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Phosphorus Ligands (phosphorus + ligand)

Distribution by Scientific Domains
Chemistry100%
Distribution within Chemistry
Organic Chemistry66%
General & Introductory Chemistry16%

Kinds of Phosphorus Ligands

  • chiral phosphorus ligand
    		•

    Selected Abstracts

    A Convenient Procedure for Palladium-Catalyzed Cyanation Using a Unique Bidentate Phosphorus Ligand.

    CHEMINFORM, Issue 12 2006
    Rader S. Jensen
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

    A Modular Approach to a New Class of Monodentate Chiral Phosphorus Ligands and Their Application in Enantioselective Copper-Catalysed Conjugate Additions of Diethylzinc to Cyclohexenone

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 16 2004
    Chiara Monti
    Abstract A new family of chiral phosphorus ligands (5) for use in enantioselective catalysis have been synthesised. The ligands contain the electron-poor bis(sulfonyl)diazaphospholidine moiety and possess a highly modular structure which is well suited to the synthesis of a library. A small library (23 members) of ligands 5 was prepared and tested in the enantioselective copper-catalysed conjugate addition of diethylzinc to cyclohexenone. Complete conversions were obtained with enantiomeric excesses (ee) of up to 75%. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

    Efficient Hydroformylation in Dense Carbon Dioxide using Phosphorus Ligands without Perfluoroalkyl Substituents

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009
    Ard C.
    Abstract Rhodium catalysts modified with triphenylphosphine, triphenyl phosphite, and tris(2,4-di- tert -butylphenyl) phosphite have been evaluated for their performance in the hydroformylation of 1-octene using carbon dioxide as the solvent. It is demonstrated that these catalysts are very efficient for the hydroformylation in carbon dioxide, although they are not designed for use in this medium. In particular, the catalyst prepared in situ from dicarbonyl(2,4-pentanedione)rhodium(I) and tris(2,4-di- tert -butyl-phenyl) phosphite gave rise to an initial turnover frequency in excess of 3×104,molaldehyde,molRh,h,1. Such a reaction rate is unprecedented for hydroformylation in supercritical carbon dioxide-rich reaction mixtures. [source]

    Rh-Catalyzed Asymmetric Hydrogenation of Prochiral Olefins with a Dynamic Library of Chiral TROPOS Phosphorus Ligands.

    CHEMINFORM, Issue 14 2006
    Chiara Monti
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

    ChemInform Abstract: Novel Monodentate Spiro Phosphorus Ligands for Rhodium-Catalyzed Hydrogenation Reactions.

    CHEMINFORM, Issue 28 2002
    Yu Fu
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    Developing a New Class of Axial Chiral Phosphorus Ligands: Preparation and Characterization of Enantiopure Atropisomeric Phosphinines

    CHEMISTRY - A EUROPEAN JOURNAL, Issue 16 2008
    Christian Müller Dr.
    Abstract Both enantiomers of the first atropisomeric phosphinine (1) have been isolated by using analytical HPLC on a chiral stationary phase. The enrichment of one enantiomer and a subsequent investigation into its racemization kinetics revealed a barrier for internal rotation of ,=(109.5±0.5),kJ,mol,1, which is in excellent agreement with the theoretically predicted value of ,=116,kJ,mol,1. Further analysis with UV and circular dichroism spectroscopies and density functional theory calculations led to the determination and assignment of the absolute configurations of both enantiomers. These results are the basis for future investigations into this new class of axially chiral phosphinine-based ligands and their possible applications in asymmetric homogeneous catalysis. [source]

    A Modular Approach to a New Class of Monodentate Chiral Phosphorus Ligands and Their Application in Enantioselective Copper-Catalysed Conjugate Additions of Diethylzinc to Cyclohexenone

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 16 2004
    Chiara Monti
    Abstract A new family of chiral phosphorus ligands (5) for use in enantioselective catalysis have been synthesised. The ligands contain the electron-poor bis(sulfonyl)diazaphospholidine moiety and possess a highly modular structure which is well suited to the synthesis of a library. A small library (23 members) of ligands 5 was prepared and tested in the enantioselective copper-catalysed conjugate addition of diethylzinc to cyclohexenone. Complete conversions were obtained with enantiomeric excesses (ee) of up to 75%. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

    Synthesis of new calix[4]arene-based phosphorus ligands and their application in the Rh(I) catalyzed hydroformylation of 1-octene

    HETEROATOM CHEMISTRY, Issue 7 2001
    C. Kunze
    The synthesis of calix[4]arene-based phosphorus diamides and phosphites is described. These oligocyclic ligands have been tested in the Rh(I)- catalyzed hydroformylation of 1-octene. Depending on the reaction conditions, yields up to 99% and n/iso -selectivities between 0.7 and 2.6 have been observed. tert -Butyl groups on the upper rim of the calix[4]arene template had a beneficial effect on the catalytic reaction. In general biuret-derived P-ligands were superior. For comparison, the corresponding "monomeric" ligands have also been synthesized and were employed in the catalytic reaction. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:577,585, 2001 [source]

    Asymmetric Hydrogenations (Nobel Lecture 2001)

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1-2 2003
    William
    Abstract The start of the development of catalysts for asymmetric hydrogenation was the concept of replacing the triphenylphosphane ligand of the Wilkinson catalyst with a chiral ligand. With the new catalysts, it should be possible to hydrogenate prochiral olefins. Knowles and his co-workers were convinced that the phosphorus atom played a central role in this selectivity, as only chiral phosphorus ligands such as (R,R)-DIPAMP, whose stereogenic center lies directly on the phosphorus atom, lead to high enantiomeric excesses when used as catalysts in asymmetric hydrogenation reactions. This hypothesis was disproven by the development of ligands with chiral carbon backbones. Although the exact mechanism of action of the phosphane ligands is not incontrovertibly determined to this day, they provide a simple entry to a large number of chiral compounds. [source]

    Edited by Armin Börner phosphorus ligands in asymmetric catalysis: synthesis and applications Wiley-VCH, 2008, 1546 pp. (hardcover) ISBN 978-3-527-31746-2

    APPLIED ORGANOMETALLIC CHEMISTRY, Issue 1 2010
    Deborah L. Dodds
    No abstract is available for this article. [source]

    Aminophosphines: their chemistry and role as ligands and synthons

    APPLIED ORGANOMETALLIC CHEMISTRY, Issue 8 2009
    Janarthanan Gopalakrishnan
    Abstract In recent years, research in organophosphorus chemistry has mainly focused in designing newer and better phosphorus ligands for synthesizing novel metal complexes with improved catalytic activities. Aminophosphines [tricoordinate phosphorus(III),nitrogen systems] are considered as versatile compounds owing to the presence of nitrogen centres which, in principle, can influence additional reactivity features. They are quite sensitive to air and moisture due to the presence of polar PN bond(s). In spite of this, research in aminophosphine chemistry is gaining momentum day-by-day and this is due mainly to one reason: their rich behaviour as ligands in metal complex chemistry and subsequently in catalysis. Their role as synthons in inorganic heterocyclic chemistry has also helped produce new types of heterocycles. In this paper, the chemistry of simple acyclic aminophosphines (synthesis, characterization, reactivity and applications) is covered and particular focus is given to their ability to form chalcogenides along with their role played as ligands in coordination chemistry and as synthons in inorganic heterocyclic chemistry. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Synthesis of Enantiomerically Pure 1,2,3,4-Tetrahydro-,-carbolines and N -Acyl-1-aryl Ethylamines by Rhodium-Catalyzed Hydrogenation

    CHEMISTRY - AN ASIAN JOURNAL, Issue 7 2008
    Stephan Enthaler Dr.
    Abstract The rhodium-catalyzed asymmetric hydrogenation of different enamides, in particular, dihydro-,-carboline derivates, was investigated in the presence of chiral phosphorus ligands. Enantioselectivities of up to 99,%,ee were obtained after ligand screening and optimization of the reaction conditions. The scope and limitation of the catalysts were shown in the synthesis of optically active tetrahydro-,-carbolines and other benchmark N -acyl-1-aryl ethylamines. Im Rahmen dieser Arbeit wird die Rhodium-katalysierte asymmetrische Hydrierung von Enamiden vorgestellt, wobei ein besonderes Augenmerk auf der Synthese von Vorstufen für Indolalkaloide (1,2,3,4-Tetrahydro-,-carboline) lag. Nach Untersuchung verschiedenster Ligandensysteme und Optimierung der Reaktionsbedingungen konnten Enantioselektivitäten von bis zu 99,%,ee erzielt werden. Dabei erwiesen sich Phospholan-basierte Diphosphane als besonders geeignet zum Chiralitätstransfer. Die hervorragenden Eigenschaften dieser Ligandklasse konnte weiterhin in der asymmetrischen Hydrierung verschiedenster Enamide erfolgreich gezeigt werden. [source]