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International audience; The synthesis of the highly functionalized tetracyclic skeleton of landomycinone (2), the aglycon of landomycins, was performed using two pivotal steps relying on metal-catalyzed reactions. They are (1) a [2 + 2 + 2] cycloaddition of alkynes promoted by Wilkinson's catalyst to build rings B and C concomitantly and (2) a ring-closing metathesis followed by aromatization to build ring D.

Original and ambivalent: We describe the preparation of a series of new potassium trifluoroborates 1, and the study of their behaviour in a Pd0-catalyzed cross-coupling reaction. We found that compounds 1 are endowed with original properties as they behave as nucleophilic cross-coupling partners chemoselectively, but also as ambivalent synthons. The usefulness of this methodology has been successfully illustrated by the first total synthesis of an N-acyl spermidine. We describe the preparation of a series of new potassium trifluoroborates 1 and the study of their behaviour in a Pd0-catalyzed cross-coupling reaction. We found that compounds 1 are endowed with original properties as they behave as nucleophilic cross-coupling partners chemoselectively but also as ambivalent synthons. The usefulness of this methodology has been successfully illustrated by the first total synthesis of an N-acyl spermidine.

Original and ambivalent: We describe the preparation of a series of new potassium trifluoroborates 1, and the study of their behaviour in a Pd0-catalyzed cross-coupling reaction. We found that compounds 1 are endowed with original properties as they behave as nucleophilic cross-coupling partners chemoselectively, but also as ambivalent synthons. The usefulness of this methodology has been successfully illustrated by the first total synthesis of an N-acyl spermidine. We describe the preparation of a series of new potassium trifluoroborates 1 and the study of their behaviour in a Pd0-catalyzed cross-coupling reaction. We found that compounds 1 are endowed with original properties as they behave as nucleophilic cross-coupling partners chemoselectively but also as ambivalent synthons. The usefulness of this methodology has been successfully illustrated by the first total synthesis of an N-acyl spermidine.

International audience; This review aims to highlight the most significant recent developments on synthetic strategies involving consecutive, domino and multicomponent reactions featuring a Michael addition-initiating step for the synthesis of polycyclic heterocycles from 1,3-dicarbonyls. These original sequences constitute more efficient and eco-compatible alternatives to known synthetic approaches to heterocyclic compounds allowing for an even faster and highly desirable generation of molecular diversity and complexity.

In this study, we focus on the Azaphosphatranes derivatives: studies on their halogen-bond donor properties, their behaviors as confined Frustrated Lewis/Bronsted Pairs and their chiral recognition properties. Firstly, we synthesized the chloroazaphosphatranes with various substituent groups, and discussed their binding constants. Then we synthesized two hemicryptophanes which contain rigid cavities, we discussed the inherent chirality and the reactivity outcome. Last, we synthesized two other hemicryptophanes to discuss their recognition properties toward neurotransmitters, and also we focus on the thermodynamic and kinetic studies, we finally calculated the value of pKa, and the rate constants. Besides, we discussed a true FLP system in the presence of TiCl4., Dans cette étude, nous nous concentrons sur les dérivés d'Azaphosphatranes : études sur leurs propriétés de donneurs de liaisons halogènes, leurs comportements en tant que paires de Lewis/Bronsted frustrées confinées et leurs propriétés de reconnaissance chirale. Tout d'abord, nous avons synthétisé les chloroazaphosphatranes avec différents groupes substituants, et discuté de leurs constantes de liaison. Ensuite, nous avons synthétisé deux hémicryptophanes qui contiennent des cavités rigides, nous avons discuté de la chiralité inhérente et des résultats de la réactivité. Enfin, nous avons synthétisé deux autres hémicryptophanes pour discuter de leurs propriétés de reconnaissance envers les neurotransmetteurs, et nous nous sommes également concentrés sur les études thermodynamiques et cinétiques, nous avons finalement calculé la valeur du pKa, et les constantes de vitesse. En outre, nous avons discuté d'un véritable système FLP en présence de TiCl4.

This thesis focuses on the development of enantioselective multicomponent reactions with 1,3-Dicarbonyls in the presence of an organocatalyst, to synthesize fused polyheterocyclic motives.At first, we describe our initial results on an enantioselective multicomponent reaction with enals and simple primary amines. In view of the low enantioselectivities achieved, functionalized amines were then introduced in these reactions, thereby synthesizing enantioenriched pyrrolopiperazines and other polyfunctionalized heterocyclic molecules, all obtained with attractive yields and high enantioselectivities.Having successfully used methylene β-Ketoamides in these enantioselective MCRs, we realized also that their simple Michael addition to electron-Poor olefins had never been described in organocatalytic conditions. We therefore studied their reaction with nitroolefins in the presence of various chiral organocatalysts, and the expected products were pleasingly obtained with high yields, excellent diastereo- and enantioselectivities.; Ce mémoire de thèse se concentre sur le développement de réactions multicomposants énantiosélectives de dérivés 1,3-Dicarbonylés en présence d'un organocatalyseur, en vue de préparer des motifs polyhétérocycliques fusionnés.Dans un premier temps, nous décrivons nos résultats initiaux sur une réaction multicomposants énantiosélective avec des énals et des amines primaires simples. Au vu des faibles énantiosélectivités obtenues, des amines fonctionnalisées ont ensuite été introduites dans ces réactions, permettant ainsi de synthétiser des pyrrolopiperazines et d'autres molécules hétérocycliques polyfonctionnalisées énantioenrichies, toutes obtenues avec des rendements intéressants et des énantiosélectivités élevées.Ayant utilisé avec succès des β-Cétoamides α-Méthyléniques dans ces réactions multicomposantes, nous avons réalisé par ailleurs que leur simple addition de Michael sur des oléfines pauvres en électrons n'avait jamais été décrite en version organocatalysée. Nous avons donc étudié leur réaction avec des nitrooléfines en présence d’organocatalyseurs chiraux, et les produits attendus ont alors été obtenus avec de bons rendements et d'excellentes diastéréo- et énantiosélectivités.