Ce manuscrit décrit la synthèse et les caractérisations physico-chimiques de nouveaux systèmes hétérocycliques π-conjugués contenant un atome de phosphore. Le chapitre d'introduction présente les différentes voies de synthèse du cycle phospholes pouvant être incorporé dans des systèmes π-conjugués. Le chapitre I décrit la synthèse et les propriétés physico-chimiques de dérivés du pyrène contenant soit un phosphole, soit un silole. La synthèse de ces nouvelles structures a été réalisée à l'aide de réactions métallo-catalysées. Deux types de régioisomères ont ainsi été synthétisés afin de déterminer l'impact de la nature de l'hétéroatome (P ou Si) sur leurs propriétés optiques et électrochimiques et sur l'organisation des molécules à l'état solide. Le chapitre II décrit la synthèse et les propriétés physico-chimiques de nouveaux complexes d'Ir(III) ortho-métallés contenant un ligand phosphole. La présence de deux centres stéréogènes induit la formation de diastéréoisomères, dont la formation peut être contrôlée par les conditions réactionnelles. De plus, les propriétés électroniques du ligand phosphole permettent de moduler à façon les propriétés redox et optiques du complexe. Le chapitre III se focalise sur l'utilisation de la phosphépine comme sous-unité pour la construction de nouveaux systèmes π-conjugués. Deux systèmes π-conjugués ont été synthétisés : un squelette de PAH contenant la phosphépine et les dithieno-phosphépines. Les propriétés optiques et redox de ces dérivés ont été étudiées et discutées dans le manuscrit. / This manuscript describes the synthesis and characterisation of new heterocyclic π-conjugated systems built around the phosphorus atom. Firstly, an introduction to the phosphole chemistry (synthesis methods and integration into π-conjugated systems) is presented. The chapter I describes the synthesis and physico-chemical properties of pyrene functionalised either by a phosphole or silole ring. The synthesis of these new structures was achieved by using a transition-metal catalysis. Two types of regioisomers were synthesised in order to study the effect of the heteroatom (P or Si) on the optical and electrochemical properties together with the impact on the solid-state organisation. The chapter II describes the synthesis and the physical properties of the first phosphole-based Ir(III) ortho-metallated complexes. The presence of two stereogenic centres in the complex induced diastereoselectivity issues that could be solved by carefully choosing the reaction conditions. Furthermore, it was demonstrated that the nature of the ligands can tune the optical and the redox properties. The chapter III describes the use of P-containing seven-membered rings (phosphepines) for the development of new π-conjugated systems. Two original π-systems have been synthesised and studied: (i) phosphepine based PAH and (ii) dithieno-phosphepines. The optical and redox properties have been investigated and discussed in the manuscript.

The topic of this thesis is the design and synthesis of biaryl-based self adaptableligands for asymmetric metal catalysis. The results discussed in papers I-III are covered, together with some unpublished results concerning substrate-adaptable catalysts. A general survey of self-adaptable catalysts is presented first. The second chapter of this thesis starts with a survey of inversion barriers in biphenyl-based ligands and catalysts. Thereafter, the determination of barriers to conformational adaptation in dibenzoazepines and dibenzophosphepines is described. Palladium complexes with a diphosphine ligand or a diamine ligand, as well as the free diamine ligand, were studied. Entropies and enthalpies of activation were determined with variable temperature NMR spectroscopy. The mechanism of conformational change in the metal complexes was elucidated. The third chapter describes the synthesis of semiflexible and rigid phosphinite ligands, as well as their application in rhodium-catalysed asymmetric hydrogenation. Modest enantioselectivities (up to 63% ee) were obtained. The semiflexible ligand was found to behave like the most active rigid diastereomer. The fourth chapter describes the behaviour of amine and phosphoramidite ligands in model complexes relevant to the palladium-catalysed asymmetricallylic alkylation of benchmark substrates. Diphosphoramidite and aminephosphoramiditeligands were designed and synthesised. Pd(olefin) complexesof diamine and diphosphoramidite ligands were studied, and their symmetry determined. It was found that both types of ligands are able to adapt their conformation to the substrate. / QC20100630

This thesis deals with the design and synthesis of ligands for asymmetric catalysis: palladium catalyzed allylic alkylations, and rho-dium and iridium catalyzed hydrogenations of olefins. Chirally flexible phosphepine ligands based on biphenyl were synthesized and their properties were studied. The rotation barrier for configurationally flexible phosphepines was determined by NMR spectroscopy. The ratio of the atropisomers was shown to depend on the group bound to phosphorus. Only complexes with two homochiral ligands bound to the metal center were observed upon complexation with Rh(I). It was shown that one diastereomer of the flexible ligand exhibits higher activity but lower selectivity than its diastereomer in the rhodium catalyzed hydrogenation of methyl alfa-acetamidocinnamate. These ligands were also tested in nickel catalyzed silabora-tions. Chiral P,N-ligands with pseudo-C2 and pseudo-CS symmetry based on pyrrolidines-phospholanes or azepines-phosphepines were synthesized and studied in palladium catalyzed allylic alkylations. Semi-flexible azepine-phosphepine based ligands were prepared and their ability to adopt pseudo-C2 or pseudo-CS symmetry depending on the substrate in allylic alkylations was studied. It was shown on model allyl systems with flexible N,N-ligands that the ligand prefers CS-symmetry in compexes with anti-anti as well as syn-syn allyl moieties, but that for the latter type of complexes, according to computations, the configuration of the ligand is R*,R* in the olefin complexes formed after addition of a nucleophile to the allylic group. A preliminary investigation of the possibilities to use a su-pramolecular approach for the preparation of P,N-ligands with pseudo-C2 and pseudo-S symmetry was made. An N,N-ligand with C2 symmetry was prepared and its activity in palladium catalyzed ally-lic alkylation was studied. Pyridine-based P,N-ligands were tested in iridium catalyzed hy-drogenations of unfunctionalized olefins with good activities and se-lectivities. In order to attempt to improve the selectivity, ligands with a chirally flexible phosphepine fragment were prepared and applied in catalysis with promising results. / QC 20100929