- Invisible Chelating Effect Exhibited between Carbodicarbene and Phosphine through π-π Interaction and Implication in the Cross-Coupling Reaction
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Palladium complexes supported with the mixed ligands carbodicarbene (CDC) and different phosphine ligands (PPh3, PTol3, and PCy3) were prepared, and their molecular structures were characterized. Examination of the structures of 2-PPh3 and 2-PTol3 with cis configuration discloses the existence of an unexpected π-π interaction between one phenyl group of the phosphine and the benzimidazole ring of a CDC. The palladium complex 2-PPh3 is an active Suzuki-Miyaura catalyst with a wide scope of substrates containing various functional groups and steric demands. In contrast to electron-withdrawing aryl bromide, the yield of product for electron-rich substrates was improved by adding a catalytic amount of DMSO under aerobic conditions. The solution NMR and structural analysis has revealed that the intramolecular π-π interaction between CDC and phosphine ligands has a positive influence on the activity of the reaction, which is further supported by quantum chemical calculations.
- Shih, Wei-Chih,Chiang, Yun-Ting,Wang, Qing,Wu, Ming-Chun,Yap, Glenn P. A.,Zhao, Lili,Ong, Tiow-Gan
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- Immobilized Pd on magnetic nanoparticles bearing proline as a highly efficient and retrievable Suzuki-Miyaura catalyst in aqueous media
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A magnetically retrievable nanocatalyst was evaluated for a microwave assisted Suzuki-Miyaura reaction in aqueous media. Excellent yields and conversions were obtained with low Pd loadings (down to 0.01 mol% Pd). It was stable up to 6 months in water under aerobic conditions and efficiency remained unaltered even after 7 repeated cycles. This journal is
- Nehlig,Waggeh,Millot,Lalatonne,Motte,Gunin
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- Suzuki-Miyaura cross-coupling catalyzed by protein-stabilized palladium nanoparticles under aerobic conditions in water: Application to a one-pot chemoenzymatic enantioselective synthesis of chiral biaryl alcohols
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The preparation of palladium nanoparticles stabilized primarily within the protein cavity of a highly thermostable Dps protein (DNA binding protein from starved cells) and the use of this precatalyst system in Suzuki-Miyaura cross-coupling reactions under
- Prastaro,Ceci,Chiancone,Boffi,Cirilli,Colone,Fabrizi,Stringaro,Cacchi
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- Alcoholic solvent-assisted ligand-free room temperature Suzuki-Miyaura cross-coupling reaction
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We have observed the enhancing effect of alcoholic solvents in palladium-catalysed ligand-free Suzuki-Miyaura reactions. No extra additives or ligands are required for the Suzuki-Miyaura reaction of aryl bromides with arylboronic acids when we carried out the reaction in alcoholic or aqueous alcoholic solvents. Moreover, ethanol or aqueous ethanol is found to be a very good solvent for the Suzuki-Miyaura reaction involving electronically diverse aryl bromides and arylboronic acids under mild and ligand-free conditions with low catalyst loading. It is observed from Hg(0) poisoning tests that the in situ generated palladium(0) species is the actual catalytic species for the reaction.
- Sarmah, Gayatri,Mondal, Manoj,Bora, Utpal
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- Highly active and reusable hydrotalcite-supported Pd(0) catalyst for Suzuki coupling reactions of aryl bromides and chlorides
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A palladium(0) nanocluster supported on hydrotalcite has been prepared and tested for the Suzuki coupling reaction. The prepared catalyst showed very efficient catalytic activity for cross coupling of iodo- and bromoarenes under very mild reaction conditions, affording >90% yield. Under the optimized reaction conditions, chloroarenenes also showed very good reactivity. Transmission electron microscopic imaging data showed the formation of very small Pd(0)-nanoclusters (d = 2.2 ± 0.5 nm) well dispersed on the support, which enhanced the activity and stability of the catalyst for the Suzuki cross-coupling reaction. This catalytic system offers an easy method of preparation with good activity and reusability up to five cycles.
- Karanjit, Sangita,Kashihara, Masaya,Nakayama, Atsushi,Shrestha, Lok Kumar,Ariga, Katsuhiko,Namba, Kosuke
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- Palladium stabilized by 3,4-dihydroxypyridine-functionalized magnetic Fe3O4 nanoparticles as a reusable and efficient heterogeneous catalyst for Suzuki reactions
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A Pd supported on 3,4-dihydroxypyridine (Py)-functionalized Fe3O4 (Fe3O4/Py/Pd) hybrid material has been synthesized for the first time. Inductively coupled plasma (ICP), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and field emission scanning electron microscopy (FESEM) and Fourier transform infrared (FTIR) studies have been used to characterize the catalyst. The catalyst exhibited very high activity for Suzuki coupling reaction of several aryl halides with phenylboronic acids in aqueous phase at room temperature. The most interesting result of this work is the possibility to perform Suzuki reactions of aryl chlorides in the presence of the prepared catalyst. The yields of the products were in the range from 70% to 98%. In this process, the novel catalyst could be recovered in a facile manner from the reaction mixture by applying an external magnet device, and reused more than eight times without any significant loss in activity.
- Pirhayati, Mozhgan,Veisi, Hojat,Kakanejadifard, Ali
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- Antihyperlipidemic morpholine derivatives with antioxidant activity: An investigation of the aromatic substitution
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Drugs affecting more than one target could result in a more efficient treatment of multifactorial diseases as well as fewer safety concerns, compared to a one-drug one-target approach. Within our continued efforts towards the design of multifunctional molecules against atherosclerosis, we hereby report the synthesis of 17 new morpholine derivatives which structurally vary in terms of the aromatic substitution on the morpholine ring. These derivatives simultaneously suppress cholesterol biosynthesis through SQS inhibition (IC50 values of the most active compounds are between 0.7 and 5.5 μM) while exhibiting a significant protection of hepatic microsomal membranes against lipid peroxidation (with IC50 values for the most active compounds being between 73 and 200 μM). Further evaluation of these compounds was accomplished in vivo in an animal model of acute experimental hyperlipidemia, where it was observed that compounds reduced the examined lipidemic parameters (TC, TG and LDL) by 15-80%. In order to examine the mode of binding of these molecules in the active catalytic site of SQS, we also performed docking simulation studies. Our results indicate that some of the new compounds can be considered interesting structures in the search for new multifunctional agents of potential application in atherosclerosis.
- Ladopoulou, Eleni M.,Matralis, Alexios N.,Nikitakis, Anastasios,Kourounakis, Angeliki P.
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- Palladium nanoparticles embedded in metal-organic framework derived porous carbon: Synthesis and application for efficient Suzuki-Miyaura coupling reactions
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A nanoporous carbon (NPC) material was prepared by one-step direct carbonization of a metal-organic framework, MOF-5, without additional carbon precursors. Pd nanoparticles were immobilized on the MOF-5-derived NPC by an impregnation method coupled with subsequent reduction with NaBH4. The prepared catalyst was in-depth characterized by X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy, and N2 adsorption. The catalyst was used to catalyze the Suzuki-Miyaura coupling reactions and exhibited high catalytic efficiency with yields ranging from 90% to 99% under mild conditions. The results demonstrated the great application potential of MOF precursor-based metal nanoparticle composites in catalysis.
- Dong, Wenhuan,Zhang, Li,Wang, Chenhuan,Feng, Cheng,Shang, Ningzhao,Gao, Shutao,Wang, Chun
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- Importance of monodentate mono-ligand designs in developing N-stabilized Pd catalysts for efficient ambient temperature C[sbnd]C coupling: Donor strengths and steric features
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Unfriendly temperature profiles and costs of carbon coupling catalysis, which pose challenge to both synthetic organic chemists as well as industrial applicability, motivated our design of new monodentate N-donors as support ligands for the purpose of constructing ambient temperature precatalysts that are molecularly close to the hypothetical active forms. Therefore, a series of sterically varied monodentate N-donor imidazoles (1–7) and oxazoles (8–9) have been synthesized and their N-donor strengths, which were estimated as pKas, are systematically varied from 0.9 to 8.5 by substituent variations. Eleven target mono-ligand complexes (1-PdCl2MeCN – 9-PdCl2MeCN, 6-PdCl2PhCN and 7-PdCl2PhCN) and six trans-bis-ligand complexes (12-PdCl2, 22-PdCl2, 32-PdCl2, 62-PdCl2, 12-Pd(OAc)2 and 22-Pd(OAc)2) were isolated and catalytically studied along with PdI2(PPh3)2. Results of coupling reactions, which were conducted both via in situ ‘Pd(II) salt + ligand’ approach and by use of the precatalysts, show that the mono-ligand precatalyst designs (1-PdCl2MeCN – 9-PdCl2MeCN, 6-PdCl2PhCN and 7-PdCl2PhCN) represent a true catalyst improvement initiative among the phosphine-free catalyst community; i.e. yields approaching 100% (TOF ≈ 2000) at 0.2 mol % catalyst loading, 45 °C and within 15 min. On the other hand, the complexes with trans-bis-ligand coordination were inactive at ambient temperatures. Therefore, it was concluded that coordinative saturation, which results from implementing two or more ligand equivalents or use of polydentate ligands on palladium, should be strongly discouraged. Such saturation necessitates the undesirable and avoidable high temperature necessities, long reflux durations and needlessly high catalyst loadings. Correlation between catalyst activity and donor strengths or steric properties were analysed leading to important conclusions. The catalyst design also supported coupling of activated aryl chlorides from 60 °C while Heck coupling activities were observed only at the early minutes of reactions.
- Eseola, Abiodun Omokehinde,G?rls, Helmar,Plass, Winfried
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- New biomaterials for Ni biosorption turned into catalysts for Suzuki-Miyaura cross coupling of aryl iodides in green conditions
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In parallel with increasing Ni production and utilisation, Ni pollution in the soil-water continuum has become an alarming and global problem. Solutions for removing Ni from industrial effluents have been widely investigated and biosorption has emerged as an efficient, cost-effective, scalable and sustainable alternative for water treatment. However, the biosorption capacity is limited by the chemical composition of the biomaterial and the Ni-enriched biomaterials are rarely valorised. In this work, the biosorption capacity of three abundant biomaterials with different chemical properties - water hyacinth, coffee grounds and pinecones - was studied before and after functionalization, and reached a maximum biosorption capacity of 51 mg g?1of Ni(ii). A bioinspired functionalization approach was investigated introducing carboxylate moieties and was conducted in green conditions. The Ni-enriched biomaterials were valorised by transformation into catalysts, which were characterised by MP-AES and XRPD. Their characterisation revealed a structure similar to nickel formate, and hence the Eco-Ni(HCOO)2catalysts were tested in Suzuki-Miyaura reactions. Several aryl iodides were successfully cross-coupled to phenylboronic acids using Eco-Ni(HCOO)2without any ligand, a mild and green base in a mixture of green solvents.
- Adler, Pauline,Boulanger, Clotilde,Cases, Lucie,Diliberto, Sébastien,Grison, Claude,Pelissier, Franck
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p. 28085 - 28091
(2021/09/15)
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- Magnetic chitosan-functionalized cobalt-NHC: Synthesis, characterization and catalytic activity toward Suzuki and Sonogashira cross-coupling reactions of aryl chlorides
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Aryl chlorides are one of the most stable and available electrophiles, however, their coupling with nucleophiles remains a challenge in organic synthesis. Herein, we prepared a Cobalt-NHC (N-Heterocyclic carbene) complex anchored on magnetic chitosan nanoparticles and assayed its catalytic activity for the reactions of substituted phenylboronic acid and also phenlacetylene with derivatives of aryl chlorides. These reactions are of great importance since they are employed for the synthesis of unsymmetrical diarylethynes and biphenyls, which belong to a prime class of building blocks. The synthesized nanocatalyst was found to be highly efficient in Suzuki and Sonogashira coupling in terms of their activity and recyclability in polyethylene glycol (PEG) as a green reaction media under conditions of temperatures (70 and 100 °C) and Co loading (3 and 6 mol%). To the best of our knowledge, this is the first attempt of using cobalt-NHC complex for catalyzing the abovementioned reactions. Moreover, replacing the earth-abundant Cobalt-based catalyst as an alternative to high cost palladium make this approach promising from sustainable chemistry view.
- Hajipour, Abdol R.,Malek, Shaghayegh Sadeghi
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- Visible light-driven Suzuki-Miyaura reaction by self-supported Pd nanocatalysts in the formation of Stille coupling-based photoactive microporous organic polymers
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Stille coupling was applied to synthesize microporous organic polymers (MOPs). Metallic Pd was in situ self-supported during the networking of 1,3,6,8-tetrabromopyrene with 1,4-bis(tributylstannyl)benzene to form Stille coupling-based MOP (St-MOP)?Pd. The size of St-MOP particles and the amount of metallic Pd in St-MOP?Pd depended on the amount of Pd catalyst. As the amount of Pd catalyst increased, the size of St-MOP particles decreased with an increase of metallic Pd, due to the increased St-MOP nuclei in the early growth stage of St-MOP. The St-MOP bearing pyrenes showed absorption and emission of visible light and St-MOP?Pd showed excellent catalytic performance in the visible light-driven Suzuki-Miyaura coupling. The optimal St-MOP?Pd-2 (0.14 mol% Pd) showed a TON of 657 and a TOF of 219 h-1 in the visible light-driven Suzuki-Miyaura coupling of 1-acetyl-4-bromobenzene and phenylboronic acid at 25 °C. The optimal amount of St-MOP and metallic Pd in St-MOP?Pd was critical to achieve excellent catalytic performance. The overall photocatalytic principles of St-MOP?Pd were rationalized by computational simulation. This journal is
- Ahn, Tae Kyu,Choi, Sung Jae,Jo, Bonghyun,Kim, Hae Jin,Ko, Kyoung Chul,Ko, Yoon-Joo,Lee, Sang Moon,Ryu, Sang Hyun,Seon, Ji Hui,Son, Seung Uk
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p. 5535 - 5543
(2020/09/17)
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- Self-Assembled Multilayer Iron(0) Nanoparticle Catalyst for Ligand-Free Carbon-Carbon/Carbon-Nitrogen Bond-Forming Reactions
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Self-assembled multilayer iron(0) nanoparticles (NPs, 6-10 nm), namely, sulfur-modified Au-supported Fe(0) [SAFe(0)], were developed for ligand-free one-pot carbon-carbon/carbon-nitrogen bond-forming reactions. SAFe(0) was successfully prepared using a well-established metal-nanoparticle catalyst preparative protocol by simultaneous in situ metal NP and nanospace organization (PSSO) with 1,4-bis(trimethylsilyl)-1,4-dihydropyrazine (Si-DHP) as a strong reducing agent. SAFe(0) was easy to handle in air and could be recycled with a low iron-leaching rate in reaction cycles.
- Akiyama, Toshiki,Arisawa, Mitsuhiro,Haneoka, Hitoshi,Harada, Kazuo,Hasegawa, Jun-Ya,Honma, Tetsuo,Mashima, Kazushi,Sato, Yoshihiro,Shimoda, Shuhei,Shio, Yasunori,Suzuki, Takeyuki,Tamenori, Yusuke,Tsurugi, Hayato,Tsuruta, Kazuki,Wada, Yuki,Yamada, Makito
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supporting information
p. 7244 - 7249
(2020/10/12)
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- Visible-Light-Enhanced Suzuki–Miyaura Reactions of Aryl Chlorides in Water with Pd NPs Supported on a Conjugated Nanoporous Polycarbazole
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The visible-light-enhanced catalytic activation of aryl chlorides for Suzuki–Miyaura cross-coupling (SMC) reactions is highly challenging because of the strength of the C?Cl bond. In this work, palladium nanoparticles (Pd NPs) were grown on a conjugated nanoporous polycarbazole (CNP), named Pd/CNP. The hybrid material Pd/CNP could catalyze the SMC reactions of aryl chlorides with arylboronic acids in water under blue LED irradiation at room temperature with high efficiency. This protocol exhibited good functional group tolerance and the catalyst could be recycled without significant loss of its catalytic activity. CNP not only provided photogenerated electrons to enrich the electron density of the Pd NPs but also generated holes for the activation of the arylboronic acids.
- Guo, Bin,Li, Hong-Xi,Zha, Cheng-Hao,Young, David James,Li, Hai-Yan,Lang, Jian-Ping
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p. 1421 - 1427
(2019/02/26)
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- Pd/MOF-199: As an efficient heterogeneous catalyst for the Suzukie Miyaura cross-coupling reaction
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Successful deposition of Pd nanoparticles is described using MOF-199 as a support. Various characterization techniques including FTIR, XRD, SEM, BET-BJH, TG-DTA, and NH3-TPD were used to verify the efficiency of catalysts. Pd/MOF-199 is utilized as a catalyst for Suzukie Miyaura reactions with reasonable to excellent reaction yields under reflux conditions in H2O: ethanol solvent.
- Sanaei, Mehran,Fazaeli, Razieh,Aliyan, Hamid
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p. 1290 - 1295
(2019/03/17)
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- Denitrogenative palladium-catalyzed coupling of aryl halides with arylhydrazines under mild conditions
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The development of a method for the Pd(ii)-catalyzed denitrogenative coupling of arylhydrazines to give functionalized biaryls in good yield, using aryl bromides or aryl iodides as convenient and inexpensive aryl sources, is reported. High functional group tolerance is demonstrated for electronically distinct arylhydrazines as well as aryl halides. The desired products were isolated in good to excellent yields for 58 examples. Control experiments and mechanism studies revealed that the transformation undergoes a base-promoted Pd-catalyzed process.
- Chang, Sheng,Dong, Lin Lin,Song, Hai Qing,Feng, Bo
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supporting information
p. 3282 - 3288
(2018/05/15)
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- Highly efficient and recyclable water-soluble fullerene-supported PdCl2 nanocatalyst in Suzuki-Miyaura cross-coupling reaction
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A water-soluble fullerene-supported PdCl2 nanocatalyst [C60-TEGS/PdCl2] was prepared by coordination of water-soluble fullerene nanoparticles with palladium chloride. In pure water, the catalytic activity of nanocatalyst [C60-TEGS/PdCl2] for Suzuki-Miyaura cross-coupling reaction was investigated under different reaction conditions. The results showed that biphenyl compounds could be synthesized in high yields at room temperature using 0.01 mol% of [C60-TEGS/PdCl2] as the catalyst and K2CO3 as the base with the reaction time of 4 h. The catalyst was recycled five times, and the yield clearly did not decrease.
- Li, Jingbo,Huo, Ping,Zheng, Junwei,Zhou, Xiuming,Liu, Wanyun
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p. 24231 - 24235
(2018/07/25)
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- A highly recoverable polymer-supported ionic salen-palladium complex as a catalyst for the Suzuki-Miyaura cross coupling in neat water
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A polymer supported Pd-salen complex (PS-Pd-salen) was synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR), Fourier-transform NMR spectroscopy (FT-NMR), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), surface area and pore size distribution by Brunauer-Emmett-Teller (BET). The heterogeneous catalytic performance of the PS-Pd-salen for the Suzuki-Miyaura coupling of variety of phenyl boronic acid with different aryl halides was successfully conducted in water with K2CO3 and 20 mg catalyst loading at room temperature. The coupling reactions with aryl iodides and bromides were achieved at room temperature with good to excellent yield; whereas the reactions with aryl chlorides were performed in aqueous-ethanol (1:1) at 90 °C. The product yields related with the substrates were optimized, and main reaction factors influencing the yields were also recognized. The results clearly indicated that the reaction constraints needed to achieve high yields are substrate-reliant. The hot filtration test verified heterogeneous nature of PS-Pd-salen complex. Moreover, the catalyst showed excellent reusability for five successive runs in slight compromising with its activity.
- Balinge, Kamlesh Rudreshwar,Khiratkar, Avinash Ganesh,Bhagat, Pundlik Rambhau
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p. 131 - 139
(2017/12/07)
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- Towards environmentally friendlier Suzuki-Miyaura reactions with precursors of Pd-NHC (NHC = N-heterocyclic carbene) complexes
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The preparation of [NHC·H][Pd(η3-R-allyl)Cl2] complexes is disclosed and represents a facile, atom-economical, environmentally friendly and rapid synthesis. These palladates are immediate synthetic precursors to the well-known [Pd(NHC)(η3-R-allyl)Cl] complexes. Their activation leading to catalytically relevant species has been studied in the Suzuki-Miyaura reaction. The need for an activation step prior to the catalysis was examined. The reaction scope showcases its ease and breadth in terms of functional group tolerance. Electron-donating and electron-withdrawing aryl chlorides and bromides were coupled effectively as well as heteroatom-containing and sterically hindered aryl halides. The catalytic reaction was conducted in ethanol with a weak and inexpensive inorganic base.
- Zinser, Caroline M.,Warren, Katie G.,Meadows, Rebecca E.,Nahra, Fady,Al-Majid, Abdullah M.,Barakat, Assem,Islam, Mohammad S.,Nolan, Steven P.,Cazin, Catherine S. J.
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supporting information
p. 3246 - 3252
(2018/07/29)
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- Method for preparing biaryl from aryl hydrazine and aryl bromide
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The invention discloses a method for preparing biaryl from aryl hydrazine and aryl bromide. The method comprises the following steps: under the action of a divalent palladium catalyst and a ligand, aryl hydrazine and aryl bromide are subjected to a denitrification coupling reaction in an organic solvent, and after the reaction is ended, the reaction product is subjected to aftertreatment to obtainthe biaryl. In the preparation method, cheap and easily available aryl bromide is used as an aryl source, and the reaction of aryl hydrazine and aryl bromide shows good functional group tolerance, and promotes the palladium catalytic process by alkali.
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Paragraph 0040; 0041; 0042; 0044
(2018/09/21)
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- Method for preparing 24'-acetyl 4-nitrobiphenyl and 14' -acetyl 2-nitrobiphenyl through nitrification of 4-acetylbiphenyl
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The invention discloses a method for preparing 24'-acetyl 4-nitrobiphenyl and 14' -acetyl 2-nitrobiphenyl through nitrification of 4-acetylbiphenyl, mainly relating to the technical field of organic synthesis. The method comprises the following steps: 1) nitrification of 4-acetylbiphenyl: dissolving the 4-acetylbiphenyl with sufficient organic solvents, adding a nitrating agent, stirring and reacting for 10-20h under the condition of 15-30 DEG C, to obtain a mixture A; and 2) separation of products: adding sufficient deionized water and methylene chloride into the mixture A, continuously stirring for 15-30min, then standing and layering, taking lower-layer organic phase and sequentially washing with water, saturated Na2CO3 solution and water, drying the washed organic phase with anhydrous sodium sulfate until the solution is clarified and transparent, performing rotary evaporation to the remaining solids, and recrystallizing, to obtain the 24'-acetyl 4-nitrobiphenyl and 14' -acetyl 2-nitrobiphenyl. The method has the beneficial effects that the control and synthesis of two nitrification products can be realized, the reaction conversion rate and selectivity can be increased, the reaction conditions are mild, the aftertreatment flow is simple, the yield nitrification products is high, and the safety performance is better.
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Paragraph 0033; 0034
(2017/08/30)
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- Suzuki-Miyaura cross-coupling reaction of aryl chlorides with aryl boronic acids catalyzed by a palladium dichloride adduct of N-diphenylphosphanyl-2-aminopyridine
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One palladium dichloride adduct of a phosphine-pyridine ligand N-diphenylphosphanyl-2-aminopyridine (L1) [(L1)PdCl2] (1) has been prepared and structurally characterized. Compound 1 can be used as an effective catalyst for the Suzuki-Miyaura cross-coupling reactions of unreactive aryl chlorides with aryl boronic acids, and worked much better than its mono- or bidentate phosphine ligands. The reactions with a wide scope of substrates proceeded to give desired products in good to excellent yields.
- Xu, Lin-Yan,Liu, Chun-Yu,Liu, Shi-Yuan,Ren, Zhi-Gang,Young, David James,Lang, Jian-Ping
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p. 3125 - 3132
(2017/05/08)
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- Highly Efficient Bulky α-Diimine Palladium Complexes for Suzuki-Miyaura Cross-Coupling Reaction
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A series of bulky 9,10-dihydro-9,10-ethanoanthracene-11,12-diimine methyl palladium chloride complexes (C1—C6) with different steric and electronic substituent have been applied in Suzuki-Miyaura cross-coupling reactions. The influence of these substituents was investigated by comparing the catalytic performance of the complexes in the cross-coupling reactions and it can be found that the complex with bulky and electron-donating substituent is facilitated for the cross-coupling reaction of aryl halides with arylboronic acids under ambient atmosphere. The most active complex shows a wide substrate scope in excellent yields using very low catalyst concentration of 0.01 mol%.
- Huo, Ping,Li, Jingbo,Liu, Wanyun,Mei, Guangquan
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p. 363 - 367
(2017/03/24)
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- Pd nanoparticles on reverse phase silica gel as recyclable catalyst for Suzuki-Miyaura cross coupling reaction and hydrogenation in water
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Two catalytic systems, consisting of palladium nanoparticles supported by reverse phase amino functionalized silica are utilized as catalysts for Suzuki-Miyaura reaction and hydrogenation in water. The catalysts were developed by modifying silica into bidentate ligands, using either 2-pyridinecarboxaldehyde or 2,2′-bipyridine-4,4′-dicarboxylic acid. The synthesized catalysts showed quantitative reaction yields and recyclability with negligible leaching of Pd nanoparticles. Various characterization techniques including XPS, ICP-MS, SEM, BET, XRD, TEM, 1H- and 13C- NMR are used to verify the efficiency of the catalysts.
- Shabbir, Saira,Lee, Sinyoung,Lim, Minkyung,Lee, Heejin,Ko, Hyeji,Lee, Youngbok,Rhee, Hakjune
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p. 296 - 304
(2017/07/12)
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- Amphipathic monolith-supported palladium catalysts for chemoselective hydrogenation and cross-coupling reactions
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A palladium catalyst immobilized on an amphipathic and monolithic polystyrene-divinylbenzene polymer bearing strongly acidic cation exchange functions (sulfonic acid moieties) (Pd/CM) was developed. It was used as a catalyst for hydrogenation and ligand-free cross-coupling reactions, such as the Suzuki-Miyaura, Mizoroki-Heck, and copper- and amine-free Sonogashira-type reactions, together with a palladium catalyst supported on monolithic polymer (Pd/AM) bearing basic anion exchange functions (ammonium salt moieties), which has been in practical use for the decomposition of hydrogen peroxide produced as a byproduct during the manufacture of ultrapure water. While the Pd/CM was highly active as a catalyst for the hydrogenation and a variety of reducible functional groups could be reduced, the use of Pd/AM led to a unique chemoselective hydrogenation. Aromatic carbonyl groups were tolerant under the Pd/AM-catalyzed hydrogenation conditions, although benzyl esters, benzyl ethers, and N-Cbz groups could be smoothly hydrocracked. The cross-coupling reactions readily proceeded using either catalyst. The palladium leaching from the Pd/CM into the reaction media was never observed during the Sonogashira-type reaction, which was hardly achieved by other palladium-supported heterogeneous catalysts due to the good affinity of the palladium species with alkynes.
- Monguchi, Yasunari,Wakayama, Fumika,Ueda, Shun,Ito, Ryo,Takada, Hitoshi,Inoue, Hiroshi,Nakamura, Akira,Sawama, Yoshinari,Sajiki, Hironao
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p. 1833 - 1840
(2017/01/21)
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- A thiosemicarbazone–palladium(II)–imidazole complex as an efficient pre-catalyst for Suzuki–Miyaura cross-coupling reactions at room temperature in aqueous media
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Abstract: A Pd(II) complex of two sterically crowded ligands, specifically an N,S-donor thiosemicarbazone and an N-donor imidazole, has been synthesized and characterized by physicochemical and spectroscopic methods. X-ray single-crystal analysis revealed that the coordination geometry around the palladium center is distorted square planar, and the chloride ligand is involved in intermolecular bifurcated X–HY-type (where X?=?C, N and Y?=?Cl) hydrogen bonding. This complex proved to be a highly active and retrievable pre-catalyst for additive-free Suzuki–Miyaura cross-coupling reactions of arylboronic acids with aryl bromides or chlorides at room temperature and 60?°C, respectively. The reactions require a low catalyst loading and the complex is converted to ~1.5–2.0 nm-sized Pd nanoparticles (probably the real catalyst). The catalyst can be reused up to seven times without significant loss in activity. Since the reaction proceeds under mild conditions in aqueous medium and the catalyst is recoverable, it provides an environmentally benign alternative to the existing protocols for Suzuki–Miyaura reactions. Graphical abstract: Biaryls can be synthesized in high yield under greener reaction conditions in the presence of efficient pre-catalyst, thiosemicarbazone–palladium(II)–imidazole.[Figure not available: see fulltext.].
- Baruah, Jayantajit,Gogoi, Rajjyoti,Gogoi, Nibedita,Borah, Geetika
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p. 683 - 692
(2017/09/06)
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- Liquid-Assisted Grinding Accelerating: Suzuki-Miyaura Reaction of Aryl Chlorides under High-Speed Ball-Milling Conditions
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The effect of liquid-assisted grinding has been studied using mechanical Suzuki-Miyaura reaction of aryl chlorides as the model reaction. Catalytic systems of Davephos and PCy3 are tested respectively showing strong influences from different liquids. Unexpected improvement of yield over 55% is observed using alcohols as additives, which is explained by in situ formed alkoxides and their participation in oxidative addition. Further expansion of substrates using Pd(OAc)2/PCy3/MeOH system gives desired products in good to high yields.
- Jiang, Zhi-Jiang,Li, Zhen-Hua,Yu, Jing-Bo,Su, Wei-Ke
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p. 10049 - 10055
(2016/11/02)
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- N -Butylpyrrolidinone as a dipolar aprotic solvent for organic synthesis
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Dipolar aprotic solvents such as N-methylpyrrolidinone (or 1-methyl-2-pyrrolidone (NMP)) are under increasing pressure from environmental regulation. NMP is a known reproductive toxin and has been placed on the EU "Substances of Very High Concern" list. Accordingly there is an urgent need for non-toxic alternatives to the dipolar aprotic solvents. N-Butylpyrrolidinone, although structurally similar to NMP, is not mutagenic or reprotoxic, yet retains many of the characteristics of a dipolar aprotic solvent. This work introduces N-butylpyrrolidinone as a new solvent for cross-coupling reactions and other syntheses typically requiring a conventional dipolar aprotic solvent.
- Sherwood, James,Parker, Helen L.,Moonen, Kristof,Farmer, Thomas J.,Hunt, Andrew J.
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p. 3990 - 3996
(2016/07/21)
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- Palladium NPs supported on novel imino-pyridine-functionalized MWCNTs: Efficient and highly reusable catalysts for the Suzuki-Miyaura and Sonogashira coupling reactions
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In this article a new heterogeneous nanocatalyst based on palladium supported on functionalized multi-walled carbon nanotubes (MWCNTs) has been introduced. The synthetic process of the mentioned nanocatalyst, MWCNT-imino-pyridine/Pd, has been described. The characterization of the MWCNT-imino-pyridine/Pd was afforded by SEM, EDX, TEM, FTIR, ICP, and XRD. The surface structure of the materials was confirmed using Fourier transform infrared (FTIR) spectroscopy. The catalytic activity of MWCNT-imino-pyridine/Pd was tested in Sonogashira and Suzuki-Miyaura cross-coupling reactions affording various derivatives of both aryl alkynes and biaryls. The catalyst can be readily recovered and recycled at least six times without significant loss of catalytic activity.
- Adib, Mehdi,Karimi-Nami, Rahman,Veisi, Hojat
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p. 4945 - 4951
(2016/07/06)
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- Palladium-phosphine compound in catalyzing the application of the Suzuki reaction
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The invention discloses an application of a palladium-phosphine compound to catalysis of Suzuki reaction. The palladium-phosphine compound serving as a catalyst is capable of efficiently catalyzing Suzuki reaction in ethyl alcohol. By virtue of the palladium-phosphine compound, the defects of aqueous phase reaction are overcome; the aqueous phase reaction can be carried out in the presence of an extremely low quantity of catalysts; the palladium-phosphine compound is high in applicability to substrate; the Suzuki reaction can be carried out in the pollution-free environment in the presence of a relatively small quantity of catalysts.
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Paragraph 0086-0089
(2017/02/02)
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- Versatile palladium(II)-catalyzed Suzuki-Miyaura coupling in ethanol with a novel, stabilizing ligand
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Suzuki-Miyaura coupling reactions of arylboronic acids with aryl bromides were mediated by PdCl2 and bdppmapy (N,N-bis-(diphenylphosphanylmethyl)-2-aminopyridine) that both stabilizes and solubilizes the catalyst in predominantly ethanol as a solvent. Excellent yields for a wide variety of substrates were obtained under relatively mild conditions in this 'green' solvent.
- Ning, Jin-Jiao,Wang, Jian-Feng,Ren, Zhi-Gang,Young, David James,Lang, Jian-Ping
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p. 4000 - 4006
(2015/06/02)
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- "On-water" Hiyama coupling catalyzed by CNC pincer complexes of Pd(II)
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The catalytic activity of two hydrophilic CNC-type palladium pincer complexes is evaluated in the coupling between trimethoxyphenylsilane and aryl bromides. A wide range of assays is performed for each palladium source, and alkaline aqueous conditions turn out to be the most efficient for the target Hiyama coupling, which is applied to the synthesis of several biaryls. In addition, the direct reuse of the aqueous layer containing the catalyst is also conducted with good yield. ARKAT USA, Inc.
- Ines, Blanca,Moure, Maria Jesus,SanMartin, Raul,Herrero, Maria Teresa,Moreno, Isabel,Dominguez, Esther
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experimental part
p. 191 - 199
(2011/05/02)
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- Palladium on carbon-catalyzed solvent-free and solid-phase hydrogenation and Suzuki-Miyaura reaction
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The solvent-free and solid-phase hydrogenation of various reducible functionalities was efficiently catalyzed by heterogeneous palladium on carbon (Pd/C) under ambient hydrogen pressure and temperature. The Pd/C-catalyzed Suzuki-Miyaura coupling reaction between solid aryl bromides and solid arylboronic acids to generate the corresponding solid biaryls was also achieved under the totally solid-phase conditions.
- Monguchi, Yasunari,Fujita, Yuki,Hashimoto, Shota,Ina, Mariko,Takahashi, Tohru,Ito, Ryo,Nozaki, Kei,Maegawa, Tomohiro,Sajiki, Hironao
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experimental part
p. 8628 - 8634
(2011/11/30)
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- The 1,3-diaminobenzene-derived aminophosphine palladium pincer complex {C6H3[NHP(piperidinyl)2]2Pd(Cl)} - A highly active Suzuki-Miyaura catalyst with excellent functional group tolerance
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The rapidly prepared 1,3-diaminobenzenederived aminophosphine pincer complex {C6H3 [NHP(piperidinyl)2] 2Pd(Cl)} (1) is an effective Suzuki catalyst with excellent functional group tolerance. Side-product formations, such as homocoupling, debromation or protodeboration have only rarely been detected and if so, were in all cases below the 5% level. The presented reaction protocol is universally applicable. Experimental observations indicate that palladium nanoparticles are the catalytically active form of 1.
- Bolliger, Jeanne L.,Frech, Christian M.
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experimental part
p. 1075 - 1080
(2010/06/17)
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- Sulfur modification of Au via treatment with piranha solution provides low-pd releasing and recyclable Pd material, SAPd
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We have found in the SR-HXPS measurement of Piranha-treated Au(111)/mica that the gold surface underwent sulfur modification during this treatment, which was believed to have only removed impurities from the gold surface. We also successfully developed a practical Pd material, SAPd, whose Pd was immobilized on sulfur-modified Au. With the lowest Pd-releasing levels and high recyclability, this is one of the best Pd materials thus far developed. Because it leaches extremely low levels of Pd into reaction mixtures, removal of the residual Pd is unnecessary using SAPd, even in syntheses involving pharmaceutical ingredients.
- Hoshiya, Naoyuki,Shimoda, Masahiko,Yoshikawa, Hideki,Yamashita, Yoshiyuki,Shuto, Satoshi,Arisawa, Mitsuhiro
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supporting information; experimental part
p. 7270 - 7272
(2010/08/05)
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- Bimetallic catalysis involving dipalladium(I) and diruthenium(I) complexes
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Dipalladium(I) and diruthenium(I) compounds bridged by two [{(5,7-dimethyl-1,8-naphthyridin-2-yl)amino}carbonyl]ferrocene (L) ligands have been synthesized. The X-ray structures of [Pd2L2][BF 4]2 (1) and [Ru2L2(CO) 4][BF4]2 (2) reveal dinuclear structures with short metal-metal distances. In both of these structures, naphthyridine bridges the dimetal unit, and the site trans to the metal-metal bond is occupied by weakly coordinating oxygen from the amido fragment. The catalytic utilities of these bimetallic compounds are evaluated. Compound 1 is an excellent catalyst for phosphine-free, Suzuki cross-coupling reactions of aryl bromides with arylboronic acids and provides high yields in short reaction times. Compound 1 is also found to be catalytically active for aryl chlorides, although the corresponding yields are lower. A bimetallic mechanism is proposed, which involves the oxidative addition of aryl bromide across the Pdi£ Pd bond and the bimetallic reductive elimination of the product. Compound 1 is also an efficient catalyst for the Heck cross-coupling of aryl bromides with styrenes. The mechanism for aldehyde olefination with ethyl diazoacetate (EDA) and PPh3, catalyzed by 2, has been fully elucidated. It is demonstrated that 2 catalyzes the formation of phosphorane utilizing EDA and PPh3, which subsequently reacts with aldehyde to produce a new olefin and phosphine oxide. The efficacy of bimetallic complexes in catalytic organic transformations is illustrated in this work. Good couple: Metal-metal singly bonded [PdIi£PdI] and [RuIi£RuI] complexes exhibit bimetallic synergy in the catalytic Ci£C bond-coupling and aldehyde-olefination reactions, respectively (see figure). Copyright
- Das, Raj K.,Saha, Biswajit,Rahaman, S. M. Wahidur,Bera, Jitendra K.
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scheme or table
p. 14459 - 14468
(2011/03/19)
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- Efficient palladium-catalysed carbonylative and Suzuki-Miyaura cross-coupling reactions with bis(di-tert-butylphosphino)-o-xylene
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The use of the ligand bis(di-tert-butylphosphino)-o-xylene (dtbpx) in palladium-catalysed carbonylative and Suzuki-Miyaura cross-coupling reactions is described. Aryl and vinyl halides readily entered into the carbonylative catalytic cycle affording carboxylic acids, amides as well as primary, secondary and tertiary esters, respectively, in good yields. Aryl iodides, bromides and chlorides gave high yields of biphenyl products upon reaction with both activated and unactivated boronic acids.
- McNulty, James,Nair, Jerald J.,Sliwinski, Marcin,Robertson, Al J.
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experimental part
p. 2342 - 2346
(2009/08/17)
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- Recyclable and highly active cationic 2,2′-bipyridyl palladium(II) catalyst for Suzuki cross-coupling reaction in water
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A water-soluble and air-stable palladium(II)/cationic 2,2′-bipyridyl catalyst is proven to be a recyclable and extremely active catalyst for Suzuki reaction in aqueous and aerobic conditions. The conveniently prepared catalyst showed little loss in the catalytic process of the coupling between 4-bromoacetophenone and phenylboronic acid after five cycles. For the reactions of aryl chlorides, biaryls were formed in high yields under refluxing temperature in the presence of TBAB.
- Wu, Wei-Yi,Chen, Shao-Nung,Tsai, Fu-Yu
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p. 9267 - 9270
(2008/02/10)
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- Efficient aqueous-phase Suzuki coupling of activated aryl chlorides with arylboronic acids using D-glucosamine-based dicyclohexylarylphosphine
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The synthesis of a new D-glucosamine-based dicyclohexylarylphosphine has been developed. The catalytic performance of this neutral ligand is demonstrated in the Suzuki-Miyaura cross-coupling reaction between several arylboronic acids and aryl or heteroaryl chlorides.
- Konovets, Anzhelika,Penciu, Alexandra,Framery, Eric,Percina, Nathalie,Goux-Henry, Catherine,Sinou, Denis
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p. 3205 - 3208
(2007/10/03)
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- Efficient protocol for the phosphine-free Suzuki-Miyaura reaction catalyzed by palladium on carbon at room temperature
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A mild and efficient protocol for the phosphine-free Suzuki-Miyaura coupling reaction of aryl bromides with arylboronic acids has been developed which utilizes the commercially available 10% Pd/C (3.5 mol% Pd) in ethanol-water (1:1) and Na2CO3 at room temperature. The reaction is convenient, environmentally benign and generates excellent yields of the coupled products (94-100%). The catalyst can be recycled using simple filtration and washing sequences without significant decrease in the yield of coupling product up to the fourth run.
- Zhang, Guolin
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p. 537 - 542
(2007/10/03)
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- Ligand-free Suzuki-Miyaura reaction catalysed by Pd/C at room temperature
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Ligand-free Suzuki-Miyaura coupling reaction has been developed which utilises a commercially available 10% Pd/C (2.6 mol% Pd) in 2-propanol-H 2O (1/1) and Na3PO4 at room temperature. The reaction is mild and generates excellent yields of the coupled products (90-100%). The catalyst is heterogeneous and ligand-free, and the product isolation is simple.
- Zhang, Guolin
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p. 593 - 595
(2007/10/03)
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- An improved preparation of arylboronates: Application in one-pot Suzuki biaryl synthesis
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We have developed a modification of the Miyaura arylboronate synthesis1a by substituting a ligandless palladium catalyst for PdCl2(dppf). Palladium acetate, free of ligand, was found highly effective for such coupling reactions. This modified procedure is advantageous over the original Miyaura synthesis in ease of workup, catalyst removal, and low catalyst cost. Furthermore, the boronates formed in this manner can be used directly for Suzuki coupling reactions in a one-pot fashion. The biaryl products have improved impurity profiles and reduced heavy metal contamination.
- Zhu, Lei,Duquette, Jason,Zhang, Mingbao
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p. 3729 - 3732
(2007/10/03)
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- Encapsulation of palladium in polyurea microcapsules
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An interfacial polymerisation approach is adopted to encapsulate palladium(II) acetate and palladium nano-particles in polyurea microcapsules for use in catalysis.
- Ramarao, Chandrashekar,Ley, Steven V.,Smith, Stephen C.,Shirley, Ian M.,DeAlmeida, Nathalie
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p. 1132 - 1133
(2007/10/03)
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- Cross-Coupling Reaction of Alkyl- or Arylboronic Acid Esters with Organic Halides Induced by Thallium(I) Salts and Palladium-Catalyst
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The cross-coupling reaction of alkylboronic acid esters with 1-alkenyl- or aryl halides is succesfully catalyzed by PdCl2 (dppf) or Pd(PPh3)4 in the presence of thallium(I) hydroxide or carbonate to give the corresponding alkenes or arenes in good yields.The coupling reaction of arylboronic acid esters with aryl halides under similar conditions to provide biaryls is also described.
- Sato, Makoto,Miyaura, Norio,Suzuki, Akira
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p. 1405 - 1408
(2007/10/02)
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- Equilibiria in Cyanohydrin Formation from, and the Kinetics of Reduction by Sodium Borohydride of, Substituted Acetylbiphenyls
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Equilibria in cyanohydrin formation from 4'-substituted-4-acetylbiphenyls in 80 percent v/v dioxan-water at 30 deg C and their rates of reduction by sodium borohydride in propan-2-ol at 30, 35, and 40 deg C have been studied.The Hammett equation is obeyed by both these reactions.The ρ values are found to be 0.52 and 0.66 at 30 deg C for cyanohydrin formation and for borohydride reduction, respectively.These results agree with the earlier conclusion that the transmission of electronic effects of substituents is less in the biphenyl than in the benzene system.
- Ananthakrishnanadar, P.,Kannan, N.
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p. 749 - 750
(2007/10/02)
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