- Polyamine anchored palladium catalyst for suzuki-miyaura and one-pot O-alkylation-suzuki reactions
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Polymer anchored amine-palladium complexes were screened as catalysts for Suzuki-Miyaura coupling reactions of aryl halides. The robust, recyclable catalyst was effective in this reaction of aryl bromides and iodides. Aryl bromide was found to undergo selective Suzuki-Miyaura reaction with phenyl boronic acid, even in presence of styrene. The catalyst system was further employed for one-pot O-alkylation-Suzuki reaction to prepare alkoxy biaryl systems in good conversions.
- Patel, Krupa N.,Bedekar, Ashutosh V.
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- Porous aromatic framework with mesopores as a platform for a super-efficient heterogeneous Pd-based organometallic catalysis
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A strategy using a mesoporous amine-tagged porous aromatic framework (PAF70-NH2) to immobilize a palladium (Pd)-based molecular catalyst has been developed. The resulting immobilized catalyst PAF70-Pd, in which the framework is entirely constructed by phenyl rings linked with stable carbon-carbon bonds, has high structural rigidity and stability. Compared with the known porous organic material immobilized Pd-based catalysts, PAF70-Pd has the highest Pd content so far. Moreover, PAF70-Pd has extremely high catalytic activity with good size selectivity and very easy recyclability in catalyzing the Suzuki-Miyaura coupling reaction. In the current system, the catalyst loading could be as low as 0.001 mol% and the TOF value could go up to 28800 h-1 which is far higher than those of the known porous organic material immobilized Pd-based catalysts. In order to elucidate the particularly high catalytic efficiency of PAF70-Pd, we prepared PAF1-Pd from PAF1-NH2 for comparison. PAF1-Pd has a higher Pd content than PAF70-Pd. However, due to the absence of large enough mesopores in PAF1-NH2, PAF1-Pd has almost no catalytic activity under the same conditions, which definitely demonstrated that the intrinsic mesoporosity of PAF70-NH2 plays a crucial role in the superb catalytic efficiency of PAF70-Pd. This strategy to immobilize Pd-based molecular catalysts has very good expansibility to be applied in the immobilization of different organometallic catalysts into the pores of PAFs, which also has very high potential in the chemical and pharmaceutical industry.
- Jing, Li-Ping,Sun, Jin-Shi,Sun, Fuxing,Chen, Peng,Zhu, Guangshan
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- Electrochemical synthesis of PdII polynuclear complexes based on biquinolyl-containing polymers and their catalytic activity in the Suzuki reaction
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Electrochemical dissolution of sacrificial Pd anode was used to synthesize novel polynuclear PdII complexes with ligands based on polyamic acids containing in the main chain biquinolyl groups capable of coordination to the metal ions. The synthesized polymeric complexes exhibit high catalytic activity in the Suzuki reaction. The reaction can be run under mild conditions, at 40 °C and with a sufficiently high product yield at a catalyst concentration of 0.05 mol.% (with respect to the starting aryl halide). The polymeric ligand allows immobilization of the catalyst on the graphite fabric with high specific surface area that enhances the catalyst turnover number and promotes its recycling.
- Magdesieva,Nikitin,Abdullin,Polyakova,Yakimanskiy,Goikhman,Podeshvo
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- Microwave-assisted Suzuki coupling on a KF-alumina surface: Synthesis of polyaryls
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A range of conjugated polyaryls has been synthesized through one-pot microwave assisted palladium-catalyzed consecutive Suzuki coupling reactions on a KF-alumina surface with notable features including rapid reaction times, solvent-free conditions, high yields, atom economic and air-insensitive reactions.
- Basu, Basudeb,Das, Pralay,Bhuiyan, Md. Mosharef H.,Jha, Satadru
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- Stable ferrocenyl-NHC Pd(II) complexes: Evidence of C-H ?H/π interaction and M-O bonding in solution
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New air stable palladium(II)-NHC complexes where carbene ligand is substituted with a bulky ferrocenylmethyl and pyranylmethyl groups viz. PdI(Phpy){FcCH2-C3H2N2-Me} (3), PdI2{FcCH2-C3H2N2-C6H11O} (4) and PdI2{FcCH2-NHC}(L) (5–10) (NHC = C3H2N2-Me or C6H11O; L = pyridine, imidazole and thiazole) are reported. The presence of C-H?H/π interactions has been confirmed for complex 3 by NOE interaction and multinuclear NMR experiments. In addition, for this complex, a quantum chemical analysis was performed using PM3 semi-empirical calculations to find the possible conformers. The conformation with minimal energy confirms the NMR interpretation for complex 3. The M-O bond in complex 4 was ruptured by the reaction of an extra pyridine ligand to afford PdI2{FcCH2-C3H2N2-C6H11O}(py) (5) which was synthetized differently by reacting NHC ligand, Pd(OAc)2 and pyridine. Molecular structure of complex 5 was determined by X-ray diffraction. The catalytic activity of these complexes was checked in Suzuki-Miyaura reaction. Complex 5 exhibits excellent conversions and selectivities (up to 99%).
- Azpiroz, Ramón,Sharma, Pankaj,Javier Pérez-Flores,Gutierrez, René,Espinosa-Pérez, Georgina,Lara-Ochoa, Francisco
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- An iron-catalysed C-C bond-forming spirocyclization cascade providing sustainable access to new 3D heterocyclic frameworks
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Heterocyclic architectures offer powerful creative possibilities to a range of chemistry end-users. This is particularly true of heterocycles containing a high proportion of sp3 -carbon atoms, which confer precise spatial definition upon chemical probes, drug substances, chiral monomers and the like. Nonetheless, simple catalytic routes to new heterocyclic cores are infrequently reported, and methods making use of biomass-accessible starting materials are also rare. Here, we demonstrate a new method allowing rapid entry to spirocyclic bis-heterocycles, in which inexpensive iron(III) catalysts mediate a highly stereoselective C-C bond-forming cyclization cascade reaction using (2-halo)aryl ethers and amines constructed using feedstock chemicals readily available from plant sources. Fe(acac) 3 mediates the deiodinative cyclization of (2-halo)aryloxy furfuranyl ethers, followed by capture of the intermediate metal species by Grignard reagents, to deliver spirocycles containing two asymmetric centres. The reactions offer potential entry to key structural motifs present in bioactive natural products.
- Adams, Kirsty,Ball, Anthony K.,Birkett, James,Brown, Lee,Chappell, Ben,Gill, Duncan M.,Lo, P.K. Tony,Patmore, Nathan J.,Rice, Craig R.,Ryan, James,Raubo, Piotr,Sweeney, Joseph B.
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- Steering Surface Reaction Dynamics with a Self-Assembly Strategy: Ullmann Coupling on Metal Surfaces
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Ullmann coupling of 4-bromobiphenyl thermally catalyzed on Ag(111), Cu(111), and Cu(100) surfaces was scrutinized by scanning tunneling microscopy as well as theoretical calculations. Detailed experimental evidence showed that initial formation of organom
- Zhou, Xiong,Wang, Chenguang,Zhang, Yajie,Cheng, Fang,He, Yang,Shen, Qian,Shang, Jian,Shao, Xiang,Ji, Wei,Chen, Wei,Xu, Guoqin,Wu, Kai
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- N-Heterocyclic Carbene–Palladium Complex onto Graphene Oxide and Poly (ethylene glycol) (PEG) Applied as Superior Catalyst for the Suzuki-Miyaura Cross-Coupling Reaction in Water
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Using polymeric nanocomposites incorporated Pd to promote C-C coupling reactions has been found as one of the most successful strategies. In this paper we apply graphene oxide (GO) as an efficient surface immobilized by water-soluble poly (ethylene glycol)-imidazole followed by introduction of PdCl2 salt to obtain the desired catalyst. Catalytic performance of this composite was investigated in the Suzuki–Miyaura cross-coupling reaction under mild reaction conditions and superior results were obtained. The hydrophilic nature of the catalyst and well distribution of Pd lead to superior catalytic activity in water media. Moreover, the Suzuki–Miyaura reaction proceed successfully with excellent yield and short reaction time without any loss of activity even after seven consecutive reaction cycles.
- Heravi, Majid M.,Asadi, Shima,Hoseini Chopani, Seyede Mahdiye,Jaderi, Elham
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- Rapid Access to Bi- and Tri-Functionalized Dibenzofurans and their Application in Selective Suzuki–Miyaura Cross Coupling Reactions
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Syntheses of 1,2-, 1,3-, 1,4-, 1,8-, 2,4-, 3,4-, 4,8-, 1,2,4-, 1,2,8- and 1,3,4-functionalized dibenzofurans in few steps with good to excellent yields starting from dibenzofuran-1-ol or -4-ol are presented. These rapidly accessible bi- or tri-functionalized building blocks are of great interest for the synthesis of bioactive substances or functional material development. Furthermore, for intermediates containing both a bromine and a triflate moiety, a selective mono-substitution by means of Suzuki–Miyaura reaction (SMR) is described.
- Wern, Caroline,Ehrenreich, Christian,Joosten, Dominik,Stein, Thorsten vom,Buchholz, Herwig,K?nig, Burkhard
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- Homocoupling of arylboronic acids and potassium aryltrifluoroborates catalyzed by protein-stabilized palladium nanoparticles under air in water
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Palladium nanoparticles stabilized primarily within the protein cavity of a highly thermostable Dps protein (DNA binding protein from starved cells) from the thermophilic bacterium Thermosynechoccus elongatus provide an efficient catalyst for the homocoupling of boronic acids and potassium aryltrifluoroborates in water under aerobic phosphine-free conditions. Symmetrical biaryls have been isolated in good to excellent yields. Potassium aryltrifluoroborates give similar or better results than the corresponding arylboronic acids.
- Prastaro, Alessandro,Ceci, Pierpaolo,Chiancone, Emilia,Boffi, Alberto,Fabrizi, Giancarlo,Cacchi, Sandro
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- Preparation and photochemical properties of p-phenylene oligomers encapsulated within faujasite Y
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Phenylene oligomers have been prepared by ship-in-a-bottle synthesis inside palladium containing basic zeolites by homocoupling of 1,4-phenylenediboronic acid. Product analysis and "in situ" IR spectroscopy support the formation of oligomers of three to f
- Alvaro, Mercedes,Ferrer, Belen,Garcia, Hermenegildo,Leyva, Antonio
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- Pd-catalyzed desulfonylative homocoupling of arenesulfonyl chlorides in the presence of hexamethyldisilane forming biaryls
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Arenesulfonyl chlorides undergo desulfonylative homo-coupling upon heating with hexamethyldisilane in the presence of Pd2(dibenzylideneacetone) 3?CHCl3 as a precatalyst to afford biaryls. Diaryl sulfides are occasionally formed as byproducts.
- Kashiwabara, Taigo,Tanaka, Masato
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- Agro-Waste Generated Pd/CAP-Ash Catalyzed Ligand-Free Approach for Suzuki–Miyaura Coupling Reaction
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Abstract: We converted agro-waste Custard Apple Peels (CAP) to ash via thermal treatment, on which Pd(OAc)2 was immobilized easily that produced a low-cost, highly efficient Pd/CAP-ash catalyst. The prepared catalyst was fully characterized by using FT-IR, SEM, EDX, XRF, DSC-TGA, BET, HR-TEM, and XPS techniques. The Pd/CAP-ash catalyst was conveniently applied for the Suzuki–Miyaura coupling reaction under external base free and ligand-free conditions in an aqueous-organic solvent to produce biphenyls in good to excellent yields. The main attraction of our protocol an application of palladium-supported agro-waste material which is easily recoverable and recyclable provides mono and bis-coupled derivatives in a short reaction time. Graphic Abstract: [Figure not available: see fulltext.].
- Patil, Rupesh C.,Jagdale, Ashutosh A.,Patil, Uttam P.,Ghodake, Jeevan S.,Mali, Sawanta S.,Hong, Chang K.,Patil, Suresh S.
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supporting information
p. 3617 - 3631
(2021/04/02)
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- Synthesis of N-Heterocyclic Carbine Silver(I) and Palladium(II) Complexes with Acylated Piperazine Linker and Catalytic Activity in Three Types of C—C Coupling Reactions
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Two bis-imidazolium salts LH2·Cl2 and LH2·(PF6)2 with acylated piperazine linker and two N-heterocyclic carbene (NHC) silver(I) and palladium(II) complexes [L2Ag2](PF6)2 (1) and [L2Pd2Cl4] (2) were prepared. The crystal structures of LH2·Cl2 and 1 were confirmed by X-ray analysis. In 1, one 26-membered macrometallocycle was generated through two silver(I) ions and two bidentate ligands L. The catalytic activity of 2 was investigated in Sonogashira, Heck-Mizoroki and Suzuki-Miyaura reactions. The results displayed that these C—C coupling reactions can be smoothly carried out under the catalysis of 2.
- Liu, Qingxiang,Zhang, Xiantao,Zhao, Zhixiang,Li, Xinying,Zhang, Wei
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supporting information
p. 605 - 613
(2021/02/01)
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- Synthesis of biaryl compounds via Suzuki homocoupling reactions catalyzed by metal organic frameworks encapsulated with palladium nanoparticles
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Heterogeneous homocoupling reactions of phenylboronic acids were greatly accelerated via Suzuki homocoupling reactions. In this work, a tandem route was designed which firstly one part of phenylboronic acids reacted with iodine to form iodobenzenes, then another part of phenylboronic acids coupled with iodobenzenes to produce biaryl compounds. The tandem reaction were catalyzed by a bifunctional heterogeneous catalyst of metal organic frameworks encapsulated with palladium nanoparticles (Pd?MOFs). This strategy for forming symmetric C-C bond between benzene rings has obvious advantages such as high efficiency, easy separation, good recyclability and no addition of toxic halogenated benzene.
- Bao, Yan-Sai,Cui, Xin-Yu,Han, Zheng-Bo,Li, Xin,Tang, Hong,Yang, Ming,Zhang, Yu-Yang,Zhao, Kun,Zhou, Mei-Li
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- Pd-catalyzed oxidative homocoupling of arylboronic acids in WEPA: A sustainable access to symmetrical biaryls under added base and ligand-free ambient conditions
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Symmetrical and unsymmetrical biaryls comprises a diverse class of biologically eloquent organic compounds. We herein report, a quick and eco-friendly protocol for the synthesis of biaryls by an oxidative (aerobic) homocoupling of arylboronic acids (ABAs) using Pd(OAc)2 in water extract of pomogranate ash (WEPA) as an efficient agro-waste(bio)-derived aqueous (basic) media. The reactions were executed at ambient aerobic conditions in the absence of external base and ligand to result symmetrical biaryls in excellent yields. The use of renewable media with an effective exploitation of waste, short reaction times, excellent yields of products, easy separation of the products, unnecessating the external base, oxidant, ligand or volatile organic solvents and ambient reaction conditions are the vital insights of the present protocol.
- Appa, Rama Moorthy,Lakshmidevi, Jangam,Naidu, Bandameeda Ramesh,Venkateswarlu, Katta
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- Green-Synthesized Nickel Nanoparticles on Reduced Graphene Oxide as an Active and Selective Catalyst for Suzuki and Glaser-Hay Coupling Reactions
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A mild and benign methodology to syntheses biaryls and 1,3-diynes has been demonstrated using the nickel nanoparticles supported on reduced graphene oxide (RGO-Ni) as a heterogeneous catalyst which is prepared using green reagents. A series of substituted biaryls and 1,3-diynes has been synthesised in good to excellent yields through C-C homocoupling reaction of arylboronic acids and terminal alkynes respectively using 1,4-dioxane as a benign solvent. The present ligand-free catalytic system proceeds smoothly under mild conditions, avoids noble and stoichiometric metal reagents and tolerates sensitive functional groups. Also has a wide substrate scope and feasible with other nitrogen and sulphur containing heteroaryl boronic acids. Hot filtration test unambiguously proves the true heterogeneity of the catalyst and which support for the further reusability of the catalyst for several times without any change in the activity. The easy preparation and simple magnetic separation, stability and reusability reveal that as-prepared RGO-Ni as a versatile catalyst for the synthesis of polyaromatic compounds both in academia and industries. Highlights: Green-synthesized RGO-Ni nanocomposite used as a heterogeneous catalyst for Suzuki type (C-C) and Glaser–Hay (C ≡ C) homocoupling coupling reactions. Ligand-free catalytic system and avoids noble and stoichiometric metal reagents Short reaction time with a minimum catalyst (nickel) loading RGO-Ni nanocomposite is highly stable, reusable, and magnetically retrievable.
- Murugan, Karthik,Nainamalai, Devarajan,Kanagaraj, Pavithara,Nagappan, Saravana Ganesan,Palaniswamy, Suresh
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- MICRO-ELECTROLYSIS REACTOR FOR ULTRA FAST, OXIDANT FREE, C-C COUPLING REACTION AND SYNTHESIS OF DACLATASVIR ANALOGS THEREOF
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The present invention relates to a continuous micro-electro-flow reactor system for ultra-fast, oxidant free, C—C coupling reaction for making symmetrical biaryls and analogs thereof. This invention further relates to the said process for preparation of antiviral drug, daclatasvir of general formula I.
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Paragraph 0105-0110; 0133-0138
(2020/12/01)
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- Palladium decorated on a new dendritic complex with nitrogen ligation grafted to graphene oxide: Fabrication, characterization, and catalytic application
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Immobilized Pd nanoparticles on a new ligand, namely, tris(pentaethylene-pentamine)triazine supported on graphene oxide (Pdnp-TPEPTA(L)-GO) was introduced as a novel and robust heterogeneous catalyst for use in C-C bond formation reaction. The Pdnp-TPEPTA(L)-GO catalyst was synthesized by complexation of Pd with TPEPTA as a ligand with high N-ligation sites that were supported on graphene oxide through 3-chloropropyltrimethoxysilane. The prepared catalyst was characterized using some microscopic and spectroscopic techniques. The TPEPTA(L)-GO substrate is a 2D heterogeneous catalyst with a high specific surface area and a large amount of N-ligation sites. The Pdnp-TPEPTA(L)-GO catalyst used in the C-C bond formation reaction between aryl or heteroaryl and phenylboronic acid derivatives was applied towards the synthesis of biaryl units in high isolated yields. Notably, a series of competing experiments were performed to establish the selectivity trends of the presented method. Also, this catalyst system was reusable at least six times without a significant decrease in its catalytic activity.
- Golestanzadeh, Mohsen,Naeimi, Hossein
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p. 27560 - 27573
(2019/09/12)
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- Micro-electro-flow reactor (μ-EFR) system for ultra-fast arene synthesis and manufacture of daclatasvir
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The World Health Organization (WHO) has listed daclatasvir (DCV), symmetrical arene, as one of the essential medicines for human health. DCV manufacturing is usually carried out in a non-continuous or "batch" approach over multiple locations and is severely limited by long production times (3-10 days), resulting in non-affordability (highly expensive) and disruption of the potential chain supply. Here, we report the total process system including the development of a novel electro-flow reactor containing patterned electrodeposited Ni or Pt nanoparticles over a copper electrode for a C-C coupling reaction in a co-reductant/oxidant-free, ultra-fast process for symmetrical substituted/unsubstituted biphenyl synthesis. This method was further extended to a new generation commercial batch synthetic route for continuous flow ultra-fast daclatasvir synthesis in 33.2 min. We envisage that this micro-electro-flow reactor (μ-EFR) system platform will substantially enable advances in continuous-μ-flow fine chemical manufacturing, multistep reaction sequences, reaction devising equipment, and real-time extraction.
- Mahajan, Bhushan,Mujawar, Taufiqueahmed,Ghosh, Subhash,Pabbaraja, Srihari,Singh, Ajay K.
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p. 11852 - 11855
(2019/10/11)
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- Catalytic activities of NHC-PdCl2 species based on functionalized tetradentate imidazolium salt in three types of C-C coupling reactions
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A functionalized tetradentate imidazolium salt 9,10-bis{di[2′-(N-ethylimidazolium-1-yl)ethyl]aminomethyl}anthracene tetrakis(hexafluorophosphate) (1) has been synthesized and characterized. The catalytic activity of the NHC-PdCl2 species formed by compound 1 and PdCl2 was tested in Suzuki-Miyaura, Heck-Mizoroki and Sonogashira reactions. The results showed that this catalytic system was effective for above three types of C-C coupling reactions.
- Liu, Qing-Xiang,Zhao, Dong-Xue,Wu, Hao,Zhao, Zhi-Xiang,Lv, Shi-Zhen
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- WEPA: a bio-derived medium for added base, π-acid and ligand free Ullmann coupling of aryl halides using Pd(OAc)2
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A bio-derived sustainable medium based on water extract of pomegranate ash (WEPA) has, for the first time, been developed for the homocoupling of aryl halides under palladium-assistance. Avoiding the requirement of an external base, ligand and π-acid, the use of the proposed renewable medium offers remarkable attributes like wide substrate scope, good to nearly quantitative yields of biphenyls with exceptional chemoselectivity and scale up viability.
- Lakshmidevi, Jangam,Appa, Rama Moorthy,Naidu, Bandameeda Ramesh,Prasad, S. Siva,Sarma, Loka Subramanyam,Venkateswarlu, Katta
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supporting information
p. 12333 - 12336
(2018/11/30)
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- Dimerization of Aromatic Compounds Using Palladium-Carbon-Catalyzed Suzuki-Miyaura Cross-Coupling by One-Pot Synthesis
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The aromatic dimers play a significant role in many aspects. Herein, we report a simple palladium-carbon catalyst that is highly effective for the dimerization of brominated aromatic compounds under mild conditions using abundant brominated aromatic compounds, bis(pinacolate)diboron and potassium acetate by a 'one-pot' method. This process, which we believe proceeds via a Suzuki-Miyaura cross-coupling reaction mechanism, allows access to a variety of aromatic compounds under mild reaction conditions and has a good functional group tolerance with moderate to high yields.
- Du, Fangyu,Zhou, Qifan,Liu, Dongdong,Fang, Ting,Shi, Yajie,Du, Yang,Chen, Guoliang
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supporting information
p. 779 - 784
(2018/02/09)
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- A ligand free protocol using Cu(OAc)2@Mont K-10 as versatile reusable catalyst for efficient homocoupling of arylboronic acids for synthesis of symmetric biaryls
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Biaryls are an important class of organic compounds that occur in many natural products and they have a wide variety of applications in drugs, agrochemicals, dyes, semi-conductors, and asymmetric syntheses. A versatile, eco-friendly, recyclable, heterogeneous catalyst has been developed for the efficient synthesis of symmetric biaryls from aryl boronic acids. The developed protocol for homocoupling of aryl boronic acid to symmetric biaryls is based on copper acetate supported on acid activated Mont K-10 which is ligand free, mild, inexpensive and compatible with wide range of functional groups and exhibit excellent yields. The catalyst is characterised by FTIR, ESR, XRD, SEM-EDX, BET surface area measurement and the catalyst can be separated from the reaction mixture by simple centrifugation and reused upto five cycles without significant loss in activity.
- Rahman, Taskia,Borah, Geetika,Gogoi, Pradip K.
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p. 795 - 800
(2020/06/26)
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- An efficient and recoverable palladium organocatalyst for Suzuki reaction in aqueous media
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Meso-tetrakis[4-(methoxycarbonyl)phenyl]porphyrinatopalladium(II) as a palladium organocatalyst was synthesized and then used in aqueous media as a heterogeneous organocatalyst in Suzuki reaction. The prepared organocatalyst was characterized using UV–visible, infrared and NMR spectroscopies. It was found to be an efficient catalyst for Suzuki coupling reaction between phenylboronic acid and a broad range of aryl halides. Mild reaction conditions, water solvent as green media, and easy catalyst separation and reusability are the advantages of the presented method.
- Fareghi-Alamdari, Reza,Golestanzadeh, Mohsen,Bagheri, Omid
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- Spectroscopic Studies of the Chan-Lam Amination: A Mechanism-Inspired Solution to Boronic Ester Reactivity
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We report an investigation of the Chan-Lam amination reaction. A combination of spectroscopy, computational modeling, and crystallography has identified the structures of key intermediates and allowed a complete mechanistic description to be presented, including off-cycle inhibitory processes, the source of amine and organoboron reactivity issues, and the origin of competing oxidation/protodeboronation side reactions. Identification of key mechanistic events has allowed the development of a simple solution to these issues: manipulating Cu(I) → Cu(II) oxidation and exploiting three synergistic roles of boric acid has allowed the development of a general catalytic Chan-Lam amination, overcoming long-standing and unsolved amine and organoboron limitations of this valuable transformation.
- Vantourout, Julien C.,Miras, Haralampos N.,Isidro-Llobet, Albert,Sproules, Stephen,Watson, Allan J. B.
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supporting information
p. 4769 - 4779
(2017/04/11)
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- Meso -Tetrakis[4-(methoxycarbonyl)phenyl]porphyrinatopalladium(ii) supported on graphene oxide nanosheets (Pd(ii)-TMCPP-GO): Synthesis and catalytic activity
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In this study, meso-tetrakis[4-(methoxycarbonyl)phenyl]porphynatopalladium(ii) as a macrocyclic palladium complex was covalently grafted to the surface of graphene oxide (Pd-TMCPP-GO). The Pd-TMCPP-GO was characterized using microscopic and spectroscopic techniques for confirmation of functionalization. The prepared catalyst was checked in a Suzuki reaction. The catalytic system showed high catalytic activity in this reaction and the yields of the products were good to excellent. Also, the proposed catalyst was reusable for seven runs with no significant decrease in catalytic activity.
- Fareghi-Alamdari, Reza,Golestanzadeh, Mohsen,Bagheri, Omid
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p. 108755 - 108767
(2016/12/02)
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- Aryl Ketones as Single-Electron-Transfer Photoredox Catalysts in the Nickel-Catalyzed Homocoupling of Aryl Halides
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An intriguing photoredox system for the homocoupling of aryl halides is reported wherein thioxanthone catalyzes a single-electron transfer from an amine reductant to nickel.
- Masuda, Yusuke,Ishida, Naoki,Murakami, Masahiro
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supporting information
p. 5822 - 5825
(2016/12/18)
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- Synthesis, structure and catalysis of a NHC-Pd(II) complex based on a tetradentate mixed ligand
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Bis-benzimidazolium salt (S)-2,2′-bis[2′′-(N-picolyl-benzimidazoliumyl)ethoxy]-1,1′-binaphthyl hexafluorophosphate [(S)-LH2]·(PF6)2 and its NHC palladium(ii) complex [(S)-LPd](PF6)2 (1) have been prepared and characterized. Complex 1 is formed by one tetradentate mixed ligand (S)-L and one Pd(ii) ion, in which one 15-membered ring and two 6-membered rings are present. In this complex, intramolecular π-π interactions between naphthalene rings and benzimidazole rings are observed. Additionally, the catalytic activity of complex 1 in three types of C-C coupling reactions (Suzuki-Miyaura, Heck-Mizoroki and Sonogashira reactions) was investigated. The results show that complex 1 is an effective catalyst in these coupling reactions.
- Liu, Qing-Xiang,Cai, Kang-Qing,Zhao, Zhi-Xiang
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p. 85568 - 85578
(2015/11/03)
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- Iodine-Promoted Metal-Free Aromatization: Synthesis of Biaryls, Oligo p-Phenylenes and A-Ring Modified Steroids
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We describe efficient procedures based on the use of iodine for the synthesis of biaryls from arylcyclohexenols or arylcyclohexanols using sub-stoichiometric/catalytic iodine and dimethyl sulfoxide (DMSO) as oxidant. Heteroarylcyclohexanols also produced the corresponding biaryl products. It was proven that biphenyl can also be efficiently obtained when the quantity of iodine was reduced to 0.05 equiv. The method is compatible with different functional groups in the aromatic ring (either electron-donating or electron-withdrawing groups). For substrate scope, apart from cyclohexanone and cyclohexenone, some substituted cyclohexanones were also used to synthesize the starting arylcyclohexanols. The process was applied to the synthesis of oligo p-phenylenes and A-ring aromatized steroids, where the combined use of I2/DMSO not only provoked the necessary migration of the methyl group at C-10, but also further extended the conjugation.
- Domingo, Victoriano,Prieto, Consuelo,Castillo, Alexis,Silva, Lucia,Quílez Del Moral, José F.,Barrero, Alejandro F.
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p. 3359 - 3364
(2015/11/03)
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- Nickel-Catalyzed Formal Homocoupling of Methoxyarenes for the Synthesis of Symmetrical Biaryls via C-O Bond Cleavage
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A new method has been developed for the nickel-catalyzed homocoupling of methoxyarenes via C-O bond cleavage using a diboron reagent. The use of 1,3-dicyclohexylimidazol-2-ylidene as a ligand was found to be critical to the success of the reaction. This new method allows the synthesis of a wide range of biaryl compounds.
- Nakamura, Keisuke,Tobisu, Mamoru,Chatani, Naoto
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supporting information
p. 6142 - 6145
(2016/01/09)
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- Facile Access to Fluoromethylated Arenes by Nickel-Catalyzed Cross-Coupling between Arylboronic Acids and Fluoromethyl Bromide
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The nickel-catalyzed fluoromethylation of arylboronic acids was achieved with the industrial raw material fluoromethyl bromide (CH2FBr) as the coupling partner. The reaction proceeded under mild reaction conditions with high efficiency; it features the use of a low-cost nickel catalyst, synthetic simplicity, and excellent functional-group compatibility, and provides facile access to fluoromethylated biologically relevant molecules. Preliminary mechanistic studies showed that a single-electron-transfer (SET) pathway is involved in the catalytic cycle.
- An, Lun,Xiao, Yu-Lan,Min, Qiao-Qiao,Zhang, Xingang
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supporting information
p. 9079 - 9083
(2015/08/03)
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- Clay encapsulated Cu(OH)x promoted homocoupling of arylboronic acids: An efficient and eco-friendly protocol
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Cu(OH)x has been encapsulated over montmorillonite-KSF by simple ologomeric deposition strategy. The resulting catalyst has been employed for selective homocoupling of arylboronic acids under ambient conditions without requirement of any ligand or base. This catalyst is easy to recover and shows excellent reusability without losing its activity. Techniques like XRD, SEM, TPR, IR, BET surface area measurement and XPS were used to characterize the catalyst. The present method promises for the simple and clean homocoupling of arylboronic acids.
- Dar, Bashir Ahmad,Singh, Snehil,Pandey, Nalini,Singh,Sharma, Priti,Lazar, Anish,Sharma, Meena,Vishwakarma, Ram A.,Singh, Baldev
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p. 232 - 238
(2014/01/06)
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- Synthesis and structure of trans-bis(1,4-dimesityl-3-methyl-1,2,3-triazol- 5-ylidene)palladium(II) dichloride and diacetate. Suzuki-Miyaura coupling of polybromoarenes with high catalytic turnover efficiencies
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trans-Bis(1,4-dimesityl-3-methyl-1,2,3-triazol-5-ylidene)palladium(II) dichloride has been shown to be an excellent catalyst for the multiple Suzuki-Miyaura coupling reactions of polybromoarenes to the corresponding fully substituted polyarylarenes. The reactions proceeded in excellent yields and with high turnover numbers. With 1,4-dibromobenzene the catalyst was found to be active for up to 13 consecutive cycles with a turnover number of 1260. The polyarylarenes were obtained in pure form after crystallization once without recourse to chromatographic purification. The single-crystal X-ray structures of the chloro (1) as well as the corresponding acetato (2) complexes are also reported and compared with the corresponding complexes of 1,4-diphenyl-3-methyl- 1,2,3-triazol-5-ylidene as the ligand.
- Shaik, Jeelani Basha,Ramkumar, Venkatachalam,Varghese, Babu,Sankararaman, Sethuraman
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supporting information
p. 698 - 704
(2013/06/05)
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- Room-temperature photoinduced direct C-H-arylation via base-promoted homolytic aromatic substitution
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Conceptually different approach toward biaryl syntheses by photoinduced direct C-H arylation of benzene and thiophene in the presence of t-BuOK is reported. The reaction proceeds through photo- and base-promoted homolytic aromatic substitution. The o-, m- and p- substituted ArI, as well as the electron-donating and electron-withdrawing nature of the substituents were found be good to excellent substrates. Heteroaryl, ArBr, ArCl and double C-H arylation were successfully achieved.
- Budén, María E.,Guastavino, Javier F.,Rossi, Roberto A.
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supporting information
p. 1174 - 1177
(2013/04/24)
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- Silica tethered Pd-DABCO complex: An efficient and reusable catalyst for suzuki-miyaura reaction
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A palladium-based catalyst supported on DABCO-functionalized silica was successfully prepared by a facile procedure. The prepared heterogeneous catalyst showed a high activity for the Suzuki-Miyaura reaction of aryl bromides, affording excellent yield in all the cases investigated. Interestingly, the catalyst could be quantitatively recovered from the reaction mixture and recycled for five times without any significant loss in activity. Furthermore, this protocol could be extended to the palladium catalyzed synthesis of annulated pyrazines. Springer Science+Business Media, LLC 2012.
- Kumbhar, Arjun,Kamble, Santosh,Jadhav, Sanjay,Rashinkar, Gajanan,Salunkhe, Rajashri
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p. 1388 - 1396
(2013/01/15)
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- Synthesis of 4-aryl-, 2,4-diaryl- and 2,4,7-triarylpyrrolo[2,3-d] pyrimidines by a combination of the Suzuki cross-coupling and N-arylation reactions
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A simple and facile synthesis of novel 4-aryl-2-chloro-, 2,4-diaryl- and 2,4,7-triarylpyrrolo[2,3-d]pyrimidines with various aryl and heteroaryl assemblies in the heterocyclic framework by a combination of Suzuki cross-coupling and N-arylation reactions of 2,4-dichloropyrrolo[2,3-d]pyrimidine with arylboronic acids and haloarenes are described. A majority of the synthesized compounds were found to emit in a near UV-blue spectral range with fluorescence quantum yields up to 67%. The impact of aryl groups attached to the pyrrole ring of pyrrolopyrimidine derivatives on optical properties is discussed.
- Dodonova, Jelena,Skardziute, Lina,Kazlauskas, Karolis,Jursenas, Saulius,Tumkevicius, Sigitas
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experimental part
p. 329 - 339
(2012/01/05)
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- Copper-catalyzed trifluoromethylation of aryl boronic acids using a CF 3+ reagent
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A copper-catalyzed process for trifluoromethylation of aryl, heteroaryl, and vinyl boronic acids has been developed. The reaction is conducted under mild conditions and shows tolerance to moisture and a variety of functional groups.
- Xu, Jun,Luo, Dong-Fen,Xiao, Bin,Liu, Zhao-Jing,Gong, Tian-Jun,Fu, Yao,Liu, Lei
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scheme or table
p. 4300 - 4302
(2011/06/21)
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- Synthesis of terphenyls and quaterphenyls via the nickel n-heterocyclic carbene-catalyzed cross-coupling of neopentyl arenesulfonates with aryl grignard reagents
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Various terphenyl and quaterphenyl derivatives were prepared by the Ni-NHC catalyzed cross coupling of the corresponding biphenyl- and terphenyl-sulfonates with arylmagnesium bromides. The reactions proceeded rapidly via a nucleophilic aromatic substitution of the alkoxysulfonyl moieties by the aryl nucleophiles to afford high yields within just 1.5 h at room temperature in spite of the low reactivity of the sulfur electrophiles.
- Jo, Hyunjong,Kim, Chul-Bae,Ryoo, Tae-Yong,Ahn, Bo-Kyoung,Park, Kwangyong
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p. 3749 - 3754
(2011/10/02)
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- Tris(4-methylpiperazin-1-yl)phosphane, P(NC4H 8NMe)3: Synthesis, structural studies, group 10 and 11 metal complexes and catalytic investigations
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Group 10 and 11 metal complexes of a multidentate phosphorus-nitrogen donor ligand tris(4-methylpiperazin-1-yl)-phosphane, P(NC4H 8NMe)3 (1) are reported. The reactions of 1 with an equimolar amount of CuX (X = Cl, Br and I) afford tetranuclear cubane-like complexes [(CuX)-{P(NC4H8NMe)3}]4 (2, X = Cl; 3, X = Br and 4, X = I) in excellent yield. Treatment of 1 with AuCl(SMe2) produces a mononuclear complex, [(AuCl){P(NC 4H8NMe)3}] (5). Reaction of 1 with AgCN produces a 2D AgI polymeric sheet, [(AgCN)2-{P(NC4H 8NMe)3}]n (6) in moderate yield. The similar 1:1 reactions of 1 with AgX (X = Cl and Br) furnish dinuclear complexes, [(AgX){P(NC4H8NMe)3}]2 (7, X = Cl and 8, X = Br). The 2:1 reactions of 1 with [M(COD)Cl2] (M = Pd or Pt) afford [{P(NC4H8NMe)3}2MCl 2] (9, M = Pd and 10, M = Pt) in quantitative yield. The molecular structures of complexes 1-3 and 6 are established through single-crystal X-ray diffraction studies. The catalytic activity of the PdII complex 9 has been investigated in Suzuki cross coupling reactions. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Ganesamoorthy, Chelladurai,Mague, Joel T.,Balakrishna, Maravanji S.
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p. 596 - 604
(2008/12/22)
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- Preparation, structure, and reactivity of nonstabilized organoiron compounds. Implications for iron-catalyzed cross coupling reactions
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A series of unprecedented organoiron complexes of the formal oxidation states -2, 0, +1, +2, and +3 is presented, which are largely devoid of stabilizing ligands and, in part, also electronically unsaturated (14-, 16-, 17- and 18-electron counts). Specifically, it is shown that nucleophiles unable to undergo β-hydride elimination, such as MeLi, PhLi, or PhMgBr, rapidly reduce Fe(3+) to Fe(2+) and then exhaustively alkylate the metal center. The resulting homoleptic organoferrate complexes [(Me4Fe)(MeLi)] [Li(OEt2)]2 (3) and [Ph4Fe][Li(Et 2O)2][Li(1,4-dioxane)] (5) could be characterized by X-ray crystal structure analysis. However, these exceptionally sensitive compounds turned out to be only moderately nucleophilic, transferring their organic ligands to activated electrophiles only, while being unable to alkylate (hetero)aryl halides unless they are very electron deficient. In striking contrast, Grignard reagents bearing alkyl residues amenable to β-hydride elimination reduce FeXn (n = 2, 3) to clusters of the formal composition [Fe(MgX)2]n. The behavior of these intermetallic species can be emulated by structurally well-defined lithium ferrate complexes of the type [Fe(C2H4) 4][Li(tmeda)]2 (8), [Fe(cod)2][Li(dme)] 2 (9), [CpFe(C2H4)2][Li(tmeda)] (7), [CpFe(cod)][Li(dme)] (11), or [Cp*Fe(C2H4) 2][Li(tmeda)] (14). Such electron-rich complexes, which are distinguished by short intermetallic Fe-Li bonds, were shown to react with aryl chlorides and allyl halides; the structures and reactivity patterns of the resulting organoiron compounds provide first insights into the elementary steps of low valent iron-catalyzed cross coupling reactions of aryl, alkyl, allyl, benzyl, and propargyl halides with organomagnesium reagents. However, the acquired data suggest that such C-C bond formations can occur, a priori, along different catalytic cycles shuttling between metal centers of the formal oxidation states Fe(+1)/Fe(+3), Fe(0)/Fe(+2), and Fe(-2)/Fe(0). Since these different manifolds are likely interconnected, an unambiguous decision as to which redox cycle dominates in solution remains difficult, even though iron complexes of the lowest accessible formal oxidation states promote the reactions most effectively.
- Fuerstner, Alois,Martin, Ruben,Krause, Helga,Seidel, Guenter,Goddard, Richard,Lehmann, Christian W.
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p. 8773 - 8787
(2008/12/23)
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- Reaction of tris-arylgallium(III) with water: Biaryl coupling versus Ga- C hydrolysis
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Reaction of toluene solutions of tris(aryl)gallium(III) compounds with water results in intra-molecular biaryl coupling (70% yield) and an oligomeric organogallium(III) hydroxide/oxide [Ga12O14H4(aryl)12], whereas reaction in THF with water leads to hydrolysis, formation of arylH, and for aryl = Ph the trimeric THF hydrogen bonded trimer, [Ph2Ga(μ-OH)]3 ·3THF.
- Nichols, Peter J.,Papadopoulos, Stavroula,Raston, Colin L.
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p. 1227 - 1228
(2007/10/03)
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- Polymer pyrolysis and oxidation studies in a continuous feed and flow reactor: Cellulose and polystyrene
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A dual-zone, continuous feed tubular reactor is developed to assess the potential for formation of products from incomplete combustion in thermal oxidation of common polymers. Solid polymer (cellulose or polystyrene) is fed continuously into a volatilization oven where it fragments and vaporizes. The gas-phase polymer fragments flow directly into a second, main flow reactor to undergo further reaction. Temperatures in the main flow reactor are varied independently to observe conditions needed to convert the initial polymer fragments to CO2 and H2O. Combustion products are monitored at main reactor temperatures from 400 to 850 °C and at 2.0-s total residence time with four on-line GC/FIDs; polymer reaction products and intermediates are further identified by GC/MS analysis. Analysis of polymer decomposition fragments at 400 °C encompasses complex oxygenated and aromatic hydrocarbon species, which range from high-molecular-weight intermediates of ca. 300 amu, through intermediate mass ranges down to C1 and C2 hydrocarbons, CO, and CO2. Approximately 41 of these species are positively identified for cellulose and 52 for polystyrene. Products from thermal oxidation of cellulose and polystyrene are shown to achieve complete combustion to CO2 and H2O at a main reactor temperature of 850 °C under fuel-lean equivalence ratio and 2.0-s reaction time. A dual-zone, continuous feed tubular reactor is developed to assess the potential for formation of products from incomplete combustion in thermal oxidation of common polymers. Solid polymer (cellulose or polystyrene) is fed continuously into a volatilization oven where it fragments and vaporizes. The gas-phase polymer fragments flow directly into a second, main flow reactor to undergo further reaction. Temperatures in the main flow reactor are varied independently to observe conditions needed to convert the initial polymer fragments to CO2 and H2O. Combustion products are monitored at main reactor temperatures from 400 to 850°C and at 2.0-s total residence time with four on-line GC/FIDs; polymer reaction products and intermediates are further identified by GC/MS analysis. Analysis of polymer decomposition fragments at 400°C encompasses complex oxygenated and aromatic hydrocarbon species, which range from high-molecular-weight intermediates of ca. 300 amu, through intermediate mass ranges down to C1 and C2 hydrocarbons, CO, and CO2. Approximately 41 of these species are positively identified for cellulose and 52 for polystyrene. Products from thermal oxidation of cellulose and polystyrene are shown to achieve complete combustion to CO2 and H2O at a main reactor temperature of 850°C under fuel-lean equivalence ratio and 2.0-s reaction time.
- Park, Byung-Ik,Bozzelli, Joseph W.,Booty, Michael R.,Bernhard, Mary J.,Mesuere, Karel,Pettigrew, Charles A.,Shi, Ji-Chun,Simonich, Staci L.
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p. 2584 - 2592
(2007/10/03)
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- Synthesis of polyphenylene derivatives by thermolysis of enediynes and dialkynylaromatic monomers
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Described are the syntheses of substituted enediynes and dialkynylaromatics using Pd- or Pd/Cu-catalyzed cross coupling procedures. The products were then thermalized to afford the corresponding poly(p- phenylene)s, poly(1,4-naphthalene)s, poly(benzo[c]thiophene)s, and poly(dibenzothiophene)s. Fifteen examples are provided that show the scope of the polymerization process based upon substituent patterns and cyclization moieties. The superb thermal resiliency of the newly derived polymers is demonstrated using thermogravimetric analysis. The polymer structure was generally confirmed using IR data correlations to small molecules that resembled the polymers' repeat unit structure. Radical trapping of dimeric intermediates, that were analyzed by GCMS, further substantiated the proposed mechanistic route. The step-growth polymerization pattern was determined by monitoring the degree of monomer consumption versus the polymer molecular weight.
- John, Jens A.,Tour, James M.
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p. 15515 - 15534
(2007/10/03)
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- Aryl Mesylates in Metal-Catalyzed Homocoupling and Cross-Coupling Reactions. 1. Functional Symmetrical Biaryls from Phenols via Nickel-Catalyzed Homocoupling of Their Mesylates
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Aryl sulfonates including mesylate derived from phenols are converted in high yields to biaryls by homocoupling in the presence of catalytic amounts of zero-valent nickel catalysts generated in situ.This reaction provides the most convenient method for the synthesis of many functional symmetrical biaryls and was applied to the preparation of 2,2'-, 3,3'-, and 4,4'-disubstituted biphenyls and other biaryls.The influence of the electronic and steric effects of substituents attached in the ortho, meta, and para positions of aryl sulfonates and the nature of the sulfonate leaving group on the yield of homocoupled product as well as their influence on the extent of various side reactions were investigated.In addition, the influence of the effects of the polarity and dryness of solvent, halide ion source and concentration, and ratio of catalyst and ligand to aryl sulfonate are discussed.
- Percec, Virgil,Bae, Jin-Young,Zhao, Mingyang,Hill, Dale H.
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p. 176 - 185
(2007/10/02)
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- Synthese et caracterisation d'oligomeres lineaires du phenylene
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Electrochemical reduction of monohalide aromatic compounds with catalytic amount of zero-valent nickel complex leads to corresponding linear dimeric oligophenylens in N,N dimethylacetamide.Effect of applied potential on a mercury pool on the yield of sublimated sexiphenyl under vacuum was studied.Oligophenylens were mainly characterized by infrared spectroscopy.Moreover, electrochemical behavior of parasexiphenyl and of 4 bromo-terphenyl were compared in acetonitrile medium.
- Faid, K.,Siove, A.,Chevrot, C.,Riou, M. T.,Froyer, G.
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p. 1305 - 1312
(2007/10/02)
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- COUPLING OF ARYL GRIGNARD REAGENTS BY ELECTRON TRANSFER TO 2,3-DICHLOROPROPENE
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A general synthesis of symmetrical biaryls in good to excellent yields via homo-coupling of aryl Grignard reagents in the presence of 2,3-dichloropropene is described.
- Cheng, Jya-Wei,Luo, Fen-Tair
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p. 1293 - 1294
(2007/10/02)
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- Syntheses and Spectral Characteristics of Seven Polyphenyls Containing Highly Branched para-Phenylene Ring(s)
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Seven polyphenyls, including four new compounds, 2,2',6'- (2) and 3,2',6'-triphenyl-p-terphenyl (3), 3',5'-diphenyl-p-quarterphenyl (4), and 2-phenyl-3'-(2-biphenylyl)-p-terphenyl (7), were synthesized by the Ullmann coupling reaction of aryl iodide(s) or by the Kharash type coupling reaction of aryl Grignard reagent with an aryl iodide catalyzed by bis(acetylacetonato)-nickel(II).Infrared spectral studies of the polyphenyls showed that the range of 730-770 cm-1, generally accepted as the position of the out-of-plane C-H bending bands of the phenyl ring, should be widened slightly to 730-786 cm-1.The high frequency bands were confirmed to be correlated closely to the overcrowding by terminal rings in the complex structures.Proton magnetic resonance spectral studies indicated that he characteristic spectral features of the branched polyphenyls were consistent with their conformational aspects deduced from stereomodels.In the ultraviolet spetcral studies the polyphenyls containing highly branched p-phenylene ring(s) showed intense K-bands or shoulders at locations very similar to those of the corresponding linear polyphenyls containing the same number of p-phenylene rings. Keywords -- Ullmannn reaction; Ni-complex-catalyzed cross-coupling; quinquephenyl; sexiphenyl; octiphenyl; IR; UV; 1H-NMR
- Fujioka, Yasuhiro,Ozasa, Shigeru,Sato, Kazumi,Ibuki, Eiichi
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