22 research outputs found

    Enantioselective Synthesis of 5,7-Bicyclic Ring Systems from Axially Chiral Allenes Using a Rh(I)-Catalyzed Cyclocarbonylation Reaction

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    A transfer of chirality in an intramolecular Rh­(I)-catalyzed allenic Pauson–Khand reaction (APKR) to access tetrahydroazulenones, tetrahydrocyclopenta­[<i>c</i>]­azepinones and dihydrocyclopenta­[<i>c</i>]­oxepinones enantioselectively (22–99% ee) is described. The substitution pattern of the allene affected the transfer of chiral information. Complete transfer of chirality was obtained for all trisubstituted allenes, but loss of chiral information was observed for disubstituted allenes. This work constitutes the first demonstration of a transfer of chiral information from an allene to the 5-position of a cyclopentenone using a cyclocarbonylation reaction. The absolute configuration of the corresponding cyclocarbonylation product was also established, something that is rarely done

    Partnership between public and private organizations for fruit breeding ; a case study : INRA and NOVADI in France

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    Partnership between public and private organizations for fruit breeding ; a case study : INRA and NOVADI in France. MACFRU

    An Allenic Pauson–Khand Approach to 6,12-Guaianolides

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    Cyclocarbonylation of α-methylene butyrolactone-containing allene-ynes affords 6,12-guaianolide ring systems. Incorporation of the α-methylene butyrolactone early in a synthetic sequence is rare for reactivity reasons; however, this moiety proves to be beneficial to the allenic Pauson–Khand reaction. The three double bonds and the ketone in the resulting 5–7–5 ring system bear significant differences in their reactivity and are ideally positioned for synthetic application to 6,12-guaianolides and analogs

    Agricultural landscapes and the Loire River influence the genetic structure of the marbled newt in Western France

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    This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Amphibians are particularly sensitive to landscape fragmentation. Potential barriers between breeding sites can negatively infuence the dispersal of individuals and increase genetic structure between populations. In this study, we genotyped 10 microsatellites for 334 marbled newts (Triturus marmoratus) at 11 diferent locations in Western France. Samples were collected in diferent regions with contrasting agricultural landscapes (low and high proportion of arable land in the north and south, respectively). We found a strong genetic structure between the northern and southern sampling sites. Isolation by distance was recorded after 62km, but within the northern region, little or no genetic structure was detected over large distances (up to 114km). Genetic structure at shorter distance (43km) was found between sites situated in landscapes with larger amounts of arable lands. A signifcant positive relationship was found between the pairwise genetic distance (Fst) between sites and the amount of arable land together with the distance between sites. Our results suggest that the Loire River might act as a corridor for the marbled newt, while arable land might act as a barrier. Finally, although a large city is located between sampling sites, no efect was detected on population structure.publishedVersio

    Agricultural landscapes and the Loire River influence the genetic structure of the marbled newt in Western France

    No full text
    Amphibians are particularly sensitive to landscape fragmentation. Potential barriers between breeding sites can negatively infuence the dispersal of individuals and increase genetic structure between populations. In this study, we genotyped 10 microsatellites for 334 marbled newts (Triturus marmoratus) at 11 diferent locations in Western France. Samples were collected in diferent regions with contrasting agricultural landscapes (low and high proportion of arable land in the north and south, respectively). We found a strong genetic structure between the northern and southern sampling sites. Isolation by distance was recorded after 62km, but within the northern region, little or no genetic structure was detected over large distances (up to 114km). Genetic structure at shorter distance (43km) was found between sites situated in landscapes with larger amounts of arable lands. A signifcant positive relationship was found between the pairwise genetic distance (Fst) between sites and the amount of arable land together with the distance between sites. Our results suggest that the Loire River might act as a corridor for the marbled newt, while arable land might act as a barrier. Finally, although a large city is located between sampling sites, no efect was detected on population structure
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