.
-
supporting information
p. 5431 - 5444
(2018/04/23)
-
- Au-Pd bimetallic nanoparticles supported on a high nitrogen-rich ordered mesoporous carbon as an efficient catalyst for room temperature Ullmann coupling of aryl chlorides in aqueous media
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An ionic liquid derived highly nitrogen-rich mesoporous carbon supported Au-Pd alloy was found to be an efficient and recyclable catalyst for the Ullmann coupling reaction of various aryl chlorides at room temperature in aqueous media.
- Karimi, Babak,Barzegar, Hossein,Vali, Hojatollah
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p. 7155 - 7158
(2018/07/05)
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- The first report on the transition metal-free homocoupling of aryl halides in the presence of l-cysteine
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A green and efficient methodology for the coupling of aryl halides without the addition of a transition metal catalyst has been presented. The biaryl coupling of haloarenes can be promoted by l-cysteine and potassium hydroxide. This is the first report on the synthesis of symmetrical biaryls under transition metal-free conditions.
- Ghorbani-Choghamarani, Arash,Taherinia, Zahra
-
supporting information
p. 10989 - 10992
(2018/07/05)
-
- Room-temperature borylation and one-pot two-step borylation/Suzuki-Miyaura cross-coupling reaction of aryl chlorides
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A highly efficient room-temperature borylation strategy of aryl chlorides is described. Utilizing Buchwald's second-generation preformed catalyst, boronate esters were obtained for a wide range of substrates in high yield. The method was also applied to Suzuki-Miyaura cross-coupling reaction in a one-pot two-step sequential manner, providing a facile and convenient access to the direct synthesis of biaryl compounds from aryl chlorides.
- Ji, Hong,Wu, Li-Yang,Cai, Jiang-Hong,Li, Guo-Rong,Gan, Na-Na,Wang, Zhao-Hua
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p. 13643 - 13648
(2018/04/24)
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- Perfluorocyclopentadienyl Radical Derivative as an Organocatalyst for Oxidative Coupling of Aryl- and Thienylmagnesium Compounds under Atmospheric Oxygen
-
The oxidative homocoupling reaction of Grignard reagents in the presence of atmospheric oxygen molecules proceeded in the presence of a heptafluorotolyl-substituted perfluorocyclopentadienyl radical. The turnover number (TON) was over 30 for the coupling reactions of PhMgBr to give biphenyl. The organocatalyst could couple thienylmagnesium compounds to give bithiophene derivatives in up to 94% yield. Furthermore, a gram-scale synthesis of 6,6'-dimethoxybiphenyl-2,2'-diyl-bis(phosphonic acid diethyl ester) was demonstrated. Stabilization of the phenyl radical for the inhibition of the side reaction was also considered using DFT calculations.
- Korenaga, Toshinobu,Nitatori, Kaoru,Muraoka, Hiroki,Ogawa, Satoshi,Shimada, Kazuaki
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p. 4835 - 4839
(2018/04/26)
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- Bench-Stable Sulfoxide-Based Boronates: Preparation and Application in a Tandem Suzuki Reaction
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A set of novel aromatic and heteroaromatic bench-stable sulfoxide-based boronates was prepared. The structure of the boronates was established by means of X-ray crystallography, and the prepared boronates were successively used in Suzuki cross-coupling reactions under different conditions. We also developed a tandem Suzuki reaction so that a base is generated during the nucleophilic addition of Grignard reagents to 4-bromobenzaldehyde. The formed intermediates were smoothly coupled with the prepared boronates and the boronic acids under external base-free conditions. (Figure presented.).
- ?ubiňák, Marek,Eigner, Václav,Tobrman, Tomá?
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p. 4604 - 4614
(2018/10/31)
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- A new method of using supercritical carbon dioxide as a green solvent for synthesis and purification of 5,5?-bis(tridecafluorohexyl)-2,2′:5′,2″:5″,2?-quaterthiophene, which is one of n-type organic semiconducting materials
-
We have investigated synthesis as well as purification of 5,5?-bis(tridecafluorohexyl)-2,2′:5′,2″:5″,2?-quaterthiophene (BFH-4 T, n-type organic semiconducting material) using supercritical carbon dioxide (scCO2) as a green solvent. BFH-4T was obtained in good selectivity and high yield by TDAE/PdCl2-catalyzed reductive coupling reaction of 5-bromo-5′-(tridecafluorohexyl)-2,2′-bithiophene in scCO2. We have also successfully established purification of the reaction mixture by passing scCO2 in the reaction vessel. The product was yellow powder of BFH-4T with purity of more than 99% and Pd catalyst was not contained.
- Hirase, Ryuji,Honda, Koji,Ishihara, Mari,Yoshioka, Hideki,Monobe, Hirosato
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p. 469 - 472
(2018/01/04)
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- Thermally induced bilayered crystals in a solution-processed polycrystalline thin film of phenylterthiophene-based monoalkyl smectic liquid crystals and their effect on FET mobility
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Herein, a series of asymmetric monoalkyl terthiophene derivatives, 5-phenyl-5''-alkyl-2,2':5',2''-terthiophene (Ph-(Tp)3-Cn, 6 ≤ n ≤ 18, where n represents the number of carbons in the alkyl group), were synthesized to investigate the formation of monolayered crystals derived from the smectic phase and their phase transition to bilayered crystals, leading to a significant increase of FET mobility when applied to organic field-effect transistors. All compounds showed a highly ordered smectic phase, i.e., SmE phase, and gave a monolayered crystal when spin-coated at SmE temperature. It was found that phase transition from monolayered to bilayered crystals was induced by thermal annealing when the alkyl side chain length n ≥ 10, and OFET mobility in FETs fabricated with polycrystalline thin films was dramatically enhanced up to one order of magnitude when the bilayered crystals were formed. This result proves that this phase transition is not limited to a particular type of smectic liquid crystals consisting of an aromatic fused ring system reported in benzothienobenzothiphene (BTBT) as a core derivative and can be extended to a variety of core systems, e.g., oligomer type of smectic liquid crystals. These findings may provide a new strategy for molecular design to boost mobility in soluble OFET materials.
- Wu, Hao,Iino, Hiroaki,Hanna, Jun-Ichi
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p. 56586 - 56593
(2017/12/26)
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- Donor-acceptor type fluorenyl nanometer grid material, preparation method and application thereof
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The invention discloses a donor-acceptor type fluorenyl nanometer grid material, a preparation method and application thereof. The nanometer grid material is of a square-ring-shaped rigid structure formed through alternative arrangement of fluorenyl ramification regarded as electron donor units and electron acceptor units. The preparation method comprises the following steps that a precursor with tertiary alcohol and aromatic nucleus terminal based hydrogen inhibitor dual binding sites is dissolved in organic solvent; at the room temperature, a catalyst is added, and stirring and reacting are conducted; and the reaction is conducted for 5 min-12 h, and products are obtained through chromatogram column separation. The donor-acceptor type fluorenyl nanometer grid material has the advantages that the compounding method is modularized, extensibility and stability of thermology, electrochemistry and photology are high; dependency of thin film solvent is reduced; large-area soluble processing is achieved; the size of apertures is accurately regulated and controlled; and accurate regulation an control of band gaps and energy level arrangement are achieved. The donor-acceptor type fluorenyl nanometer grid material has potential application prospects in the fields of photoelectric function materials of organic solar cells, storage and memory resistor, sensing, detecting and the like.
- -
-
Paragraph 0064; 0066
(2017/04/21)
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- A two-dimensional molecule with a large conjugation degree: Synthesis, two-photon absorption and charge transport ability
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A new molecule, 5,5′-bis(4,6-bis((E)-4-(octyloxy)styryl)pyrimidin-2-yl)-2,2′-bithiophene (OSPB), was designed and synthesized. It contains two D-π-A-π-D (donor-π-acceptor-π-donor) segments with an alkoxy group D and a pyrimidine moiety A, and these two segments are connected through a bithiophene moiety to shape a two-dimensional (2D) multibranched conjugated system. The molecule showed high thermal stability. It demonstrated good solubility in THF with an emission maximum at 470 nm, and excimer emission appeared in poor solvents such as aqueous media showing an obvious red-shift. A two-photon excited fluorescence (TPEF) test revealed that the maximal two-photon absorption (2PA) cross-section of the molecule was 1352 GM, which is comparable with the reported bipyrimidine-based multibranched compounds with a stronger donor. Theoretical calculation suggested that the molecule showed good coplanarity made up by two conjugated segments with a small dihedral angle. The charge transport ability of OSPB was preliminarily studied using an organic thin-film transistor (OTFT) device via a low-cost solution processing technique, and the results demonstrated that it was a p-type semiconductor.
- Chen, Dugang,Zhong, Cheng,Zhao, Yan,Nan, Lingyan,Liu, Yunqi,Qin, Jingui
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supporting information
p. 5199 - 5206
(2017/07/10)
-
- Reductive Homocoupling of Organohalides Using Nickel(II) Chloride and Samarium Metal
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A homocoupling method for organohalides and organosulfonates promoted by samarium metal and HMPA, and catalyzed by NiCl2 has been developed. Various organohalides (benzyl, aryl, heterocyclic, alkenyl and alkyl halides), α-haloacetophenones, and phenyl organosulfonates were tolerated, and the reaction afforded coupling products with high efficiency. Excellent chemoselectivity was exhibited between halides and other groups, such as ?COOH, ?NO2, halogen, heterocyclic ring, ester, and ketone groups. The stereoselectivity suggested that the reaction mechanism might involve an organosamarium species.
- Liu, Yongjun,Xiao, Shuhuan,Qi, Yan,Du, Feng
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p. 673 - 678
(2017/03/22)
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- Method for cleaving alpha carbon-carbon single bonds in ketone under condition of metal-free catalysis
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The invention discloses a method for selectively activating and cleaving alpha carbon-carbon single bonds in ketone under the condition of metal-free catalysis. The method is characterized in that the alpha carbon-carbon single bonds in the ketone are activated and cleaved by solvent induction and driving of intermediate structure factors formed by the ketone and hydrazine without metal catalysts. Transition metal for catalysis is omitted, the method is environmentally friendly, reaction cost is reduced to a certain degree, methodology of selective cleavage of the carbon-carbon single bonds is enriched, and a new idea is provided for activation of inertial chemical bonds under mild conditions.
- -
-
Paragraph 0017; 0037
(2017/10/07)
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- Thiophene oxide derivative and organic light-emitting device thereof
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The invention discloses a thiophene oxide derivative and an organic light-emitting device thereof and belongs to the technical field of organic photoelectric materials. [2,2'-bithiophene]1,1,1',1'-tetroxide is taken as a main body structure, and the pi conjugacy, electrophilicity and charge transfer ability of the material are adjusted through changing a structure and a link method of a ligand, so that the thiophene oxide derivative has high luminous performance, electronic transmission performance, membrane stability and heat stability and high triplet level, and is capable of effectively solving the problem of charge carrier imbalance of unipolar luminescent materials. The luminous efficiency of the organic light-emitting device prepared from the thiophene oxide derivative is strengthened, and the organic light-emitting device is more stable in light and color, has the characteristics of excellent electron chemistry and heat stability and long service life, and also has high luminous efficiency under the condition of low starting voltage.
- -
-
Paragraph 0040; 0041; 0044; 0045
(2017/10/13)
-
- [...] compounds (by machine translation)
-
[Problem] self-assembly to form an integrated spiral, circular polarized light emitting [...] shown compound. (1) a compound represented by the formula [a] [...]. (R1 And R2 Both or either one of the substrate having asymmetric centers; R4 OR is hydrogen or3 )Figure 1 [drawing] (by machine translation)
- -
-
Paragraph 0024; 0028-0029
(2017/11/18)
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- FUSED RING DERIVATIVE AND ORGANIC SOLAR CELL COMPRISING THE SAME
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The present invention relates to a condensed cyclic derivative represented by chemical formula 1, and an organic solar cell containing the same. According to an embodiment of the present invention, the condensed cyclic derivative exhibits excellent coating properties by having a hydroxyl group, an alkyl group, an alkoxy group, and a sulfide group as a substituent.COPYRIGHT KIPO 2017
- -
-
Paragraph 0216; 0217
(2017/08/02)
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- New methods for the synthesis of 4H-dithieno[3,2-b:2′,3′-d]pyrrole
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Various alternative methods for the synthesis of 4H-dithieno[3,2-b:2′,3′-d]pyrrole (DTP) starting from commercially available bromothiophene precursors are presented. Crucial steps involve the Cadogan reaction, Ullmann-type C─N couplings, or Buchwald-Hartwig–type aminations to build up the central pyrrole ring of DTP, respectively. The use of ammonia surrogates afforded the fused target heteroacene in overall yields of 33% to 63%, and the corresponding methods are applicable on large scale.
- F?rtsch, Sebastian,Vogt, Astrid,B?uerle, Peter
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supporting information
(2017/08/23)
-
- Copper-free palladium-catalysed desulfinative homocoupling of sodium arylsulfinates under mild and aerobic conditions
-
A Pd(II)-catalysed homocoupling of sodium arylsulfinates has been successfully achieved under mild conditions. This transformation is a new method for the homocoupling reaction of sodium arylsulfinates, thus providing an alternative synthesis of symmetric biaryls. The reported homocoupling reaction is tolerant to many common functional groups, such as ester, halo, cyano and nitro and works well in the presence of electron-donating and electron-withdrawing substituents. Notably, the reported desulfinative homocoupling does not require Cu salts, ligands and bases, making this newly developed transformation attractive.
- Zhang, Wei
-
-
- Ecocatalyzed Suzuki cross coupling of heteroaryl compounds
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A bio-based EcoPd was developed for the Suzuki cross coupling of heteroaryl compounds. Based on the ability of Eichhornia crassipes to bioconcentrate Pd in its roots, we addressed the transformation of plant-derived Pd metals to green catalysts. The methodology is based on eco-friendly procedures. It allowed the preparation of a wide range of heterocyclic biaryl and heterocyclic-heterocyclic biaryl compounds, with a low Pd catalyst loading. EcoPd was found to have the ideal microstructure to promote complex Suzuki reactions without ligands or additives. For the first time, post-reaction solution was treated by rhizofiltration. The resulting EcoPd has been reused with the same performance. This work has established the ecocatalysis concept as a powerful strategy for Pd sustainability, with the development of homogeneous catalysts that are easily recycled and reused.
- Clavé, Guillaume,Pelissier, Franck,Campidelli, Stéphane,Grison, Claude
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p. 4093 - 4103
(2017/09/07)
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- A benzo thiophene group-containing indole salt dye and its preparation and use
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The invention relates to a benzindole salt dye containing a thiophene group, which is as shown in formula (1) and has a relatively strong surface-enhanced Raman scattering (SERS) effect, and a preparation method and application of the benzindole salt dye. Cations of a benzindole salt are of a D-pi-A structure, dialkylamino is taken as an electron donor, nitrogen-containing heterocyclic benzindole cations are taken as electron acceptors, and thiophene vinyl is taken as a conjugated bridge respectively. Dye molecules with the structure can be compounded with nano-gold or silver particles to form an SERS marker for surface-enhanced Raman spectral detection, the SERS intensity is high, and the reaction is sensitive; and the absorption wavelength of the dye is controllable by regulating and controlling the length of a molecular conjugated chain, and the SERS dye molecules are expected to be applied in the field of biomedical spectral detection.
- -
-
Paragraph 0036-0040
(2017/04/11)
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- New dithienophosphole-based donor-acceptor alternating copolymers: Synthesis and structure property relationships in OFET
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Two donor-acceptor conjugated copolymers comprised of a novel dithienophosphole (DTP) as the acceptor unit and bithiophene (BT) or decylthiophenebenzodithiophene (DTBDT) as the donor unit were synthesized and characterized to elucidate the relationship between donor-acceptor (D-A) architecture and organic field-effect transistors (OFETs) performance. These characteristics of D-A copolymers were affected by the structural suitability of donor and acceptor units. Poly(DTP-BT) had an ordered structure that facilitated charge carrier transfer. The crystallinity of poly(DTP-BT) increased as annealing temperature (Tann) increased. In contrast, poly(DTP-DTBDT) was amorphous regardless of Tann due to the long alkyl chains of the DTBDT units. OFET devices made with poly(DTP-BT) and annealed at 200°C exhibit a highly crystalline morphology and a relatively high field-effect mobility (4.9 × 10-3 cm2/(V·s)).
- Sung, Min Jae,Kim, Yebyeol,Lee, Sang Bong,Lee, Gi Back,An, Tae Kyu,Cha, Hyojung,Kim, Se Hyun,Park, Chan Eon,Kim, Yun-Hi
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p. 316 - 322
(2015/11/24)
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- Development of solvent-driven iron-catalyzed reactions
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The possibility of solvent-driven iron-catalyzed reactions has been investigated using ionic liquids and acetonitrile as key solvents. Three iron-catalyzed reactions, the intramolecular cyclization of cyclopropane dithioacetals, the [2+2]-cycloaddition of (trans)-anethole, and the [2+3]-type cycloaddition of styrene derivatives with 1,4-benzoquinone, were first developed using acetonitrile as solvent in the presence of 3～5 mol% of Fe(ClO4 )3 ?Al2 O3 or Fe(BF4 )2 ?6H2 O under air conditions. In particular, we found the rapid cycloaddition of iron-catalyzed [2+3]-type cycloaddition of styrene derivatives with 1,4-benzoquinone when the reaction was carried out in an ionic liquid which contained [PF6 ] or [Tf2N] anion. Homo-coupling reaction of aryl or alkynyl Grignard reagent was next discovered using 1 mol% of FeCl3 as catalyst and the reaction also proceeded very rapidly in an ionic liquid. We also found that 3～5 mol% of Fe(ClO4 )2 ?Al2 O3 or Fe(BF4 )2 ?6H2 O-successfully catalyzed Friedel-Crafts type alkylation of indoles or pyrroles with vinyl ketones or α-aryl-β-silylalcohol. In particular, the reaction of chiral α-aryl-β-silylalcohol with indole using Fe(ClO4 )3 ?nH2 O as catalyst proceeded with retention of the configuration of stereochemistry of the hydroxyl group. Then, we discovered the first example of iron-catalyzed enantioselective C-S bond formation via Michael addition of thiols to (E)-3-crotonoyloxazolidin-2-one using 10 mol% of Fe(BF4 )2 /Pybox. We further demonstrated that Fe(ClO4 )3 ?Al2 O3 -catalyzed the Nazarov type cyclizations of thiophene, pyrrole, indole, benzofuran, and benzo[b]thiophene derivatives using ionic liquids as solvent. Solvents have been recognized as a by-player in chemical reactions in the process of "optimization of reaction conditions". However, further investigation of the solvent-driven iron-catalyzed reaction will allow discovery of useful reactions for organic syntheses.
- Itoh, Toshiyuki
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p. 1373 - 1395
(2016/08/06)
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- Homocoupling of heteroaryl/aryl/alkyl Grignard reagents: I2-promoted, or Ni- or Pd- or Cu- or nano-Fe-based salt catalyzed
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Five efficient processes for the homo-coupling of various Grignard reagents including aryl, heteroaryl and aliphatic ones in the presence of I2, Pd(OAc)2, Ni(OAc)2, CuI, and nano-Fe3O4 were developed, respectively.
- Li, Xing,Li, Dongjun,Li, Yingjun,Chang, Honghong,Gao, Wenchao,Wei, Wenlong
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p. 86998 - 87002
(2016/09/23)
-
- Synthesis and photophysical properties of semiconductor molecules D1-A-D2-A-D1-type structure based on derivatives of quinoxaline and dithienosilole for organics solar cells
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A novel small molecule with D1-A-D2-A-D1 structure denoted as DTS(QxHT2)2 based on quinoxaline acceptor and dithienosilone donor units was synthesized and its optical and electrochemical properties were investigated. The thin film of DTS(QxHT2)2 showed a broad absorption profile covering the solar spectrum from 350?nm to 780?nm with an optical bandgap of 1.63?eV. The energy levels estimated from the cyclic voltammetry indicate that this small molecule is suitable as donor along with PC71BM as acceptor for the fabrication solution processed bulk heterojunction solar cells for efficient exciton dissociation and high open circuit voltage. The organic solar cells based on optimized DTS(QxHT2)2:PC71BM active layers processed with chloroform and DIO/CF showed overall power conversion efficiency of 3.16% and 6.30%, respectively. The higher power conversion efficiency of the solar cell based on the DIO/CF processed active layer is attributed to enhanced short circuit photocurrent and fill factor may be related to better phase separation between donor and acceptor in the active layer and more balanced charge transport, induced by the solvent additive. The power conversion efficiency of the organic solar cell was further improved up to 7.81% based on active layer processed with solvent additive, using CuSCN as hole transport layer instead of PEDOT:PSS and mainly attributed to increased fill factor and open circuit voltage due the formation of better Ohmic contact between the active layer and the CuSCN layer.
- Keshtov,Godovsky, D. Yu,Kuklin,Nicolaev,Lee,Lim,Lee,Koukaras,Sharma, Ganesh D.
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p. 361 - 370
(2016/11/09)
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- Cobalt-Catalyzed Oxidative Homocoupling of Arylzinc Species
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A novel procedure for the synthesis of functionalized symmetrical biaryl compounds is described. The reaction proceeds via the oxidative homocoupling of arylzinc species formed by cobalt catalysis in the presence of air or p-benzoquinone depending on the nature of the functional group.
- Bourne-Branchu, Yann,Moncomble, Aurélien,Corpet, Martin,Danoun, Gregory,Gosmini, Corinne
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p. 3352 - 3356
(2016/09/12)
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- Integration of borylation of aryllithiums and Suzuki-Miyaura coupling using monolithic Pd catalyst
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Integration of the preparation of arylboronic esters via aryllithiums and Suzuki-Miyaura coupling using monolithic Pd catalyst without an intentionally added base was achieved. A continuous operation has been done successfully for over 21 hours.
- Nagaki,Hirose,Moriwaki,Mitamura,Matsukawa,Ishizuka,Yoshida
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p. 4690 - 4694
(2016/07/07)
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- Biarylalkyl Carboxylic Acid Derivatives as Novel Antischistosomal Agents
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Parasitic platyhelminths are responsible for serious infectious diseases, such as schistosomiasis, which affect humans as well as animals across vast regions of the world. The drug arsenal available for the treatment of these diseases is limited; for example, praziquantel is the only drug currently used to treat ≥240 million people each year infected with Schistosoma spp., and there is justified concern about the emergence of drug resistance. In this study, we screened biarylalkyl carboxylic acid derivatives for their antischistosomal activity against S. mansoni. These compounds showed significant influence on egg production, pairing stability, and vitality. Tegumental lesions or gut dilatation was also observed. Substitution of the terminal phenyl residue in the biaryl scaffold with a 3-hydroxy moiety and derivatization of the terminal carboxylic acid scaffold with carboxamides yielded compounds that displayed significant antischistosomal activity at concentrations as low as 10 μm with satisfying cytotoxicity values. The present study provides detailed insight into the structure–activity relationships of biarylalkyl carboxylic acid derivatives and thereby paves the way for a new drug-hit moiety for fighting schistosomiasis.
- M?der, Patrick,Blohm, Ariane S.,Quack, Thomas,Lange-Grünweller, Kerstin,Grünweller, Arnold,Hartmann, Roland K.,Grevelding, Christoph G.,Schlitzer, Martin
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supporting information
p. 1459 - 1468
(2016/07/16)
-
- Convenient synthesis of organic-electronics-oriented building blocks via on-water and under-air homocoupling of (hetero)aryl iodides
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We report herein an operationally simple homocoupling reaction that targets the convenient synthesis of organic-electronically important building blocks. A variety of synthetically useful bithiophene derivatives and functionalized biphenyls are efficiently prepared by an on-water and under-air protocol using Pd/C as catalyst. We find that Pd/C gives generally higher and cleaner homocoupling conversions than using Pd(OAc)2 in the cases of (hetero)aryl iodides since Pd(OAc)2 triggers more side reactions including dehalogenations and oligomerizations. Under the optimum conditions, a broad range of functional groups such as ester, ketone, aldehyde, nitrile, nitro, chloride, and bromide are well tolerated. We expect the present methodology would make a valuable synthetic contribution towards bridging green chemistry with thiophene-based organic materials.
- Chen, Yi-An,Liu, Ching-Yuan
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p. 74180 - 74188
(2015/09/21)
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- Salt-Free Reduction of Nonprecious Transition-Metal Compounds: Generation of Amorphous Ni Nanoparticles for Catalytic C-C Bond Formation
-
A salt-free procedure for the generation of a wide variety of metal(0) particles, including Fe, Co, Ni, and Cu, was achieved using 2,3,5,6-tetramethyl-1,4-bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene (1), which reduced the corresponding metal precursors under mild conditions. Notably, Ni particles formed in situ from the treatment of Ni(acac)2 (acac=acetylacetonate) with 1 in toluene exhibited significant catalytic activity for reductive C-C bond-forming reactions of aryl halides in the presence of excess amounts of 1. By examination of high-magnification transmission electron microscopy images and electron diffraction patterns, we concluded that amorphous Ni nanoparticles (Ni aNPs) were essential for the high catalytic activity.
- Yurino, Taiga,Ueda, Yohei,Shimizu, Yoshiki,Tanaka, Shinji,Nishiyama, Haruka,Tsurugi, Hayato,Sato, Kazuhiko,Mashima, Kazushi
-
supporting information
p. 14437 - 14441
(2016/01/25)
-
- N-Heterocyclic Carbene-Pd Polymers as Reusable Precatalysts for Cyanation and Ullmann Homocoupling of Aryl Halides: The Role of Solvent in Product Distribution
-
A main-chain N-heterocyclic carbene (NHC) polymer with N-dodecyl-substituted groups was found to be a highly efficient precatalyst for cyanation of various aryl halides by using nontoxic cyanic source [K4Fe(CN)6] under relatively mild reaction conditions. Several aryl iodides, bromides, and activated chlorides were successfully converted to their corresponding benzonitrile derivatives without using additives (such as reducing agents or exogenous organic ligands) in good to excellent yields. Our investigations showed that changing the solvent from DMF to polyethylene glycol (PEG-200) resulted in dramatic decline of cyanation product formation to the benefit of the Ullmann homocoupling reaction. The catalyst could be reused four and five times with only slight loss of activity in cyanation and the Ullmann coupling, respectively.
- Karimi, Babak,Vafaeezadeh, Majid,Akhavan, Pari Fadavi
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p. 2248 - 2254
(2015/11/24)
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- Pd(OAc)2/PPh3-catalyzed desulfonylative homocoupling of arylsulfonyl chlorides
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The Pd-catalyzed homodimerization with respect to arylsulfonyl chlorides as an efficient method for the synthesis of biaryls has been developed. This desulfonylative reaction which was performed at reflux in 1,4-dioxane for 4 h under air afforded the desired products in good to excellent yields. The Pd(OAc)2/PPh3-catalyzed desulfonylative homodimerization of arenesulfonyl chlorides as an efficient method for the synthesis of biaryls was described. The corresponding products were obtained in good to excellent yields.
- Zhao, Qiao,Chen, Liangshun,Lang, Hongyue,Wu, Shengying,Wang, Limin
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p. 535 - 538
(2015/05/27)
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