Synthesis and palladium-catalysed isomerisation of fused polycyclic tetrahydrofurans : efficient and stereoselective one-pot domino construction of functionalised bridged bicyclo[n.2.1] ring systems

International audienceA new one-pot domino reaction for a general entry to functionalised bridged bicyclo[n.2.1] ring systems from α,α'-diactivated cyclic ketones and trans-1,4-dihalides is described. The sequence combines a base promoted C-O cycloalkylation reaction leading to fused polycyclic enol ethers and their in situ palladium-catalysed isomerisation

Basic Properties of Calcocambisol from a Location on North Dalmatian Plain

Calcocambisol is the most dominant soil type developed on Dinaric karst. It is formed by pedogenic processes acting on carbonate rocks, which include weathering, accumulation of insoluble residue, organic matter, and allogenic material and braunification. Further development of Calcocambisol includes leaching of clay from upper soil horizons and secondary accumulation in lower horizons. Calcocambisols are exclusively developed on carbonate rocks characterised by diverse relief forms resulting in variable soil depth over short distances and consequently different phases of soil development. Thus, the goal of this study was to analyse morphological, physical, and chemical properties of Calcocambisols in different stages of development from a location within the Krka National Park. Results of soil analysis showed similarities in morphological properties, soil field and air capacity, density and SOC content. On the other hand, differences in properties included different carbonate content and pH values of topsoil and difference in particle size distribution. These differences can be attributed to irregular rocky surface which plays important role in allogenic particles distribution and water percolation. Increased leaching of clay particles to deeper horizons results in diversification of Bt (argic) horizon, indicating more advanced stage of soil development towards Luvisol formation

Basic Properties of Calcocambisol from a Location on North Dalmatian Plain

Calcocambisol is the most dominant soil type developed on Dinaric karst. It is formed by pedogenic processes acting on carbonate rocks, which include weathering, accumulation of insoluble residue, organic matter, and allogenic material and braunification. Further development of Calcocambisol includes leaching of clay from upper soil horizons and secondary accumulation in lower horizons. Calcocambisols are exclusively developed on carbonate rocks characterised by diverse relief forms resulting in variable soil depth over short distances and consequently different phases of soil development. Thus, the goal of this study was to analyse morphological, physical, and chemical properties of Calcocambisols in different stages of development from a location within the Krka National Park. Results of soil analysis showed similarities in morphological properties, soil field and air capacity, density and SOC content. On the other hand, differences in properties included different carbonate content and pH values of topsoil and difference in particle size distribution. These differences can be attributed to irregular rocky surface which plays important role in allogenic particles distribution and water percolation. Increased leaching of clay particles to deeper horizons results in diversification of Bt (argic) horizon, indicating more advanced stage of soil development towards Luvisol formation

DMTs and Covid-19 severity in MS: a pooled analysis from Italy and France

We evaluated the effect of DMTs on Covid-19 severity in patients with MS, with a pooled-analysis of two large cohorts from Italy and France. The association of baseline characteristics and DMTs with Covid-19 severity was assessed by multivariate ordinal-logistic models and pooled by a fixed-effect meta-analysis. 1066 patients with MS from Italy and 721 from France were included. In the multivariate model, anti-CD20 therapies were significantly associated (OR = 2.05, 95%CI = 1.39–3.02, p < 0.001) with Covid-19 severity, whereas interferon indicated a decreased risk (OR = 0.42, 95%CI = 0.18–0.99, p = 0.047). This pooled-analysis confirms an increased risk of severe Covid-19 in patients on anti-CD20 therapies and supports the protective role of interferon

Etude de la cascade MARDi. Application en série hétéroatomique et stéréosélectivité

Notre équipe a développé une séquence domino originale appelée cascade MARDi (addition de Michael, Aldolisation, Rétro-Dieckmann) conduisant sélectivement à des cycloheptanes ou cycloheptènes polyfonctionnalisés par extension de cycle à deux atomes de carbone de dérivés 1,3-dicarbonylés. Dans ce contexte, nous avons tout d'abord étudié l'utilisation en quantité catalytique de bases de type phosphazène dans l'addition de Michael en vue d'appliquer une version asymétrique à la cascade MARDi. Cette étude a permis de mettre en évidence l'effet synergique de H2O sur la vitesse de la réaction entre les b-cétoesters et divers accepteurs. Nous avons ensuite exploré la faisabilité de la cascade MARDi pour la synthèse de cycloheptanes hétérocycliques soulignant l'influence de la position et de l'électronégativité de l'hétéroatome. Dans cette séquence, nous nous sommes par ailleurs intéressés à la réactivité de cétones thiofonctionnalisées, au mécanisme inhérent aux aldéhydes méthacryliques et à l'étude de la diastéréosélectivité.AIX-MARSEILLE3-BU Sc.St Jérô (130552102) / SudocSudocFranceF

Synthetic Studies on the MARDi Cascade: Stereoselective Preparation of Sulfonyl-Substituted Seven-Membered Rings

International audienc

Synthetic Studies on the MARDi Cascade: Stereoselective Synthesis of Heterocyclic Seven-Membered Rings

International audienc

The MARDi cascade : A Michael-Initiated Domino-Multicomponent Approach for the Stereoselective Synthesis of Seven-Membered Rings

International audienceThe MARDi cascade is a recently invented three-component condensation involving 1,3-dicarbonyl derivatives. It allows the regio- and stereocontrolled access to a variety of functionalized and substituted seven-membered rings. The substitution array can be diastereoselectively modulated by appropriate choice of the reaction partners, and the reaction allows the control of up to five newly created stereocenters and a complete chiral induction in the case of an optically active ketone precursor. The high level of diastereoselectivity observed has been attributed to a total thermodynamical control of the reaction. The attractiveness of the present domino three-component approach to seven-membered rings resides in the diversity of carbo- and heterocyclic structures that can be accessed with total regiocontrol and high stereocontrol starting from simple substrates, under user and environmentally friendly conditions, as now required in modern organic chemistry

Le pouvoir, sa folie et sa théâtralisation : En lien avec le spectacle Richard III de William Shakespeare, mise en scène de David Gauchard

Le Théâtre de la Renaissance d'Oullins organise depuis deux ans un cycle de débats de société, « Consonances », en partenariat avec le musée des Confluences. Ils reposent sur des thématiques traitées dans certaines de leurs productions ou coproductions. Ces rencontres répondent aussi à la vocation ancestrale du théâtre. Depuis Socrate, le théâtre est pensé comme un lieu d'expression et de confrontation d'idées centrées sur des thématiques contemporaines. Nous donnons ici la retranscription de la rencontre du 4 février 2010