- Copper catalysed Gomberg-Bachmann-Hey reactions of arenediazonium tetrafluoroborates and heteroarenediazonium o-benzenedisulfonimides. Synthetic and mechanistic aspects
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Gomberg-Bachmann-Hey reactions were carried out in the presence of copper as a catalyst and gave rise to biaryls or heterobiaryls in good yields and in mild reaction conditions. A computational study of some key points of the reaction was performed. The results are coherent with the experimental data and confirm some aspects of the mechanism. The reaction free energies for the reduction in benzene by CuI of a set of 40 (hetero)arenediazonium tetrafluoroborates were calculated. Both the experiments and the calculations showed that in the coupling with substituted solvents (toluene, bromobenzene, nitrobenzene and anisole) the binding to the ortho position was always favoured.
- Antenucci, Achille,Barbero, Margherita,Dughera, Stefano,Ghigo, Giovanni
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- Atom-efficient Pd-catalyzed cross-couplings of chloroarenes with triarylbismuth reagents
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Various Pd-catalyzed protocols have been developed for the atom-efficient cross-coupling of chloroarenes with triarylbismuth reagents. Using the developed protocols, an efficient synthesis of unsymmetrical biaryls in good to excellent yields was achieved by employing electron-deficient chloroarenes and a range of triarylbismuth reagents.
- Rao, Maddali L.N.,Meka, Suresh
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supporting information
(2019/07/30)
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- Gold catalysed Suzuki-Miyaura coupling of arenediazonium o-benzenedisulfonimides
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Arenediazonium o-benzenedisulfonimides have been used as efficient electrophilic partners in Au(I) catalysed Suzuki coupling reactions. The synthetic protocol is general, easy and produced either biaryls or heteroaryl arenes in good yields (51 positive examples, average yield 80%). o-Benzenedisulfonimide was recovered at the end of the reactions and was reused to prepare the starting salts for further reactions. Mechanistic insights suggest that the o-benzenedisulfonimide anion act as an electron transfer agent and promotes a catalytic cycle which does not require the presence of photocatalysts or external oxidants.
- Barbero, Margherita,Dughera, Stefano
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p. 5758 - 5769
(2018/09/10)
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- Integrating Organic Lewis Acid and Redox Catalysis: The Phenalenyl Cation in Dual Role
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In recent years, merging different types of catalysis in a single pot has drawn considerable attention and these catalytic processes have mainly relied upon metals. However, development of a completely metal free approach integrating organic redox and organic Lewis acidic property into a single system has been missing in the current literature. This study establishes that a redox active phenalenyl cation can activate one of the substrates by single electron transfer process while the same can activate the other substrate by a donor-acceptor type interaction using its Lewis acidity. This approach has successfully achieved light and metal-free catalytic C-H functionalization of unactivated arenes at ambient temperature (39 entries, including core moiety of a top-selling molecule boscalid), an economically attractive alternative to the rare metal-based multicatalysts process. A tandem approach involving trapping of reaction intermediates, spectroscopy along with density functional theory calculations unravels the dual role of phenalenyl cation.
- Ahmed, Jasimuddin,Chakraborty, Soumi,Jose, Anex,Sreejyothi,Mandal, Swadhin K.
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supporting information
p. 8330 - 8339
(2018/06/19)
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- An active catalytic system for Suzuki-Miyaura cross-coupling reactions using low levels of palladium loading
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An easily available Pd(OAc)2/(2-(anthracen-9-yl)-1H-inden-3-yl) dicyclohexylphosphine/toluene/iPrOH/water catalytic system was developed, which shows high catalytic activity in the Suzuki-Miyaura cross-coupling reactions of a diverse array of aryl and heteroaryl chlorides with Pd loadings down to 0.01 mol%.
- Yan, Meng-Qi,Yuan, Jia,Lan, Fang,Zeng, Si-Hao,Gao, Meng-Yue,Liu, Sheng-Hua,Chen, Jian,Yu, Guang-Ao
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supporting information
p. 3924 - 3929
(2017/07/10)
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- Water-soluble palladium click chelating complex: An efficient and reusable precatalyst for Suzuki-Miyaura and Hiyama reactions in water
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A water-soluble ionic palladium(II) nitrogen-containing chelating complex, [palladium(II) 1-(4-N,N′,N′′-trimethylbutylammonium)-4-(2- pyridyl)-1H-1,2,3-triazole dichloride] chloride (3), was prepared through the click reaction of 1-chloro-4-bromobutane, sodium azide, and 2-ethynylpyridine, followed by the quarternization of Me3N and subsequent reaction with [Pd(cod)Cl2] (cod=1,5-cyclooctadiene). The catalytic performances of complex 3 were preliminarily evaluated through Suzuki-Miyaura and Hiyama cross-coupling reactions of aryl bromides; excellent catalytic activity in water was observed. TEM analysis revealed that small palladium nanoparticles (NPs) with a narrow size distribution were formed after the catalytic reaction. The NPs were stabilized by the synergetic effect of coordination and electrostatic interactions from the ionic, bidentate, nitrogen-containing ligand; no palladium black was detected after the aqueous solution of palladium NPs was stored in air for months. The use of 3 as a precursor in the formation of palladium NPs was further explored by using NaBH4 and hydrogen as reductive reagents. The resulting NPs displayed different sizes, surface properties, and catalytic performances in the Suzuki-Miyaura cross-coupling reaction in water. Copyright
- Kong, Fanzhen,Zhou, Chunshan,Wang, Jinyun,Yu, Zhangyu,Wang, Ruihu
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p. 536 - 545
(2013/07/26)
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- A palladium chelating complex of ionic water-soluble nitrogen-containing ligand: The efficient precatalyst for Suzuki-Miyaura reaction in water
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An ammonium-functionalized water-soluble bidentate nitrogen-containing ligand (3) and its palladium chelating complex (4) have been easily prepared from the commercial available starting materials in high overall yields. The charge distributions and molecular orbital analyses of 3, 4 and non-ionic hydrophobic analogue (2a) based on the optimized structures were implemented. The crystal structure of 4 has been established by single-crystal X-ray diffraction. The water-soluble palladium complex was a much more effective catalyst than 2a in palladium-catalyzed Suzuki-Miyaura cross-coupling reaction in air and pure water. High catalytic activity of aryl chlorides and aryl bromides was observed. The mercury drop test, poison experiments and TEM analysis of the catalytic solution showed Pd(0) were involved in catalysis. The palladium nanoparticles of 3.0 ± 0.6 nm were formed after the catalytic reaction, they were stabilized by synergetic effect of coordination and electrostatic interactions from the ammonium-functionalized chelating ligand. No precipitate was observed when the aqueous nanoparticles were stored in air for months.
- Zhou, Chunshan,Wang, Jinyun,Li, Liuyi,Wang, Ruihu,Hong, Maochun
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experimental part
p. 2100 - 2106
(2011/10/03)
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- In situ formation of N,O-bidentate ligand via the hydrogen bond for highly efficient Suzuki reaction of aryl chlorides
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A highly efficient protocol for the Pd(OAc)2-catalyzed aerobic Suzuki reaction of aryl chlorides is reported, which is proposed to be promoted by the N,O-bidentate ligand formed in situ via the hydrogen bond of solvents.
- Yang, Weibo,Liu, Chun,Qiu, Jieshan
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supporting information; experimental part
p. 2659 - 2661
(2010/07/09)
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- Aerobic ligand-free Suzuki coupling reaction of aryl chlorides catalyzed by in situ generated palladium nanoparticles at room temperature
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An aerobic, ligand-free Suzuki coupling reaction catalyzed by in situ generated palladium nanoparticles in polyethylene glycol with an average molecular weight of 400 Da (PEG-400) at room temperature has been developed. This catalytic system is a very simple and highly active protocol for the Suzuki coupling of aryl chlorides with arylboronic acids, which proceed smoothly in excellent yields in short times using low catalyst loadings. Control experiments demonstrated that the Suzuki reaction catalyzed by the in situ generated palladium nanoparticles can be carried out much quicker than that using the preprepared particles under the same conditions. The formation of palladium nanoparticles in PEG-400 was promoted by arylboronic acids.
- Han, Wei,Liu, Chun,Jin, Zilin
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supporting information; experimental part
p. 501 - 508
(2009/04/08)
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- Generation of Aryl Radicals by the Oxidation of α-(Arylazo)triphenylmethanes by Cerium(IV) Ammonium Nitrate
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The one-electron oxidation of α-(arylazo)triphenylmethanes by cerium(IV) ammonium nitrate (CAN) generated aryl radicals along with the triphenylmethyl cation.When the reaction was carried out in the presence of appropriate radical-trapping agents, such as arenes and olefins, the corresponding addition products were obtained in moderate yield.The oxidation of the arylazo compounds with CAN was accelerated by the addition of acids.
- Arai, Noriyoshi,Narasaka, Koichi
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p. 1707 - 1714
(2007/10/02)
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- REACTIONS OF ORGANOMETALLIC COMPOUNDS CATALYZED BY THE COMPLEXES OF TRANSITION METALS. STOICHIOMETRIC REACTIONS OF ORGANOTIN COMPOUNDS RSnMe3 WITH trans-ArPdI(PPh3)2
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The stoichiometric reactions of RSnMe3 ( R = Ph , m-MeC6H4, p-MeC6H4, PhCC) with complexes of palladium trans-ArPdI(PPh3)2 (Ar = Ph, m-MeC6H4, p-NO2C6H4) in dichloroethane were investigated at 120-130 deg C.It was shown that in the reactions of RSnMe3 (R = Ph, p-MeC6H4) with p-NO2C6H4PdI(PPh3)2 nitrobenzene and R-Ph are formed in addition to the product from cross coupling RC6H4NO2-p.In the presence of one equivalent of p-NO2C6H4I the yield of the product from cross coupling becomes quantitative.In the reactions of ArSnMe3 (Ar = Ph, m-MeC6H4) with Ar'PdI(PPh3)2 (Ar' = m-MeC6H4, Ph) in the presence of one equivalent of p-nitrophenyl iodide products of the Ar-Ar' and ArC6H4NO2-p type are formed, but the product Ar'C6H4NO2-p is not formed.The possible participation of Pd(0), Pd(II), and Pd(IV) intermediates in the catalytic cycle is discussed.
- Bumagin, N. A.,Bumagina, I. G.,Beletskaya, I. P.
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p. 411 - 417
(2007/10/02)
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- REACTIONS OF ORGANOMETHALIC COMPOUNDS CATALYZED BY THE COMPLEXES OF TRANSITION METALS. I. COUPLING OF ORGANOTIN COMPOUNDS WITH ARYL HALIDES CATALYZED BY PALLADIUM COMPLEXES
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The reactions of organotin compounds RSnMe3 C, C9H7 (indenyl), C13H9 (9-fluorenyl)> with aryl halides ArX , catalyzed by palladium complexes ArPdI(PPh3)2 in dichloroethane under vacuum conditions were investigated.In the reactions of RSnMe3 (where R = Ph, m-CH3C6H4, or PhCC) the RAr compounds are formed with good yields.In the stoichiometric reactions of RSnMe3 (where R = Ph or PhCC) with ArPdI(PPh3)2 (where Ar = Ph, p-NO2C6H4, or 2,4-(NO2)2C6H3> the dimers R2 are formed in addition to RAr, while in the case of the reactions of RSnMe3 (where R = C9H7 or C13H9) only R2 compounds are obtained.The possible mechanisms of the catalytic and stoichiometric reactions are discussed.
- Kashin, N. A.,Bumagina, I. G.,Bumagin, N. A.,Beletskaya, I. P.
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- Direct Conversion of Arylamines to the Corresponding Halides, Biphenyls, and Sulfides with t-Butyl Thionitrate
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t-Butyl thionitrate have been found to be an excellent diazotizing reagent of arylamines in aprotic nonpolar media, affording eventually such products as aryl chlorides, aryl bromides, aryl iodides, biphenyls, and aryl methyl sulfides in the presence of CCl4, CHBr3, I2, benzene, and dimethyl disulfide, respectively, via extrusion of N2.
- Oae, Shigeru,Shinhama, Koichi,Kim, Yong Hae
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p. 2023 - 2026
(2007/10/02)
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