Search results for "azamacrocycles"
showing 8 items of 8 documents
Synthesis of 1,3-bis(trimethylcyclam) and 1,3-bis(trimethylcyclen) substituted benzenes
2009
Pd-catalyzed amination of 1,3-dibromobenzene with N,N',N''-trimethylcyclam and N,N',N''-trimethylcyclen provided corresponding 1,3-bis(tetraazamacrocyclic) derivatives of benzene in 25-32% yields. The dependence of the products yields on the phosphine ligand applied (BINAP, DavePHOS) as well as on the stoichiometry of starting compounds was established. Scope and limitations for the synthesis of N-phenyl and N-(3-bromophenyl) derivatives of trimethylcyclam and trimethylcyclen were demonstrated.
Exceptional affinity of nanostructured organic-inorganic hybrid materials towards dioxygen: confinement effect of copper complexes
2007
We report the exceptional reactivity towards dioxygen of a nanostructured organic-inorganic hybrid material due to the confinement of copper cyclam within a silica matrix. The key step is the metalation reaction of the ligand, which can occur before or after xerogel formation through the sol-gel process. The incorporation of a Cu(II) center into the material after xerogel formation leads to a bridged Cu(I)/Cu(II) mixed-valence dinuclear species. This complex exhibits a very high affinity towards dioxygen, attributable to auto-organization of the active species in the solid. The remarkable properties of these copper complexes in the silica matrix demonstrate a high cooperative effect for O(2…
Construction of green nanostructured heterogeneous catalysts via non-covalent surface decoration of multi-walled carbon nanotubes with Pd(II) complex…
2017
Abstract Green nanostructured heterogeneous catalysts were prepared via a bottom-up strategy. Designed ligands were synthesized joining covalently an electrondeficient pyrimidine residue and a scorpiand azamacrocycle. The desired molecular properties were easily transferred to nanostructured materials in two steps: first, exploiting their spontaneous chemisorption onto multi-walled carbon nanotubes (MWCNTs) via the pyrimidinic moiety in water at room temperature, then, taking advantage of the easy coordination of Pd(II) to the azamacrocycle in the same conditions. An evenly distribution of catalytic centres was obtained on the MWCNTs surface. Catalytic properties of these materials were ass…
Porphyrines et tétraazamacrocycles dérivés du DOTA : association de deux ligands pour la chélation de métaux d'intérêt en imagerie médicale multimoda…
2012
The goal of my PhD thesis was to synthesize new molecules, which give access to heterobimetallic complexes with interesting properties for multimodal imaging. In this manuscript, several main points have been studied. The first part of this work concerns the synthesis and characterization of ligands. We describe here the synthesis of five new ligands based on the association of one porphyrin and one or several cyclen derivatives. Those ligands are water-soluble. During the synthesis, we have targeted improvements to our work and developed a new synthetic pathway, which allowed us to obtain one ligand incorporating a porphyrin, a cyclen derivative and a free amine function. This function cou…
A New Heterogeneous Catalyst Obtained via Supramolecular Decoration of Graphene with a Pd2+ Azamacrocyclic Complex
2019
A new G-(H2L)-Pd heterogeneous catalyst has been prepared via a self-assembly process consisting in the spontaneous adsorption, in water at room temperature, of a macrocyclic H2L ligand on graphene (G) (G + H2L = G-(H2L)), followed by decoration of the macrocycle with Pd2+ ions (G-(H2L) + Pd2+ = G-(H2L)-Pd) under the same mild conditions. This supramolecular approach is a sustainable (green) procedure that preserves the special characteristics of graphene and furnishes an efficient catalyst for the Cu-free Sonogashira cross coupling reaction between iodobenzene and phenylacetylene. Indeed, G-(H2L)-Pd shows an excellent conversion (90%) of reactants into diphenylacetylene under mild conditio…
Synthèse de nouveaux agents bimodaux hydrosolubles pour l'IRM, l'imagerie nucléaire, l'imagerie biphotonique et la génération de second harmonique
2015
The goal of my PhD studies was to synthesize new compounds for possible medical imaging applications. The first part of my thesis focused on the synthesis of heteroleptic ligands to achieve the chelation of two different metals aimed at addressing two types of medical imaging. We first synthesized porphyrins, which are well-known for the chelation of numerous transition metals. We focused on copper, whose copper-64 isotope is a β+ emitter usable in Positron Emission Tomography (PET). These porphyrins have been coupled with a DOTA derivative. This molecule, metallated with gadolinium, is well-known in Magnetic Resonance Imaging (MRI). Our compounds display encouraging relaxivities for MRI ap…
Synthèse et étude physico-chimique de ligands macrocycliques, macrobicycliques et macrotricycliques dérivés du 5,12-dioxocyclame
2002
The synthesis and the physico-chemical studies of macropolycyclic ligands based on 5,12-dioxocyclam L1 are presented. The first part of this dissertation presents the structural and physico-chemical properties of L1 and its N-substituted derivatives L2 and L3. A potentiometric study reveald a cooperative protonation of the two macrocyclic ligands L1 and L2 whereas the study of the macrotricycle L3 in a methanol-water mixture revealed a sequential cooperative diprotonation of the four tertiary amines. The square planar nickel and copper complexes were synthesized and characterized using infrared, UV-vis and ESR spectgroscopy. The spectroscopic studies showed the presence of intermolecular hy…
The Scope of Application of Macrocyclic Polyamines Beyond Metal Chelation
2019
International audience; Recent advances in the use of radiometals for both imaging and therapy has spurred on the development of an original chemistry that endows radionuclide-chelating molecular cages with ever sharper physicochemical properties. Macrocyclic polyamines (MPAs) such as cyclen and DOTA are among the most frequently encountered cages for the design of new radiotracers, owing to their versatile chemistry that makes them customizable molecular tools. The idea of using MPAs for alternative purposes has recently emerged, with an eye towards benefiting from their unique topology, versatility, symmetry and water-solubility. This review summarizes strategies that have been recently i…