Search results for "Catalyse"
showing 10 items of 43 documents
Propriétés et performances de phosphines ferrocéniques dans le couplage C-O, C-S et C-N : nouvelles méthodologies de synthèse au palladium
2012
Multidentate ligands usually show great activities in low loading organometallic catalysis in palladium. Among these ligands, the use of ferrocenyl polyphosphane ligands give interesting results. Robust palladium-ferrocenyl triphosphane catalytic systems have permitted to obtain biarylamines and aryl-heteroaryl ethers in the presence of low catalytic loadings. DFT studies on catalytic cycle during formation of aryl-heteroaryl ethers were carried out. The presence of third phosphino group stabilizes a transition state which enhances the rate of the reductive elimination. Triarylamines were obtained with ferrocenyl diphosphane in the presence of 2 mol% of palladium loading. Moderate to excell…
Phosphine-diène and Salicylamidines ligands : coordination chemistry, catalysis and therapy
2017
The subject of this thesis concerns the development of new ligands, their coordination chemistry, and the synthesis of the corresponding metal complexes for catalysis and therapy.The first part of this work relates to the synthesis of diene-phosphine ligands, their saturated analogs, and the corresponding arene-ruthenium complexes. Arene decoordination allows the formation of a cationic bimetallic complex where the ligand is diène-η4/κ-P coordinated to the ruthenium. These complexes have been applied to atom transfer radical addition (ATRA) of CCl4 to styrene. When harsh reaction conditions are used, the superiority of the “diene” complexes is highlighted comparing to saturated analogs.The …
Porous thin films obtained by DLI-CVD as mu-PEMFC catalysts to replace platinum
2016
This work is focused on development of growth protocols by direct liquid injection chemical vapor deposition (DLI-CVD) of catalytic porous films which could be used in proton exchange membrane fuel cells (PEMFC). The aim of this work was to reduce or even proscribe platinum in catalysts having large specific surface area i.e. being very porous. Besides, the aim is also to use mainly low cost precursors.Cerium oxide, which is a material widely used as catalyst, has been chosen to partially substitute platinum. Porous CeO2 layers were obtained by the optimization of processing parameters such as deposition temperature or precursors flow rates. Controlled platinum doping of cerium oxide surfac…
Ligands P-stéréogéniques dérivés du calix[4]arène. Synthèses et applications en catalyse asymétrique
2010
We were interested in synthesis of P-stereogenic ligands derived from calix[4]arene and in their application in asymmetric catalysis. Mono et diphosphines were prepared on the upper rim of the macrocyle starting from the mono or dianion of the calix[4]arene and chlorophosphines borane or the oxazaphospholidine borane complex. The best selectivity was obtained by reaction of the dianion with the oxazaphospholidine borane complex leading to a bisaminophosphine borane. After acidolysis with HCl giving the corresponding bischlorophosphine and reaction with organolithium reagents, diphosphines diborane were obtained with good yields (40 à 60 %). X-ray structures of the prepared ligands confirmed…
Synthèse de ligands macrocycliques comportant des fragments aromatiques et leur application pour la détection des cations métalliques
2011
The PhD thesis deals with the synthesis of polyazaligands using Pd-catalyzed amination of aryl halides. The manuscript consists of two parts. In the first part the scope of the Pd-catalyzed amination reaction for the synthesis of polyazamacrocyclic ligands is studied. The Pd-catalyzed amination of 2,7-dibromonaphthalene, 3,3’-dibromobiphenyl and 6,6’-dibromo-2,2’-bipyridyl with linear polyamines and oxadiamines is thoroughly investigated, and corresponding nitrogen- and oxygen-containing macrocycles is synthesized in yields up to 45%. The dependence of the formation of macrocycles and cyclic oligomers on the nature of the starting compounds is established. Two alternative approaches to cycl…
PRIMO experiment: study-action on the dynamics of the creation of new enterprises and jobs in the Social and Solidarity Economy
2016
A research-action was carried out in 2015 and 2016 by the Regional Chamber of the Social and Solidarity Economy (CRESS) of Franche-Comté, accompanied by public partners, scientific and from the field of support, with the aim of better understand the dynamics of the creation of SSE enterprises in the regions, identified by the criterion of employment. The results of the survey component, obtained through the Catalyse® method (see http://www.acokima.org), make it possible to establish a typology of primary-employer structures. In particular, they show that the ability of a territory to "generate" new employers in the ESS is primarily linked to the existing voluntary sector and to the possibil…
Template-Assembled Synthetic G-Quartets (TASQ) hydrosolubles : du ligand de quadruplexes d'ADN et d'ARN à la plateforme catalytique
2013
Natural G-quartets, a cyclic and coplanar array of four guanine residues held together via Hoogsteen H-bond network, have recently received much attention due to their involvement in G-quadruplex-DNA, an alternative higher-order DNA structure strongly suspected to play important roles in key cellular events (chromosomal stability, regulation of gene expression). Besides this, synthetic G-quartets, which artificially mimic native G-quartets, have also been widely studied for their involvement in nanotechnological applications (i.e. nanowires, artificial ion channels, etc.). In contrast, intramolecular synthetic G-quartets, also named template-assembled synthetic G-quartet (TASQ), have been m…
Reactivity of arsenic compounds on trapping masses and role of the active phase
2019
The aim of the thesis is to study the reactivity of organic arsenic compounds on various recovery masses and to identify the role of the nature of the active phase and the reaction mechanisms involved. The active phase is composed of metals (Ni, Co, Mo, Cu, Zn, Fe, etc.), pure or in a mixture, in the reduced state or in the sulphide state. The selection of the metallic phases will be carried out by molecular modeling "ab initio", and the synthesis by impregnation of metallic salts on mesoporous aluminas). The reactivity of the solids will be studied in a static reactor on simplified model loads, with kinetic monitoring. The advanced characterization of the solids after synthesis and after r…
P-chirogenic secondary phosphine oxides : new synthesis and applications
2015
A new stereoselective synthesis of phosphinous acid boranes is described by hydrolysis of aminophosphines boranes prepared by reaction of the oxazaphospholidine complex derived from ephedrine with organolithium reagents.By reaction with a strong acid, the phosphinous acid boranes lead to the corresponding P-chirogenic secondary phosphine oxides in very good yields (90%) and with complete retention of the configuration at the phosphorus atom. The secondary phosphine oxides have been used in asymmetric hydrogenation and intramolecular Heck cyclisation using rhodium and palladium complexes, respectively. In a second part, a new synthesis of P-chirogenic ortho-halogenophenyl phosphine oxides is…
Superior Fischer-Tropsch performance of uniform cobalt nanoparticles deposited into mesoporous SiC
2020
Electrochemically-derived well-crystalline mesoporous silicon carbide (pSiC) was used as a host for cobalt nanoparticles to demonstrate superior catalytic performance during the CO hydrogenation according to Fischer-Tropsch. Colloidal Co nanoparticles (9 ± 0.4 nm) were prepared independently using colloidal recipes before incorporating them into pSiC and, for comparison purposes, into commercially available silica (Davisil) as well as foam-like MCF-17 supports. The Co/pSiC catalyst demonstrated the highest (per unit mass) catalytic activity of 117 µmol.g(CO)-1.g-1(Co).s-1 at 220 °C which was larger by about one order of magnitude as compared to both silica supported cobalt catalysts. Furthe…