- HCl-Catalyzed Aerobic Oxidation of Alkylarenes to Carbonyls
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The construction of C?O bonds through C?H bond functionalization remains fundamentally challenging. Here, a practical chlorine radical-mediated aerobic oxidation of alkylarenes to carbonyls was developed. This protocol employed commercially available HCl as a hydrogen atom transfer (HAT) reagent and air as a sustainable oxidant. In addition, this process exhibited excellent functional group tolerance and a broad substrate scope without the requirement for external metal and oxidants. The mechanistic hypothesis was supported by radical trapping, 18O labeling, and control experiments.
- Niu, Kaikai,Shi, Xiaodi,Ding, Ling,Liu, Yuxiu,Song, Hongjian,Wang, Qingmin
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- Catalytic reduction of nitroarenes and Suzuki-Miyaura reactions using Pd complex stabilized on the functionalized polymeric support
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The significance of aromatic amines as crude substances in diverse applications has attracted extensive consideration in the field of economic procedures for the reduction of nitroarenes. Also, the formation of Carbon–Carbon bond as a dominant step in the structure of complex molecules is an important phenomenon in chemical reactions. Improvements of eco-friendly methodologies for reduction process and Carbon–Carbon bond formation have been noticeable. The present work represents through a capable heterogeneous Pd catalyst, the reduction of nitroarenes to the corresponding amines in the presence of N2H4 as a weak hydrogen donor reagent in the room temperature and solvent-free condition was progressed. In addition, several C–C bond formations through Suzuki-Miyaura reaction using one-pot mixture containing aryl halide, arylboronic acid in the presence of Pd catalyst at refluxed condition proceeded. Furthermore, the reusability of Pd catalyst for both reduction and Suzuki reactions showed five successive runs without any significant loss in its activity.
- Ariannezhad, Maryam,Esperi, Melika,Pourmorteza, Narges,Yousefi, Abed
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- Selective electrochemical oxidation of aromatic hydrocarbons and preparation of mono/multi-carbonyl compounds
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A selective electrochemical oxidation was developed under mild condition. Various mono-carbonyl and multi-carbonyl compounds can be prepared from different aromatic hydrocarbons with moderate to excellent yield and selectivity by virtue of this electrochemical oxidation. The produced carbonyl compounds can be further transformed into α-ketoamides, homoallylic alcohols and oximes in a one-pot reaction. In particular, a series of α-ketoamides were prepared in a one-pot continuous electrolysis. Mechanistic studies showed that 2,2,2-trifluoroethan-1-ol (TFE) can interact with catalyst species and generate the corresponding hydrogen-bonding complex to enhance the electrochemical oxidation performance. [Figure not available: see fulltext.]
- Li, Zhibin,Zhang, Yan,Li, Kuiliang,Zhou, Zhenghong,Zha, Zhenggen,Wang, Zhiyong
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p. 2134 - 2141
(2021/09/29)
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- A comparative study of catalytic activity on iron-based carbon nanostructured catalysts with Pd loading: Using the Box–Behnken design (BBD) method in the Suzuki–Miyaura coupling
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Highly dispersed palladium nanoparticles immobilized on surface-modified Fe3O4 NPs and magnetic carbon nanostructures (CNSs; carbon nanotubes/graphene oxide) were synthesized and applied as a recyclable and reusable nanocatalyst to achieve palladium (II)-catalyzed Suzuki–Miyaura reaction of arylboronic acid with aryl bromides. Carbon nanostructures with immobilized hydantoin (PH)-Pd complex display excellent stability, including a high performance at low catalyst loading. Magnetic separation prevents catalyst centrifuge or filtration and also contributes to practical techniques for recovery. Next, a response surface method based on a three-level Box–Behnken design was used, which involved three factors: catalyst loading, reaction time, and solvent. The Box–Behnken method was advantageous to parameters optimization for obtaining a yield, with high efficiency and accuracy. As a result of catalytic tests, the TONs and TOFs were calculated from all coupling reactions. The prepared nano-magnetic catalysts, after the catalysis reaction, can be easily recovered through the magnetic field. Evaluated catalytic performance indicates that these types of catalysts can function as effective recyclable catalysts at least five times without losing the initial level of catalytic activity.
- Moniriyan, Faezeh,Sabounchei, Seyyed Javad
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- A one-pot protocol for the fluorosulfonation and Suzuki coupling of phenols and bromophenols, streamlined access to biaryls and terphenyls
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A one-pot protocol for the fluorosulfation and Suzuki coupling of phenols is described. The tandem reaction proceeds efficiently at room temperature, and various biaryls and biaryl fluorosulfates were obtained in good to excellent yields. Furthermore, biaryl fluorosulfates were utilized as versatile building blocks for the preparation of terphenyls. The Royal Society of Chemistry 2020.
- Hu, Rui,Li, Xinmin,Ren, Changyue,Yuan, Zeli,Zhang, Hang,Zhang, Tingting
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supporting information
p. 4748 - 4753
(2020/08/17)
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- DFT studies of the full mechanistic Suzuki–Miyaura reaction: synthesis, structural analysis and cytotoxicity of P,C-chelated palladium(II) and platinum(II) complexes
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The new Pd/Pt(II) complexes, [MBr2(Ph2PCH2PPh2C(H)C(O)C6H4-m-Br)] (M = Pd (1); M = Pt (2)), with unsymmetrical phosphorus ylide [Ph2PCH2PPh2=C(H)C(O)C6H4Br] (Y) have been synthesized through a simple procedure and were screened in a search for novel antitumor agents. These compounds were characterized by FT-IR, NMR (1H, 13C and 31P) spectroscopic methods and density functional theory methods. The crystal structures of 1 and 2 were elucidated by single-crystal X-ray diffraction. The results indicated that the complexes were P,C-chelated. Also, a theoretical study on the structure of the complexes has been investigated at the BP86/def2-SVP level of theory. The nature of metal-ligand bonds in the complexes was analyzed using EDA and ETS-NOCV analyses. In particular, a mechanistic pathway of the Suzuki–Miyaura reaction catalyzed by Pd(II) complex 1 with a P,C-donor ligand has been investigated by DFT studies, which the computational results were in agreement with those of experiments. Moreover, the cytotoxic effects of the compounds were studied in four human carcinoma cell lines: PC3, A2780, MCF-7 and PC-12 by MTT assay. Compound 1 proved to be an outstanding potent cytotoxic agent against PC3 cell line and can be considered as a promising lead in cancer drug discovery and development.
- Badpa, Khadijeh,Sabounchei, Seyyed Javad,Hosseinzadeh, Leila,Gable, Robert W.
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p. 2941 - 2962
(2020/11/23)
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- ONO pincer palladium (II) complexes featuring furoylhydrazone ligands: Synthesis, characterization and catalytic activity towards Suzuki–Miyaura coupling reaction
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Four new palladium pincer complexes incorporating ONO type furoylhydrazone ligands have been prepared in good yields. These palladium complexes were structurally characterized by elemental analysis, infrared, 1H- and 13C-NMR spectra. X-ray single crystal analyses of Pd1–Pd4 revealed that the metal center adopted a slightly distorted square planar geometry in which the hydrazone bound the metal ion via the phenolic-O, azomethine-N and imidolate-O atoms. Using these ONO pincer complexes as catalyst, excellent yields of biaryls could be obtained for coupling of arylboronic acids with aryl bromides at a low catalyst loading (0.01?mol%).
- Qian, Hengyu,Yu, Shuyan,Song, Liping,Zhang, Tongyan,Yin, Zhigang,Zhao, Feng,Yang, Jiale,Wang, Caihong
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- Iridium-Catalyzed Alkene-Selective Transfer Hydrogenation with 1,4-Dioxane as Hydrogen Donor
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The iridium-catalyzed transfer hydrogenation of alkenes using 1,4-dioxane as a hydrogen donor is described. The use of 1,2-bis(dicyclohexylphosphino)ethane (DCyPE), featuring bulky and highly electron-donating properties, led to high catalytic activity. A polystyrene-cross-linking bisphosphine PS-DPPBz produced a reusable heterogeneous catalyst. These homogeneous and heterogeneous protocols achieved chemoselective transfer hydrogenation of alkenes over other potentially reducible functional groups such as carbonyl, nitro, cyano, and imino groups in the same molecule.
- Zhang, Deliang,Iwai, Tomohiro,Sawamura, Masaya
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supporting information
p. 5867 - 5872
(2019/08/26)
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- Ferrocenyl palladacycles derived from unsymmetrical pincer-type ligands: Evidence of Pd(0) nanoparticle generation during the Suzuki-Miyaura reaction and applications in the direct arylation of thiazoles and isoxazoles
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A new family of ferrocenyl-palladacycle complexes Pd(L1)Cl (Pd1) and Pd(L2)Cl (Pd2) were synthesized and characterized by UV-visible, IR, ESI-MS, and NMR spectral studies. The molecular structures of Pd1 and Pd2 were determined by X-ray crystallographic studies. Palladacycle catalyzed Suzuki-Miyaura cross-coupling reactions were investigated utilizing the derivatives of phenylboronic acids and substituted chlorobenzenes. Mechanistic investigation authenticated the generation of Pd(0) nanoparticles during the catalytic cycle and the nanoparticles were characterized by XPS, SEM and TEM analysis. Direct C-H arylation of thiazole and isoxazole derivatives employing these ferrocenyl-palladacycle complexes was examined. The reaction model for the arylation reaction implicating the in situ generation of Pd(0) nanoparticles was proposed.
- Maji, Ankur,Singh, Anshu,Mohanty, Aurobinda,Maji, Pradip K.,Ghosh, Kaushik
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supporting information
p. 17083 - 17096
(2019/11/26)
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- Different properties of P,C-donor Pd(II) and Pt(II); spectroscopic and X-ray analysis, catalytic potential and anti-proliferative potency
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This account describes our recent studies on pallada-and platinaphosphacycle complexes with an unsymmetrical phosphonium ylide, Ph2PC(CH2)PPh2 = C(H)C(O)C6H4-p-NO2 (Y), derived from 1,1-bis(diphenylphosphino)ethylene (dppee). These complexes have been prepared through reactions between (Y) and [MCl2(cod)] (M = Pd (C1) or Pt (C2); cod = 1,5-cyclooctadiene) in equimolar ratio in the hope of finding new compounds that may be useful in stereoselective catalysis and find use as antitumor metallodrugs. Characterization of these compounds was performed by elemental analysis, IR, 1H, 13C, and 31P NMR spectroscopic methods. The structures of the Pd and Pt complexes were determined by single crystal x-ray structural analyses, showing that both complexes consist of five-membered rings formed by coordination of the phosphorus ylide (Y) through the phosphine group and the ylidic carbon atom to the metal center. The catalytic activity of the complexes, using the Mizoroki–Heck and Suzuki-Miyaura cross-coupling reactions, have been evaluated and compared. Moreover, both compounds have been found to have antitumor activity against AGS (gastric carcinoma), MCF-7 (breast carcinoma) and A549 (non-small lung carcinoma) cells with the average of IC50 values from 61.19 to 290.17 μM. Generally, C2 reveals high anticancer activity than C1.
- Yousefi, Abed,Sabounchei, Seyyed Javad,Moazzami Farida, Seyed Hamed,Karamian, Roya,Rahmani, Nosrat,Gable, Robert W.
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- Synthesis, X-ray structural and DFT studies of n-membered ring P, C-chelated complexes of Pd(II) and pt(II) derived from unsymmetrical phosphorus ylides and application of pd(II) complexes as catalyst in suzuki reaction
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The phosphonium salts [Ph2P(CH2)nPPh2CH2C(O)C6H4-m-OMe]Br (n = 1 (S1) and n = 2 (S2)) were synthesized in the reaction of bis(diphenylphosphino) methane (dppm) and bis(diphenylphosphino)ethane (dppe) with 2-bromo-3?-methoxy acetophenone, respectively. Further treatment with NEt3 gave the phosphorus ylides Ph2P(CH2)nPPh2C(H)C(O)C6H4-m-OMe (n = 1 (Y1) and n = 2 (Y2)). These ligands were treated with [MCl2(cod)] (M = Pd or Pt; cod = 1,5-cyclooctadiene) to give the P, C-chelated complexes, [MCl2(Ph2P(CH2)nPPh2C(H)C(O)C6H4-m-OMe)] (n = 1, M = Pd (3), Pt (4), and n = 2, M = Pd (5), Pt (6)). These compounds were characterized by elemental analysis, spectroscopic methods, UV–visible, and fluorescence emission spectra. Further, the structures of complexes 3 and 6 were characterized crystallographically. The palladium complexes 3 and 5 proved to be excellent catalysts for the Suzuki reactions of various aryl chlorides. Also, a theoretical study on the structure of complexes 3–6 has been investigated at the BP86/def2-SVP level of theory. The strength and nature of donor?acceptor bonds between the phosphorus ylides (L) and MCl2 fragment in the [LMCl2] (M = Pd, Pt, L = Y1, Y2) were studied by NBO and energy decomposition analysis (EDA), as well as their natural orbitals for chemical valence variation (EDA-NOCV).
- Sabounchei, Seyyed Javad,Sayadi, Mohsen,Bayat, Mehdi,Sedghi, Asiyeh,Gable, Robert W.
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p. 3727 - 3748
(2017/11/15)
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- Pd(II) and Pt(II) complexes of α-keto stabilized sulfur ylide: Synthesis, structural, theoretical and catalytic activity studies
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Reaction of dimethyl sulfide with 2, 3′-dibromoacetophenone led to formation of sulfonium salt [Me2SCH2C(O)C6H4-m-Br]Br (1). The resulted sulfonium salt was treated with NaOH and gave the α-keto stabilized sulfur ylide Me2SC(H)C(O)C6H4-m-Br (2). This ligand was reacted with [MCl2(cod)] (M?=?Pd, Pt; cod?=?1,5-cyclooctadiene) to form the new cis- and trans-[MCl2(ylide)2] (M?=?Pd (cis- and trans-3), Pt (cis- and trans-4)) complexes. Characterization of the obtained compounds was performed by elemental analysis, IR, 1H and 13C NMR. Recrystallization of dichlorobis(ylide) palladium(II) and platinum(II) complexes from DMSO solution yielded the crystalline products, which X-ray diffraction data revealed that the both compounds were crystallized as cis-[MCl2(ylide)(DMSO)] (M?=?Pd (5), Pt (6)) complexes. Also, a theoretical study on structure and nature of the M[sbnd]C bonding between the Y ligand (ylide) and [MCl2·DMSO] fragments in [YMCl2·DMSO] (M?=?Pd, Pt) complexes has been reported via NBO and energy-decomposition analysis (EDA). Furthermore, the palladium catalyzed Suzuki-Miyaura reaction of various aryl chlorides with arylboronic acids was performed. The results showed that the Pd(II) complexes cis- and trans-3 catalyzed efficiently coupling reactions at low catalyst loading and short reaction time.
- Sabounchei, Seyyed Javad,Hashemi, Ali,Sedghi, Asieh,Bayat, Mehdi,Akhlaghi Bagherjeri, Fateme,Gable, Robert W.
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p. 174 - 185
(2017/02/05)
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- Pallada- and platinacycle complexes of phosphorus ylides; synthesis, X-ray characterization, theoretical and electrochemical studies and application of Pd(II) complexes as catalyst in Suzuki-Miyaura coupling reaction
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The new unsymmetrical phosphonium salts [Ph2PCH2PPh2CH2C(O)C6H4R]Br (R= m-Br (S1) and p-CN (S2)) were synthesized in the reaction of 1,1-bis(diphenylphosphino)methane (dppm) and BrCH2C(O)C6H4R (R= m-Br and p-CN) ketones, respectively. Further treatment with NEt3 gave the α-keto stabilized phosphorus ylides Ph2PCH2PPh2C(H)C(O)C6H4R (R= m-Br (Y1) and p-CN (Y2)). These ligands were reacted with [MCl2(cod)] (M= Pd and Pt; cod= 1,5-cyclooctadiene) to give the pallada- and platinacycle complexes [MCl2(Ph2PCH2PPh2C(H)C(O)C6H4R)] (M= Pd, R= m-Br (3); R= p-CN (4) and M= Pt, R= m-Br (5); R= p-CN (6)). Cyclic voltammetry, elemental analysis, IR and NMR (1H, 13C and 31P) spectroscopic methods were used for characterization of the obtained compounds. Further, the structure of complexes 3 and 4 were characterized crystallographically. Palladacycles 3 and 4 were proved to be excellent catalysts for the Suzuki-Miyaura coupling reactions of various aryl chlorides and arylboronic acids in mixed DMF/H2O media. Also, the bonding situations between two interacted fragments [PtCl2] and Y1 and Y2 ligands in platinacycles 5 and 6 were investigated based on DFT method by using NBO, EDA and ETS-NOCV analysis.
- Sabounchei, Seyyed Javad,Sedghi, Asieh,Hashemi, Ali,Hosseinzadeh, Marjan,Bayat, Mehdi,Gable, Robert W.
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- Palladium immobilized on Fe3O4/ZnO nanoparticles: A novel magnetically recyclable catalyst for Suzuki-Miyaura and heck reactions under ligand-free conditions
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Magnetically separable Pd(0)/Fe3O4/ZnO catalyst was easily synthesized by immobilizing Pd on the surface of magnetic Fe3O4-ZnO nanoparticles. The nano-Pd/Fe3O4/ZnO was found as a magnetically separable and highly active catalyst for Suzuki-Miyaura as well as Heck cross-coupling reactions under ligand-free conditions. Under appropriate conditions, all reactions afforded the desired products in moderate to excellent yields. Moreover, this catalyst can be easily recovered using simple magnet and directly reused without significant loss of its activity.
- Hosseini-Sarvari, Mona,Khanivar, Ameneh,Moeini, Fatemeh
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- A new Pd(II) complex of a sulfur ylide; Synthesis, X-ray characterization, theoretical study and catalytic activity toward the Suzuki-Miyaura reaction
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The new sulfonium salt [SMe2CH2C(O)C6H4-m-OCH3]Br (1) was synthesized from the reaction of dimethyl sulfide and 2-bromo-3′-methoxyacetophenone. Further treatment with NaOH 10% gave the α-keto stabilized sulfur ylide SMe2C(H)C(O)C6H4-m-OCH3 (2). This ligand was reacted with the dichloro(1,5-cyclooctadiene)palladium(II) complex, [PdCl2(cod)], in a 2:1 ratio to give the new Cα-coordinated complexes cis- and trans-[PdCl2(SMe2C(H)C(O)C6H4-m-OCH3)2] (3a and 3b). Characterization of the obtained compounds was performed by elemental analysis, IR, 1H, 13C NMR and mass spectroscopies. Since complexes 3a and 3b were insoluble in most organic solvents, we chose DMSO as a suitable solvent for the NMR spectroscopies. Crystallization of above solution led to the formation of single crystals. The X-ray analysis results revealed that complex 3a has undergone a ligand replacement reaction and the complex [PdCl2(SMe2C(H)C(O)C6H4-m-OCH3)·DMSO] (4) was formed. This complex has two Cl atoms in cis positions, one sulfur ylide and one S-coordinated DMSO as ligands. The air/moisture stable complexes 3a and 3b were employed as efficient catalysts for the Suzuki-Miyaura cross-coupling reaction of several aryl halides. The coupled products of these reactions were obtained in good to excellent yields and purity, with short reaction times and low catalyst loading. Also a theoretical study on the structure and nature of the Pd-C bond in complex 4 is reported here at the BP86/def2-SVP level of theory.
- Sabounchei,Yousefi,Ahmadianpoor,Hashemi,Bayat,Sedghi,Bagherjeri,Gable
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p. 273 - 282
(2016/07/06)
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- Palladium supported on zinc oxide nanoparticles as efficient heterogeneous catalyst for Suzuki-miyaura and hiyama reactions under normal laboratory conditions
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Nanoscale Pd supported on ZnO was prepared by a facile coprecipitation method. Pd/ZnO Nanoparticles were characterized by using XRD, TEM, SEM, XPS, BET specific surface area measurement, and thermogravimetric analysis. This catalyst was used as novel and excellent heterogeneous catalyst for ligand-free C-C bond-formation particularly in the synthesis of unsymmetrical biaryls by Suzuki-Miyaura and Hiyama cross-coupling reactions under air atmosphere without use of any Ar or N2 flow. The catalyst can be recovered and recycled several times without marked loss of activity.
- Hosseini-Sarvari, Mona,Razmi, Zahra
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p. 805 - 818
(2015/06/25)
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- A palladium-phosphine catalytic system as an active and recycable precatalyst for Suzuki coupling in water
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Abstract The Suzuki-Miyaura reaction of various aryl halides with aryl boronic acids using {[Ph2PCH2PPh2CH=C(O)(C10H7)]PdCl2} as a catalyst has been investigated. The X-ray crystal structur
- Sabounchei, Seyyed Javad,Hosseinzadeh, Marjan,Panahimehr, Mohammad,Nematollahi, Davood,Khavasi, Hamid Reza,Khazalpour, Sadegh
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p. 657 - 663
(2015/08/06)
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- Synthesis and structural characterization of dimeric phosphine ylide Cu(I) complexes: Application in Suzuki cross-coupling reactions and biological evaluation as antibacterial agents
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In this work we report the synthesis of the complexes of the type [Cu(μ-Cl){Ph2P(CH2)nPPh2C(H)C(O) PhR}]2 (n = 1: R = Cl (1), NO2 (2); n = 2: R = Cl (3), NO2 (4)) derived from the reactions of the copper(I) chloride with related phosphorus ylides in equimolar ratios using dry methanol as solvent. The identity of complex 1 was unequivocally determined by single crystal X-ray diffraction techniques, its structure consisting of five-membered rings formed by coordination of the ligands through the phosphine group and the ylidic carbon atom to the metal center. The coordination geometry around the Cu atoms in this complex can be defined as slightly distorted tetrahedral. Characterization of the obtained compounds was also performed by IR, 1H, 31P and 13C NMR spectroscopy and analytical data indicated a 1:1 stoichiometry between the Cu(I) chloride and ylide. Well-defined phosphine bis-ylide Cu(I) complexes 1 and 3 were found to be an effective catalyst for the Suzuki coupling of various aryl halides including with 4-ethyl phenylboronic acid, giving the desired coupling products at low catalyst loading in moderate to good yields. Also, the antibacterial activities of DMSO-solved complexes were measured by disc diffusion method against 6 Gram positive and negative bacteria. All Cu(I) complexes exhibited antibacterial activities against bacteria tested especially Gram negative ones.
- Sabounchei, Seyyed Javad,Pourshahbaz, Mahbubeh,Hashemi, Ali,Ahmadi, Mohsen,Karamian, Roya,Asadbegy, Mostafa,Khavasi, Hamid Reza
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p. 111 - 119
(2014/05/06)
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- Phosphine mono- and bis-ylide palladacycles as homogeneous molecular precatalysts: Simple and efficient protocol greatly facilitate Suzuki and Heck coupling reactions
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Moisture/air-stable and robust phosphine mono- and bis-ylide palladacycles as catalyst precursors were used in Suzuki and Heck cross-coupling reactions with different aryl halides including electron-rich and electron-deficient substituents. These coupling
- Sabounchei, Seyyed Javad,Ahmadi, Mohsen,Panahimehr, Mohammad,Bagherjeri, Fateme Akhlaghi,Nasri, Zahra
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p. 249 - 259
(2014/02/14)
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- Functionalized α-keto stabilized sulfonium ylides as highly active ligand precursors for palladium catalyzed Suzuki-Miyaura cross-couplings
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Five α-keto stabilized sulfonium ylides as type (Me) 2SCHC(O)C6H4-p-X (X = H, Br, NO2, CH3 and OCH3) {L1-L5} were used as ligand precursors in the Suzuki-Miyaura cross-coupling reaction. The best catalytic performance was obtained by using a sulfonium ylide/Pd ratio of 2:1. The catalytic systems displayed high activities, which increased in the order R = NO2 (L3) 2) 1) 3 (L4) 3 (L5). The coupling reactions proceeded smoothly with 0.05 mol% PdCl2 and 0.1 mol% L5 in DMF at 130 °C between varieties of electronically activated, deactivated and neutral aryl halides and aryl boronic acids within short reaction times and without the need for exclusion of air which gave good to high yields of the corresponding products. All the studied ligands demonstrated very high activity in the Suzuki-Miyaura cross-coupling, which yielded turnover numbers up to 1940. Comparative studies showed that the performance of sulfonium ylide L5 is significantly superior to that of related phosphine-free ligands.
- Sabounchei, Seyyed Javad,Hashemi, Ali
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p. 123 - 127
(2014/08/18)
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- Five-membered cyclopalladated complex containing bidentate phosphine ligands; Synthesis, characterization, and highly efficient Suzuki cross-coupling reactions
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A nonsymmetric phosphorus ylide and its palladium(II) complex have been synthesized as potential catalytically active compounds. The reaction of 1 equiv nonsymmetric phosphorus ylide, Ph2PCH2PPh 2C(H)C(O)PhBr with [Pd(dppe)Cl2], followed by treatment with 2 equiv AgOTf led to [(dppe)Pd(Ph2PCH2PPh 2C(H)C(O)PhBr)](OSO2CF3)2, which contains a five-membered P,P chelate ring on one side and a five-membered P,C chelate ring on the other side. The palladium complex was synthesized and investigated by fourier transform infrared spectroscopy (FT-IR), UV-visible, multinuclear (1H, 31P and 19F) nuclear magnetic resonance (NMR), and electrospray ionisation-mass spectroscopic techniques. FT-IR and 31P NMR studies revealed that the phosphorus ylide is coordinated to palladium via the terminal phosphorus (Pc) of the ylide and methene group (CH). Suzuki reactions for varying aryl halides using the cyclopalladated complex as an efficient catalyst were performed. Various aryl halides were coupled with arylboronic acids in DMF, under air, in the presence of 0.001 mol% of the homogeneous catalyst to afford the corresponding cross-coupled products in good to excellent yields.
- Sabounchei, Seyyed Javad,Ahmadi, Mohsen,Nasri, Zahra
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p. 411 - 423
(2013/08/24)
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- PEG (300)-PdCl2 promoted efficient and convenient Suzuki-Miyaura coupling of aryl chlorides with arylboronic acids
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PEG (300) was found as an effective medium for the PdCl2-catalyzed Suzuki-Miyaura cross-coupling of aryl chlorides with various phenylboronic acids. This cross-coupling pathway conveniently and efficiently gave good to excellent yields of corresponding biaryl nucleus under mild conditions.
- Yin, Liang,Zhang, Zhan-hui,Wang, Yong-mei
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p. 9359 - 9364
(2007/10/03)
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- Use of substituted 4-biarylbutyric and 5-biarylpentanoic acid derivatives for the treatment of cerebral diseases
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Use of substituted 4-Biarylbutyric and 5-Biarylpentanoic Acid Derivatives for the Treatment of Cerebral Diseases, pharmaceutical compositions containing them, and a process for using them. The compounds of the invention have the generalized formula(T)sub
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- Palladium-Catalyzed Stille Couplings with Fluorous Tin Reactants
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A new class of "fluorous" aryl tin reactants was investigated for use in the Stille coupling. Fluorous compounds partition into a fluorocarbon (fluorous) phase in a fluorous/organic extraction. The coupling of tris[(perfluorohexyl)ethyl]phenyl tin [(C6F13CH2CH2)3SnPh] with bromobenzene occurs smoothly in DMF/THF (1/1) at 80 °C in the presence of a catalytic amount of PdCl2(PPh3)2 and 3 equiv of LiCl. Partitioning between CH2Cl2 and FC-72 (a mixture of perfluorohexanes) provided biphenyl in 90% yield from the organic phase and tris[(perfluorohexyl)ethyl]tin chloride in > 90% yield from the fluorous phase. The tin chloride was reacted with phenylmagnesium bromide to regenerate the starting tin reactant. A study to optimize reaction conditions is described, and the scope of the method is illustrated with 20 coupling reactions. The beneficial effect of lithium choride is an unusual feature of the reaction, but it also promotes the formation of some fluoroalkyl-coupled products. These can be suppressed by adding CuI. The paper describes a prototypical example of how to render a tin reactant fluorous. This process should be advantageous in small- and large-scale synthesis, as well as in automated synthesis.
- Hoshino, Masahide,Degenkolb, Peter,Curran, Dennis P.
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p. 8341 - 8349
(2007/10/03)
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