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Ullmann Coupling Reaction (ullmann + coupling_reaction)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Mild Method for Ullmann Coupling Reaction of Amines and Aryl Halides.

CHEMINFORM, Issue 48 2003
Dawei Ma
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Copper(II) and 2,2,-Biimidazolyl-promoted Ullmann Coupling Reaction of Phenols and Aryl Iodides

CHINESE JOURNAL OF CHEMISTRY, Issue 8 2006
Bao-An Wang
Abstract Ullmann-type diaryl ether synthesis can be performed at 100 °C in good to excellent yields by aryl iodides as the substrates under the assistance of copper(II) and 2,2,-biimidazolyl. [source]

A Highly Active Heterogeneous Palladium Catalyst for the Suzuki,Miyaura and Ullmann Coupling Reactions of Aryl Chlorides in Aqueous Media,

ANGEWANDTE CHEMIE, Issue 24 2010
Bizhen Yuan
Ein Palladium-Heterogenkatalysator mit dem Metall-organischen Gerüst MIL-101 als Träger vermittelt effiziente Kupplungen in Wasser; so lieferten Suzuki-Miyaura-Kreuzkupplungen und Ullmann-Homokupplungen von substituierten Arylchloriden hohe Ausbeuten. Der Katalysator lässt sich darüber hinaus leicht zurückgewinnen und wiederverwenden (siehe Bild; Cr,blau, O,rot, C,weiß). [source]

Periodic Mesoporous Organosilicas: A Type of Hybrid Support for Water-Mediated Reactions

CHEMISTRY - AN ASIAN JOURNAL, Issue 7 2007
Ying Wan Prof.
Abstract Hybrid mesoporous periodic organosilicas (Ph-PMOs) with phenylene moieties embedded inside the silica matrix were used as a heterogeneous catalyst for the Ullmann coupling reaction in water. XRD, N2 sorption, TEM, and solid-state NMR spectroscopy reveal that mesoporous Ph-PMO supports and Pd/Ph-PMO catalysts have highly ordered 2D hexagonal mesostructures and covalently bonded organic,inorganic (all Si atoms bonded with carbon) hybrid frameworks. In the Ullmann coupling reaction of iodobenzene in water, the yield of biphenyl was 94,%, 34,%, 74,% and for palladium-supported Ph-PMO, pure silica (MCM-41), and phenyl-group-modified Ph-MCM-41 catalysts, respectively. The selectivity toward biphenyl reached 91,% for the coupling of boromobenzene on the Pd/Ph-PMO catalyst. This value is much higher than that for Pd/Ph-MCM-41 (19,%) and Pd/MCM-41 (0,%), although the conversion of bromobenzene for these two catalysts is similar to that for Pd/Ph-PMO. The large difference in selectivity can be attributed to surface hydrophobicity, which was evaluated by the adsorption isotherms of water and toluene. Ph-PMO has the most hydrophobic surface, and in turn selectively adsorbs the reactant haloaryls from aqueous solution. Water transfer inside the mesochannels is thus restricted, and the coupling reaction of bromobenzene is improved. [source]