Ligand assembly

Figure 11. Potent tyrosine kinase inhibitors discovered through Combinatorial Target-Guided Ligand Assembly.

D. J. Maly, I. C. Choong, J. A. Ellman, Combinatorial Target-Guided Ligand Assembly. Identification of Potent, Sub-type Selective c-Src Inhibitors , Proc. Natl. Acad. Sci, USA, 2000, 97, 2419-2424. 

Maly, D.J., Choong, I.C., Ellman, J.A. Combinatorial target-guided ligand assembly identification of potent subtype-selective c-Src inhibitors. 

Whitney, A. M. Ladame, S. Balasubramanian, S. Templated ligand assembly by using G-quadruplex DNA and dynamic covalent chemistry. Angew. Chem. Int. Ed. 2004,43, 1143-1146. 

Ramstrom, O. Lehn, J.-M. Dynamic ligand assembly. In Comprehensive medicinal chemistry II (Volume 3), Taylor, J.B. Triggle, D.J. editors. Elsevier Ltd., Oxford, UK, pp. 959-976, 2006. 

Figure 5.17 Structure of the ligand, linker precursor and immobilized ligand assembl)r for silica supports and subsequent functionalization with [Rh(COD)2]Bp4. (Redrawn from Pugin and Blaser [49].)...

The role of multicomponent ligand assembly into a highly enantioselective catalyst is shown in the enantioselective catalysis for the carbonyl-ene reaction (Table 8.9). The catalyst is prepared from an achiral precatalyst, Ti(0 Pr)4 and a combination of BINOL with various chiral diols such as TADDOL and 5-Cl-BIPOL in a molar ratio of 1 1 1 (10mol% with respect to the olefin and glyoxylate) in... 

Analysis of the activation parameters for the different encapsulated substrates reveals that the source of catalysis is more complex than simply a reduction of the entropy of activation, since different effects are observed for substrates 26,27,30. While the rate acceleration for the encapsulated 26 was exclusively due to lowering the entropic barrier, for 27 and 30 a decrease in the enthalpic barrier for rearrangement is observed in addition. It is possible that, for 27 and 30 binding into the narrow confines of the metal-ligand assembly induces some strain on the bound molecules, thereby raising their ground-state energies compared to those of the unbound... 

Fiedler, D., Leung, D.H., Bergman, R.G. and Raymond, K.N. (2004) Enantioselective guest binding and dynamic resolution of cationic ruthenium complexes by a chiral metal-ligand assembly. J. Am. Chem. Soc., 126 (12), 3674-3675. 

Assemblies based on 8 and pyridine phosphorus ligands 5-7 were used as supramolecular ligands in the rhodium-catalyzed hydroformylation and showed typical bidentate behavior. The chelating bidentate assembly exhibited lower activities (a factor of three) than the monodentate analogue. Only a slightly higher selectivity for the linear aldehyde was observed. The chiral ligand assemblies based... 

The chelating behavior was also evident from H P-NM R experiments. The addition of triphenylphosphine (a) to a catalyst solution of [HRh(CO)2(13 b)] did not affect the complex. Moreover, the addition of 1 equiv. of b to a solution of HRh(CO)2(13) PPhj resulted in the exclusive formation of [HRh(CO)2(13 b)] upon release of free triphenylphosphine. The chelating effect of the supramolecular ligand assembly effectively competes with triphenylphosphine, leading to exclusive formation of the rhodium complex of 13 b. In the complex [HRh(CO)2(13 b) the supramolecular ligand 13 b coordinates in an equatorial-equatorial fashion to the rhodium metal center, whereas the HRh(CO)2(13)PPh3 exists in a mixture of complexes (ee and ea). 

Ligand assembly in the metal coordination sphere is also implied by the unusual stoichiometries of extraction shown when hydrophobic carboxylic acids are used in hydrocarbon diluents. [1, 9]... 

III. LUMINESCENT POLYMERIC SYSTEMS CONTAINING AN ISOCYANIDE LIGAND ASSEMBLED VIA M M INTERACTIONS... 

Another class of chiral tetranuclear complexes are tetrahedral metal-ligand assembled clusters of M4L6 stoichiometry for Ga(III), A1(III), and Fe(III) with A,/V -bis(2,3-dihydroxybenzoyl)-1,5-diamino-naphthalene. This ligand acts as a... 

Fig. 10 Phosphine ligands assembled to the periphery of a urea adamantyl-functionalized poly(propylene imine) dendrimer 33...

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