1528-74-1Relevant articles and documents
Homocoupling of Organostannanes Catalyzed by Iminophosphine-Palladium
Shirakawa, Eiji,Murota, Yasubumi,Nakao, Yoshiaki,Hiyama, Tamejiro
, p. 1143 - 1144 (1997)
An iminophosphine-palladium complex has been successfully utilized as a catalyst for the oxidative homocoupling reaction of organostannanes using air as an oxidant.
Immobilization of copper(II) in organic-inorganic hybrid materials: A highly efficient and reusable catalyst for the classic Ullmann reaction
Wu, Qiang,Wang, Lei
, p. 2007 - 2012 (2008)
The immobilization of copper(II) in organic - inorganic (silica gel) hybrid materials as catalysis for the homocoupling of aryl halides (classic Ullmann reaction) has been described. The homocoupling of aryl iodides, bromides and chlorides underwent smoothly in the presence of a 3-(2-aminoethylamino)propyl- functionalized silica gel immobilized copper(II) catalyst. The protocol involved the use of DMSO as the solvent and potassium fluoride as the base. The reactions generated the corresponding homocoupling products in good to excellent yields. Furthermore, the silica-supported copper(II) could be recovered and recycled by simple filtration and used for five consecutive trials without loss of its reactivity. Thieme Stuttgart.
Carbon-carbon bond formation via homocoupling reaction of substrates with a broad diversity in water using Pd(OAc)2 and agarose hydrogel as a bioorganic ligand, support and reductant
Firouzabadi, Habib,Iranpoor, Nasser,Kazemi, Faezeh
, p. 94 - 99 (2011)
In this study, we have presented a new catalytic system in which Pd(OAc)2 has been used as a pre-catalyst and agarose as a degradable bioorganic ligand, support and reductant for carbon-carbon bond formation via homocoupling reaction of different aryl halides, β-bromo styrene, phenylboronic acid and phenylacetylene as the substrates. The reactions proceeded smoothly with high yields at temperature 100 °C in water without using any organic co-solvent, phosphorus ligand or reducing agents. The catalyst is recyclable and has been recycled for four times with a tiny amount of leaching of Pd into the reaction media. The amount of leaching has been determined by ICP analysis.
Water-dispersible and magnetically separable gold nanoparticles supported on a magnetite/s-graphene nanocomposite and their catalytic application in the Ullmann coupling of aryl iodides in aqueous media
Dabiri, Minoo,Shariatipour, Monire,Kazemi Movahed, Siyavash,Bashiribod, Sahareh
, p. 39428 - 39434 (2014)
Water-dispersible sulfonated graphene (s-G) was synthesized by anchoring sulfonic acid groups on graphene sheets. Subsequently, magnetically separable Fe3O4/s-G was synthesized from the Fe3O 4 nanoparticles decorated on s-G sheets by the co-precipitation method of iron ions. Finally, Fe3O4/s-G was successfully decorated with gold nanoparticles in a facile route by reducing chloroauric acid in the presence of sodium dodecyl sulfate, which is used as both a surfactant and reducing agent. The obtained Au/Fe3O4/s-G nanocomposite remained soluble in water, but could be easily separated from reaction solutions by an external magnetic field and then used as a heterogeneous catalyst for the Ullmann coupling reaction in water. The catalytic activity reduction was not significant even after five consecutive reaction runs due to the efficient magnetic separation, the high dispersion and stability of the catalyst in aqueous solution.
DAB-Cy as an inexpensive and effective ligand for palladium-catalyzed homocoupling reaction of aryl halides
Ma, Ning,Duan, Zheng,Wu, Yangjie
, p. 5709 - 5712 (2006)
A novel catalytic system of PdCl2(CH3CN)2 with N,N′-dicyclohexyl-1,4-diazabutadiene (DAB-Cy) ligand was successfully used in reductive coupling of aryl halides.
Au-Pd bimetallic nanoparticles supported on a high nitrogen-rich ordered mesoporous carbon as an efficient catalyst for room temperature Ullmann coupling of aryl chlorides in aqueous media
Karimi, Babak,Barzegar, Hossein,Vali, Hojatollah
, p. 7155 - 7158 (2018)
An ionic liquid derived highly nitrogen-rich mesoporous carbon supported Au-Pd alloy was found to be an efficient and recyclable catalyst for the Ullmann coupling reaction of various aryl chlorides at room temperature in aqueous media.
Band Gap Modification of TiO2 Nanoparticles by Ascorbic Acid-Stabilized Pd Nanoparticles for Photocatalytic Suzuki–Miyaura and Ullmann Coupling Reactions
Feizpour, Fahimeh,Jafarpour, Maasoumeh,Rezaeifard, Abdolreza
, (2019)
In this study, synthesis, characterization and photocatalytic performance of surface-modified TiO2 nanoparticles with ascorbic acid-stabilized Pd nanoparticles are presented. The structure, composition and morphology of as-prepared nanophotocatalyst were characterized by UV-DRS, FT-IR, ICP-AES, TEM and XPS analysis. Ascorbic acid-stabilized Pd nanoparticles induced visible light driven photocatalytic property on the surface of TiO2 which are otherwise insensitive to visible light owing to the wide band gap. The catalytic system worked well for the Suzuki–Miyaura cross-coupling and Ullmann homocoupling under compact fluorescent light as a visible source with significant activity, selectivity and recyclability. Good to excellent yields of biaryl products were obtained for various aryl halides having different electronic demands and even aryl chlorides. Our results proposed that the improved photoactivity predominantly benefits from the synergistic effects of ascorbic acid-stabilized Pd nanoparticles on TiO2 nanoparticles that cause efficient separation and photoexcited charge carriers and photoredox capability of nanocatalyst. Thus, tuning of band gap of TiO2 making a visible light sensitive photocatalyst, demonstrates a significant advancement in the photocatalytic Suzuki–Miyaura and Ullmann coupling reactions. Graphical Abstract: [Figure not available: see fulltext.].
An effective and environment-friendly system for Cu NPs@RGO-catalyzed C-C homocoupling of aryl halides or arylboronic acids in ionic liquids under microwave irradiation
Zhao, Hongyan,Mao, Guijie,Han, Huatao,Song, Jinyi,Liu, Yang,Chu, Wenyi,Sun, Zhizhong
, p. 41108 - 41113 (2016)
As an outstanding mesh catalyst support, reduced graphene oxide (RGO) has attracted enormous attention in recent years. Cu nanoparticles-RGO (Cu NPs@RGO) as a green catalyst was prepared through a green reduction method by ascorbic acid in N-methyl-2-pyrrolidone. The structure of prepared Cu NPs@RGO was characterized. The catalytic activity of Cu NPs@RGO was estimated. A green and efficient method for synthesizing symmetrical biaryl compounds was developed by Cu NPs@RGO-catalyzed Ullmann homocoupling of aryl halides or arylboronic acids in ionic liquids under microwave (MW) irradiation. The catalytic system could be recycled five times with slight loss of activity. Through this method, nine kinds of biaryls were prepared by homocoupling reaction of the corresponding aryl iodides, aryl bromides, aryl chlorides and aryl boronic acids in moderate to good yields.
Direct homocoupling of aryl halides catalyzed by palladium
Penalva, Vincent,Hassan, Jwanro,Lavenot, Laurence,Gozzi, Christel,Lemaire, Marc
, p. 2559 - 2560 (1998)
Symmetrical functionnalized biaryls are obtained in good yield via homocoupling of aryl halides, bromo or iodo ones, using the combination of Pd(OAc)2 and nBu4NBr as catalyst system.
PdAu alloy nanoparticles supported on nitrogen-doped carbon black as highly active catalysts for Ullmann coupling and nitrophenol hydrogenation reactions
Han, Fengyan,Xia, Jiawei,Zhang, Xinglong,Fu, Yongsheng
, p. 17812 - 17823 (2019)
Noble metal-based catalysts have been proven to be active for catalytic organic reactions. The selectivity and conversion can be improved by integration with proper carrier materials, and further modulated by tuning the composition as well as the electronic structure of the active noble metals. Compared with unsupported monometallic catalysts, the synergistic interactions between neighboring metals and the combined effects between the carrier materials and the active components often give rise to positive influences on the enhancement of the catalytic efficiency and selectivity. In this work, we report a facile process for the fabrication of nitrogen-doped carbon black (NCB) supported PdAu bimetallic nanoparticles (NPs) with a uniform dispersion and narrow size distribution. The PdAu/NCB catalyst with a Pd/Au mole ratio of 1/1 shows the highest activity towards both Ullmann coupling reactions of aryl halides and the hydrogenation reaction of nitrophenols. Moreover, this bimetallic catalyst also exhibits a superior recycling durability to that of monometallic Pd/NCB and Au/NCB catalysts. The enhanced catalytic performance of the bimetallic catalyst is mainly due to the large BET specific surface area (125.45 m2 g-1) and the synergy between the individual components of the catalyst.
