10486-61-0Relevant academic research and scientific papers
Improved synthesis of a terthiophene-based monomeric ligand that forms a highly active polymer for the carbon dioxide reduction
Quagliotto, Pierluigi,Prosperini, Simona,Viscardi, Guido
, p. 472 - 478 (2017)
Background: The carbon-dioxide reduction to obtain important chemicals such as fuels is a topic of high current interest. Recently, monomeric thiophenes and terthiophenes linked to a bipyridine ligand were designed and their polymeric films achieved very high turnover numbers during electrocatalytic CO2 reduction. In this paper we improved the protocol to access the ligand that shows the best performances, in view of opening the way to a general method to obtain side-functionalized terthiophenes. Methods: Several reactions were attempted to improve the synthetic pathway. Different approaches were attempted to convert the 3-bromothiophene into its 3-iodo analog and to brominate it to obtain the 2,5-dibromo-3-iodothiophene. The synthetic pathway was completed by using Pd-catalyzed crosscoupling reactions such as Sonogashira and Suzuki. The removal of a trimethylsilyl protection was attempted by common methods. However, with the use of a one-pot reaction, both the alkyne deprotection and the final Sonogashira coupling were performed as the key point of the pathway to obtain the final product. Results: The key intermediate 2,5-dibromo-3-iodothiophene was obtained by a CuI assisted electrophilic aromatic substitution, followed by a bromination with NBS in ethyl acetate. This compound was reacted with TMS-acetylene to obtain the ((2,5-dibromothiophen-3-yl)ethynyl)trimethylsilane which, by a Suzuki reaction, afforded the ([2,2':5',2''-terthiophen]-3'-ylethynyl)trimethylsilane. Using a onepot reaction for the last step, the deprotection of the TMS-protected alkyne and its coupling with 4- bromo-2,2'-bipyridine was accomplished easily. A final 52% yield was achieved over 5 steps. Conclusion: The ligand 4-([2,2':5',2''-terthiophen]-3'-ylethynyl)-2,2'-bipyridine was prepared in a 52% yield, over 5 steps, improving the previous protocol (17% yield over 4 steps). The rhenium complex of this ligand is still under study for CO2 reduction. This novel protocol can be used to produce a series of analog terthiophene monomers bearing side-attached ligands.
A facile synthesis of aryl iodides via potassium aryltrifluoroborates
Kabalka, George W.,Mereddy, Arjun R.
, p. 343 - 345 (2004)
Aryl- and heteroaryltrifluoroborates are rapidly converted to aryl and heteroaryl iodides under mild conditions using sodium iodide in the presence of mild oxidizing agents.
Synthesis of N-Substituted Condensed Tetrahydropyridine-Based Enaminones via Palladium-Catalyzed Intramolecular C–N Cross-coupling
Dou?ová, Hana,R??i?ková, Zdeňka,?im?nek, Petr
, p. 670 - 684 (2018)
A number of β-enaminones with secondary amino group (alkyl, cyclopropyl, and aryl) were prepared from corresponding β-diketones. Two general protocols for their palladium-catalyzed intramolecular C–N cross-coupling were established to give corresponding N-substituted condensed tetrahydropyridines in good yields. The methodology is applicable for a wide variety of structural motifs. The work also extends the applicability of novel, recently established, palladium precatalysts to new substrates.
Selective metallation of 3-halothiophenes: Practical methods for the synthesis of 2-bromo-3-formylthiophene
Sonoda, Motohiro,Kinoshita, Shoko,Luu, Thanh,Fukuda, Hiroshi,Miki, Koji,Umeda, Rui,Tobe, Yoshito
, p. 3315 - 3323 (2009)
Selective lithiation of 3-bromothiophene was accomplished under controlled conditions without formation of undesired thienyllithium compounds. A thienyl Grignard reagent derived from 2-bromo-3-iodothiophene was transformed into 2-bromo-3-formylthiophene in high selectivity by formylation with dimethylformamide (DMF) at optimal reaction temperature. Copyright Taylor & Francis Group, LLC.
Incorporation of perfluorohexyl-functionalised thiophenes into oligofluorene-truxenes: Synthesis and physical properties
Thomson, Neil,Kanibolotsky, Alexander L.,Cameron, Joseph,Tuttle, Tell,Findlay, Neil J.,Skabara, Peter J.
, p. 1243 - 1251 (2013)
Oligofluorene-functionalised truxenes containing perfluorohexylthiophene units at the terminal positions on the arms were synthesised, and their optical and electrochemical properties were investigated to determine the effect that the perfluorohexylthiophene unit has on the HOMO and LUMO properties of the oligomers. By synthesising a molecule with longer oligofluorene arms the effects of the perfluorohexylthiophene unit on larger oligomers was explored. The effect of steric hindrance from the perfluorohexyl chain was also evaluated by altering the position of the chain on the thiophene moiety.
Impact of pendant 1,2,3-triazole on the synthesis and properties of thiophene-based polymers
Nagarjuna,Yurt, Serkan,Jadhav, Kedar G.,Venkataraman
, p. 8045 - 8050 (2010)
π-Conjugated moieties are often attached to conjugated polymers to systematically alter their electronic properties. Herein, we report the synthesis and properties of a thiophene polymer bearing a triazole moiety in the third position. Through NMR-based quenching studies, we show that the placement of the triazole moiety alters reaction pathway of the Ni(0)-mediated Grignard metathesis polymerization possibly through chelation. When compared with a triazole on the main chain, the pendant triazole moiety acts as an electron donor and lowers the band gap of the polymer. The triazole moiety also does not hinder the packing of the conjugated backbone. We also show that the fluorescence of this polymer is quenched with PCBM, indicating its potential as a candidate for organic photovoltaic devices.
Domino Direct Arylation and Cross-Aldol for Rapid Construction of Extended Polycyclic π-Scaffolds
Nitti, Andrea,Bianchi, Gabriele,Po, Riccardo,Swager, Timothy M.,Pasini, Dario
, p. 8788 - 8791 (2017)
Five-membered aromatic heterocycles are a ubiquitous skeleton of π-conjugated organic compounds, and their incorporation requires synthetic protocols that are not easily industrially sustainable or scalable. Improved methodologies for their insertion into π-scaffolds are therefore necessary. We report an efficient and scalable protocol involving a one-pot cross-Aldol direct arylation reaction protocol for the rapid construction of thiophene- and furan-based π-extended organic materials.
Regioselective iodination of arenes using iodine/NaBO3· 4H2O system in ionic liquid
Bhilare, Sachin V.,Deorukhkar, Amol R.,Darvatkar, Nitin B.,Salunkhe, Manikrao M.
, p. 2881 - 2888 (2008)
A mild, efficient, and simple protocol was developed for iodination of arenes and heterocyclic compounds with molecular iodine catalyzed by sodium perborate in ionic liquid. The methodology offered iodoarenes in good to excellent yields at room temperature. The protocol proved to be highly selective, as a single isomer was formed exclusively in most of the substrates. Copyright Taylor & Francis Group, LLC.
Copper-catalyzed conversion of aryl and heteroaryl bromides into the corresponding iodide
Feng, Xiujuan,Li, Lingyu,Yu, Xiaoqiang,Yamamoto, Yoshinori,Bao, Ming
, p. 129 - 132 (2016)
An efficient method for the synthesis of aryl and heteroaryl iodides is described in this study. The reactions of aryl and heteroaryl bromides with potassium iodide proceeded smoothly in the presence of a copper catalyst under mild reaction conditions to produce the corresponding iodides in satisfactory to excellent yields.
Mild preparation of haloarenes by ipso-substitution of arylboronic acids with N-halosuccinimides
Thiebes, Christoph,Prakash, G. K. Surya,Petasis, Nicos A.,Olah, George A.
, p. 141 - 142 (1998)
Aryl and heteroaryl boronic acids react with N-iodosuccinimide and N-bromosuccinimide to give the corresponding iodo-and bromo- arenes in good to excellent yields. The reaction is usually highly regioselective and yields only the ipso-substituted product. Esters of arylboronic acids react similarly, but less readily.
