- C(sp2)-C(sp2) Suzuki cross-coupling of arylammonium salts catalyzed by a stable Pd–NHC complex
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We have developed the Suzuki-Miyaura cross-coupling of aryl ammonium salts via C–N bond activation catalyzed by an easily prepared and bench-stable palladium-N-heterocyclic carbene complex. The reaction proceeded well under mild conditions with phenylboronic acid, pinacol ester or anhydride and provided yields of products up to 97% with good functional group compatibility. The direct arylation of arylamine can be performed by a two-step one-pot process and the protocol can be performed on the gram scale.
- Tang, Huiling,Liu, Mengna,Zhu, Meiqi,Cui, Benqiang,Shi, Yanhui,Cao, Changsheng
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- Air-Stable Fe3O4@SiO2-EDTA-Ni(0) as an Efficient Recyclable Magnetic Nanocatalyst for Effective Suzuki-Miyaura and Heck Cross-Coupling via Aryl Sulfamates and Carbamates
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The synthesis of inexpensive and novel air-stable Ni(0) nanoparticles immobilized on the EDTA-modified Fe3O4@SiO2 nanocatalyst was investigated in Suzuki-Miyaura and Heck cross-coupling reactions. This catalytic system displayed a greatly improved substrate scope for the carbon–carbon bond formations starting from a wide range of green and economical electrophiles aryl and heteroaryl carbamates and sulfamates via highly efficient method under mild, operationally simple reaction conditions. The synthesized heterogeneous catalyst was also fully characterized by FT-IR, TEM, XRD, DLS, FE-SEM, UV–Vis, EDX, XPS, TGA, NMR, VSM, ICP and elemental analysis techniques. The heterogeneous magnetic nanocatalyst can easily be recovered by an external magnetic field and reused for the next reactions for at least seven times with negligible leaching of catalyst and no substantial decrement in the activity. All these highlights have made the present protocol an interesting, simple and environmentally benign process with low catalyst loading and easy manipulations.
- Dindarloo Inaloo, Iman,Majnooni, Sahar,Eslahi, Hassan,Esmaeilpour, Mohsen
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- Nickel-Catalyzed Stille Cross Coupling of C-O Electrophiles
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Aryl sulfamates, tosylates, and mesylates undergo efficient Ni-catalyzed cross coupling with diverse organostannanes in the presence of relatively unhindered alkylphosphine ligands and KF. The coupling is valuable for difficult bond constructions, such as aryl - heteroaryl, aryl - alkenyl, and aryl - alkynyl, using nontriflate phenol derivatives. A combination of experimental and computational studies implicates an unusual mechanism for transmetalation involving an 8-centered cyclic transition state. This reaction is inhibited by chloride sources due to slow transmetalation of organostannanes at a Ni(II) - chloride intermediate. These studies help to explain why prior efforts to achieve Ni-catalyzed Stille coupling of phenol derivatives were unsuccessful.
- Russell, John E. A.,Entz, Emily D.,Joyce, Ian M.,Neufeldt, Sharon R.
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p. 3304 - 3310
(2019/03/26)
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- Catalyst shuttling enabled by a thermoresponsive polymeric ligand: Facilitating efficient cross-couplings with continuously recyclable ppm levels of palladium
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A polymeric monophosphine ligand WePhos has been synthesized and complexed with palladium(ii) acetate [Pd(OAc)2] to generate a thermoresponsive pre-catalyst that can shuttle between water and organic phases, with the change being regulated by temperature. The structure of the polymeric ligand was confirmed with matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry and size-exclusion chromatography (SEC) analysis, as well as nuclear magnetic resonance (NMR) measurements. This polymeric metal complex enables highly efficient Pd-catalyzed cross-couplings and tandem reactions using 50 to 500 ppm palladium, and this can facilitate reactions that are tolerant to a broad spectrum of (hetero)aryl substrates and functional groups, as demonstrated with 73 examples with up to 99% isolated yields. Notably, 97% Pd remained in the aqueous phase after 10 runs of catalyst recycling experiments, as determined via inductively coupled plasma-atomic emission spectrometry (ICP-AES) measurements, indicating highly efficient catalyst transfer. Furthermore, a continuous catalyst recycling approach has been successfully developed based on flow chemistry in combination with the catalyst shuttling behavior, allowing Suzuki-Miyaura couplings to be conducted at gram-scales with as little as 10 ppm Pd loading. Given the significance of transition-metal catalyzed cross-coupling and increasing interest in sustainable chemistry, this work is an important step towards the development of a responsive catalyst, in addition to having high activity, by tuning the structures of the ligands using polymer science.
- Wang, Erfei,Chen, Mao
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p. 8331 - 8337
(2019/09/30)
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- N,S-chelating triazole-thioether ligand for highly efficient palladium-catalyzed Suzuki reaction
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1,2,3-Triazole-thioether compounds could serve as efficient ligands for Pd-catalyzed Suzuki reactions of various aryl iodides, bromides and chlorides. The reactions feature wide substrate scope and mild reaction conditions. Besides, shorter reaction time, lower catalyst loadings and quantitative yields with a turnover-frequency (TOF) value of up to 11,880 h?1 are other advantageous of this attractive protocol. The crystal structure analyses and computational studies revealed that the higher catalytic activity of the corresponding chelated palladium complex ascribed to the lower energy gap and the lower redox potential.
- Yan, Qiong,Zheng, Lei,Li, Miaomiao,Chen, Yunfeng
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p. 101 - 105
(2019/07/19)
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- N-heterocyclic carbene-Pd(II) complex based on theophylline supported on Fe3O4@SiO2 nanoparticles: Highly active, durable and magnetically separable catalyst for green Suzuki-Miyaura and Sonogashira-Hagihara coupling reactions
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In this paper, a novel heterogeneous palladium catalyst was synthesized by anchoring N-heterocyclic carbene-Pd(II) complex based on theophylline on magnetic Fe3O4@SiO2 nanoparticles. The synthesized magnetic composite was characterized by fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray analysis (EDX), thermogravimetric analysis (TGA), vibration sample magnetometry (VSM), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS), N2 adsorption-desorption isotherm analysis (BET), UV–vis spectroscopy and elemental analysis. Also, loading content of palladium on the catalyst was measured by inductive coupled plasma (ICP) analysis. The synthesized catalyst was used successfully for the Suzuki cross-coupling reactions of various aryl halides (I, Br, Cl) with phenylboronic acids. This reaction was best performed in water as a green solvent in the presence of just 0.37–0.5 mol% of the catalyst at 60 °C. Also, we have reported this recyclable catalytic system as a stable phosphine-free Pd catalyst for the Sonogashira cross-coupling of aryl halides (I, Br, Cl) with terminal aromatic and aliphatic alkynes under solvent-free conditions. All coupling reactions proceeded with good to excellent yields. The catalyst showed good stability and was recovered and reused for eight reaction cycles without a significant loss in its catalytic activity. Also, the leaching of the catalyst has been examined by a hot filtration test and ICP-AES analysis.
- Esmaeilpour, Mohsen,Sardarian, Ali Reza,Firouzabadi, Habib
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- Palladium nanoparticles immobilized on EDTA-modified Fe3O4@SiO2 nanospheres as an efficient and magnetically separable catalyst for Suzuki and Sonogashira cross-coupling reactions
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In this study, a novel heterogeneous palladium catalyst was synthesized by anchoring palladium onto ethylenediaminetetraacetic acid (EDTA)-coated Fe3O4@SiO2 magnetic nanocomposite and used for the Suzuki and Sonogashira cross-coupling reactions. The properties of the magnetic catalyst were characterized by FT-IR, XRD, TEM, FE-SEM, DLS EDX, XPS, N2 adsorption-desorption isotherm analysis, TGA, VSM, elemental analysis and the loading level of Pd in catalyst was measured to be 0.51?mmol/g by ICP. The catalyst was used in Suzuki cross-coupling reactions of various aryl halides, including less reactive chlorobenzenes with phenylboronic acid without any additive or ligand under green conditions. Furthermore, we have reported this recyclable catalytic system for Sonogashira cross-coupling reactions of various aryl halides (I, Br, Cl) under copper and ligand-free conditions in the presence of DMF/H2O (1:2/v:v) as a solvent. The magnetic catalyst could also be separated by an external magnet and reused six times without any significant loss of activity.
- Esmaeilpour, Mohsen,Zahmatkesh, Saeed,Fahimi, Nafiseh,Nosratabadi, Mehran
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- The Highly Efficient Suzuki–Miyaura Cross-Coupling of (Hetero)aryl Chlorides and (Hetero)arylboronic Acids Catalyzed by “Bulky-yet-Flexible” Palladium–PEPPSI Complexes in Air
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A series of Pd–PEPPSI complexes were designed and synthesized. The relationship between catalyst structure and properties was systematically investigated. It was revealed that “bulky-yet-flexible” C3 bearing ancenaphthyl backbone was a highly efficient precatalyst and could be successfully employed in Suzuki–Miyaura reactions of (hetero)aryl chlorides with (hetero)arylboronic acids at a low palladium loading in the presence of a weak inorganic base in air.
- Ouyang, Jia-Sheng,Li, Yan-Fang,Huang, Fei-Dong,Lu, Dong-Dong,Liu, Feng-Shou
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p. 371 - 375
(2017/12/15)
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- Iron-Catalyzed Borylation of Aryl Chlorides in the Presence of Potassium t-Butoxide
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A catalytic amount of an inorganic iron salt such as Fe(acac)3 catalyzes borylation of various aryl and heteroaryl chlorides with bis(pinacolato)diboron, where the presence of potassium t-butoxide is crucially important. The alkoxide is considered to produce in situ an electron-rich iron alkoxide complex as the active species. The reaction requires only an iron salt and potassium t-butoxide as promoters and is easily scalable. The arylboron compound prepared by this reaction can be further coupled in situ with an aryl halide under the Suzuki-Miyaura conditions.
- Yoshida, Takumi,Ilies, Laurean,Nakamura, Eiichi
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p. 3199 - 3203
(2017/06/09)
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- Oxygen Activated, Palladium Nanoparticle Catalyzed, Ultrafast Cross-Coupling of Organolithium Reagents
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The discovery of an ultrafast cross-coupling of alkyl- and aryllithium reagents with a range of aryl bromides is presented. The essential role of molecular oxygen to form the active palladium catalyst was established; palladium nanoparticles that are highly active in cross-coupling reactions with reaction times ranging from 5 s to 5 min are thus generated in situ. High selectivities were observed for a range of heterocycles and functional groups as well as for an expanded scope of organolithium reagents. The applicability of this method was showcased by the synthesis of the [11C]-labeled PET tracer celecoxib.
- Heijnen, Dorus,Tosi, Filippo,Vila, Carlos,Stuart, Marc C. A.,Elsinga, Philip H.,Szymanski, Wiktor,Feringa, Ben L.
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supporting information
p. 3354 - 3359
(2017/03/17)
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- Nickel-Catalyzed Cross-Coupling of Organolithium Reagents with (Hetero)Aryl Electrophiles
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Nickel-catalyzed selective cross-coupling of aromatic electrophiles (bromides, chlorides, fluorides and methyl ethers) with organolithium reagents is presented. The use of a commercially available nickel N-heterocyclic carbene (NHC) complex allows the reaction with a variety of (hetero)aryllithium compounds, including those prepared via metal-halogen exchange or direct metallation, whereas a commercially available electron-rich nickel-bisphosphine complex smoothly converts alkyllithium species into the corresponding coupled product. These reactions proceed rapidly (1 h) under mild conditions (room temperature) while avoiding the undesired formation of reduced or homocoupled products. Nickel-catalyzed cross-coupling of aromatic electrophiles with organolithium reagents is presented. The use of a commercially available nickel N-heterocyclic carbene complex allows reaction with a variety of (hetero)aryllithium compounds, whereas a commercially available electron-rich nickel bisphosphine complex smoothly converts alkyllithium species into the corresponding coupled product.
- Heijnen, Dorus,Gualtierotti, Jean-Baptiste,Hornillos, Valentín,Feringa, Ben L.
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supporting information
p. 3991 - 3995
(2016/03/16)
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- Pd-PEPPSI Complexes bearing bulky [(1,2-Di-(tert-butyl)acenaphthyl] (DtBu-An) on N-heterocarbene backbones: Highly efficient for suzuki-miyaura cross-coupling under aerobic conditions
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With the goal of achieving highly efficient palladium-catalyzed cross-coupling reactions under mild reaction conditions, the Pd-PEPPSI complexes C1 and C2 bearing 1,2-di(tert-butyl)acenaphthyl (DtBu-An) backbones were synthesized and characterized, and their use in Suzuki-Miyaura cross-coupling was investigated. The effects of catalyst structure and reaction conditions on the cross-coupling efficiency were evaluated in detail. The significant differences in catalytic activity compared with classical PEPPSI-IPr and PEPPSI-IPrAn precatalysts are discussed, where the axial sterics on the backbone play an important role. At low palladium loadings of 0.05-0.1 mol % and upon the addition of the relatively weak base K3PO4, the palladium complex C1 was found to be highly efficient for the coupling of (hetero)aryl chlorides with arylboronic acids under aerobic conditions, affording the corresponding biaryls in excellent yields.
- Lan, Xiao-Bing,Chen, Fu-Min,Ma, Bei-Bei,Shen, Dong-Sheng,Liu, Feng-Shou
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p. 3852 - 3860
(2016/12/07)
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- 2-Aryl-indenylphosphine ligands: Design, synthesis and application in Pd-catalyzed Suzuki-Miyaura coupling reactions
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A focused library of phosphine ligands was constructed for structural optimization. The catalyst can be used to perform the Suzuki-Miyaura cross-coupling reaction of aryl and heteroaryl chlorides.
- Lian, Ze-Yu,Yuan, Jia,Yan, Meng-Qi,Liu, Yan,Luo, Xue,Wu, Qing-Guo,Liu, Sheng-Hua,Chen, Jian,Zhu, Xiao-Lei,Yu, Guang-Ao
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supporting information
p. 10090 - 10094
(2016/11/06)
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- Biarylalkyl Carboxylic Acid Derivatives as Novel Antischistosomal Agents
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Parasitic platyhelminths are responsible for serious infectious diseases, such as schistosomiasis, which affect humans as well as animals across vast regions of the world. The drug arsenal available for the treatment of these diseases is limited; for example, praziquantel is the only drug currently used to treat ≥240 million people each year infected with Schistosoma spp., and there is justified concern about the emergence of drug resistance. In this study, we screened biarylalkyl carboxylic acid derivatives for their antischistosomal activity against S. mansoni. These compounds showed significant influence on egg production, pairing stability, and vitality. Tegumental lesions or gut dilatation was also observed. Substitution of the terminal phenyl residue in the biaryl scaffold with a 3-hydroxy moiety and derivatization of the terminal carboxylic acid scaffold with carboxamides yielded compounds that displayed significant antischistosomal activity at concentrations as low as 10 μm with satisfying cytotoxicity values. The present study provides detailed insight into the structure–activity relationships of biarylalkyl carboxylic acid derivatives and thereby paves the way for a new drug-hit moiety for fighting schistosomiasis.
- M?der, Patrick,Blohm, Ariane S.,Quack, Thomas,Lange-Grünweller, Kerstin,Grünweller, Arnold,Hartmann, Roland K.,Grevelding, Christoph G.,Schlitzer, Martin
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supporting information
p. 1459 - 1468
(2016/07/16)
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- Nickel-catalyzed one-pot synthesis of biaryls from phenols and arylboronic acids via C-O activation using TCT reagent
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In this study, the direct Nickel-catalyzed Suzuki-Miyaura coupling reaction of phenols and arylboronic acids via C-O bond activation using 2,4,6-trichloro-1,3,5-triazine (TCT) is described. Initially, phenols were reacted with TCT to give the corresponding 2,4,6-triaryloxy-1,3,5-triazine (TAT) products. Subsequently, arylboronic acid, base and Ni-catalyst were added to the generated aryl C-O electrophile to obtain the final biaryl product. This study represents a simple and direct method for the synthesis of biaryls from phenolic compounds using sub-stoichiometric amounts of TCT as a cheap and readily available C-O activating reagent.
- Iranpoor, Nasser,Panahi, Farhad,Jamedi, Fereshteh
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- A novel polymer containing phosphorus-nitrogen ligands for stabilization of palladium nanoparticles: An efficient and recyclable catalyst for Suzuki and Sonogashira reactions in neat water
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A new polymer containing phosphorus and nitrogen ligands was successfully synthesized, characterized and used for the stabilization of highly monodispersed palladium nanoparticles having an average diameter of 2-3 nm. The thermally stable heterogeneous catalyst was successfully applied in Suzuki-Miyaura and copper-free Sonogashira-Hagihara coupling reactions of aryl halides under low palladium loading conditions. Reactions were proceeded in neat water without using any organic co-solvents. The catalyst was successfully recycled for the sample Suzuki-Miyaura reaction nine consecutive times with small drop in catalytic activity.
- Gholinejad,Hamed,Biji
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p. 14293 - 14303
(2015/08/24)
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- Palladium-Catalysed Direct Cross-Coupling of Organolithium Reagents with Aryl and Vinyl Triflates
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A palladium-catalysed cross-coupling of organolithium reagents with aryl and vinyl triflates is presented. The reaction proceeds at 50 or 70 C with short reaction times, and the corresponding products are obtained with moderate to high yields, with a variety of alkyl and (hetero)aryl lithium reagents.
- Vila, Carlos,Hornillos, Valentín,Giannerini, Massimo,Fa?anás-Mastral, Martín,Feringa, Ben L.
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supporting information
p. 13078 - 13083
(2016/02/19)
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- An efficient palladium N-heterocyclic carbene catalyst allowing the suzuki-miyaura cross-coupling of aryl chlorides and arylboronic acids at room temperature in aqueous solution
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The application of a highly active Pd-NHC catalyst for the Suzuki-Miyaura cross-coupling of a broad variety of electronically activated and deactivated aryl chlorides with different arylboronic acids in excellent yields is described. This catalyst can be handled under aerobic conditions, is active with low catalyst loadings at room temperature and in an aqueous reaction medium and allows the application of cheap potassium carbonate as the base.
- Rajabi, Fatemeh,Thiel, Werner R.
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p. 1873 - 1877
(2014/06/09)
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- Catalytic direct cross-coupling of organolithium compounds with aryl chlorides
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Palladium-catalyzed direct cross-coupling of aryl chlorides with a wide range of (hetero)aryl lithium compounds is reported. The use of Pd-PEPPSI-IPent or Pd2(dba)3/XPhos as the catalyst allows for the preparation of biaryl and heterobiaryl compounds in high yields under mild conditions (room temperature to 40 C) with short reaction times.
- Hornillos, Valentin,Giannerini, Massimo,Vila, Carlos,Fananas-Mastral, Martin,Feringa, Ben L.
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supporting information
p. 5114 - 5117
(2013/10/22)
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- Copper-catalyzed decarboxylation of aromatic carboxylic acids: En route to milder reaction conditions
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The copper-catalyzed decarboxylation of carboxylic aromatic acids has been advantageously achieved by using aliphatic amines like tetramethylethylenediamine (TMEDA) or hexamethylenetetraamine (HMTA) as ligands instead of the aromatic heterocyclic amines (quinoline, phenanthroline) used until now. The improvement is significant since the reaction can be performed at a lower temperature (ca. 50 °C less) and the reaction time is clearly shorter (15 min instead of 12 to 24 h). Copyright
- Cahiez, Gerard,Moyeux, Alban,Gager, Olivier,Poizat, Mael
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supporting information
p. 790 - 796
(2013/04/10)
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- Palladium-catalyzed intermolecular desulfinylative cross-coupling of heteroaromatic sulfinates
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Beauty lies in simplicity: An efficient and environmentally benign palladium-catalyzed protocol has been developed using a sulfinate as a nucleophilic coupling partner. The sulfinate position is arylated chemoselectively in very good yields. The bench-stable, non-hygroscopic heteroaromatic sulfinate salts rapidly undergo cross-coupling without the need of a co-catalyst, base, or additives (see scheme; mw=microwave). Copyright
- Sévigny, Stéphane,Forgione, Pat
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supporting information
p. 2256 - 2260
(2013/03/28)
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- Efficient desulfinylative cross-coupling of thiophene and furan sulfinates with aryl bromides in aqueous media
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This letter describes the development of an environmentally benign palladium-catalyzed cross-coupling reaction using heteroaromatic sulfinates as nucleophilic coupling partners in aqueous media. This method accesses aryl-substituted heteroaromatics in very good yields chemoselectively without the need for base, additives or co-catalysts.
- Sévigny, Stéphane,Forgione, Pat
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supporting information
p. 589 - 592
(2013/04/10)
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- Room-temperature Suzuki-Miyaura coupling of heteroaryl chlorides and tosylates
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Suzuki-Miyaura coupling of heteroaryls is an important method for the preparation of compound libraries for medicinal chemistry and materials research. Although many catalysts have been developed, none of them have been generally applicable to the coupling reactions of heteroaryl chlorides and tosylates at room temperature. We discovered that a catalyst combination of Pd(OAc)2 and XPhos (2-dicyclohexylphosphanyl-2',4',6'- triisopropylbiphenyl) could efficiently catalyze these couplings. Besides the choice of catalyst, the use of hydroxide bases in an aqueous alcoholic solvent was essential for fast couplings. These conditions promoted fast release of active catalyst (XPhos)Pd0, and accelerated the transmetalation in the catalytic cycle. Most of the major families of heteroaryl chlorides (31 examples) and tosylates (17 examples) reached full conversion within minutes to hours at room temperature. The method could be easily scaled up for gram-scale synthesis. Furthermore, we examined the relative reactivity of coupling partners in whole reactions. Electron-rich heteroaryl chlorides and tosylates reacted more slowly than electron-deficient ones, in the order of indole, pyrrole furan, thiophene > pyridine. Similarly, electron-deficient arylboronic acids were less reactive than electron-neutral and electron-rich ones. The reactivity trends from this study can help to choose appropriate coupling partners for Suzuki reactions.
- Yang, Junfeng,Liu, Sijia,Zheng, Jian-Feng,Zhou, Jianrong
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supporting information
p. 6248 - 6259,12
(2020/09/16)
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- A highly active catalytic system for Suzuki-Miyaura cross-coupling reactions of aryl and heteroaryl chlorides in water
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An easily available Pd(OAc)2/(2-mesitylindenyl) dicyclohexylphosphine/Me(octyl)3N+Cl-/K 3PO4·3H2O catalytic system was developed and it shows high catalytic activity in the Suzuki-Miyaura cross-coupling reaction of a diverse array of aryl and heteroaryl chlorides in water. Notably, this catalytic system also works with ultra-low loading of the catalyst with high turnover numbers.
- Mao, Shu-Lan,Sun, Yue,Yu, Guang-Ao,Zhao, Cui,Han, Zhi-Jun,Yuan, Jia,Zhu, Xiaolei,Yang, Qihua,Liu, Sheng-Hua
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p. 9410 - 9417
(2013/01/15)
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- Direct 2-arylation of thiophene using low loading of a phosphine-free palladium catalyst
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The direct coupling of aryl halides with thiophene would be a considerable advantage for sustainable development because of only HBr associated with a base as by-product is formed and the number of steps to prepare these compounds is less than in more cla
- Bensaid, Souhila,Roger, Julien,Beydoun, Kassem,Roy, David,Doucet, Henri
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experimental part
p. 3524 - 3531
(2011/09/16)
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- Nickel-catalyzed cross-coupling of phenols and arylboronic acids through an in situ phenol activation mediated by PyBroP
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A new method for the Suzuki-Miyaura cross-coupling of phenols and arylboronic acids through in situ phenol activation mediated by PyBroP is presented. The reaction proceeds efficiently by using cost-effective, markedly stable [NiCl2(dppp)] (dppp=1,3-bis(diphenylphosphino)propane) as the catalyst in only 5 mol % loading, as well as in the absence of extra ligands. The method exhibits broad applicability and high efficiency towards a wide range of both phenols and boronic acids, including activated, nonactivated, deactivated, and heteroaromatic coupling partners. In addition, various functional groups, such as ether, amino, cyano, ester, and ketone groups, are compatible with this transformation. Notably, arylboronic acids containing an unprotected NH2 group and 2-heterocyclic boronic acids, which are generally problematic for coupling under conventional conditions, are also viable substrates, although moderate yields were obtained for sterically hindered substrates. Consequently, the in situ cross-coupling methodology coupled with the use of an inexpensive and stable nickel catalyst provides a rapid and efficient pathway for the assembly of biaryls and heterobiaryls with structural diversity from readily available phenol compounds.
- Chen, Guo-Jun,Huang, Jie,Gao, Lian-Xun,Han, Fu-She
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supporting information; experimental part
p. 4038 - 4042
(2011/05/05)
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- Nickel-catalyzed C-O activation of phenol derivatives with potassium heteroaryltrifluoroborates
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A general method based on nickel-catalyzed C-O activation of various phenol derivatives with potassium (hetero)aryltrifluoroborates has been developed. A large number of heterobiaryls can be easily obtained with yields up to 99% using methanesulfonate cross-coupling partners.
- Molander, Gary A.,Beaumard, Floriane
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supporting information; experimental part
p. 4022 - 4025
(2010/11/05)
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- Efficient synthesis of biaryls through the kumada reaction catalyzed by carbene adducts of cyclopalladated ferrocenylimine
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A series of carbene adducts of cyclopalladated ferrocenylimine were prepared, and evaluated in the cross-coupling reaction of aryl halides with Grignard reagents (the Kumada reaction). Complex d exhibited high catalytic activity for the coupling of aryl chlorides with sterically hindered Grignard reagents and the reaction tolerated various functional groups. A wide range of biaryls were efficiently obtained in good to excellent yields in the presence of 0.5 mol-% catalyst under mild reaction conditions.
- Ren, Gerui,Cui, Xiuling,Wu, Yangjie
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experimental part
p. 2372 - 2378
(2010/07/04)
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- Palladium-catalyzed cross-coupling of five-membered heterocyclic silanolates
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(Chemical Equation Presented) The preparation of π-rich 2-aryl heterocycles by palladium-catalyzed cross-coupling of sodium heteroarylsilanolates with aryl iodides, bromides, and chlorides is described. The cross-coupling process was developed through extensive optimization of the following key variables: (1) identification of stable, isolable alkali metal silanolates, (2) identification of conditions for preformation and isolation of silanolate salts, (3) judicious choice in the palladium catalyst/ligand combination, and (4) selection of the protecting group on the nitrogen of indole. It was found that the alkali metal silanolates, either isolated or formed in situ, offered a significant rate enhancement and broader substrate scope over the use of silanols activated by Bronsted bases such as NaOt-Bu. In addition, the optimized conditions for the cross-coupling of 2-indolylsilanolates were readily applied to the cross-coupling of 2-pyrrolyl-, 2-furyl-, and 2-thienylsilanolates.
- Denmark, Scott E.,Baird, John D.,Regens, Christopher S.
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p. 1440 - 1455
(2008/04/12)
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- Palladium-catalyzed cross-coupling reactions of heterocyclic silanolates with substituted aryl iodides and bromides
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Sodium silanolates derived from a number of heterocyclic silanols undergo cross-coupling with a variety of aromatic iodides and bromides under mild conditions. In situ deprotonation of the silanols with an equivalent amount of sodium hydride in toluene ge
- Denmark, Scott E.,Baird, John D.
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p. 793 - 795
(2007/10/03)
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- Efficient coupling of heteroaryl halides with arylboronic acids in the presence of a palladium-tetraphosphine catalyst
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Cis, cis, cis-1,2,3,4-tetrakis(diphenylphosphinomethyl) cyclopentane: ·1/2[PdCl(C3H5)]2 system catalyses the Suzuki cross-coupling of heteroaryl halides with a range of arylboronic acids with very high ratio substrate/catalyst in good yields. Substrates such as pyridines, quinolines, thiophenes, an indole, pyrimidines or a furane have been used successfully.
- Feuerstein, Marie,Doucet, Henri,Santelli, Maurice
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p. 327 - 336
(2007/10/03)
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- An amphiphilic resin-supported palladium catalyst for high-throughput cross-coupling in water
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(figure presented) The Suzuki-Miyaura coupling of aryl halides (8 varieties) and aryl-or vinylboronic acids (12 varieties) took place in water in the presence of a palladium complex of an amphiphilic polystyrene-poly(ethylene glycol) copolymer resin-supported N-anchored 2-aza-1,3-bis(diphenylphosphino)-propane ligand and potassium carbonate to give uniform and quantitative yields of the corresponding biaryls (96 varieties).
- Uozumi, Yasuhiro,Nakai, Yasushi
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p. 2997 - 3000
(2007/10/03)
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- Synthesis and Properties of 1,8-Di(2-thienyl)-, 1,8-Bs(5,2'-bithiophene-2-yl)-, 1,8-Bis(5,2':5',2''-terthiophene-2-yl)-, and 1,8-Bis(5,2':5',2'':5'',2'''-quaterthiophene-2-yl)naphthalenes and Related Compounds
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1,8-Di(2-thienyl)-, 1,8-bis(5,2'-bithiophene-2-yl), 1,8-bis(5,2':5',2''-terthiophene-2-yl)-, and 1,8-bis(5,2':5',2'':5'',2'''-quaterthiophene-2-yl)naphthalenes (1a, 1b, 1c, and 1d, respectively) were synthesized starting from 1,8-dibromonaphthalene by application of NiCl2(dppp)-catalyzed coupling of aryl bromides with thienylmagnesium bromides.For comparison with these compounds, 1-(2-thienyl)-, 1-(5,2'-bithiophene-2-yl)-, 1-(5,2':5',2''-terthiophene-2-yl)-, and 1-(5,2':5',2'':5'',2'''-quaterthiophene-2-yl)naphthalenes (2a-d) were also prepared.Inspection of 1H and 13C NMR and UV/Vis data of 1a-d and 2a-d including X-ray single crystal structure data of 1b suggests that the planes of two oligothiophene units of 1a-d are approximately parallel to each other and are at large angles to the naphthalene ring.In accordance with these findings, CV oxidation potential data show that the radical cations formed from 1a-d are stabilized by intramolecular electron transfer interaction of the two oligothiophene units.
- Kuroda, Masami,Nakayama, Juzo,Hoshino, Masamatsu,Furusho, Noboru,Kawata, Takashi,Ohba, Shigeru
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p. 3735 - 3748
(2007/10/02)
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- Synthesis and properties of naphthalenes carrying two cofacially oriented α-oligothiophene units at the peri positions
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Two cofacially oriented (oligo)thiophene units of 1,8-di(2-thienyl)-, 1,8-bis(5,2'-bithiophene-2-yl)-, and 1,8-bis(5,2':5',2''-terthiophene-2-yl)naphthalenes, which were synthesized starting from 1,8-dibromonaphthalene, interact with each other to stabilize the radical cations of these compounds, thus decreasing their CV oxidation potentials.
- Kuroda,Nakayama,Hoshino,Furusho
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p. 7553 - 7556
(2007/10/02)
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- Phototoxic compounds for use as insect control agents
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A method is provided herein for controlling insects which are harmful to agriculture and forestry and which are also harmful both to humans and to domestic animals. The method involves the steps of applying to a locus infested with such insects, a composi
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- PALLADIUM-CATALYZED ARYLATION OF FURAN, THIOPHENE, BENZOFURAN AND BENZOTHIOPHENE
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Treatment of ?-electron sufficient aromatic heterocycles such as furan, thiophene, benzofuran and benzothiophene with aryl bromides in the presence of tetrakis(triphenyphosphine)palladium gave the corresponding 2-aryl aromatic heterocycles.
- Ohta, Akihiro,Akita, Yasuo,Ohkuwa, Teruya,Chiba, Mari,Fukunaga, Ryuichi,et al.
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p. 1951 - 1958
(2007/10/02)
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- NICKEL-PHOSPHINE COMPLEX-CATALYZED GRIGNARD COUPLING-II; GRIGNARD COUPLING OF HETEROCYCLIC COMPOUNDS
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A general, versatile method for alkylation and arylation of haloheterocyclic compounds is reported.In the presence of a catalytic quantity of , where dppp stands for Ph2P(CH2)3PPh2, bromothiophenes, halopyridines, haloquinoline, and haloisoquinolines reacted with alkyl and aryl Grignard reagents at room temperature or at ether refluxing temperature to give the cross-coupling products.The coupling reactions has been applied to the synthesis of isoquinoline alkaloids.Reactivities of 2-thienyl and 2-pyridyl Grignard reagents have also been examined.
- Tamao, K.,Kodama, S.,Nakajima, I.,Kumada, M.,Minato, A.,Suzuki, K.
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p. 3347 - 3354
(2007/10/02)
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