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Ligand Library (ligand + library)

Distribution by Scientific Domains

Chemistry	85%

Selected Abstracts

Pyranoside Phosphite-Oxazoline Ligand Library: Highly Efficient Modular P,N Ligands for Palladium-Catalyzed Allylic Substitution Reactions.

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2009
A Study of the Key Palladium Allyl Intermediates
Abstract We have screened a library of modular phosphite-oxazoline ligands for asymmetric allylic substitution reactions. The library is efficiently prepared from the commercially available and cheap D -glucosamine. The introduction of a phosphite moiety into the ligand design is highly advantageous for the product outcome. Therefore, this ligand library affords good-to-excellent reaction rates [TOFs up to 600 mol substrate×(mol Pd×h),1] and enantioselectivities (ees up to 99%) and, at the same time, shows a broad scope for mono-, di- and trisubstituted linear hindered and unhindered substrates and cyclic substrates. The NMR studies on the palladium allyl intermediates provide a deeper understanding about the effect of the ligand parameters on the origin of enantioselectivity. [source]

Modular Furanoside Phosphite-Phosphoroamidites, a Readily Available Ligand Library for Asymmetric Palladium-Catalyzed Allylic Substitution Reactions.

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2009
Origin of Enantioselectivity
Abstract A library of furanoside phosphite-phosphoroamidite ligands has been synthesized and screened in the palladium-catalyzed allylic substitution reactions of several substrate types. These series of ligands can be prepared efficiently from easily accessible D -xylose and D -glucose. Their modular nature enables the position of the phosphoroamidite group, configuration of C-3 of the furanoside backbone and the substituents/configurations in the biaryl phosphite/phosphoroamidite moieties to be easily and systematically varied. By carefully selecting the ligand components, therefore, high regio- and enantioselectivities (ees up to 98%) and good activities have been achieved in a broad range of mono- and disubstituted hindered and unhindered linear and cyclic substrates. The NMR studies on the palladium-,-allyl intermediates provide a deeper understanding about the effect of the ligand parameters on the origin of enantioselectivity. They also indicate that the nucleophilic attack takes place predominantly at the allylic terminal carbon atom located trans to the phosphoroamidite moiety. [source]

ChemInform Abstract: Screening of a Modular Sugar-Based Phosphoroamidite Ligand Library in the Asymmetric Nickel-Catalyzed Trialkylaluminium Addition to Aldehydes.

CHEMINFORM, Issue 51 2009
Eva Raluy
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 of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Identification of Suitable Ligands for a Transition Metal Catalyzed Reaction: Screening of a Modular Ligand Library in the Enantioselective Hydroboration of Styrene.

CHEMINFORM, Issue 5 2003
Florian Blume
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Screening of a Modular Sugar-Based Phosphite,Oxazoline Ligand Library in Asymmetric Pd-Catalyzed Heck Reactions

CHEMISTRY - A EUROPEAN JOURNAL, Issue 12 2007
Yvette Mata
Abstract We have synthesised a library of phosphite,oxazoline ligands derived from readily available D -glucosamine. These ligands have been successfully screened in the palladium-catalysed Heck reaction of several substrates with high regio- (up to 99,%) and enantioselectivities (ee's up to 99,%) as well as with improved activities under standard thermal conditions. The results indicate that the catalytic performance is highly affected by the oxazoline and biarylphosphite substituents and the axial chirality of the biaryl moiety of the ligand. The Heck reactions were also performed under microwave irradiation conditions, allowing a considerably shorter reaction time (full conversion in minutes) maintaining the excellent regio- and enantioselectivities. [source]

Cover Picture: Electrophoresis 16'2010

ELECTROPHORESIS, Issue 16 2010
Article first published online: 19 AUG 2010
Issue no. 16 is a regular issue with an Emphasis on "Proteins and Proteomics" comprising 20 manuscripts distributed over 4 separate parts. Part I has 7 research articles on various aspects of proteins and proteomics including combinatorial peptide ligand library for accessing low abundance proteins, analysis of membrane proteins, proteomic profiling of human colon cancer cells, quantitative determinations of biomarkers in clinical diagnostics, recombinant factor VIII, analysis of E. coli soluble proteins, and a weakly basic amino-reactive fluorescent label for IEF of proteins and chip electrophoresis. Part II has 2 research articles dealing with the CE analysis of magnetic nanoparticles and a microfluidic magnetic bead impact for cell stimulation. Part III consists of 2 research articles dealing with on-line preconcentration in CE. Instrumentation, devices and various methodologies are described in 9 research articles, which make the content of Part IV. Featured articles include: Combinatorial peptide ligand library plasma treatment: Advantages for accessing low-abundance proteins ((doi: 10.1002/elps.201000188)) Precautions to improve the accuracy of quantitative determinations of biomarkers in clinical diagnostics ((doi: 10.1002/elps.201000243)) Rapid identification of Candida albicans in blood by combined capillary electrophoresis and fluorescence in situ hybridization ((doi: 10.1002/elps.201000138)) [source]