35 research outputs found

    Microsatellite Markers Confirm Self‐Pollination and Autogamy in Wild Populations of Vanilla mexicana Mill. (syn. V. inodora) (Orchidaceae) in the Island of Guadeloupe

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    The study aimed at evaluating the mating system of Vanilla mexicana (Orchidaceae) in natural populations in the island of Guadeloupe. A total of 132 V. mexicana samples were collected from 12 sites in Guadeloupe (Basse‐Terre). Five other samples coming from Martinique and Mexico completed our analyses. Reproductive biology experiments excluding pollinators with bagged flowers revealed 53.9% fruit set, a value identical to the natural fruit set measured in the populations. These results suggested that V. mexicana, unlike most Vanilla species, was reproducing by self‐pollination and autogamy. Due to lack of specific DNA markers for V. mexicana, microsatellite markers, previously developed in other Vanilla species, were used for the genetic analyses. Only 6 out of the 33 markers tested were transferable and polymorphic in V. mexicana. A panel of 51 V. mexicana samples genotyped with 3 polymorphic loci was finally retained for Guadeloupe population genetic analyses. A heterozygote deficiency was detected, and the selfing rate was estimated to 74%. These results confirmed the reproductive biology results as self‐pollination and autogamy were the most likely explanation for this deficit. Results were compared to those from allogamous wild Vanilla species and discussed in the light of suggested existence of a pollinator for V. mexicana in other areas (Mexico)

    BLOOM: A 176B-Parameter Open-Access Multilingual Language Model

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    Large language models (LLMs) have been shown to be able to perform new tasks based on a few demonstrations or natural language instructions. While these capabilities have led to widespread adoption, most LLMs are developed by resource-rich organizations and are frequently kept from the public. As a step towards democratizing this powerful technology, we present BLOOM, a 176B-parameter open-access language model designed and built thanks to a collaboration of hundreds of researchers. BLOOM is a decoder-only Transformer language model that was trained on the ROOTS corpus, a dataset comprising hundreds of sources in 46 natural and 13 programming languages (59 in total). We find that BLOOM achieves competitive performance on a wide variety of benchmarks, with stronger results after undergoing multitask prompted finetuning. To facilitate future research and applications using LLMs, we publicly release our models and code under the Responsible AI License

    Synthesis and reactivity of enamides, toward the molecular diversity and the synthesis of bioactive and/or natural compounds

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    La nĂ©cessitĂ© grandissante de disposer d’une large librairie de diverses petites molĂ©cules pour le screening biologique constitue une puissante force motrice pour les chimistes organiciens et requiert en amont le dĂ©veloppement de mĂ©thodologies rapides et efficaces. Dans ce cadre, nous nous sommes plus particuliĂšrement intĂ©ressĂ©s Ă  la fonctionnalisation d’énamides qui reprĂ©sentent des blocs molĂ©culaires intĂ©ressants permettant d’introduire des fonctionnalitĂ©s aminĂ©es dans des systĂšmes variĂ©s. Notre objectif a Ă©tĂ© de synthĂ©tiser des petites bibliothĂšques de molĂ©cules azotĂ©es Ă  partir de substrats communs tout en mettant en oeuvre les diffĂ©rentes stratĂ©gies de la synthĂšse orientĂ©e vers la diversitĂ© et en s’attachant Ă  respecter les rĂšgles suivantes : Ă©conomie d’atomes, processus catalysĂ©s, synthĂšses rapides en peu d’étapes et contrĂŽle de la stĂ©rĂ©oselectivitĂ©. Dans un premier temps, nous avons principalement synthĂ©tisĂ© divers Ă©namides, nous permettant par la suite de dĂ©velopper des mĂ©thodologies innovantes et d’accĂ©der Ă  des « structures privilĂ©giĂ©es » ou des fragments clĂ©s prĂ©sents dans des produits naturels ou dans des substances potentiellement biologiquement actives en mettant en jeu des processus variĂ©s telles que des rĂ©actions d’aza-Michael, d’oxyamidation ou en cascade et la chimie du palladium avec de la CH insertion, des dioxoazoborocanes ou encore l’utilisation de l’auxiliaire chiral SAMP.The continuing demand to synthesize new and original collections of small molecules for the biological screening is an attractive subject for organic chemists and requires upstream the development of fast and easy synthetic methods. In this context, we decided to focus particularly on the functionalization of enamides which represent valuable building blocks in order to introduce nitrogen based functionality into various organic systems. Our objective was to synthesize new nitrogen containing compound libraries starting from common substrates by applying Diversity-Oriented Synthesis strategy and following these rules: atom economy, catalyzed reactions, fast synthesis in few steps and control of stereoselectivity. Firstly we mainly synthesized enamides. Thereafter, we developped efficient methodologies giving access to motifs frequently found in “privileged structures” or key scaffolds present in natural products or potential bioactive compounds thanks to various processes like aza-Michael, oxyamidation or cascade reactions, palladium chemistry with CH activation, dioxoazoborocanes or chiral auxiliary SAMP

    SynthÚse et réactivité d'énamides, de la diversité moléculaire à la synthÚse de molécules bioactives et/ou naturelles

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    La nécessité grandissante de disposer d une large librairie de diverses petites molécules pour le screening biologique constitue une puissante force motrice pour les chimistes organiciens et requiert en amont le développement de méthodologies rapides et efficaces. Dans ce cadre, nous nous sommes plus particuliÚrement intéressés à la fonctionnalisation d énamides qui représentent des blocs moléculaires intéressants permettant d introduire des fonctionnalités aminées dans des systÚmes variés. Notre objectif a été de synthétiser des petites bibliothÚques de molécules azotées à partir de substrats communs tout en mettant en oeuvre les différentes stratégies de la synthÚse orientée vers la diversité et en s attachant à respecter les rÚgles suivantes : économie d atomes, processus catalysés, synthÚses rapides en peu d étapes et contrÎle de la stéréoselectivité. Dans un premier temps, nous avons principalement synthétisé divers énamides, nous permettant par la suite de développer des méthodologies innovantes et d accéder à des structures privilégiées ou des fragments clés présents dans des produits naturels ou dans des substances potentiellement biologiquement actives en mettant en jeu des processus variés telles que des réactions d aza-Michael, d oxyamidation ou en cascade et la chimie du palladium avec de la CH insertion, des dioxoazoborocanes ou encore l utilisation de l auxiliaire chiral SAMP.The continuing demand to synthesize new and original collections of small molecules for the biological screening is an attractive subject for organic chemists and requires upstream the development of fast and easy synthetic methods. In this context, we decided to focus particularly on the functionalization of enamides which represent valuable building blocks in order to introduce nitrogen based functionality into various organic systems. Our objective was to synthesize new nitrogen containing compound libraries starting from common substrates by applying Diversity-Oriented Synthesis strategy and following these rules: atom economy, catalyzed reactions, fast synthesis in few steps and control of stereoselectivity. Firstly we mainly synthesized enamides. Thereafter, we developped efficient methodologies giving access to motifs frequently found in privileged structures or key scaffolds present in natural products or potential bioactive compounds thanks to various processes like aza-Michael, oxyamidation or cascade reactions, palladium chemistry with CH activation, dioxoazoborocanes or chiral auxiliary SAMP.ORLEANS-SCD-Bib. electronique (452349901) / SudocSudocFranceF

    Aerobic Double Dehydrogenative Cross Coupling between Cyclic Saturated Ketones and Simple Arenes

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    The synthesis of 3-aryl-2-cyclohexenones is a topic of current interest as they are not only privileged structures in bioactive molecules, but they are also relevant feedstocks for the synthesis of substituted phenols or anilines, which are ubiquitous structural elements both in drug design and medicinal chemistry. A simple and sustainable one-pot aerobic double dehydrogenative reaction under mild conditions for the introduction of arenes in the -position of cyclic ketones has been developed. Starting from the corresponding saturated ketone, this reaction sequence proceeds under relatively low Pd catalyst loading and involves catalytic amounts of electron-transfer mediators (ETMs) under ambient oxygen pressure.AuthorCount:2;</p

    Construction of Nitrogen-Fused Tetrahydroquinolines via a Domino Reaction

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    An efficient domino approach for the diastereoselective synthesis of polyfunctionalized nitrogen-fused tetrahydroquinoline frameworks under mild conditions has been developed. The scope and limitation of this transformation were investigated by using a range of readily accessible enamides and benzyl azides. This method is also applicable to the formation of 2,3-functionalized enamides

    Construction of Nitrogen-Fused Tetrahydroquinolines via a Domino Reaction

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    An efficient domino approach for the diastereoselective synthesis of polyfunctionalized nitrogen-fused tetrahydroquinoline frameworks under mild conditions has been developed. The scope and limitation of this transformation were investigated by using a range of readily accessible enamides and benzyl azides. This method is also applicable to the formation of 2,3-functionalized enamides

    Aerobic Direct C–H Arylation of Nonbiased Olefins

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    An efficient ligand-promoted biomimetic aerobic oxidative dehydrogenative cross-coupling between arenes and nonbiased olefins is presented. Acridine as a ligand was found to significantly enhance the rate, the yield, and the scope of the reaction under ambient oxygen pressure, providing a variety of alkenylarenes via an environmentally friendly procedure
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