239075-02-6Relevant academic research and scientific papers
Synthesis of 2,3-Dihydrothieno[2,3-b]-1,4-dithiine, 2,3-Dihydrothieno-[3,2-b]-1,4-oxathiine, 2,3-Dihydrothieno[2,3-b]-1,4-oxathiine and Their Transformation into Corresponding End-Capped Oligomers
Hellberg, Jonas,Remonen, Tommi,Allared, Fredrik,Slaett, Johnny,Svensson, Mats
, p. 2199 - 2205 (2003)
Three new heterocyclic parent compounds, 2,3-dihydrothieno[2,3-b][1,4]dithiine (TDT), 2,3-dihydrothieno[3,2-b][1,4]oxathiine (TOT), and 2,3-dihydrothieno[2,3-b][1,4]oxathiine, have been synthesized by acid-catalyzed transformations starting from 3-methoxy
Synthesis of a 1,2-Dithienylethene-Containing Donor-Acceptor Polymer via Palladium-Catalyzed Direct Arylation Polymerization (DArP)
Wakioka, Masayuki,Yamashita, Natsumi,Mori, Hiroki,Nishihara, Yasushi,Ozawa, Fumiyuki
, (2018)
This paper reports the synthesis of D-A polymers containing 1,2-dithienylethene (DTE) units via palladium-catalyzed direct arylation polymerization (DArP). The reaction of dibromoisoindigo (1-Br) and DTE (2-H), in the presence of Pd2(dba)3·CHCl3 (0.5 mol%), P(2-MeOC6H4)3 (L1) (2 mol%), pivalic acid (1 equiv) as catalyst precursors, and Cs2CO3 (3 equiv) as a base affords poly(1-alt-2) with a high molecular weight (Mn up to 44,900). Although, it has been known that monomers, with plural C–H bonds, tend to form insoluble materials via direct arylation at undesirable C–H positions; the reaction of 1-Br and 2-H cleanly proceeds without insolubilization. The resulting polymer has a well-controlled structure and exhibits good charge transfer characteristics in an organic field-effect transistor (OFET), compared to the polymer produced by Migita–Kosugi–Stille cross-coupling polymerization. The DArP product displays an ideal linear relationship in the current–voltage curve, whereas the Migita–Kosugi–Stille product shows a VG-dependent change in the charge mobility.
Iridium-bipyridine periodic mesoporous organosilica catalyzed direct C-H borylation using a pinacolborane
Maegawa, Yoshifumi,Inagaki, Shinji
supporting information, p. 13007 - 13016 (2016/01/09)
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.
Nucleophile-selective cross-coupling reactions with vinyl and alkynyl bromides on a dinucleophilic aromatic substrate
He, Lu-Ying,Schulz-Senft, Mathias,Thiedemann, Birk,Linshoeft, Julian,Gates, Paul J.,Staubitz, Anne
, p. 2498 - 2502 (2015/04/22)
A nucleophile-selective cross-coupling reaction on an aromatic compound bearing two metal groups, Bpin and SnMe3, has been developed. Previously, only aryl bromides and iodides could be used as electrophilic components, but in this work, the scope could be extended to vinyl and alkynyl bromides as electrophiles. This means that the roles typical in Sonogashira couplings or Heck reactions of the aromatic ring as the dielectrophile coupling to vinyl and alkynyl metal species are reversed, which presents a new tool for organic synthesis. The first nucleophilic site to react is the stannyl group, and subsequently, a Suzuki-Miyaura cross-coupling reaction can take place on the same molecule.
Mechanistic studies into amine-mediated electrophilic arene borylation and its application in MIDA boronate synthesis
Bagutski, Viktor,Del Grosso, Alessandro,Carrillo, Josue Ayuso,Cade, Ian A.,Helm, Matthew D.,Lawson, James R.,Singleton, Paul J.,Solomon, Sophia A.,Marcelli, Tommaso,Ingleson, Michael J.
, p. 474 - 487 (2013/02/25)
Direct electrophilic borylation using Y2BCl (Y2 = Cl2 or o-catecholato) with equimolar AlCl3 and a tertiary amine has been applied to a wide range of arenes and heteroarenes. In situ functionalization of the ArBCl2 products is possible with TMS 2MIDA, to afford bench-stable and easily isolable MIDA-boronates in moderate to good yields. According to a combined experimental and computational study, the borylation of activated arenes at 20 C proceeds through an S EAr mechanism with borenium cations, [Y2B(amine)] +, the key electrophiles. For catecholato-borocations, two amine dependent reaction pathways were identified: (i) With [CatB(NEt 3)]+, an additional base is necessary to accomplish rapid borylation by deprotonation of the borylated arenium cation (σ complex), which otherwise would rather decompose to the starting materials than liberate the free amine to effect deprotonation. Apart from amines, the additional base may also be the arene itself when it is sufficiently basic (e.g., N-Me-indole). (ii) When the amine component of the borocation is less nucleophilic (e.g., 2,6-lutidine), no additional base is required due to more facile amine dissociation from the boron center in the borylated arenium cation intermediate. Borenium cations do not borylate poorly activated arenes (e.g., toluene) even at high temperatures; instead, the key electrophile in this case involves the product from interaction of AlCl3 with Y2BCl. When an extremely bulky amine is used, borylation again does not proceed via a borenium cation; instead, a number of mechanisms are feasible including via a boron electrophile generated by coordination of AlCl3 to Y2BCl, or by initial (heteroarene)AlCl3 adduct formation followed by deprotonation and transmetalation.
PROCESS FOR THE BORYLATION OF ARENES AND HETEROARYLS
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Page/Page column 49-50, (2012/03/26)
This invention relates to a novel process for the borylation of arenes and heteroaryls. The present invention also provides novel borenium cations, which act as electrophiles for electrophilic substitution on the arene or heteroaryl ring, as well as to methodology for the preparation of these cations.
Simple inexpensive boron electrophiles for direct arene borylation
Del Grosso, Alessandro,Helm, Matthew D.,Solomon, Sophia A.,Caras-Quintero, Dolores,Ingleson, Michael J.
, p. 12459 - 12461 (2012/01/12)
Electrophilic direct borylation is facilitated, and arene substrate scope enhanced, by using electrophiles derived from inexpensive reagents; specifically an amine, BCl3 and AlCl3.
Novel low-bandgap oligothiophene-based donor-acceptor alternating conjugated copolymers: Synthesis, properties, and photovoltaic applications
Li, Yaowen,Li, Zaifang,Wang, Chunyu,Li, Hui,Lu, Hongguang,Xu, Bin,Tian, Wenjing
experimental part, p. 2765 - 2776 (2011/03/19)
A series of novel soluble donor-acceptor lowbandgap-conjugated polymers consisting of different oligothiophene (OTh) coupled to electron-accepting moiety 2-pyran-4ylidenemalononitrile (PM)-based unit were synthesized by Stille or Suzuki coupling polymerization. The combination of electron-accepting PM building block with varied OThn (the number of thiophene unit increases from 3 to 5) results in enhanced π-π stacking in solid state and intramolecular charge transfer (ICT) transition, which lead to an extension of the absorption spectra of the copolymers. Cyclic voltammetry measurements and molecular orbital distribution calculations indicate that the highest occupied molecular orbitals (HOMO) energy levels could be fine-tuned by changing the number of thiophene units of the copolymers, and the resulting copolymers possessed relatively low HOMO energy levels promising good air stability and high-open circuit voltage (Voc) for photovoltaic application. Bulk heterojunction photovoltaic devices were fabricated by using the copolymers as donors and (6,6)phenyl C61-butyric acid methyl ester as acceptor. It was found that the highest Voc reached 0.94 V, and the short circuit currents (Jsc) were improved from 1.78 to 2.54 mA/cm2, though the power conversion efficiencies of the devices were measured between 0.61 and 0.99% under simulated AM 1.5 solar irradiation of 100 mW/cm 2, which indicated that this series copolymers can be promising candidates for the photovoltaic applications.
Dithienosilole- and dibenzosilole-thiophene copolymers as semiconductors for organic thin-film transistors
Usta, Hakan,Lu, Gang,Facchetti, Antonio,Marks, Tobin J.
, p. 9034 - 9035 (2007/10/03)
The synthesis and physicochemical properties of a new class of thiophene/arenesilole-containing π-conjugated polymers are reported. Examples of this new polymer class include the following: poly(2,5-bis(3′,3′′-dihexylsilylene-2′,2′′-bithieno)thiophene) (TS6T1), poly(2,5′-bis(3′′,3′″-dihexylsilylene-2′′,2′″-bithieno)bithiophene) (TS6T2), poly(2,5′-bis(2′′,2′″-dioctylsilylene-1′′,1′″-biphenyl)thiophene) (BS8T1), and poly(2,5′-bis(2′′,2′″-dioctylsilylene-1′′,1′″-biphenyl)bithiophene) (BS8T2). Organic field-effect transistors (OFETs) with hole carrier mobilities as high as 0.02-0.06 cm2/V s in air, low turn-on voltages, and current on/off ratios >105-106 are fabricated using solution processing techniques with the above polymers as the active channel layer. OFETs based on this polymer class exhibit excellent ambient operational stability. Copyright
Solvent-free, microwave-assisted synthesis of thiophene oligomers via suzuki coupling
Melucci, Manuela,Barbarella, Giovanna,Sotgiu, Giovanna
, p. 8877 - 8884 (2007/10/03)
The purpose of this study was to obtain a rapid, efficient, and environmentally friendly methodology for the synthesis of highly pure thiophene oligomers. The solvent-free, microwave-assisted coupling of thienyl boronic acids and esters with thienyl bromides, using aluminum oxide as the solid support, allowed us to rapidly check the reaction trends on changing times, temperature, catalyst, and base and easily optimize the experimental conditions to obtain the targeted product in fair amounts. This procedure offers a novel, general, and very rapid route to the preparation of soluble thiophene oligomers. Thus, for example, quaterthiophene was obtained in 6 min by reaction of 2-bromo-2,2′-bithiophene with bis(pinacolato)diboron (isolated yield 65%), whereas quinquethiophene was obtained in 11 min by reaction of dibremoterthiophene with thienylboronic acid (isolated yield 74%). The synthesis of new chiral 2,2′-bithiophenes is reported. The detailed analysis of the byproducts of some reactions allowed us to elucidate a few aspects of reaction mechanisms. While the use of microwaves proved to be very convenient for the coupling between conventional thienyl moieties, the same was not true for the coupling of thienyl rings to thienyl-S,S-dioxide moieties. Indeed, in this case, the targeted product was obtained in low yields because of the competitive, accelerated, Diels-Alder reaction that affords a variety of condensation products.
