Cyclic glyceryl sulfate: a simple and versatile bio-based synthon for the facile and convergent synthesis of novel surface-active agents

In the frame of biomass valorization, a novel and simple cyclic glyceryl sulfate was efficiently prepared in two steps from glycerol. It was shown to react efficiently with primary, secondary as well as tertiary amines to afford either the corresponding anionic or zwitterionic surface-active agents

Positive and negative viral associations in patients with acute respiratory tract infections in primary care: the ECOVIR study

IntroductionAcute respiratory infections (ARIs) are the most common viral infections encountered in primary care settings. The identification of causal viruses is still not available in routine practice. Although new strategies of prevention are being identified, knowledge of the relationships between respiratory viruses remains limited.Materials and methodsECOVIR was a multicentric prospective study in primary care, which took place during two pre-pandemic seasons (2018–2019 and 2019–2020). Patients presenting to their General practitioner (GP) with ARIs were included, without selecting for age or clinical conditions. Viruses were detected on nasal swab samples using a multiplex Polymerase Chain Reaction test focused on 17 viruses [Respiratory Syncytial Virus-A (RSV-A), RSV-B, Rhinovirus/Enterovirus (HRV), human Metapneumovirus (hMPV), Adenovirus (ADV), Coronaviruses (CoV) HKU1, NL63, 229E, OC43, Influenza virus (H1 and H3 subtypes), Influenza virus B, Para-Influenza viruses (PIVs) 1–4, and Bocavirus (BoV)].ResultsAmong the 668 analyzed samples, 66% were positive for at least one virus, of which 7.9% were viral codetections. The viral detection was negatively associated with the age of patients. BoV, ADV, and HRV occurred more significantly in younger patients than the other viruses (p < 0.05). Codetections were significantly associated with RSV, HRV, BoV, hMPV, and ADV and not associated with influenza viruses, CoV, and PIVs. HRV and influenza viruses were negatively associated with all the viruses. Conversely, a positive association was found between ADV and BoV and between PIVs and BoV.ConclusionOur study provides additional information on the relationships between respiratory viruses, which remains limited in primary care

Applications de la Chimie Radicalaire des Xanthates : Synthèse d'Alcaloïdes d'Origine Marine ; Synthèse de Thiéno[2,3-b]thiopyranones ; Synthèse de Thioéthers Aryliques ; Approche à la Synthèse Totale du (+)-Maritimol.

We have developed a useful synthetic β-keto γ-xanthyl phosphonate that is able to create two new carbon-carbon bonds in both a radical and an ionic manner. We have shown that it adds to various olefins in xanthate radical transfer reactions and that the resultant compounds undergo HWE olefination to form α,β-unsaturated ketones. Moreover, we successfully demonstrated its high conjunctivity by completing the first total synthesis of antimicrobial xestamines C, E, and H. We have also developed a facile and highly efficient one-pot synthetic route toward functionalized 2,3,5,6-tetrahydro-thieno[2,3-b]thiopyran-4-ones from easily accessible β-keto ε-xanthyl phosphonates. A broad molecular diversity around the thieno[2,3-b]thiopyran-4-one scaffold could be introduced in only two steps from simple β-keto γ-xanthyl phosphonate. The syntheses of novel and unprecedented spiro thieno[2,3-b]thiopyran-4-ones were also readily achieved. We have also developed a novel one-step, radical approach to aryl thioethers. A number of xanthates were successfully transformed into the corresponding aryl thioethers. The easy access to valuable vinylsilanes in only three steps from simple xanthate adducts is worthy of note and underscores the synthetic potential of this functional group exchange process. We have also established a fast entry into the stemodane natural product family by using the radical transfer technology. A late intermediate of a model of maritimol has been prepared in only 9 steps from commercially available 4,4-dimethylcyclohexenone. Furthermore, we are currently working on the asymmetric synthesis of (+)-maritimol and an advanced intermediate has already been prepared.Dans un premier temps, nous avons développé un synthon original équipé à la fois d'une fonction phosphonate et d'une fonction xanthate qui a permis la création de deux liaisons carbone–carbone à la suite, dans une séquence efficace d'addition radicalaire–oléfination de Horner–Wadsworth–Emmons. L'intérêt de ce nouveau xanthate a été par ailleurs illustré en réalisant la synthèse d'alcaloïdes présentant un noyau pyridine, les xestamines C, E, et H. Ce synthon s'est montré aussi très utile dans la synthèse d'hétérocycles soufrés peu décrits dans la littérature, les thiéno[2,3-b]thiopyranones. Une séquence réalisée dans le même pot a permis l'obtention de divers composés très fonctionnalisés. La chimie radicalaire a servi pour la fonctionnalisation de la position 2 alors que la chimie ionique a servi pour la fonctionnalisation de la position 6. Nous avons aussi développé une nouvelle réaction radicalaire qui permet de transformer la fonction xanthate en thioéther arylique. Dans certains cas, une oxydation suivie d'une élimination du sulfoxyde résultant a conduit à des vinylsilanes intéressants. Enfin, nous avons mis au point une nouvelle méthodologie qui permet d'accéder rapidement et efficacement à des motifs bicyclo[3.2.1]octanes fonctionnalisés. Ceci nous a permis par la suite de réaliser une synthèse relativement courte du précurseur insaturé d'un modèle du maritimol, un diterpènoïde tétracyclique. La stratégie appliquée repose principalement sur une étape d'addition radicalaire par transfert de xanthate et de cyclisation radicalaire. La synthèse de l'énantiomère naturel du maritimol a ensuite été entreprise, et un intermédiaire relativement avancé a pu être obtenu

Facile and efficient one-pot synthesis of highly functionalized thieno[2,3-b]thiopyran-4-ones from beta-keto epsilon-xanthyl phosphonates

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Facile and Efficient One-Pot Synthesis of Highly Functionalized Thieno[2,3b]thiopyran-4-ones from b-Keto e-Xanthyl Phosphonates

International audienceSynthesis of various functionalized thieno[2,3-b]thiopyran-4-ones from readily available β-keto ε-xanthyl phosphonates has been accomplished by combining a Horner−Wadsworth−Emmons olefination with a base-induced intramolecular domino cyclization/thio-Michael addition. The use of cyclic ketones in this transformation allowed a facile access to novel spiro-type thieno[2,3-b]thiopyran structures

Applications de la chimie radicalaire des xanthates (synthèse d'alcaloïdes d'origine marine ; synthèse de thiéno[2,3-b]thiopyranones ; synthèse de thioéthers aryliques ; approche à la synthèse totale du (+)-maritimol)

PALAISEAU-Polytechnique (914772301) / SudocSudocFranceF

A highly conjunctive beta-keto phosphonate: Application to the synthesis of pyridine alkaloids xestamines C, E, and H

International audienceThe synthesis of a novel β-keto γ-xanthyl phosphonate has been achieved. This highly conjunctive reagent has been utilized in a combination of radical and ionic reactions to create new carbon−carbon bonds. Its usefulness was demonstrated by realizing the first total synthesis of naturally occurring pyridine alkaloids xestamines C, E, and H

Radical, one-step approach to o-chlorophenyl thioethers from xanthates. A rapid access to vinylsilanes

International audienceXanthates have been readily converted into o-chlorophenyl thioethers using a one-step procedure conducted under radical conditions. In some selected cases, these aryl thioethers were successfully oxidized to the corresponding sulfoxides and sulfenic acid elimination afforded the corresponding vinylsilanes

Pickering emulsions assisted synthesis of fatty acetal over phenyl sulfonic groups grafted on activated charcoal

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Upgrading of furfural by Knœvenagel condensation over functionalized carbonaceous basic catalysts

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