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  1. Article ; Online: Phosphine Catalyzed Michael-Type Additions: The Synthesis of Glutamic Acid Derivatives from Arylidene-

    Rodríguez-Flórez, Lesly V / González-Marcos, María / García-Mingüens, Eduardo / Retamosa, María de Gracia / Kawase, Misa / Selva, Elisabet / Sansano, José M

    Molecules (Basel, Switzerland)

    2024  Volume 29, Issue 2

    Abstract: The reaction of arylidene-α-amino esters with electrophilic alkenes to yield Michael-type addition ...

    Abstract The reaction of arylidene-α-amino esters with electrophilic alkenes to yield Michael-type addition compounds is optimized using several phosphines as organocatalysts. The transformation is very complicated due to the generation of several final compounds, including those derived from the 1,3-dipolar cycloadditions. For this reason, the selection of the reaction conditions is a very complex task and the slow addition of the acrylic system is very important to complete the process. The study of the variation in the structural components of the starting imino ester is performed as well as the expansion of other electron-poor alkenes. The crude products have a purity higher than 90% in most cases without any purification. A plausible mechanism is detailed based on the bibliography and the experimental results. The synthesis of pyroglutamate entities, after the reduction of the imino group and cyclization, is performed in high yields. In addition, the hydrolysis of the imino group, under acidic media, represents a direct access to glutamate surrogates.
    Language English
    Publishing date 2024-01-10
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 1413402-0
    ISSN 1420-3049 ; 1431-5165 ; 1420-3049
    ISSN (online) 1420-3049
    ISSN 1431-5165 ; 1420-3049
    DOI 10.3390/molecules29020342
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.MO 81: Show issues

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  2. Article ; Online: Reinvigorating aza-Michael reactions under ionic liquid catalysis: a greener approach.

    Izquierdo, Silvia / Cintas, Pedro / Durán-Valle, Carlos J / de la Concepción, Juan García / López-Coca, Ignacio M

    Organic & biomolecular chemistry

    2024  Volume 22, Issue 12, Page(s) 2423–2434

    Abstract: ... illustrate their catalytic advantage in aza-Michael reactions in terms of low loading, acceleration and ...

    Abstract Cholinium α-amino carboxylates, which debuted in the ionic liquid arena over a decade ago, exhibit superior stability and suitable physical properties relative to other RTILs. Although synthetic pursuits in such media, leveraging their dual role as solvents and catalysts, have been scarce so far, we herein illustrate their catalytic advantage in aza-Michael reactions in terms of low loading, acceleration and improved yields with respect to conventional conditions and other imidazolium-based ILs. These highly structured salts most likely act through multiple and cooperative non-covalent interactions. These mechanistic features have also been investigated through high-level computational analyses as well.
    Language English
    Publishing date 2024-03-20
    Publishing country England
    Document type Journal Article
    ZDB-ID 2097583-1
    ISSN 1477-0539 ; 1477-0520
    ISSN (online) 1477-0539
    ISSN 1477-0520
    DOI 10.1039/d3ob02006a
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Mechanochemistry and Eco-Bases for Sustainable Michael Addition Reactions.

    Lock Toy Ki, Yvette / Garcia, Armelle / Pelissier, Franck / Olszewski, Tomasz K / Babst-Kostecka, Alicja / Legrand, Yves-Marie / Grison, Claude

    Molecules (Basel, Switzerland)

    2022  Volume 27, Issue 10

    Abstract: The Michael addition reaction was revisited with a full focus on sustainability combined ...

    Abstract The Michael addition reaction was revisited with a full focus on sustainability combined with efficiency, using mechanochemistry in mild conditions. First, the synthesis of cyclopentenone derivatives was chosen as a model reaction to find optimal conditions in mechanochemistry while using classical but weak bases. The reaction was efficient (84-95% yields), fast (2-6 h), solvent free, and required 0.1 equivalent of base. Aiming to reach greener conditions, classical bases were then replaced using new bio-sourced bases, called Eco-bases, that were easily prepared from plants and led to heterogeneous catalysts. The composition and structure of Eco-bases were characterized by MP-AES, XRPD, EBSD/EDS, HRTEM/EDX and ion chromatography. Interestingly, a high ratio of potassium was observed with the presence of K
    MeSH term(s) Catalysis ; Recycling ; Solvents
    Chemical Substances Solvents
    Language English
    Publishing date 2022-05-21
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 1413402-0
    ISSN 1420-3049 ; 1431-5165 ; 1420-3049
    ISSN (online) 1420-3049
    ISSN 1431-5165 ; 1420-3049
    DOI 10.3390/molecules27103306
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.MO 81: Show issues

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  4. Article ; Online: Organocatalytic Michael Addition of Unactivated α-Branched Nitroalkanes to Afford Optically Active Tertiary Nitrocompounds.

    Lorea, Beñat / García-Urricelqui, Ane / Odriozola, José M / Razkin, Jesús / Espinal-Viguri, Maialen / Oiarbide, Mikel / Mielgo, Antonia / García, Jesús M / Palomo, Claudio

    Organic letters

    2023  Volume 25, Issue 48, Page(s) 8590–8595

    Abstract: The direct, asymmetric conjugate addition of unactivated α-branched nitroalkanes is developed based on the combined use of chiral amine/ureidoaminal bifunctional catalysts and a tunable acrylate template to provide tertiary nitrocompounds in 55-80% ... ...

    Abstract The direct, asymmetric conjugate addition of unactivated α-branched nitroalkanes is developed based on the combined use of chiral amine/ureidoaminal bifunctional catalysts and a tunable acrylate template to provide tertiary nitrocompounds in 55-80% isolated yields and high enantioselectivity (
    Language English
    Publishing date 2023-11-27
    Publishing country United States
    Document type Journal Article
    ISSN 1523-7052
    ISSN (online) 1523-7052
    DOI 10.1021/acs.orglett.3c03340
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Repercussão da Teoria do Conhecimento Tácito de Michael Polanyi

    Josemar Elias da Silva Junior / Joana Coeli Ribeiro Garcia

    Em Questão, Vol 27, Iss 3, Pp 328-

    anais da KM Brasil 2002-2018

    2021  Volume 349

    Abstract: ... das Ciências da Saúde até as Sociais Aplicadas. Nela temos uma figura importante: Michael Polanyi, propondo ... ocupe o centro das discussões do evento, somente tal percentual cita os estudos de Michael Polanyi ...

    Abstract As discussões acerca da epistemologia do conhecimento são bastante antigas e percorrem áreas das Ciências da Saúde até as Sociais Aplicadas. Nela temos uma figura importante: Michael Polanyi, propondo uma perspectiva harmoniosa para a criação do conhecimento, rompendo o ideal de objetividade absoluto herdado da Revolução Científica do século XVIII. A pesquisa quali-quanti utiliza como coleta de dados os documentos publicados nos anais do Congresso Nacional de Gestão do Conhecimento - KM BRASIL (2002-2018) que citam o conceito de Polanyi sobre conhecimento tácito com o objetivo de identificar como suas ideias estão referidas, os sentidos usados e seu desenvolvimento. Nessa direção, a partir do KM BRASIL evidenciamos autores, filiações, data de publicação, incluindo possibilidades de interpretar as ideias de Polanyi. Constatamos que a teoria é abordada conceitualmente no contexto brasileiro, correspondendo a pouco mais de 5% do total de trabalhos publicados nos 13 anos de evento. Embora a temática da gestão do conhecimento ocupe o centro das discussões do evento, somente tal percentual cita os estudos de Michael Polanyi. Com efeito, os autores selecionados afirmam ancorar-se nos preceitos de Polanyi para explicar a epistemologia do conhecimento e sua categorização. Posteriormente os autores inserem a noção de gestão e a distinção entre o tácito e o explicíto a partir de Nonaka e Takeuchi. Apreendemos que o introito para as discussões sobre gestão, criação, transferência ou armazenamento de conhecimento partiram sempre da epistemologia polanyiana embora nem sempre de forma fidedigna.
    Keywords conhecimento tácito ; michael polany ; km brasil ; Bibliography. Library science. Information resources ; Z
    Language English
    Publishing date 2021-07-01T00:00:00Z
    Publisher Universidade Federal do Rio Grande do Sul
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Mechanochemistry and Eco-Bases for Sustainable Michael Addition Reactions

    Yvette Lock Toy Ki / Armelle Garcia / Franck Pelissier / Tomasz K. Olszewski / Alicja Babst-Kostecka / Yves-Marie Legrand / Claude Grison

    Molecules, Vol 27, Iss 3306, p

    2022  Volume 3306

    Abstract: The Michael addition reaction was revisited with a full focus on sustainability combined ... to excellent yields to different Michael donors and acceptors. Eco-bases were recycled and reused four times ... with the same performances. Combining Eco-bases and mechanochemistry in Michael addition reactions allowed ...

    Abstract The Michael addition reaction was revisited with a full focus on sustainability combined with efficiency, using mechanochemistry in mild conditions. First, the synthesis of cyclopentenone derivatives was chosen as a model reaction to find optimal conditions in mechanochemistry while using classical but weak bases. The reaction was efficient (84–95% yields), fast (2–6 h), solvent free, and required 0.1 equivalent of base. Aiming to reach greener conditions, classical bases were then replaced using new bio-sourced bases, called Eco-bases, that were easily prepared from plants and led to heterogeneous catalysts. The composition and structure of Eco-bases were characterized by MP-AES, XRPD, EBSD/EDS, HRTEM/EDX and ion chromatography. Interestingly, a high ratio of potassium was observed with the presence of K 2 Ca(CO 3 ) 2 for the most effective Eco-base. The new Eco-bases were used for the mechanical-assisted construction of functionalized alkenone derivatives. The versatility of the method has been successfully applied with good to excellent yields to different Michael donors and acceptors. Eco-bases were recycled and reused four times with the same performances. Combining Eco-bases and mechanochemistry in Michael addition reactions allowed reaching a maximum degree of sustainability (efficient, rapid, low catalyst loading, solvent-free reactions with bio-sourced catalysts) and participating in the development of mechanochemistry in sustainable chemistry.
    Keywords Michael addition ; mechanochemistry ; eco-base ; alien invasive plants ; phytomanagement ; Organic chemistry ; QD241-441
    Subject code 540
    Language English
    Publishing date 2022-05-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Building Covalent Molecular Capsules by Thiol-Michael Addition Click Reaction.

    Perretti, Marcelle D / Pérez-Márquez, Lidia A / García-Rodríguez, Raúl / Carrillo, Romen

    The Journal of organic chemistry

    2019  Volume 84, Issue 2, Page(s) 840–850

    Abstract: The thiol-Michael addition (TMA) is a powerful methodology to click several fragments together ...

    Abstract The thiol-Michael addition (TMA) is a powerful methodology to click several fragments together, despite having been underestimated in the synthesis of complex systems for supramolecular chemistry. Herein, a very fast and efficient method has been developed to make covalent molecular capsules by taking advantage of the TMA click reaction. Several scaffolds commonly used in supramolecular chemistry, such as calixarenes, CTV, or cavitands, have been used to quickly obtain covalent cages. Additionally, a ' click&click' procedure has been also developed, by sequential combination of TMA and CuAAC click reaction, as an easy and quick way to build complex molecular structures.
    Language English
    Publishing date 2019-01-04
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 123490-0
    ISSN 1520-6904 ; 0022-3263
    ISSN (online) 1520-6904
    ISSN 0022-3263
    DOI 10.1021/acs.joc.8b02677
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    Zs.A 4473: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

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  8. Article ; Online: Las ideas de Michael Sandel contra la visión transhumanista del perfeccionamiento de seres humanos

    Javier García Herrería

    Jounal of Negative and No Positive Results, Vol 5, Iss 7, Pp 674-

    2020  Volume 682

    Abstract: ... responsabilidad, el aprecio de la vida como un don, la inclinación a compartir nuestro destino ...

    Abstract Las tentadoras promesas del transhumanismo parecen estar cada vez más cerca, pero cabe preguntarse si no resultarán contraproducentes en algún sentido. El profesor Sandel expone los problemas sociales que conllevaría el desarrollo de seres humanos mejorados en nuestra concepción del mérito, la libertad y responsabilidad, el aprecio de la vida como un don, la inclinación a compartir nuestro destino con el de los demás y la concepción de los derechos individuales.
    Keywords transhumanismo ; sandel ; lógica del don ; justicia ; responsabilidad ; Medicine ; R ; Science ; Q
    Language English
    Publishing date 2020-03-01T00:00:00Z
    Publisher Asociación Para el Progreso de la Biomedicina
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: "Anti-Michael addition" of Grignard reagents to sulfonylacetylenes: synthesis of alkynes.

    Esteban, Francisco / Boughani, Lazhar / García Ruano, José L / Fraile, Alberto / Alemán, José

    Organic & biomolecular chemistry

    2017  Volume 15, Issue 18, Page(s) 3901–3908

    Abstract: ... Michael addition", resulting in their alkynylation under very mild conditions is described. The simplicity ... the synthesis of diynes and other examples showing functional group tolerance in this anti-Michael reaction is ...

    Abstract In this work, the addition of Grignard reagents to arylsulfonylacetylenes, which undergoes an "anti-Michael addition", resulting in their alkynylation under very mild conditions is described. The simplicity of the experimental procedure and the functional group tolerance are the main features of this methodology. This is an important advantage over the use of organolithium at -78 °C that we previously reported. Moreover, the synthesis of diynes and other examples showing functional group tolerance in this anti-Michael reaction is also presented.
    Language English
    Publishing date 2017-05-10
    Publishing country England
    Document type Journal Article
    ZDB-ID 2097583-1
    ISSN 1477-0539 ; 1477-0520
    ISSN (online) 1477-0539
    ISSN 1477-0520
    DOI 10.1039/c7ob00783c
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  10. Article ; Online: [2]Rotaxane End-Capping Synthesis by Click Michael-Type Addition to the Vinyl Sulfonyl Group.

    David, Arthur H G / García-Cerezo, Pablo / Campaña, Araceli G / Santoyo-González, Francisco / Blanco, Victor

    Chemistry (Weinheim an der Bergstrasse, Germany)

    2019  Volume 25, Issue 24, Page(s) 6170–6179

    Abstract: We report the application of the click Michael-type addition reaction to vinyl sulfone or vinyl ...

    Abstract We report the application of the click Michael-type addition reaction to vinyl sulfone or vinyl sulfonate groups in the synthesis of rotaxanes through the threading-and-capping method. This methodology has proven to be efficient and versatile as it allowed the preparation of rotaxanes using template approaches based on different noncovalent interactions (i.e., donor-acceptor π-π interactions or hydrogen bonding) in yields of generally 60-80 % and up to 91 % aided by the mild conditions required (room temperature or 0 °C and a mild base such as Et
    Language English
    Publishing date 2019-04-01
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1478547-x
    ISSN 1521-3765 ; 0947-6539
    ISSN (online) 1521-3765
    ISSN 0947-6539
    DOI 10.1002/chem.201900156
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