- Pseudo-Solid-State Suzuki–Miyaura Reaction and the Role of Water Formed by Dehydration of Arylboronic Acids
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Solvent-free reactions belong to a very attractive area of organic chemistry. The solvent-free Suzuki–Miyaura coupling is of special importance due to the problem of catalyst leaching in the presence of a solvent. This study investigates the course of reaction of solid aryl halides with arylboronic acids in the absence of a solvent and without any liquid additives. For the first time, a number of important conditions for performing a solid-state Suzuki–Miyaura reaction were analyzed in details. The results indicate a prominent role of water, which is formed as a by-product in the side reaction of arylboronic acid trimerization. Electron microscopy study revealed surprising changes occurring within the reaction mixture during the reaction and indicated the formation of spherical nano-sized particles containing the reaction product. Catalyst recycling was easily performed in the developed system and the product was isolated by sublimation, thus providing a possibility to completely avoid the use of solvents at all stages.
- Pentsak, Evgeniy O.,Ananikov, Valentine P.
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supporting information
p. 4239 - 4247
(2019/06/17)
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- Rapid “Mix-and-Stir” Preparation of Well-Defined Palladium on Carbon Catalysts for Efficient Practical Use
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A facile direct deposition approach for the preparation of recyclable Pd/C catalysts simply by stirring a solution of tris(dibenzylideneacetone)dipalladium(0) with a suitable carbon material was evaluated. An extraordinarily rapid catalyst preparation procedure (0 centers onto the highly accessible surface area and the avoidance of ill-defined PdII/Pd0 states.
- Yakukhnov, Sergey A.,Pentsak, Evgeniy O.,Galkin, Konstantin I.,Mironenko, Roman M.,Drozdov, Vladimir A.,Likholobov, Vladimir A.,Ananikov, Valentine P.
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p. 1869 - 1873
(2018/04/30)
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- Mono-arylation method of dichlorobenzene compounds
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A mono-arylation method of dichlorobenzene compounds comprises the steps as follows: dichlorobenzene compounds shown in formula (I), arylboronic acid shown in formula (2), a N-heterocyclic carbene-palladium complex catalyst, an alkaline substance and a reaction solvent are mixed to react at 0-100 DEG C for 1-24 h under the protection of nitrogen, a reaction solution is subjected to posttreatment,and a mono-arylation product shown in formula (3) is obtained. A novel catalytic system is developed, the catalyst is stable and easy to obtain, the stable and cheap dichlorobenzene compounds can be subjected to the selective mono-arylation reaction, and the method has multiple advantages that the reaction operation is simple, the cost is low, the product is high in yield and purity and the like,is a brand-new method for synthesizing chloro-biphenyl compounds, provides a new synthesis route for the compounds and has good research value and industrial application prospects.
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Paragraph 0024; 0026; 0028; 0029
(2018/05/16)
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- Novel phosphorus-coordinated palladium(II) complexes derived from 3,5-disubstituted-1H-1,2,4-diazaphospholes: Synthesis and catalytic application in Suzuki-Miyaura cross-coupling reactions
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Four novel phosphorus-coordinated palladium(II) complexes(I-IV) were easily prepared by the reaction of 3,5-disubstituted-1H-1,2,4-diazaphospholes with Pd(CH3CN)2Cl2at room temperature and characterized. The catalytic activity of palladium(II) complexes was further evaluated in Suzuki-Miyaura reaction of aryl halides with arylboronic acids, giving the biphenyl derivatives in good yields.
- Jia, Xuefeng,Zhao, Fang
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p. 145 - 149
(2017/03/09)
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- Cubical Palladium Nanoparticles on C@Fe3O4 for Nitro reduction, Suzuki-Miyaura Coupling and Sequential Reactions
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Cubical Pd nanoparticles incorporated magnetically recyclable nanoreactor (Pd cNPs/C@Fe3O4) are found to be efficient catalysts for the hydrogenation or aromatic nitrocompounds, Suzuki-Miyaura coupling and the sequential reaction of [Formula presented] coupling followed by reduction of nitrobiphenyl substrates. A variety of aryl iodides, bromides and chlorides were coupled with phenylboronic acids to form corresponding biaryl products and variety of nitro aromatic compounds was hydrogenated with excellent yield and high TON. The catalytic activity of palladium cubical nanoparticles (Pd cNPs) embedded with excess of {100} surface facets are superior compared to Pd spherical nanoparticles (Pd sNPs) embedded with mixed surface facets. The catalytic efficiency remains unaltered even after five repeated cycles. The observed enhanced catalytic activity is attributed to the high density of low-coordinated Pd {100} atoms present at the surface of the Pd cNPs/C@Fe3O4 catalyst, confirmed by HR-TEM studies. Also, the catalyst is truly heterogeneous, highly stable, does not require any toxic ligands, has wide substrate scope in both nitroreduction and Suzuki-Miyaura coupling reaction along with the ability to catalyse in a sequential manner, magnetically separable from the reaction mixture and can be reused.
- Kumar, Basuvaraj Suresh,Amali, Arlin Jose,Pitchumani, Kasi
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p. 511 - 519
(2016/08/15)
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- A practical and general synthesis of unsymmetrical terphenyls
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(Chemical Equation Presented) A synthetic procedure was developed that enables sequential chemoselective Suzuki-Miyaura cross-coupling of chlorobromobenzene with arylboronic acids. The first coupling is achieved at room temperature using a ligandless palladium catalyst. The chlorobiaryl product can then be subjected directly to the second coupling, facilitated by the SPhos ligand. Using this methodology, parallel synthesis of 32 unsymmetrical o-, m-, and p-terphenyl compounds was accomplished in good to excellent overall yields.
- Antelo Miguez, Jose M.,Adrio, Luis Angel,Sousa-Pedrares, Antonio,Vila, Jose M.,Hii, King Kuok
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p. 7771 - 7774
(2008/02/12)
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- Synthesis and cross-coupling reactions of tetraalkylammonium organotrifluoroborate salts
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Treatment of organoboronic acids with hydrofluoric acid generates an in situ tetracoordinate hydronium organotrifluoroborate species which undergoes counterion exchange with tetra-n-butylammonium hydroxide. The resultant tetraalkylammonium salts are as air and moisture stable as their potassium organotrifluoroborate counterparts with the added advantage of being readily soluble in organic media. They were found to undergo Pd-catalyzed Suzuki-Miyaura cross-couplings with a variety of aryl- and alkenylhalides under mild conditions. Their Pd-catalyzed cross-coupling with acid halides is also possible for the generation of ketones.
- Batey, Robert A,Quach, Tan D
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p. 9099 - 9103
(2007/10/03)
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- Highly Selective Cross-Coupling Reactions of Aryl(halo)silanes with Aryl Halides: A General and Practical Route to Functionalized Biaryls
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The palladium catalyzed cross-coupling reaction of aryl halides with aryl(halo)silanes (halogen=F, Cl) gives good yields of unsymmetrical biaryls and p-terphenyls.The reaction takes place smoothly in N,N-dimethylformamide in the presence of an appropriate palladium catalyst and potassium fluoride.Since this reaction is tolerant of a variety of reactive functional groups, highly functionalized 4,4'-, 3,4'-, 2,4'- and even sterically crowded 2,2'-disubstituted biaryls can be obtained in moderate to high yields.The synthetic utility of the method has been demonstrated by its application to a short synthesis of liquid crystals.Mechanistic aspects of transmetalation of an aryl(fluoro)silicate intermediate with a palladium complex are discussed on the basis of the substituent effects on the rate of the cross-coupling reactions.
- Hatanaka, Yasuo,Goda, Ken-ichi,Okahara, Yoshinori,Hiyama, Tamejiro
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p. 8301 - 8316
(2007/10/02)
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- Selective Synthesis of Unsymmetrical Biaryls via Palladium-Catalyzed Cross-Coupling of Arylfluorosilanes with Aryl Iodides
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In the presence of potassium fluoride, arylfluorosilanes readily participate in Pd-catalyzed cross-coupling reaction of aryl iodides to give the corresponding unsymmetrical biaryls in good yields.
- Hatanaka, Yasuo,Fukushima, Satoshi,Hiyama, Tamejiro
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p. 1711 - 1714
(2007/10/02)
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- Formation Constants of Cyanohydrins of Substituted Acetylbiphenyls
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The formation constants of cyanohydrins of 2'- and 3'-substituted 4-acetylbiphenyls have been determined at 30 deg C in 80percent dioxan-water (v/v).The 3'-substituted 4-acetylbiphenyls obey the Hammett equation giving a ρ-value of 0.52; 2'-substituted cyanohydrins do not obey the Hammett equation.The formation constants of 3'-substituted 4-acetylbiphenyls and their rate constants for the reduction by sodium borohydride reveal a linear relationship (r = 0.990).The influence of 2'-substituents reveals the existence of ?-electron steric effect.
- Ananthakrishnanadar, P.,Kannan, N.
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