- Control Interlayer Stacking and Chemical Stability of Two-Dimensional Covalent Organic Frameworks via Steric Tuning
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Layer stacking and chemical stability are crucial for two-dimensional covalent organic frameworks (2D COFs), but are yet challenging to gain control. In this work, we demonstrate synthetic control of both the layer stacking and chemical stability of 2D COFs by managing interlayer steric hindrance via a multivariate (MTV) approach. By co-condensation of triamines with and without alkyl substituents (ethyl and isopropyl) and a di- or trialdehyde, a family of two-, three-, and four-component 2D COFs with AA, AB, or ABC stacking is prepared. The alkyl groups are periodically appended on the channel walls and their contents, which can be synthetically tuned by the MTV strategy, control the stacking model and chemical stability of 2D COFs by maximizing the total crystal stacking energy and protecting hydrolytically susceptible backbones through kinetic blocking. Specifically, the COFs with higher concentration of alkyl substituents adopt AB or ABC stacking, while lower amount of functionalities leads to the AA stacking. The COFs bearing high concentration of isopropyl groups represent the first identified COFs that can retain crystallinity and porosity in boiling 20 M NaOH solution. After postsynthetic metalation with an iridium complex, the 2,2′-bipyridyl-derived COFs can heterogeneously catalyze C-H borylation of arenes, whereas the COF with isopropyl groups exhibits much higher activity than the COFs with ethyl groups and nonsubstituents due to the increased porosity and chemical stability. This work underscores the opportunity in using steric hindrance to tune and control layer stacking, chemical stability and properties of 2D COFs.
- Wu, Xiaowei,Han, Xing,Liu, Yuhao,Liu, Yan,Cui, Yong
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Read Online
- A series of selective and sensitive fluorescent sensors based on a thiophen-2-yl-benzothiazole unit for Hg2+
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Different types of fluorescent probes for Hg2+ based on the 5-thiophen-2-yl-benzothiazole derivatives (TBT, 2-thiophen-2-yl-benzothiazole; CTBT, 9-(5-benzothiazol-2-yl-thiophen-2-yl)-9H-carbazole; DTBT, 2-(5-acenaphthen-5-yl-thiophen-2-yl)-benzothiazole; and NTBT, 6-(5-benzothiazol-2-yl-thiophen-2-yl)-2-hexyl-benzo[de]isoquinoline-1,3-dione) were realized by changing the subsituents. Multisignaling changes were observed through UV-vis absorption and fluorescence spectra upon addition of Hg2+. The addition of Hg2+ on TBT induced a remarkable OFF/ON-type fluorescence signaling behavior. With the introduction of electron-donating carbazole, the detection behavior of CTBT was just the reverse of what TBT displayed, while a ratiometric fluorescent probe based on DTBT for Hg2+ was prepared by introducing the weak electron-drawing group acenaphthene. Moreover, the dichloromethane solution of CTBT and DTBT showed a distinct color change from colorless to yellow with the addition of Hg2+, which indicated that these two probes would facilitate the naked-eye detection of Hg2+. However, both UV-vis absorption and fluorescence spectra of NTBT with strong electron-withdrawing substituents showed no obvious change upon addition of Hg2+. It would be concluded that the electronic properties of the molecule was one of the vital factors in designing chemosensor molecules.
- Mei, Qunbo,Tian, Ruqiang,Shi, Yujie,Hua, Qingfang,Chen, Chen,Tong, Bihai
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- Azo compounds with different sized fluorophores and characterization of their photophysical properties based on trans to cis conformational change
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We synthesized fluorophores of different sizes attached to azo derivatives, such as thiophene-, naphthalene-, anthracene-, and pyrene-based azo compounds, and studied their photophysical properties. The compounds exhibited strong color and intensity changes in absorption and emission during the structural change from trans to cis, which also resulted in a large Stokes shift and a difference in quantum yield. Depending on their size, the compounds had different rates of transformation from the trans to cis structure: less conjugated (smaller) fluorophore azo compounds showed higher transition rates than more conjugated (larger) ones.
- Ingale, Gajanan,Seo, Young Jun
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- Cu-mediated: vs. Cu-free selective borylation of aryl alkyl sulfones
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A Cu-catalysed borylation of aryl alkyl sulfones was developed for the high yield synthesis of versatile arylboronic esters using a readily prepared NHC-Cu catalyst. In addition, the selective cleavage of either alkyl(C)-sulfonyl or aryl(C)-sulfonyl bonds
- Hu, Jiefeng,Huang, Mingming,Marder, Todd B.,Radius, Udo,Tang, Man,Westcott, Stephen A.
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supporting information
p. 395 - 398
(2022/01/19)
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- Palladium-catalyzed borylation of aryl bromides and chlorides using phosphatrioxa-adamantane ligands
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Catalysts based on the combination of Pd(OAc)2 and the electron-deficient phosphatrioxa-adamantane ligands are described for borylation of aryl bromides and chlorides. Catalytic evaluation of a small library of phosphatrioxa-adamantane ligands provided some insights on the preferred ligand steric profile for borylation reactions. The corresponding aryl boronate esters were accessed under mild conditions (25–70 °C) and isolated in high yields (up to 96%).
- Lamola, Jairus L.,Moshapo, Paseka T.,Holzapfel, Cedric W.,Christopher Maumela, Munaka
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supporting information
(2021/12/13)
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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,Luo, Chengkai,Xu, Caifeng,Huang, Bin
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p. 1339 - 1346
(2021/12/02)
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- Photocytotoxicity of Thiophene- And Bithiophene-Dipicolinato Luminescent Lanthanide Complexes
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New thiophene-dipicolinato-based compounds, K2nTdpa (n = 1, 2), were isolated. Their anions are sensitizers of lanthanide ion (LnIII) luminescence and singlet oxygen generation (1O2). Emission in the visible and near-infrared regions was observed for the LnIII complexes with efficiencies (φLn) φEu = 33% and φYb = 0.31% for 1Tdpa2- and φYb = 0.07% for 2Tdpa2-. The latter does not sensitize EuIII emission. Fluorescence imaging of HeLa live cells incubated with K3[Eu(1Tdpa)3] indicates that the complex permeates the cell membrane and localizes in the mitochondria. All complexes generate 1O2 in solution with efficiencies (φO12) as high as 13 and 23% for the GdIII complexes of 1Tdpa2- and 2Tdpa2-, respectively. [Ln(nTdpa)3]3- (n = 1, 2) are phototoxic to HeLa cells when irradiated with UV light with IC50 values as low as 4.2 μM for [Gd(2Tdpa)3]3- and 91.8 μM for [Eu(1Tdpa)3]3-. Flow cytometric analyses indicate both apoptotic and necrotic cell death pathways.
- Rodrigues, Carime V.,Johnson, Katherine R.,Lombardi, Vincent C.,Rodrigues, Marcelo O.,Sobrinho, Josiane A.,De Bettencourt-Dias, Ana
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p. 7724 - 7734
(2021/06/21)
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- Benzoic Acid-Promoted C2-H Borylation of Indoles with Pinacolborane
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A benzoic acid-promoted C2-H borylation of indoles with pinacolborane to afford C2-borylated indoles is developed. Preliminary mechanistic studies indicate BH3-related borane species formed via the decomposition of pinacolborane to be the probable catalyst. This transformation provides a prompt route toward the synthesis of diverse C2-functionalized indoles.
- Zou, Youliang,Zhang, Binfeng,Wang, Li,Zhang, Hua
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supporting information
p. 2821 - 2825
(2021/04/13)
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- Improvement in the Palladium-Catalyzed Miyaura Borylation Reaction by Optimization of the Base: Scope and Mechanistic Study
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Aryl boronic acids and esters are important building blocks in API synthesis. The palladium-catalyzed Suzuki-Miyaura borylation is the most common method for their preparation. This paper describes an improvement of the current reaction conditions. By using lipophilic bases such as potassium 2-ethyl hexanoate, the borylation reaction could be achieved at 35 °C in less than 2 h with very low palladium loading (0.5 mol %). A preliminary mechanistic study shows a hitherto unrecognized inhibitory effect by the carboxylate anion on the catalytic cycle, whereas 2-ethyl hexanoate minimizes this inhibitory effect. This improved methodology enables borylation of a wide range of substrates under mild conditions.
- Barroso, Santiago,Joksch, Markus,Puylaert, Pim,Tin, Sergey,Bell, Stephen J.,Donnellan, Luke,Duguid, Stewart,Muir, Colin,Zhao, Peichao,Farina, Vittorio,Tran, Duc N.,De Vries, Johannes G.
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supporting information
p. 103 - 109
(2020/12/22)
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- C-H Borylation Catalysis of Heteroaromatics by a Rhenium Boryl Polyhydride
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Transition metal complexes bearing metal-boron bonds are of particular relevance to catalytic C-H borylation reactions, with iridium polyboryl and polyhydrido-boryl complexes the current benchmark catalysts for these transformations. Herein, we demonstrate that polyhydride boryl phosphine rhenium complexes are accessible and catalyze the C-H borylation of heteroaromatic substrates. Reaction of [K(DME)(18-c-6)][ReH4(Bpin)(ν2-HBpin)(κ2-H2Bpin)] 1 with 1,3-bis(diphenylphosphino)propane (dppp) produced [K(18-c-6)][ReH4(ν2-HBpin)(dppp)] 2 through substitution of two equivalents of HBpin, and protonation of 2 formed the neutral complex [ReH6(Bpin)(dppp)] 3. Combined X-ray crystallographic and DFT studies show that 2 is best described as a σ-borane complex, whereas 3 is a boryl complex. Significantly, the boryl complex 3 acted as a catalyst for the C(sp2)-H borylation of a variety of heteroarenes (14 examples including furan, thiophene, pyrrole and indole derivatives) and displayed similar reactivity to the iridium analogues.
- Donnelly, Liam J.,Faber, Teresa,Morrison, Carole A.,Nichol, Gary S.,Thomas, Stephen P.,Love, Jason B.
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p. 7394 - 7400
(2021/06/30)
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- Manganese-Catalyzed C(sp2)-H Borylation of Furan and Thiophene Derivatives
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Aryl boronic esters are bench-stable, platform building-blocks that can be accessed through metal-catalyzed aryl C(sp2)-H borylation reactions. C(sp2)-H bond functionalization reactions using rare- and precious-metal catalysts are well established, and while examples utilizing Earth-abundant alternatives have emerged, manganese catalysis remains lacking. The manganese-catalyzed C-H borylation of furan and thiophene derivatives is reported alongside an in situ activation method providing facile access to the active manganese hydride species. Mechanistic investigations showed that blue light irradiation directly affected catalysis by action at the metal center, that C(sp2)-H bond borylation occurs through a C-H metallation pathway, and that the reversible coordination of pinacolborane to the catalyst gave a manganese borohydride complex, which was as an off-cycle resting state.
- Britton, Luke,Skrodzki, Maciej,Nichol, Gary S.,Dominey, Andrew P.,Pawlu?, Piotr,Docherty, Jamie H.,Thomas, Stephen P.
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p. 6857 - 6864
(2021/06/28)
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- Cyclometalated Platinum(II) Complexes with Donor-Acceptor-Containing Bidentate Ligands and Their Application Studies as Organic Resistive Memories
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A series of heteroleptic cyclometalated platinum(II) complexes, [Pt(C^N)(O^O)], (1–10) with various donors and acceptors has been synthesized and characterized by 1H NMR spectroscopy, elemental analyses, infrared spectroscopy and mass spectrometry. The X-ray structure of 2 has also been determined. The electrochemical and photophysical properties of the platinum(II) complexes were studied. These experimental results have been supported by computational studies. Furthermore, two of the complexes have been employed as the active material in the fabrication of resistive memory devices, exhibiting stable binary memory performance with low operating voltage, high ON/OFF ratio and long retention time.
- Poh, Wei Church,Au-Yeung, Ho-Leung,Chan, Alan Kwun-Wa,Hong, Eugene Yau-Hin,Cheng, Yat-Hin,Leung, Ming-Yi,Lai, Shiu-Lun,Low, Kam-Hung,Yam, Vivian Wing-Wah
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supporting information
p. 3669 - 3676
(2021/09/29)
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- Photocytotoxicity of Oligothienyl-Functionalized Chelates That Sensitize LnIII Luminescence and Generate 1O2
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Three new compounds containing a heptadentate lanthanide (LnIII) ion chelator functionalized with oligothiophenes, nThept(COOH)4 (n=1, 2, or 3), were isolated. Their LnIII complexes not only display the characteristic metal-centered emission in the visible or near-infrared (NIR) but also generate singlet oxygen (1O2). Luminescence efficiencies (?Ln) for [Eu1Thept(COO)4]? and [Eu2Thept(COO)4]? are ?Eu=3 percent and 0.5 percent in TRIS buffer and 33 percent and 3 percent in 95 percent ethanol, respectively. 3Thept(COO)44? does not sensitize EuIII emission due to its low-lying triplet state. Near infra-red (NIR) luminescence is observed for all NIR-emitting LnIII and ligands with efficiencies of ?Yb=0.002 percent, 0.005 percent and 0.04 percent for [YbnThept(COO)4]? (n=1, 2, or 3), and ?Nd=0.0007 percent, 0.002 percent and 0.02 percent for [NdnThept(COO)4]? (n=1, 2, or 3) in TRIS buffer. In 95 percent ethanol, quantum yields of NIR luminescence increase and are ?Yb=0.5 percent, 0.31 percent and 0.05 percent for [YbnThept(COO)4]? (n=1, 2, or 3), and ?Nd=0.40 percent, 0.45 percent and 0.12 percent for [NdnThept(COO)4]? (n=1, 2, or 3). All complexes are capable of generating 1O2 in 95 percent ethanol with ?1Ο2 efficiencies which range from 2 percent to 29 percent. These complexes are toxic to HeLa cells when irradiated with UV light (λexc=365 nm) for two minutes. IC50 values for the LnIII complexes are in the range 15.2–16.2 μm; the most potent compound is [Nd2Thept(COO)4]?. The cell death mechanisms are further explored using an Annexin V—propidium iodide assay which suggests that cell death occurs through both apoptosis and necrosis.
- Johnson, Katherine R.,Lombardi, Vincent C.,de Bettencourt-Dias, Ana
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supporting information
p. 12060 - 12066
(2020/08/21)
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- Rh-Catalyzed Base-Free Decarbonylative Borylation of Twisted Amides
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We report the rhodium-catalyzed base-free decarbonylative borylation of twisted amides. The synthesis of versatile arylboronate esters from aryl twisted amides is achieved via decarbonylative rhodium(I) catalysis and highly selective N-C(O) insertion. The method is notable for a very practical, additive-free Rh(I) catalyst system. The method shows broad functional group tolerance and excellent substrate scope, including site-selective decarbonylative borylation/Heck cross-coupling via divergent N-C/C-Br cleavage and late-stage pharmaceutical borylation.
- Bie, Fusheng,Liu, Xuejing,Shi, Yijun,Cao, Han,Han, Ying,Szostak, Michal,Liu, Chengwei,Liu, Xuejing,Szostak, Michal,Liu, Chengwei
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p. 15676 - 15685
(2020/11/13)
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- Visible-Light-Induced Ni-Catalyzed Radical Borylation of Chloroarenes
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A highly selective and general photoinduced C-Cl borylation protocol that employs [Ni(IMes)2] (IMes = 1,3-dimesitylimidazoline-2-ylidene) for the radical borylation of chloroarenes is reported. This photoinduced system operates with visible light (400 nm) and achieves borylation of a wide range of chloroarenes with B2pin2 at room temperature in excellent yields and with high selectivity, thereby demonstrating its broad utility and functional group tolerance. Mechanistic investigations suggest that the borylation reactions proceed via a radical process. EPR studies demonstrate that [Ni(IMes)2] undergoes very fast chlorine atom abstraction from aryl chlorides to give [NiI(IMes)2Cl] and aryl radicals. Control experiments indicate that light promotes the reaction of [NiI(IMes)2Cl] with aryl chlorides generating additional aryl radicals and [NiII(IMes)2Cl2]. The aryl radicals react with an anionic sp2-sp3 diborane [B2pin2(OMe)]- formed from B2pin2 and KOMe to yield the corresponding borylation product and the [Bpin(OMe)]?- radical anion, which reduces [NiII(IMes)2Cl2] under irradiation to regenerate [NiI(IMes)2Cl] and [Ni(IMes)2] for the next catalytic cycle.
- Tian, Ya-Ming,Guo, Xiao-Ning,Krummenacher, Ivo,Wu, Zhu,Nitsch, J?rn,Braunschweig, Holger,Radius, Udo,Marder, Todd B.
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supporting information
p. 18231 - 18242
(2020/11/02)
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- Iron-catalysed C(sp2)-H borylation enabled by carboxylate activation
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Arene C(sp2)-H bond borylation reactions provide rapid and efficient routes to synthetically versatile boronic esters. While iridium catalysts are well established for this reaction, the discovery and development of methods using Earth-abundant alternatives is limited to just a few examples. Applying an in situ catalyst activation method using air-stable and easily handed reagents, the iron-catalysed C(sp2)-H borylation reactions of furans and thiophenes under blue light irradiation have been developed. Key reaction intermediates have been prepared and characterised, and suggest two mechanistic pathways are in action involving both C-H metallation and the formation of an iron boryl species.
- Britton, Luke,Docherty, Jamie H.,Dominey, Andrew P.,Thomas, Stephen P.
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- A Monophosphine Ligand Derived from Anthracene Photodimer: Synthetic Applications for Palladium-Catalyzed Coupling Reactions
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Herein, we present an air-stable dianthracenyl monophosphine ligand (diAnthPhos) which can be prepared in two steps from commercially available anthracene derivatives. The ligand exhibits excellent efficiency for palladium-catalyzed coupling reactions. In particular, Miyaura borylation of heterocycle-containing electrophiles can be facilitated employing the diAnthPhos ligand with a broad substrate scope and low catalyst loading. The valuable synthetic utility of the new ligand is further demonstrated by a one-pot Miyaura borylation/Suzuki coupling protocol for heteroaryl-containing substrates.
- Wang, Xin,Liu, Wei-Gang,Tung, Chen-Ho,Wu, Li-Zhu,Cong, Huan
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supporting information
p. 8158 - 8163
(2019/09/07)
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- Catalytic C?H Borylation Using Iron Complexes Bearing 4,5,6,7-Tetrahydroisoindol-2-ide-Based PNP-Type Pincer Ligand
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Catalytic C?H borylation has been reported using newly designed iron complexes bearing a 4,5,6,7-tetrahydroisoindol-2-ide-based PNP pincer ligand. The reaction tolerated various five-membered heteroarenes, such as pyrrole derivatives, as well as six-membered aromatic compounds, such as toluene. Successful examples of the iron-catalyzed sp3 C?H borylation of anisole derivatives were also presented.
- Kato, Takeru,Kuriyama, Shogo,Nakajima, Kazunari,Nishibayashi, Yoshiaki
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supporting information
p. 2097 - 2101
(2019/05/28)
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- Copper-catalysed borylation of aryl chlorides
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We report herein the first Cu-catalysed borylation of a wide range of aryl chlorides with different electronic and steric properties using a readily prepared NHC-stabilised Cu catalyst and KOtBu as the base with B2pin2 (pin = pinacolato) as the boron reagent. The aryl chlorides are converted into their corresponding arylboronic esters in good yields. The new procedure shows broad functional group tolerance, and B2neop2 (neop = neopentyl glycolato) can also be applied as the boron reagent.
- Kuehn, Laura,Huang, Mingming,Radius, Udo,Marder, Todd B.
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supporting information
p. 6601 - 6606
(2019/07/16)
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- Method for preparing aryl boronate at room temperature
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The invention discloses a method for preparing aryl boronate represented by a formula I at a room temperature. The method comprises: carrying out a reaction on a diboron compound represented by a formula II and an aryl halide in an organic solvent for 0.5-8 h at a room temperature under the actions of an alkali, a chloro(2-dicyclohexylphosphino-2',4',6'-tri-isopropyl-1,1'-biphenyl)(2'-amino-1,1'-biphenyl-2-yl)palladium (II) catalyst and a 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl ligand, and carrying out post-treatment to obtain the corresponding aryl boronate. According to the present invention, the method has characteristics of mild reaction conditions, simple operation, wide application range, good compatibility with various functional groups on aryl, high efficiency and economy, can achieve high yield of aryl borate under normal pressure and normal pressure conditions, and is suitable for large-scale preparation of aryl borate. The formulas I and II are defined in the specification, wherein R' represents any one selected from phenyl with substituent, pyridyl, thienyl, indyl, pyrazolyl and naphthyl.
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Paragraph 0020-0022; 0058-0060; 0075-0077
(2019/05/11)
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- 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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- Photoinduced Miyaura Borylation by a Rare-Earth-Metal Photoreductant: The Hexachlorocerate(III) Anion
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The first photoinduced carbon(sp2)–heteroatom bond forming reaction by a rare-earth-metal photoreductant, a Miyaura borylation, has been achieved. This simple, scalable, and novel borylation method that makes use of the hexachlorocerate(III) anion ([CeIIICl6]3?, derived from CeCl3) has a broad substrate scope and functional-group tolerance and can be conducted at room temperature. Combined with Suzuki–Miyaura cross-coupling, the method is applicable to the synthesis of various biaryl products, including through the use of aryl chloride substrates.
- Qiao, Yusen,Yang, Qiaomu,Schelter, Eric J.
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supporting information
p. 10999 - 11003
(2018/07/31)
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- Ortho-Selective C-H Borylation of Aromatic Ethers with Pinacol-borane by Organo Rare-Earth Catalysts
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The regioselective C-H borylation of aromatic ethers such as anisoles is of much interest and importance, but has remained a challenge to date. We report herein the catalytic ortho-selective C-H borylation of a wide range of aromatic ethers with pinacolborane (HBpin) by rare-earth metallocene complexes. This protocol offers an efficient and straightforward route for the synthesis of a variety of borylated aromatic ether derivatives. A proper metal/ligand combination for the rare-earth metal catalysts was found to be critically important to promote this transformation.
- Xue, Can,Luo, Yong,Teng, Huailong,Ma, Yuanhong,Nishiura, Masayoshi,Hou, Zhaomin
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p. 5017 - 5022
(2018/05/14)
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- Control of Chain Walking by Weak Neighboring Group Interactions in Unsymmetrical Catalysts
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A combined theoretical and experimental study shows how weak attractive interactions of a neighboring group can strongly promote chain walking and chain transfer. This accounts for the previously observed very different microstructures obtained in ethylene polymerization by [κ2-N,O-{2,6-(3′,5′-R2C6H3)2C6H3-Rfnet=C(H)-(3,5-X,Y-2-O-C6H2)}NiCH3(pyridine)], namely hyperbranched oligomers for remote substituents R = CH3 versus high-molecular-weight polyethylene for R = CF3. From a full mechanistic consideration, the alkyl olefin complex with the growing chain cis to the salicylaldiminato oxygen donor is identified as the key species. Alternative to ethylene chain growth by insertion in this species, decoordination of the monomer to form a cis β-agostic complex provides an entry into branching and chain-transfer pathways. This release of monomer is promoted and made competitive by a weak η2-coordination of the distal aryl rings to the metal center, operative only for the case of sufficiently electron-rich aryls. This concept for controlling chain walking is underlined by catalysts with other weakly coordinating furan and thiophene motifs, which afford highly branched oligomers with >120 branches per 1000 carbon atoms.
- Falivene, Laura,Wiedemann, Thomas,G?ttker-Schnetmann, Inigo,Caporaso, Lucia,Cavallo, Luigi,Mecking, Stefan
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supporting information
p. 1305 - 1312
(2018/02/09)
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- Rhodium-Catalyzed Decarbonylative Borylation of Aromatic Thioesters for Facile Diversification of Aromatic Carboxylic Acids
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Transformation of aromatic thioesters into arylboronic esters was achieved efficiently using a rhodium catalyst. The broad functional-group tolerance and mild conditions of the method have allowed for the two-step decarboxylative borylation of a wide range of aromatic carboxylic acids, including commercially available drugs.
- Ochiai, Hidenori,Uetake, Yuta,Niwa, Takashi,Hosoya, Takamitsu
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supporting information
p. 2482 - 2486
(2017/02/23)
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- Asymmetric supercapacitor devices based on dendritic conducting polymer and activated carbon
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Dendritic conducting polymers(CPs) are a novel class of porous pseudocapacitive electrode materials assembled with the combination of highly reversible redox active triphenylamine(TPA) and thiophene, 3-methylthiophene, selenophene and thieno[3,2-b]thiophen moieties. Due to the unique combination of three dimensional conducting network, fast redox reversible reactions, porous morphology, high thermal and electrochemical stability have fetched these pseudocapacitive polymers to exhibit high specific capacitance and emerged as an ideal candidate for energy storage devices. The electrochemical performance of as-prepared polymers showed specific capacitance of 278, 257, 246 and 315 Fg?1 for poly tris[4-(2-thienyl)phenyl]amine (P1), poly tris(4-(3-methylthiophene-2-yl)phenyl)amine (P2), poly tris(4-(selenophen-2-yl)phenyl)amine (P3) and poly tris(4-thieno[3,2-b]thiophen-2-yl) phenyl)amine (P4) respectively with low internal resistance. An insertion of selenophene and thieno(3,2-b)thiophene linkers in TPA block showed enhanced electrochemical performance than the thiophene-TPA pair. Furthermore, asymmetric supercapacitors were assembled with the polymer as cathode and activated carbon as an anode and the detailed electrochemical characterizations has been investigated. This research may shed light on designing new redox active psuedocapacitors and other electrochemical devices.
- Potphode, Darshna D.,Mishra, Sarada P.,Sivaraman,Patri, Manoranjan
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- Miyaura Borylation and One-Pot Two-Step Homocoupling of Aryl Chlorides and Bromides under Solvent-Free Conditions
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Solvent-free protocols for Miyaura borylation and the one-pot, two-step homocoupling of aryl halides are reported for the first time. Bis(dibenzylideneacetone)palladium(0) [Pd(dba)2] is an optimal source of palladium for Miyaura borylation, while for one-pot two-step homocoupling palladium(II) acetate [Pd(OAc)2] gives highest yields. Aryl bromides are coupled most efficiently using the DPEphos ligand. Chlorides are coupled using XPhos. The developed protocols are robust, versatile and easily reproducible on a large scale.
- Dzhevakov, Pavel B.,Topchiy, Maxim A.,Zharkova, Daria A.,Morozov, Oleg S.,Asachenko, Andrey F.,Nechaev, Mikhail S.
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p. 977 - 983
(2016/04/05)
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- Cobalt-catalyzed borylation of aryl halides and pseudohalides
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We report the first Co-catalyzed borylation of aryl halides and pseudohalides with bis(pinacolato)diboron (B2pin2). The synthesis of two new Co(II) complexes of oxazolinylferrocenylphosphine ligands is described. Upon activation with LiMe, the Co complex catalyzes the borylation reactions of aryl bromides, iodides, sulfonates, arenediazonium salts, and even aryl chlorides under mild conditions, providing the borylated products in excellent to moderate yields and with high functional group tolerance.
- Yao, Wubing,Fang, Huaquan,Peng, Sihan,Wen, Huanan,Zhang, Lei,Hu, Aiguo,Huang, Zheng
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p. 1559 - 1564
(2016/06/09)
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- Iridium/N-heterocyclic carbene-catalyzed C-H borylation of arenes by diisopropylaminoborane
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Catalytic C-H borylation of arenes has been widely used in organic synthesis because it allows the introduction of a versatile boron functionality directly onto simple, unfunctionalized arenes. We report herein the use of diisopropylaminoborane as a boron source in C-H borylation of arenes. An iridium(I) complex with 1,3-dicyclohexylimidazol-2-ylidene is found to efficiently catalyze the borylation of arenes and heteroarenes. The resulting aminoborylated products can be converted to the corresponding boronic acid derivatives simply by treatment with suitable diols or diamines.
- Tobisu, Mamoru,Igarashi, Takuya,Chatani, Naoto
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supporting information
p. 654 - 661
(2016/07/06)
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- Base-Free Palladium-Catalyzed Borylation of Aryl Chlorides with Diborons
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The base-free palladium-catalyzed borylation of aryl chlorides with diborons was achieved. The base-free conditions offered acceptable functional group compatibility. Based on experimental and computational studies, it was shown that smooth boryl transfer from the diborons to the arylpalladium chloride was promoted by strong interaction between the Lewis acidic boron and the chlorine atom on palladium.
- Yamamoto, Yutaro,Matsubara, Hiroshi,Yorimitsu, Hideki,Osuka, Atsuhiro
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p. 2317 - 2320
(2016/07/28)
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- Synthesis of 3-Aryl-1-aminopropane Derivatives: Lithiation-Borylation-Ring-Opening of Azetidinium Ions
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In situ generated 2-phenyl-azetidinium ylides react with boronic esters to form acyclic γ-dimethylamino tertiary boronic esters. The transformation is believed to involve the formation of a zwitterionic boronate, which subsequently undergoes ring-opening 1,2-migration, which is promoted by the relief of ring strain. Owing to the configurational instability of the initially formed ylides, which appear to be in equilibrium with the open-chain carbene form, the reaction is not stereospecific. The C-B bond of the γ-dimethylamino tertiary boronic esters can be transformed into a variety of functional groups (C-OH, C-vinyl, C-H, C-BF3), thus giving a diverse selection of 3-aryl-1-aminopropanes, which represent a privileged motif among drug molecules.
- Casoni, Giorgia,Myers, Eddie L.,Aggarwal, Varinder K.
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p. 3241 - 3253
(2016/09/12)
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- Novel organic semiconductors based on phenyl and phenylthienyl derivatives for organic thin-film transistors
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New phenyl and phenylthienyl derivatives end-functionalized with carbazole and α-carboline, 9-(4- (9H-carbazol-9-yl)phenyl)-9H-carbazole, 9-(4-(9H-carbazol-9-yl)phenyl)-9H-pyrido[2,3-b]indole, 9- (3-(9H-carbazol-9-yl)phenyl)-9H-carbazole, 9-(3-(9H-carbazol-9-yl)phenyl)-9H-pyrido[2,3-b]indole, 9-(4-(5-(9H-carbazol-9-yl)thiophen-2-yl)phenyl)-9H-carbazole, and 9-(3-(5-(9H-carbazol-9-yl) thiophen-2-yl)phenyl)-9H-carbazole were synthesized and characterized as organic semiconductors for organic thin-film transistors (OTFTs). Most compounds exhibited p-channel characteristics with carrier mobility as high as 1.7 × 10-5 cm2/Vs and a current on/off ratio of 102-104 for top-contact/bottom-gate OTFT devices.
- Lee, Eunsoo,Thirupathaiah, Bodakuntla,Han, Jaeuk,Jung, Dahae,Kwon, Guhyun,Kim, Choongik,Seo, Sung Yong
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p. 910 - 919
(2016/03/08)
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- Direct Access to α,α-Difluoroacylated Arenes by Palladium-Catalyzed Carbonylation of (Hetero)Aryl Boronic Acid Derivatives
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A palladium-catalyzed carbonylative coupling of (hetero)aryl boronates or boronic acid salts with carbon monoxide and α-bromo-α,α-difluoroamides and bromo-α,α-difluoroesters is described herein. The method is useful for the synthesis of a diverse selection of (hetero)aryl α,α-difluoro-β-ketoamides and α,α-difluoro-β-ketoesters, which are useful building blocks for the generation of functionalized difluoroacylated and difluoroalkyl arenes. The method could be further extended to a one-pot protocol for the formation of difluoroacetophenones.
- Andersen, Thomas L.,Frederiksen, Mette W.,Domino, Katrine,Skrydstrup, Troels
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supporting information
p. 10396 - 10400
(2016/08/24)
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- BASE METAL CATALYZED BORYLATION OF ARENES AND AROMMATIC HETEROCYCLES
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In one aspect, cobalt complexes are described herein. In some embodiments, such cobalt complexes employ bis(phosphine) or bis(imine) ligand and are operable as catalysts for borylation of arenes and aromatic heterocycles.
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Page/Page column 34
(2015/06/25)
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- Amine-borane complexes: Air- and moisture-stable partners for palladium-catalyzed borylation of aryl bromides and chlorides
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A method for using amine-borane complexes directly in palladium catalyzed borylation has been developed. The reaction proceeds through the sequential formation of a boronium species followed by deprotonation leading to the aminoborane. This reagent is then directly used in the borylation process leading, after work-up, to various boronic acid derivatives. The reaction was applied to (hetero)aryl triflates, iodides, bromides and chlorides.
- Guerrand, Hélène D. S.,Vaultier, Michel,Pinet, Sandra,Pucheault, Mathieu
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supporting information
p. 1167 - 1174
(2015/04/22)
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- Method for preparing aminoarylborane compounds or derivatives thereof
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The present invention provides a process for the preparation of aminoarylborane compounds and derivatives thereof comprising a step of arylation by reacting an aryl chloride with an aminoborane compound in the presence of a catalytic system. Typically, th
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Paragraph 0267
(2015/06/17)
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- METHOD FOR PREPARING AMINOARYLBORANE COMPOUNDS OR DERIVATIVES THEREOF
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The present invention provides a process for the preparation of aminoarylborane compounds and derivatives thereof comprising a step of arylation by reacting an aryl chloride with an aminoborane compound in the presence of a catalytic system.
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Page/Page column 86; 87
(2015/06/18)
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- Iridium-bipyridine periodic mesoporous organosilica catalyzed direct C-H borylation using a pinacolborane
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Heterogeneous catalysis for direct C-H borylation of arenes and heteroarenes in the combination of iridium (Ir) complex fixed on periodic mesoporous organosilica containing bipyridine ligands within the framework (Ir-BPy-PMO) and pinacolborane (HBpin) is reported. Ir-BPy-PMO showed higher catalytic activity toward the borylation of benzene with inexpensive HBpin compared to expensive bis(pinacolato)diboron (B2pin2). The precatalyst could be handled without the use of a glove box. The catalyst was easily recovered from reaction mixtures by simple filtration under air. The recovered catalyst still showed good catalytic activity for at least three more times for the borylation of benzene. A variety of arenes and heteroarenes were successfully borylated with high boron efficiency by Ir-BPy-PMO using HBpin, whereas almost no activity was observed for borylation of some heteroarenes with B2pin2. The system using Ir-BPy-PMO and HBpin was also utilized in syntheses of multi-boronated thiophene-based building blocks containing ladder-, acenefused-, and fused-thiophene skeletons. The combination of a stable and reusable solid catalyst and inexpensive HBpin is expected to be superior to conventional approaches for the development of industrial applications.
- Maegawa, Yoshifumi,Inagaki, Shinji
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supporting information
p. 13007 - 13016
(2016/01/09)
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- Novel carbazole derivative as a host material for blue phosphorescent organic light-emitting diodes
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A novel bipolar compound with a thiophene modified 9-phenylcarbazole and phosphine oxide moieties, (5-(4-(9H-carbazol-9-yl)phenyl)thiophen-2-yl)diphenylphosphine oxide (CPTPO), was synthesized and characterized as a high triplet energy host material. Bipolar charge transport character and a high triplet energy of 2.72 eV of CPTPO allowed the development of blue phosphorescent organic light-emitting diodes with an external quantum efficiency of 18.4%.
- Jeon, Sang Kyu,Thirupathaiah, Bodakuntla,Kim, Choongik,Lim, Kwon Taek,Lee, Jun Yeob,Seo, Sungyong
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p. 146 - 150
(2015/03/31)
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- Efficient synthesis of aryl boronates via zinc-catalyzed cross-coupling of alkoxy diboron reagents with aryl halides at room temperature
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A zinc(II)/NHC system catalyzes the borylation of aryl halides with diboron (4) reagents in the presence of KOMe at rt. This transformation can be applied to a broad range of substrates with high functional group compatibility. Radical scavenger experiments do not support a radical-mediated process.
- Bose, Shubhankar Kumar,Marder, Todd B.
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p. 4562 - 4565
(2015/01/08)
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- Application of cooperative iron/copper catalysis to a palladium-free borylation of aryl bromides with pinacolborane
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A new cooperative copper/iron catalysis for the borylation of various aryl bromides with pinacolborane, at -10 °C, is reported. Use of the toxic, precious metal Pd is avoided. The mechanism of the protodebromination side reaction is discussed.
- Labre, Flavien,Gimbert, Yves,Bannwarth, Pierre,Olivero, Sandra,Dunach, Elisabet,Chavant, Pierre Y.
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supporting information
p. 2366 - 2369
(2014/05/20)
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- Borylation of unactivated aryl chlorides under mild conditions by using diisopropylaminoborane as a borylating reagent
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The synthesis of arylboronic ester derivatives from aryl chlorides by using aryl(amino)boranes is described. Palladium-catalyzed coupling between aryl chlorides and diisopropylaminoborane leads to the formation of a C-B bond under mild conditions. A wide range of functional groups are tolerated, making this method particularly useful for the borylation of functionalized aromatics. Salts make the difference: The synthesis of arylboronic ester derivatives from aryl chlorides by using aryl(amino)boranes is described. Palladium-catalyzed coupling between aryl chlorides and diisopropylaminoborane leads to the formation of a C-B bond under mild conditions. A wide range of substituents, including electron-withdrawing groups, are tolerated (see scheme).
- Guerrand, Helene D. S.,Marciasini, Ludovic D.,Jousseaume, Melissa,Vaultier, Michel,Pucheault, Mathieu
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supporting information
p. 5573 - 5579
(2014/05/20)
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- Sequential dehydrogenation-arylation of diisopropylamine-borane complex catalyzed by palladium nanoparticles
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Palladium nanoparticles have been prepared using different techniques, CO2-assisted microfluidics coflow or thermolysis using ionic liquids. Both techniques displayed interesting activities in dehydrogenation of diisopropylamine-borane complex, and allowed performing a dehydrogenation-arylation sequence with the creation of a carbon-boron bond.
- Guerrand, Hélène D.S.,Marciasini, Ludovic D.,Gendrineau, Thomas,Pascu, Oana,Marre, Samuel,Pinet, Sandra,Vaultier, Michel,Aymonier, Cyril,Pucheault, Mathieu
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p. 6156 - 6161
(2015/03/30)
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- Silica-supported tripod triarylphosphines: Application to palladium-catalyzed borylation of chloroarenes
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Silica-supported tripod triarylphosphines that have a Ph3Ptype core tripodally immobilized on a silica surface enabled the Pd-catalyzed borylation of chloroarenes with bis(pinacolato)diboron under mild conditions. The immobilization in tripod was crucial for the excellent performance of the Ph3P-based ligands.
- Iwai, Tomohiro,Harada, Tomoya,Tanaka, Ryotaro,Sawamura, Masaya
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supporting information
p. 584 - 586
(2014/05/20)
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- Investigation of a lithium-halogen exchange flow process for the preparation of boronates by using a cryo-flow reactor
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Conducting low-temperature organometallic reactions under continuous flow conditions offers the potential to more accurately control exotherms and thus provide more reproducible and scalable processes. Herein, progress towards this goal with regards to the lithium-halogen exchange/borylation reaction is reported. In addition to improving the scope of substrates available on a research scale, methods to improve reaction profiles and expedite purification of the products are also described. On moving to a continuous system, thermocouple measurements have been used to track exotherms and provide a level of safety for continuous processing of organometallic reagents. The use of an in-line continuous liquid-liquid separation device to circumvent labour intensive downstream off-line processing is also reported. A cool setup: A small footprint, modular setup based around a cryo-flow reactor is reported for the preparation of gram quantities of boronic esters. With minimum alteration, including the addition of a data logger with thermocouples and a liquid-liquid separator, the same equipment can be used to scale the process, inclusive of an in-line extraction. Copyright
- Newby, James A.,Huck, Lena,Blaylock, D. Wayne,Witt, Paul M.,Ley, Steven V.,Browne, Duncan L.
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p. 263 - 271
(2014/01/17)
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- Cobalt-catalyzed C-H borylation
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A family of pincer-ligated cobalt complexes has been synthesized and are active for the catalytic C-H borylation of heterocycles and arenes. The cobalt catalysts operate with high activity and under mild conditions and do not require excess borane reagents. Up to 5000 turnovers for methyl furan-2-carboxylate have been observed at ambient temperature with 0.02 mol % catalyst loadings. A catalytic cycle that relies on a cobalt(I)-(III) redox couple is proposed.
- Obligacion, Jennifer V.,Semproni, Scott P.,Chirik, Paul J.
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supporting information
p. 4133 - 4136
(2014/04/03)
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- ORGANIC COMPOUNDS, PROCESS FOR PREPARING SAME AND USES IN ELECTRONICS
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The present disclosure relates to novel organic compounds, to the processes for preparing same and to the uses thereof, firstly in the electronics field, in particular in the fields referred to as plastic electronics and molecular electronics, and, secondly, in the coatings field, in particular in the fields of adhesion primers and intelligent coatings. The disclosure also relates to a material comprising a novel compound according to the invention.
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Paragraph 0148; 0149; 0150; 0151; 0152; 0153; 0154
(2013/04/10)
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- Molecular engineering of organic sensitizers with planar bridging units for efficient dye-sensitized solar cells
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Here comes the sun: Three highly efficient organic sensitizers with sterically hindered fluorenyl units and planar indenothiophene derivatives were designed and synthesized (see figure). Devices based on one of these compounds, JK-303, gave overall conversion efficiencies of 8.69, 9.04, 7.27, and 5.82 % using I-/I3-, CoII/CoIII, polymer gel, and solid-state electrolytes, respectively. These efficiencies are some of the highest reported for DSSCs based on organic sensitizers. Copyright
- Lim, Kimin,Ju, Myung Jong,Na, Jongbeom,Choi, Hyeju,Song, Min Young,Kim, Byeonggwan,Song, Kihyung,Yu, Jong-Sung,Kim, Eunkyoung,Ko, Jaejung
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supporting information
p. 9442 - 9446
(2013/07/26)
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- Design, generation, and synthetic application of borylzincate: Borylation of aryl halides and borylzincation of benzynes/terminal alkyne
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Borylzincate was generated in situ from dialkylzinc, diboron, and metal alkoxide. Model DFT calculations showed that although the formation of borylzincate is kinetically favorable, it is thermodynamically unfavorable. Therefore, we designed a successive reaction sequence that would provide a compensating energy gain. This enabled Zn-catalyzed borylation of aryl halides and borylzincation of benzynes and terminal alkyne from diborons without the need for any cocatalyst.
- Nagashima, Yuki,Takita, Ryo,Yoshida, Kengo,Hirano, Keiichi,Uchiyama, Masanobu
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supporting information
p. 18730 - 18733
(2014/01/06)
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- Synthesis of nitro- and amino-functionalized π-conjugated oligomers incorporating 3,4-ethylenedioxythiophene (EDOT) units
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Dissymmetric π-conjugated oligomers incorporating 3,4- ethylenedioxythiophene (EDOT) units and bearing nitro and amino end-groups were synthesized in good yields through Pd-catalyzed Suzuki coupling reactions and direct C-H bond arylation. Their spectrosc
- Trippé-Allard, Ga?lle,Lacroix, Jean-Christophe
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p. 861 - 866
(2013/07/27)
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