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Syntheses of the Ligands

Pincer and Pincer-Type Complexes Applications in Organic Synthesis and Catalysis, First Edition. [Pg.213]


Most immobilization methods require modification of the ligands for anchoring to the support by introducing functional groups such as vinyl, trialkoxysilyl, sulfonic acid, and amino groups. The consequence is often a more elaborate synthesis of the ligand, which adds to the costs of an immobilized catalyst. However, two interesting approaches were developed in recent years, when unmodi-... [Pg.1427]

Ruthenium complexes of a novel silsesquioxane-based tridentate phosphine ligand have been prepared and characterized by Mitsudo et al The synthesis of the ligand 178 is depicted in Scheme 60. Reactions of 178 with several late transition metal complexes were examined. A typical example is the reaction with three equivalents of [RuCl2(cymene)]2, which produced the red triruthenium complex (c-C5H9)7Si709[0SiMe2CH2CH2PPh2RuCl2(cymene)]3 (179) in almost quantitative yield. [Pg.145]

Double lithiation of the xanthene derivative 146 is the key step in an important synthesis of the ligand xantphos 147 Benzofuran 148 is also doubly lithiated by excess BuLi/TMEDA (Scheme 72) . [Pg.536]

Unfortunately, the utility of this method for many of the more interesting enzymes is restricted by the complexity of the protein. If more than one type of cluster is present, the multiple component analysis on the extruded mixture may lead to ambiguous conclusions. In addition non-metallochromophores may interfere. Holm and co-workers (Wong et ai, 1979) circumvented some of these problems for Fe S proteins by their choice of spectral analysis and exogenous thiolate ligand. Namely, they used F NMR spectroscopy to analyze the products of thiolate extrusion with /)-trifluoromethylbenzenethiol. Contact shifts for the fluorine resonances are considerably different for 2Fe and 4Fe clusters. Important restrictions on the use of the F NMR detection are the quantity of protein needed, the synthesis of the ligand, and access to the spectrometer. [Pg.220]

Compounds of aza macrocycles are prepared by three main types of procedure (1) conventional organic synthesis of the ligand, (2) metal-ion-promoted reactions, involving condensation of non-cyclic components in the presence of a suitable metal ion, and (3) modification of a compound prepared by methods (1) or (2). [Pg.900]

The modified mix-and-splif combinatorial method is used for the synthesis of the ligand library yields n<->n members, where n represents the number of different amines chosen. Usually 5 g of each immobilized ligand are synthesized however, this amount depends on the screening strategy preferred (for example, the FITC-based system or the ELISA on beads require less resin than the conventional affinity chromatography). [Pg.59]

The synthesis of the ligand system is very elegant and involves 2,6-dihydroxy-nitrobenzol as the starting material. The reduction of the oxalic acid dianude to a substituted diamino... [Pg.106]

We will now turn our attention towards the synthesis and application of phosphane functionalised carbenes. A very interesting class of ligands is based on the ferrocene [265-267] scaffold. Cp functionahsed carbenes will be discussed in Section 4.3 and we will find our ferrocene functionalised carbenes there as well. However, the synthesis of the ligands involves a strategy to introduce the phosphane and carbene moieties onto the ferrocene scaffold in a way that optimises results despite the fact that both groups are best introduced last. [Pg.120]

The synthesis of the ligand system starts with the stepwise alkylation of imidazole using... [Pg.211]

Sun et al. introduced another functionality, an imino group, into the linker unit [68], The resulting phenoxyimino functionalised imidazolium salt is a potential tridentate ligand. Synthesis of the ligand starts with the corresponding salicylaldehyde and a... [Pg.214]

Sulfato(bipyridyl)platinum(II) is yellow, unlike (pyridine)2PtSO4 which is reported to be black (286). It is not possible to introduce A,A,A, A -tetramethylethylenediamine directly into a platinum(II) complex. An indirect route involving the in situ synthesis of the ligand is available bipyridyl is present in the molecule (725-727). Other mixed... [Pg.186]

In 1972 Bayer and Kneifel isolated (98) a pale blue compound from A. muscaria containing vanadium, which they named amavadine. They proposed (98,99) that it consisted of a complex of AT-hydroxyimino-a,a -dipropionic acid with in a 2 1 ratio. From a comparison of the EPR spectra of segments of frozen mushrooms with those of vanadyl complexes of various amino acids, it was concluded (100,101) that this proposal was not very likely. However, Krauss et al. (102) synthesized amavadine and compared its EPR properties with the complex extracted from the mushroom and concluded that it was the same. Others were unable to reproduce the synthesis (103), although models analogous to amavadine were reported. The synthesis of the ligand N-hydroxy-a,a -iminodipropionic acid, and related compounds was, however, later confirmed (104-106). The stereochemistry and total synthesis of the vanadium compound of A. muscaria has now been elucidated (107). [Pg.96]

A chiral C2-symmetric bridged ferrocene was constructed from a synthetic ligand containing two cyclopentadiene units (Fig. 4-12d). The key step in the synthesis of the ligand is a diastereoselective Diels — Alder reaction of anthracene with bis[(S)-l-ethoxycarbonylethyl]fumarate. When oxidized to the ferrocinium salt, the ferrocene derivative has Lewis acid properties and catalyzes Diels — Alder reactions with some enantioselectivity [85]. [Pg.187]

Syntheses are reported for 113 compounds along with resolution procedures for some metal complexes. Several organic ligands are included, but their inclusion is warranted, since they are of interest primarily for the preparation of metal complexes. In several cases metal ions play an important role in the template synthesis of the ligands. There are several chapters of nonmetals, including an interesting phosphorus ylide and some of its metal complexes. [Pg.243]

The synthesis, structures, and reactivity of the related silylene-linked cyclopentadienyl-phosphido lanthanide complexes has been studied. Scheme 37 illustrates the synthesis of the ligand precursors and the corresponding lanthanide(n) derivatives as well as reactions of the latter with 1,2-diiodoethane and benzophenone, which lead to binuclear lanthanide(m) species.196... [Pg.23]

In a similar manner, consecutive Negishi reactions were carried out in one pot between 14 and 2,6-dibromopyridine. The application of this reaction resulted in a shorter and more simple synthesis of the ligand 15 [16]. [Pg.411]


See other pages where Syntheses of the Ligands is mentioned: [Pg.229]    [Pg.189]    [Pg.98]    [Pg.267]    [Pg.386]    [Pg.995]    [Pg.458]    [Pg.12]    [Pg.190]    [Pg.48]    [Pg.123]    [Pg.98]    [Pg.121]    [Pg.43]    [Pg.662]    [Pg.177]    [Pg.125]    [Pg.11]    [Pg.14]    [Pg.15]    [Pg.292]    [Pg.247]    [Pg.11]    [Pg.14]    [Pg.15]    [Pg.412]    [Pg.175]    [Pg.415]    [Pg.46]    [Pg.217]    [Pg.93]    [Pg.62]    [Pg.215]   


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Ligand synthesis

Synthesis of the BINAP Ligand

Synthesis of the Diphosphane Ligands

The Ligands

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