Transition metal catalysis as methods for the elaboration of phosphorus heterocycles

International audienceA review. Among the heterocyclic compds., phosphorus heterocycles are still scarcely studied although they seem to hold promises in term of biol. potential. The last few years were the witness of remarkable developments and strategies for their synthesis. In this context, organometallic chem., using coupling reactions, C-C insertion or ring closing metathesis appears to be valuable and general approaches to achieve the formation of phosphorus heterocycles

Calcul économique. Prix fictifs et contrainte extérieure

Cost-benefit analysis. Shadow prices and foreign trade constraint Claude Fourgeaud, Bernard Lenclud, Pierre Picard When foreign-trade constraint implies market disequilibrium the classical methods of cost benefit analysis do not apply. To solve this problem, we introduce an optimisation model which measures the social value of domestic good and labor using shadow prices. Conditions under which a change in the exchange rate increases social well-being are also investigated. Finally, we obtain a generalization of the concept of discounted surplus within the framework of an investment decision model.L'article analyse les modifications aux règles habituelles du calcul économique en présence de déséquilibre dû à l'existence d'une contrainte extérieure. Les propriétés du modèle font apparaître des prix fictifs définissant les valeurs sociales des biens et du travail. On examine également les circonstances dans lesquelles une modification du taux de change s'avère favorable. Enfin l'analyse est complétée par l'étude d'un modèle avec choix d'investissement qui conduit à une généralisation du bilan actualisé.Fourgeaud Claude, Lenclud Bernard, Picard Pierre. Calcul économique. Prix fictifs et contrainte extérieure. In: Revue économique, volume 35, n°3, 1984. pp. 425-446

Taux d'actualisation et prix de l'énergie

[fre] On présente un modèle permettant de mettre en évidence l'influence des prix de l'énergie sur le taux d'actualisation à long terme pour une économie soumise à une contrainte extérieure. Le modèle comporte un bien agrégé produit à l'aide de trois facteurs : main-d'œuvre, capital, énergie. On étudie l'évolution du modèle avec un taux d'épargne constant et le régime stationnaire associé. Si par unité produite la consommation en énergie est fonction croissante du capital, le renché­rissement des prix de l'énergie conduit à long terme à une réduction du taux d'actualisation. C'est l'inverse qui se produit dans le cas opposé. Le résultat est confirmé par l'étude d'un modèle d'optimisation. Les résultats théoriques sont illustrés par une étude économétrique sur données françaises. [eng] On the social rate of discount and the energy price . Claude Fourgeaud, Bernard Lenclud Et Pierre Michel. When a country imports the energy necessary for production, increases of energy prices certainly have consequences ont the value of social rate of discount in the long run. In order to study this problem, we consider a simple macroeconomic model with one single produced good and three factors : labor, capital and energy. The energy consumption simultaneously depends on the level of production and on the level of capital.. We first study the evolution of the economy and the corresponding steady state with a constant rate of saving. In the case where the energy input for one unit of production is an increasing function of the level of capital (or equivalently the elasticity of energy input per head with respect to production per head exceeds 1), the increase of energy prices leads in the long run to a reduction of the discount rate. We obtain the opposite result in the other case.. This result is conforted by the study of an optimal growth model with an inter­temporal utility function depending on consumption per head. The study concerns the linearization of the optimal growth path near the steady state. Finally we make an econometric estimation on French data.

Synthèse et réactivité de nouvelles familles d'hétérocycles phosphorés

Les molécules phosphorées, à la fois par leur présence dans les grands mécanismes biologiques et leurs grande diversité chimique, font l objet de recherches attentives notamment à cause de leurs activités biologiques potentielles. Ces recherches ont notamment abouti à la mise sur le marché de molécules phosphorées à visées médicinales ou phytosanitaires. Dans ce contexte, nous avons choisi de synthétiser différentes familles d hétérocycles phosphoré avec un atome de phosphore intracyclique. Tout d abord nous avons utilisé une réaction de métathèse cyclisante puis pour contourner certaines limitations dues à cette méthode, nous nous sommes tournés vers les allénylphosphinates que nous avons mis en jeu dans des réactions de cyclisations électrophiles et nucléophiles. Cela a permis l obtention d hétérocycles originaux, par une séquence de réactions cascades en controlant la stéréochimie des différents centres asymétriques. Enfin, nous avons étudié la réactivité des molécules ainsi obtenues, nous permettant ainsi d introduire la diversité moléculaire via des réactions d arylations palladocatalysées, d hydroxyl- et d aminoalkilation en utilisant des techniques de synthèse en parallèle permettant ainsi l obtention des différentes familles de composés. Cinq familles différentes d hétérocycles ont été synthétisées et plus de 80 composés ont été soumis pour évaluation biologique dans le domaine de l agrochimie.Phosphorus molecules, due to their key roles in biochemistry and wide chemical diversity, are intensively studied because of their potential biological activities. Those research led to the commercial use of phosphorus molecules in the field of medicine and agrochemistry. We synthesized five and six membered rings using ring closing metathesis and to avoid some drawbacks of such a method, we used allenic compounds with nucleophilic or electrophilic compounds. We managed to synthesize new heterocycles and we set up a new chain of reactions. Finally, we introduced molecular diversity on the previously synthesized heterocyles using pallado-catalysed arylation, hydroxyl- and aminoalkylation reactions using parallel synthesis. Five families of heterocycles were obtained and more than eigthty compounds were submitted to biological evaluatin in the agrochemistry field.MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF

Oxaphospholene and oxaphosphinene heterocycles via RCM using unsymmetrical phosphonates or functional phosphinates

International audienceNew phosphorus heterocycles were synthesized using RCM reaction. They were prepared from unsymmetrical or polyfunctional insaturated precursor in 50 to 87% yields solving the problem of possible competitive side reactions. In parallel hydroxyphosphinate scaffolds represent a versatile starting material and could be of great interest for the synthesis of phosphosugar libraries

Highly Convergent Synthesis of Chiral Bicyclophosphinates by Domino Hydrophosphinylation/Michael/Michael Reaction

International audienceDiastereoselective domino reactions of iminoalcohols and allenyl H-phosphinates produce chiral phosphorus bicycles in a regio- and stereoselective fashion. A predictive model for diastereoselection is used for these new chiral phosphinic ester

Renal arcuate vein thrombosis–induced acute kidney injury: a rare multiple-Hit–mediated disease

International audienceBackgroundRenal arcuate vein thrombosis (RAVT) is a rare and recently recognized cause of acute kidney injury (AKI) in young adults. However, the precise incidence and underlying pathophysiologic mechanisms leading to AKI in these patients remain elusive.MethodsThis study included all patients who underwent a kidney biopsy over a 40-month period sent to the pathology department of Necker-Enfants Malades Hospital, with evidence of RAVT. We performed coagulation tests, genetic testing for thrombophilia, complete urine toxicologic screening and kidney metagenomic sequencing to identify an underlying cause of thrombosis.ResultsWe report five pediatric cases of RAVT discovered on kidney biopsy performed in the setting of unexplained AKI. Investigations did not reveal an underlying cause of thrombosis but only a significant nonsteroidal anti-inflammatory drugs (NSAIDs) use was reported in 4/5 patients, supporting a potential link between NSAIDs use and RAVT. By performing metagenomic sequencing on kidney biopsy samples, we detected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in the kidney of one patient. These results suggest that systemic SARS-CoV-2 infection may also be a key contributing factor of renal thrombosis, particularly by inducing potential endothelial disruption.ConclusionsIn conclusion, RAVT-induced AKI appears to be a multiple hit–mediated disease in which NSAIDs consumption and viral infection such as SARS-CoV-2 may be crucial contributing factors. These findings may have significant public health implications given the prevalence of NSAIDs use in the general population. Increased awareness and additional study of future cases may lead to a better understanding of this rare cause of AKI in children and young adults

Chronic Aichi virus infection as a cause of long-lasting multi-organ involvement in patients with primary immune deficiencies

International audienceBackgroundMetagenomic Next Generation Sequencing (mNGS) was used to assess patients with primary or secondary Immune Deficiencies (PIDs and SIDs) presenting with immunopathological conditions related to immunodysregulation.Methods30 patients with PIDs and SIDs presenting symptoms related to immunodysregulation and 59 asymptomatic patients with similar PIDs and SIDs were enrolled. mNGS was performed on organ biopsy. Specific AiV RT-PCR was used to confirm Aichi virus (AiV) infection and screen the other subjects. In situ hybridization assay (ISH) was done on AiV infected organs to identify infected cells. Virus genotype was determined by phylogenetic analysis.ResultsAiV sequences were detected by mNGS in tissue samples of 5 patients and by RT-PCR in peripheral samples of another patient who all presented with PID and long-lasting multi-organ involvement, including hepatitis, splenomegaly and nephritis in 4. CD8+ T cell infiltration was a hallmark of the disease.RT-PCR detected intermittent low viral loads in urine and plasma from infected patients but in none of the other subjects. Viral detection stopped after immune reconstitution obtained by hematopoietic stem cell transplantation. ISH demonstrated the presence of the AiV RNA in hepatocytes (n = 1) and spleen tissue (n = 2). AiV belonged to genotype A (n = 2) or B (n = 3).ConclusionsThe similarity of the clinical presentation, the detection of AiV in a sub-group of patients suffering from immunodysregulation, its absence in asymptomatic patients, the detection of viral genome in infected organs by ISH, and the reversibility of symptoms after treatment argue for AiV causality