- Synthesis and catalytic activity of a poly(N,N-dialkylcarbodiimide)/ palladium nanoparticle composite: A case in the Suzuki coupling reaction using microwave and conventional heating
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Poly(N,N-dialkylcarbodiimide) was found to be an effective polymeric ligand system for preparing and stabilizing palladium nanoparticles (1-5 nm). The composite material prepared in situ was found to be a robust catalyst for the Suzuki coupling reaction under microwave or regular heating.
- Liu, Yubiao,Khemtong, Chalermchai,Hu, Jun
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- Iron-catalysed regioselective thienyl C–H/C–H coupling
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Regioselective thienyl–thienyl coupling is arguably one of the most important transformations for organic electronic materials. A prototype of ideal organic synthesis to couple two thienyl groups by cutting two C–H bonds requires formal removal of two hydrogen atoms with an oxidant, which often limits the synthetic efficiency and versatility for oxidation-sensitive substrates (for example, donor and hole-transporting materials). Here, we found that diethyl oxalate, used together with AlMe3, acts as a two-electron acceptor in an iron-catalysed C–H activation. We describe the regioselective thienyl C–H/C–H coupling with an iron(III) catalyst, a trisphosphine ligand, AlMe3 and diethyl oxalate under mild conditions. The efficient catalytic system accelerated by ligand optimization polymerizes thiophene-containing monomers into homo- and copolymers bearing a variety of electron-donative π motifs. The findings suggest the versatility of iron catalysis for the synthesis of functional polymers, for which the potential of this ubiquitous metal has so far not been fully appreciated. [Figure not available: see fulltext.].
- Doba, Takahiro,Ilies, Laurean,Nakamura, Eiichi,Sato, Wataru,Shang, Rui
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p. 631 - 638
(2021/07/25)
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- A Bithiophene-Promoted ppm Levels of Palladium-Catalyzed Regioselective Hydrosilylation of Terminal Allenes
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A bithiophene?alkyne-based compound was synthesized and first utilized as a ligand for the selective hydrosilylation of allenes with primary and secondary phenylsilanes. It shows high selectivity towards the production of branched allylsilanes with a wide range of allenes. It is worth mentioning that the catalytic loading of the palladium can be reduced to 500 ppm. This work opens a new front of using bidentate thiophene ligand as a reaction promoter in transition-metal-catalyzed organic reaction. (Figure presented.).
- Chen, Jun-Jia,Zeng, Jia-Hao,Yang, Ying,Liu, Zhi-Kai,Jiang, Ya-Nan,Li, Miao-Ran,Chen, Li,Zhan, Zhuang-Ping
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p. 2360 - 2366
(2020/04/28)
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- Superelectrophilic-initiated C-H functionalization at the β-position of thiophenes: A one-pot synthesis of trans-stereospecific saddle-shaped cyclic compounds
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Superelectrophilic-initiated direct C-H functionalization of thiophenes at the β-position was developed. A series of trans-stereospecific [2,1-a]-IF-thiophene-fused cyclic compounds (4) with saddle-shaped structure were prepared in 17-30% yields through a
- Wei, Ying,Zheng, Xiangping,Lin, Dongqing,Yuan, Haoxuan,Yin, Zhipeng,Yang, Lei,Yu, Yang,Wang, Shasha,Xie, Ling-Hai,Huang, Wei
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p. 10701 - 10709
(2019/09/09)
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- Pd-catalyzed oxidative cross-coupling between two electron rich heteroarenes
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The transition-metal-catalyzed oxidative cross-coupling between two coupling partners with similar structure and electronic characteristics remains a challenge owing to difficulty in suppressing undesired homo-couplings. We herein report a Pd-catalyzed oxidative cross-coupling between two thiophenes under mild reaction conditions. This approach can also be extended to furans. Some notable advantages of this reaction lie in its synthetic simplicity with the omission of the toxic stannanes coupling partner and excellent functional-group compatibility. The features of this protocol make it an ideal strategy for the construction of a 2,2′-thiophene-thiophene linkage of interest in electronic and optoelectronic materials.
- He, Chun-Yang,Wang, Zhen,Wu, Cai-Zhi,Qing, Feng-Ling,Zhang, Xingang
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p. 3508 - 3513
(2013/11/19)
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- Dichloro-bis(aminophosphine) complexes of palladium: Highly convenient, reliable and extremely active suzuki-miyaura catalysts with excellent functional group tolerance
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Dichloro-bis(aminophosphine) complexes are stable depot forms of palladium nanoparticles and have proved to be excellent SuzukiMiyaura catalysts. Simple modifications of the ligand (and/or the addition of water to the reaction mixture) have allowed their formation to be controlled. Dichlorobis[1- (dicyclohexylphosphany1)piperidine]palladium (3), the most active catalyst of the investigated systems, is a highly convenient, reliable, and extremely active Suzuki catalyst with excellent functional group tolerance that enables the quantitative coupling of a wide variety of activated, nonactivated, and deactivated and/or sterically hindered functionalized and heterocyclic aryl and benzyl bromides with only a slight excess (1.1-1.2 equiv) of arylboronic acid at 80°C in the presence of 0.2 mol % of the catalyst in technical grade toluene in flasks open to the air. Conversions of >95% were generally achieved within only a few minutes. The reaction protocol presented herein is universally applicable. Side-products have only rarely been detected. The catalytic activities of the aminophosphine-based systems were found to be dramatically improved compared with their phosphine analogue as a result of significantly faster palladium nanoparticle formation. The decomposition products of the catalysts are dicyclohexylphosphinate, cyclohexylphosphonate, and phosphate, which can easily be separated from the coupling products, a great advantage when compared with non-water-soluble phosphine-based systems.
- Bolliger, Jeanne L.,Frech, Christian M.
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supporting information; experimental part
p. 4075 - 4081
(2010/08/05)
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- Synthesis of 5,5′-diarylated 2,2′-bithiophenes via palladium-catalyzed arylation reactions
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2,2′-Bithiophene and 3,3′-dicyano-2,2′-bithiophenes are diarylated directly with aryl bromides at the 5- and 5′-positions accompanied by C-H bond cleavage in the presence of Pd(OAc)2 and a bulky phosphine ligand using Cs2CO3 as base. In the reaction using (2,2′-bithiophen-5-yl)diphenylmethanol as the substrate, monoarylation at the 5-position via C-C bond cleavage occurs selectively to give 5-aryl-2,2′-bithiophenes and the subsequent arylation with a different aryl bromide affords the corresponding unsymmetrically 5,5′-diarylated products.
- Yokooji, Aya,Satoh, Tetsuya,Miura, Masahiro,Nomura, Masakatsu
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p. 6757 - 6763
(2007/10/03)
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- Molecular compound, luminous material using the same, and luminous element
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Provided is a new molecular compound excellent in luminous property, which has a molecular structure wherein a thiophene ring and a benzene (or naphthalene) ring are directly bonded to each other, as a molecular compound making it possible to control its
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- Optical and redox properties of a series of 3,4-ethylenedioxythiophene oligomers
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The optical and redox properties of a series of 3,4-ethylenedioxythiophene oligomers (EDOTn, n=1-4) and their β,β'-unsubstituted analogues (Tn, n=1-4) are described. Both series are end capped with phenyl groups to prevent irreversible a-coupling reaction
- Apperloo, Joke J.,Bert Groenendaal,Verheyen, Hilde,Jayakannan, Manickam,Janssen, Rene A. J.,Dkhissi, Ahmed,Beljonne, David,Lazzaroni, Roberto,Bredas, Jean-Luc
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p. 2384 - 2396
(2007/10/03)
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- Synthesis of thiophene/phenylene co-oligomers. I. Phenyl-capped oligothiophenes
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We report the synthesis of phenyl-capped oligothiophenes via improved synthetic schemes. These schemes are based on the Grignard coupling reaction and enable us to obtain the target compounds at high yields. The resulting materials have been fully charact
- Hotta,Lee,Tamaki
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- The preparations and some properties of mixed aryl-thienyl oligomers and polymers
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The syntheses by transition metal coupling reactions of a large number of oligomers constructed from benzene and thiophene rings are described. The first use of arylcadmium chlorides for such coupling reactions is reported. The routes chosen allow for rational variation in the modes of linkage, the substitution and the proportions of the two units. The benzene and thiophene rings are always joined in a known order and may bear a wide variety of regularly spaced functional groups. Additionally the shape of the oligomers may be varied at will. In all cases p-type doping with iodine or ferric chloride leads to large enhancements in conductivity.
- Pelter, Andrew,Jenkins, Ieuan,Jones, D. Elfyn
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p. 10357 - 10400
(2007/10/03)
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- UNSYMMETRICAL COUPLING OF 2-ARYLTHIOPHENES BY CATION EXCHANGE RESIN
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2-Arylthiophenes coupled through the 4,5'-positions of the two thiophene rings by the action of cation exchange resin to afford unsymmetrical 5,5'-diaryl-2,3'-bithienyls as principal products.
- Sone, Tyo,Kubo, Masaaki,Kanno, Tsutomu
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p. 1195 - 1198
(2007/10/02)
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