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.
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.
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.].
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.
Synthesis of gold nanoparticles decorated on sulfonated three-dimensional graphene nanocomposite and application as a highly efficient and recyclable heterogeneous catalyst for Ullmann homocoupling of aryl iodides and reduction of p-nitrophenol
Dabiri, Minoo,Kashi, Seyede Razie Banifatemi,Lehi, Noushin Farajinia,Bashiribod, Sahareh
, (2018)
Gold nanoparticles were decorated onto sulfonated three-dimensional graphene (3DG-SO3H) through spontaneous chemical reduction of HAuCl4 by 3DG-SO3H. This nanocomposite exhibited excellent catalytic activity for the synthesis of symmetric biaryls via the Ullmann homocoupling of aryl iodides in an aqueous medium. Additionally, this nanocomposite was used as a catalyst for the reduction of p-nitrophenol to p-aminophenol. The catalyst could be used more than six times successively without significant deactivation.
Au25 nanocluster-catalyzed Ullmann-type homocoupling reaction of aryl iodides
Li, Gao,Liu, Chao,Lei, Yu,Jin, Rongchao
, p. 12005 - 12007 (2012)
The Au25(SR)18/CeO2 nanocluster catalyst showed high activity in the homocoupling of aryl iodides (e.g. up to 99.8% yield with iodobenzene) and excellent recyclability. The Royal Society of Chemistry.
DEDIAZONIATION OF ARENEDIAZONIUM SALT WITH TRIVALENT PHOSPHORUS COMPOUNDS BY ONE-ELECTRON TRANSFER MECHANISM
Yasui, Shinro,Fujii, Masayuki,Kawano, Chihiro,Nishimura, Yukihiro,Ohno, Atsuyoshi
, p. 5601 - 5604 (1991)
Trivalent phosphorus compounds, triphenylphosphine and triethyl phosphite, gave rise to dediazoniation of an arenediazonium salt in alcoholic solvent at ambient temperature in the dark.The reaction was well interpreted in terms of radical-chain mechanism initiated by an electron transfer from the trivalent phosphorus to a diazonium salt, which postulates a cation radical from the trivalent phosphorus as an intermediate.
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Davey,Latter
, p. 264 (1948)
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Tandem intramolecular silylformylation and silicon-assisted cross-coupling reactions. Synthesis of geometrically defined α,β-unsaturated aldehydes
Denmark, Scott E.,Kobayashi, Tetsuya
, p. 5153 - 5159 (2003)
The palladium- and copper-catalyzed cross-coupling reactions of cyclic silyl ethers with aryl iodides are reported. Silyl ethers 3 were readily prepared by intramolecular silylformylation of homopropargyl silyl ethers 2 under a carbon monoxide atmosphere. The reaction of cyclic silyl ethers 3 with various aryl iodides 7 in the presence of [(allyl)PdCl]2, CuI, a hydrosilane, and KF·2H2O in DMF at room temperature provided the α,β-unsaturated aldehyde coupling products 8 in high yields. The need for copper in this process suggested that transmetalation from silicon to copper is an important step in the mechanism. Although siloxane 3 and the product 8 are not stable under basic conditions, KF·2H2O provided the appropriate balance of reactivity toward silicon and reduced basicity. The addition of a hydrosilane to [(allyl)PdCl]2 was needed to reduce the palladium(II) to the active palladium(0) form.
Recyclable and reusable Pd(OAc)2/PPh3/PEG-2000 system for homocoupling reaction of arylboronic acids under air without base
Xia, Jianhui,Cheng, Mingzhu,Chen, Qiurong,Cai, Mingzhong
, p. 113 - 116 (2015)
A stable and efficient Pd(OAc)2/PPh3/PEG-2000 catalytic system for homocoupling of arylboronic acids has been developed. In the presence of Pd(OAc)2 and PPh3, the homocoupling reaction of arylboronic acids was carried out smoothly in PEG-2000 at 70°C under air without base to afford a variety of symmetric biaryls in good to excellent yields. The isolation of the products was readily performed by extractionwith diethyl ether, and the Pd(OAc)2/PPh3/PEG-2000 systemcould be easily recycled and reused six times without significant loss of catalytic activity.
Suzuki Coupling of Chiral 1,1′-Binaphthyl Systems - New Synthetic Routes to Functionalize the 2- and 2,2′-Positions
Schilling, Birgit,Kaufmann, Dieter E.
, p. 701 - 709 (1998)
1,1′-Binaphthyl derivatives 1-5, substituted in the 2- or 2,2′-positions are used in palladium-catalyzed Suzuki coupling reactions. The mono- and bis-borylated coupling components 2, 4 and 5 can easily be prepared and purified, are air-stable and are therefore interesting starting materials for Suzuki coupling reactions with several aryl halides. Thus a variety of new axially-chiral 2- and 2,2′-arylated 1,1′-binaphthyls can be synthesized. Selective monoarylation of 3, 4 and 5 can be performed. Subsequent and stepwise arylation offers general access to unsymmetrically substituted binaphthyls. Moreover, interesting atropisomeric complex molecules, such as 4,4′-bis[2-(1,1′-binaphthyl)]-1,1′-biphenyl (18a), are accessible. Compounds of type 18, which can be obtained by twofold Pd-catalyzed coupling reactions, are of high potential value as ligands or promoters in catalytic, asymmetric processes or as chiral precursor molecules for host-guest interactions.
Electroreductive palladium-catalysed Ullmann reactions in ionic liquids: Scope and mechanism
Pachon, Laura Duran,Elsevier, Cornells J.,Rothenberg, Gadi
, p. 1705 - 1710 (2006)
A room-temperature catalytic alternative to the Ullmann reaction is presented, based on electroreductive homocoupling of haloarenes catalysed by palladium naaoparticles. The particles are generated in situ in an electrochemical cell, and electrons are used to close the catalytic cycle and provide the motivating force for the reaction. This system gives good yields using iodo- and bromoarenes, and requires only electric current and water as reagents. Using an ionic liquid solvent combines the advantages of excellent conductivity and cluster stabilising. The solvent is reusable at least five times. Kinetic experiments at different electrode potentials show that the two-electron oxidation of water closes the catalytic cycle by regenerating the Pd(0). A mechanism involving radical anion formation is proposed. The advantages and limitations of this new system for carbon-carbon homocoupling and cross-coupling are discussed.
Pd/TEMPO-catalyzed electrooxidative synthesis of biaryls from arylboronic acids or arylboronic esters
Mitsudo, Koichi,Shiraga, Takuya,Kagen, Daisuke,Shi, Deqing,Becker, James Y.,Tanaka, Hideo
, p. 8384 - 8388 (2009)
A facile electrooxidative method for synthesizing biaryls from arylboronic acids or arylboronic esters is described. In the presence of a catalytic amount of Pd(OAc)2 and TEMPO, the electrooxidation of arylboronic acids or arylboronates gave the corresponding biaryls in moderate to excellent yields.
A comparative homocoupling reaction of aryl halides using monomeric orthopalladated complex of 4-methoxybenzoylmethylenetri-phenylphosphorane under conventional and microwave irradiation conditions
Hajipour, Abdol R.,Karami, Kazem,Tavakoli, Ghazal
, p. 567 - 576 (2011)
The activity of [Pd(C6H4CH2NH 2-K2-C-N)PPh3MOBPPY]OTf complex, A (MOBPPY = 4-methoxybenzoylmethylenetriphenylphosphoraneylide) was investigated in the homocoupling reaction of a vast range of aryl halides under both conventional and microwave irradiation conditions and their results were compared. The complex was active and showed high efficiency in the formation of new C-C bonds. The yields were excellent using a catalytic amount of [Pd(C6H 4CH2NH2-K2-C-N)PPh 3MOBPPY]OTf complex in N, N-dimethylformamide at 120 °C. In comparison to conventional heating conditions, the reactions under microwave irradiation gave higher yields in shorter reaction times.
Absolute Configuration Assignment from Optical Rotation Data by Means of Biphenyl Chiroptical Probes
Vergura, Stefania,Scafato, Patrizia,Belviso, Sandra,Superchi, Stefano
, p. 5682 - 5690 (2019)
A non-empirical approach for the assignment of the absolute configuration of chiral 2-alkyl-substituted carboxylic acids and primary amines by [α]D measurements has been developed. The method requires the conversion of the chiral acids or amines into the corresponding 4,4′-disubstituted biphenylamides or biphenylazepines, respectively. In these derivatives a central-to-axial chirality transfer induces a preferred torsion in the biphenyl moiety revealed by the sign of the biphenyl A band in the ECD spectrum. By 4,4′-substitution on the biphenyl moiety a redshift of the A band is obtained, leading to an increase of its relative contribution to optical rotation. This allows to reliably establish a direct correlation between the [α]D sign, the biphenyl twist and, then, the substrate absolute configuration. This approach thus constitutes a really practical and reliable method to assign the absolute configuration of chiral carboxylic acids and primary amines by simple and straightforward [α]D measurement, readily obtainable by a routine instrumentation like the polarimeter.
Synthesis of DMF-protected Au NPs with different size distributions and their catalytic performance in the Ullmann homocoupling of aryl iodides
Yao, Wang,Gong, Wei-Jie,Li, Hong-Xi,Li, Fei-Long,Gao, Jun,Lang, Jian-Ping
, p. 15752 - 15759 (2014)
DMF-stabilized Au nanoparticles (NPs) with three different particle sizes were prepared by controlling the reaction temperatures and times. In the absence of any additional ligands, these Au NPs showed high catalytic activity in the Ullmann homocoupling of aryl iodides in DMF. The effects of Au particle size on the coupling reaction were investigated by the use of three Au catalysts with mean particle sizes of ca. 1.0 nm, 2.5 nm, and 5.5 nm, respectively. The catalytic activity of the Au NPs was found to be in the order of Au (2.5 nm) > Au ( Au (5.5 nm), indicating that surface Au atoms do not have the same catalytic activity toward such a homocoupling reaction.
A Bio-Inspired Magnetically Recoverable Palladium Nanocatalyst for the Ullmann Coupling reaction of Aryl halides and Arylboronic acids In Aqueous Media
Dubey, Abhishek V.,Kumar, A. Vijay
, (2020)
Palladium nanoparticles supported on polydopamine-coated iron oxide nanoparticles (Pd/Fe3O4@PDA) were found to catalyze the Ullmann homocoupling of a wide variety of aryl halides, arylboronic acids and aryldiazonium salts in aqueous media in the presence of randomly methylated β-cyclodextrin (RM-β-CD). The synthesized nanoparticles were characterized by techniques such as TEM, SEM, EDX, XPS, ICP-AES and XRD. The synthesized catalyst can be easily recovered magnetically and reused up to five cycles without any significant loss of activity. This is the first report demonstrating the use of magnetically recoverable catalyst for Ullmann homocoupling reactions of aryl halides, arylboronic acids and aryldiazonium salts in water.
One-pot two-step stannylation/Stille homocoupling of aryl bromides and iodides under solvent-free conditions
Gribanov, Pavel S.,Golenko, Yulia D.,Topchiy, Maxim A.,Philippova, Anna N.,Kirilenko, Nikita Yu.,Krivoshchapov, Nikolai V.,Sterligov, Grigorii K.,Asachenko, Andrey F.,Bermeshev, Maxim V.,Nechaev, Mikhail S.
, p. 323 - 325 (2018)
A new highly efficient solvent-free method for aryl bromide (iodide) homocoupling comprising the use of Pd(OAc)2/PCy3 system in the presence of CsF is suitable for substrates bearing functional groups not tolerant to lithium-, magnesium-, zincorganic reagents and strong bases.
Nursten
, p. 3081,3083 (1955)
Facile construction of symmetric biaryls using (BeDABCO)2Pd2Cl6 as an efficient and highly active catalyst under microwave irradiation
Hajipour, Abdol Reza,Rafiee, Fatemeh
, p. 147 - 151 (2015)
An efficient catalytic system using (BeDABCO)2Pd2Cl6 (BeDABCO, benzyl-1,4-diazabicyclo[2.2.2]octane) was developed for the homo-coupling reaction of various aryl halides. Due to the combination of ionic homogeneous metal catalyst and microwave irradiation, symmetric biaryls were produced in excellent yields and short reaction times in N-methyl-2-pyrrolidone at 120 °C. BeDABCO as an efficient ligand and also a quaternary ammonium salt had an efficient stabilizing effect on the Pd(0) species in this coupling reaction.
PALLADIUM CATALYZED REACTION OF HEXABUTYLDITIN WITH ARYL BROMIDES: PREPARATION OF NEGATIVELY SUBSITUTED ARYLTRIBUTYLTIN
Kosugi, Masanori,Shimizu, Kohji,Ohtani, Atsushi,Migita, Toshihiko
, p. 829 - 830 (1981)
Reaction of hexabutylditin with aryl bromides in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium was found to be a promising tool to prepare aryltributyltins, particularly negatively substituted (-NO2, -COMe, -CN) phenyltin compounds.
Homocoupling of aryl halides promoted by tetrabutylammonium fluoride
Albanese, Domenico,Landini, Dario,Penso, Michele,Petricci, Silvia
, p. 199 - 200 (1999)
The palladium-catalysed homocoupling of aryl halides takes place in the presence of anhydrous, in situ generated, tetrabutylammonium fluoride (TBAF).
Zeolite-assisted nitration of biphenyl using nitric acid
Tai, Yanfang,Peng, Xinhua,Shi, Chunjie,Dong, Xiongzi
, p. 867 - 872 (2015)
The nitration process using 95 % nitric acid instead of the classical nitric acid-sulfuric acid system appears to be attractive and promising in the preparation of nitro compounds. The ratio of 2-nitrobiphenyl (2a) isomer to 4-nitrobiphenyl (2b) can reach 0.69 in a good yield of 78.42 %. The isomeric distribution of the product mononitrobiphenyl was found to be superior to traditional methods. Raising the ratio of 95 % nitric acid and biphenyl to 4:1, the yield of dinitration products can reach more than 78.08 %, as a mixture of 2,2-dinitrobiphenyl (3a), 2,4-dinitrobiphenyl (3b), and 4,4-dinitrobiphenyl (3c).
Pd-Catalyzed desulfitative arylation of olefins by: N -methoxysulfonamide
Ojha, Subhadra,Panda, Niranjan
supporting information, p. 1292 - 1298 (2022/02/19)
A novel Pd-catalyzed protocol for the desulfitative Heck-type reaction of N-methoxy aryl sulfonamides with alkenes was reported. The cross-coupling reaction was performed successfully with a variety of olefins to obtain aryl alkenes. Different substituents on the aromatic ring of N-methoxysulfonamides were also found to be compatible with the reaction conditions. Expectedly, the reaction proceeds through CuCl2-promoted generation of the nitrogen radical and subsequent desulfonylation under thermal conditions to afford the aryl radical for the Pd-catalyzed coupling reaction. N-Methoxysulfonamide was further exploited for the synthesis of symmetrical biaryls in the presence of CuCl2. This journal is
Valorisation of urban waste to access low-cost heterogeneous palladium catalysts for cross-coupling reactions in biomass-derived γ-valerolactone
Valentini, Federica,Ferlin, Francesco,Lilli, Simone,Marrocchi, Assunta,Ping, Liu,Gu, Yanlong,Vaccaro, Luigi
, p. 5887 - 5895 (2021/08/23)
Herein we report a simple protocol for the valorisation of a common urban biowaste. The lignocellulosic biomass obtained after the pre-treatment of pine needle urban waste is efficiently transformed into a low-cost support (PiNe) for the immobilization of Pd nanoparticles. The final Pd/PiNe heterogeneous catalyst features a small particle size (4.5 nm) and a metal loading (9.9 wt%) comparable with most commercially available and generally used counterparts. In this contribution, we tested the catalytic efficiency of the Pd/PiNe system in two representative cross-couplings, Heck and Hiyama reactions, and compared the results obtained with commercial Pd/C catalyst. The good reactivity in the biomass-derived solvent (GVL) confirms that the Pd/PiNe heterogeneous catalyst is a valid system that can be integrated into a waste valorization chain within a circular economy approach. In addition, the efficiency of the catalyst has also been extended to perform the challenging consecutive Hiyama-Heck reaction to afford differently substituted (E)-1,2-diarylethenes.
Identification of a Surprising Boronic Acid Homocoupling Process in Suzuki-Miyaura Cross-Coupling Reactions Utilizing a Hindered Fluorinated Arene
Gargaro, Samantha L.,Dunson, Bre'Shon,Sieber, Joshua D.
supporting information, p. 511 - 516 (2020/09/21)
The Suzuki-Miyaura cross-coupling reaction of 2-bromo-1,3-bis(trifluoromethyl)benzene with arylboronic acids was evaluated and determined to suffer from the formation of large amounts of boronic acid homocoupling products in conjunction with dehalogenation. Homocoupling product formation in this process likely occurs through a rare protonolysis/second transmetalation event rather than by the well-established mechanism requiring the involvement of O 2. The scope of this boronic acid homocoupling reaction was investigated and shown to predominate with electron-deficient arylboronic acids. Finally, a good yield of cross-coupling products could be obtained by employing dicyclohexyl(2′,6′-dimethoxybiphenyl-2-yl)phosphine (SPhos) as the ligand.
