- 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 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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- A highly efficient catalyst of a nitrogen-based ligand for the Suzuki coupling reaction at room temperature under air in neat water
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Glycine, as a kind of commercially available and inexpensive ligand, is used to prepare an air-stable and water-soluble catalyst for the Suzuki-Miyaura reaction in our study. In the presence of 0.1% [PdCl2(NH 2CH2COOH)2] as the catalyst, extremely excellent catalytic activity towards the Suzuki-Miyaura coupling of aryl halides containing the carboxyl group with various aryl boronic acids is observed at room temperature under air in neat water. the Partner Organisations 2014.
- Liu, Shiwen,Lv, Meiyun,Xiao, Daoan,Li, Xiaogang,Zhou, Xiuling,Guo, Mengping
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supporting information
p. 4511 - 4516
(2014/06/23)
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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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- Four-coordinate Pd(II) complexes containing non-symmetric phosphorus ylides: Synthesis, characterization, and catalytic behavior towards Suzuki reaction
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In this paper it is reported the synthesis of the complexes of the type {[Ph2PCH2PPh2CHC(O)R]PdCl2} (R = 4′-biphenyl (1), OCH2Ph (2), 4-methylphenyl (3), 2-naphtyl (4), 2,4-dichlorophenyl (5), 3-nitro
- Sabounchei, Seyyed Javad,Panahimehr, Mohammad,Ahmadi, Mohsen,Nasri, Zahra,Khavasi, Hamid Reza
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p. 207 - 213
(2013/02/25)
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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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- N-acylsulfonamide apoptosis promoters
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N-Benzoyl arylsulfonamides having the formula are BCL-Xl inhibitors and are useful for promoting apoptosis. Also disclosed are BCL-Xl inhibiting compositions and methods of promoting apoptosis in a mammal.
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- Self-folding cavitands of nanoscale dimensions
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New types of resorcinarene-based nanoscale container molecules 2 and 3 are described. They feature reversibly folding unimolecular cavities of nanoscale dimensions and ~800 A3 internal volume; they are among the largest synthetic unimolecular hosts prepared to date. Two seams of intramolecular hydrogen bonds, provided by 12 secondary amides, control the guest uptake and release. The hydrogen bonds resist the unfolding of the host and increase the energetic barrier to guest exchange. Exchange is slow on the NMR time scale (room temperature), and kinetically stable complexes result. The direct observation of bound species and the stoichiometry of the complexes are reported. A series of adamantyl and cyclohexyl guests 11-19 of various shapes and lengths were prepared and used to estimate the hosts' capacities. Compound 2 exists in an S-shaped conformation and its two cavities act independently; each half of host 2 formed kinetically stable complexes with either two identical or different guest molecules. The C-shaped host 3 accommodates rigid and long guests with association constants (K(a)) between 500 ± 50 M-1 (-ΔG295 = 3.6 ± 0.1 kcal mol-1) and 270 ± 100 M-1 (-ΔG295 = 3.2 ± 0.2 kcal mol-1) for adamantyl derivatives. With the more flexible and/or shorter guests, fast exchange between the free and complexed guest species was observed at room and higher temperatures (in toluene-d8). Guest exchange rates of the new hosts are considerably faster than rates seen with typical hemicarceplexes but slower than those of other open-ended cavitands.
- Lucking,Tucci,Rudkevich,Rebek Jr.
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p. 8880 - 8889
(2007/10/03)
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- 2-(BIPHENYL-4-YL)-5-PHENYL-1,3,4-OXADIAZOLE (PBD): ELECTROPHILIC 4'-SUBSTITUTION AND FOLLOWING TRANSFORMATIONS
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PBD was converted into 4'-substituted derivatives I-XII using usual electrophilic reagents.The decompositions of PBD, 4'-acetyl derivative I and 4'-nitro derivative VI with hydroiodic acid gave 4'-substituted 4-biphenylcarboxylic acids XIIIa-XIIIc and benzoic acid, respectively.The regioselectivity of the reactions was also proved by means of high resolution NMR spectroscopy.
- Kurfuerst, Antonin,Lhotak, Pavel,Nadenik, Petr,Raclova-Pavlikova, Frantiska,Kuthan, Josef
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p. 1495 - 1504
(2007/10/02)
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- Biphenyl esters and liquid crystalline mixtures comprising them
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Biphenyl esters of the formula STR1 wherein X is --CO--O-- or --O--CO-- and R1 and R2 each are alkyl or alkoxy of 1 - 8 carbon atoms, enlarge significantly the temperature range of the nematic phase of liquid-crystalline compositions without adversely affecting other properties.
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