- Synergistic Activities in the Ullmann Coupling of Chloroarenes at Ambient Temperature by Pd-Supported Calcined Ferrocenated La2O3
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Novel palladium-doped nanoparticles have been explored to serve as the first metal oxide-derived heterogeneous catalyst for Ullmann reaction of chloroarenes under mild condition (34?°C). This heterogeneous catalyst exhibited high catalytic activity towards the Ullmann homocoupling of chloroarenes into a series of useful symmetrically biaryl products with good to excellent yields in the presence of ethanol and NaOH, thereby leading to green and economical Ullmann reaction. The produced nanoparticles were successfully characterized by various techniques including PXRD, XPS, HRTEM, SEM-EDS, BET, TGA techniques, elemental mapping analysis and ICP-OES. Interestingly, based on characterization and experimental data, a reasonable mechanism has been proposed. Also, the formation of aryl methyl ketone as a by-product has been further confirmed by isotopic labelling experiments that the acetyl moiety is derived from ethanol. Moreover, the catalyst was stable and could be easily reused up to 5 times under atmospheric air without suffering significant loss in catalytic activity.
- Chumkaeo, Peerapong,Poonsawat, Thinnaphat,Meechai, Titiya,Somsook, Ekasith
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- Biaryl diketone synthesis via palladium-catalyzed carbonylative coupling with carbon monoxide or various metal carbonyls
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Biaryl diketones were synthesized via palladium-catalyzed carbonylative coupling in the presence of a palladium N-heterocyclic carbene complex and CO or metal carbonyls. Different arylboronic acids along with various CO-releasing molecules were tested to
- Cho, Soo Kyung,Song, Ju Hyun,Hahn, Jung Tae,Jung, Dai Il
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p. 1567 - 1570
(2016/10/13)
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- Synthesis of biphenyl- 4,4'-diyl bis(phenyl-methanone) via carbonylative coupling
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Luminescent meterials have a major technological role for human kind in the form of application such as organic and inorganic light emitters for flat panel and flexible displays such as plasma displays, LCD displays and OLED displays. To develop a luminescent material with high colour purity, luminous efficiency and stability, we synthesized diketone by carbonylative Suzuki coupling in the presence of Pd(NHC) (NHC = N-heterocyclic carbene) complex as the catalyst. Carbonylative coupling of 4,42-diiodobiphenyl and phenylboronic acid was investigated to study in detail the catalytic ability of the Pd(NHC) complex. Reactions were carried out using both CO and metal carbonyls. Bis-(1,3-dihydro-1,3-dimethyl-2H-imidazol-2-ylidene) diiodo palladium was used as the catalytic complex. Reaction products biphenyl-4,4'-diyl bis(phenyl methanone) 3 and (4'-iodobiphenyl-4-yl)(phenyl)methanone 4 were obtained as a result of CO insertion into the palladium(II)-aryl bond. However, when pyridine-4-yl boronic acid was used in place of phenylboronic acid as the starting reagent, synthetic reaction yielding 3 and 4 were found not to occur.
- Lee, Do-Hun,Hahn, Jung-Tai,Jung, Dai-Il
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p. 8611 - 8613
(2013/11/06)
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- Miyaura borylations of aryl bromides in water at room temperature
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New technology for palladium-catalyzed cross-couplings between B 2pin2 and aryl bromides leading to arylboronates is described. Micellar catalysis serves to enable borylations to take place in water as the only medium at ambient temperatures. Copyright
- Lipshutz, Bruce H.,Moser, Ralph,Voigtritter, Karl R.
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p. 691 - 695
(2013/01/09)
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- Palladium(II) chloride/EDTA-catalyzed biaryl homo-coupling of aryl halides in aqueous medium in the presence of ascorbic acid
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Both electron-deficient and electron-rich aryl bromides undergo biaryl homo-coupling in a basic aqueous-ethanolic medium in the presence of PdCl2-EDTA (1:1 molar ratio, 3 mol %) as catalyst and ascorbic acid as reductant (1 mol equiv) in acceptable to good yields.
- Ram, Ram N.,Singh, Virinder
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p. 7625 - 7628
(2007/10/03)
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- Multifunctional lithium containing initiator
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Highly desirable multifunctional lithium containing initiators are prepared by reacting a compound such as an organo lithium with an organic compound containing at least two 1,1-diphenylethylene groups. Such initiators can be prepared in the absence of polar solvents and are very desirable for the polymerization of dienes such as butadiene to a desirable 1,4 configuration. Several di-lithium compounds have been employed to initiate polymerization of various unsaturated organic monomers.
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