10486-61-0Relevant articles and documents
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.
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.
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.
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.
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.
Room Temperature Stable 3-Lithiothiophene: a Facile Synthesis of 3-Functional Thiophenes
Wu, Xiaoming,Chen, Tian-An,Zhu, Lishan,Rieke, Reuben D.
, p. 3673 - 3674 (1994)
3-Functionalized thiphenes were readily prepared by reacting electrophiles with 3-lithiothiophene at room temperature. 3-Lithiothiophene was found to be stable in hexane at room temperature.
Orthogonal Stability and Reactivity of Aryl Germanes Enables Rapid and Selective (Multi)Halogenations
Deckers, Kristina,Fricke, Christoph,Schoenebeck, Franziska
supporting information, p. 18717 - 18722 (2020/08/25)
While halogenation is of key importance in synthesis and radioimaging, the currently available repertoire is largely designed to introduce a single halogen per molecule. This report makes the selective introduction of several different halogens accessible. Showcased here is the privileged stability of nontoxic aryl germanes under harsh fluorination conditions (that allow selective fluorination in their presence), while displaying superior reactivity and functional-group tolerance in electrophilic iodinations and brominations, outcompeting silanes or boronic esters under rapid and additive-free conditions. Mechanistic experiments and computational studies suggest a concerted electrophilic aromatic substitution as the underlying mechanism.
