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Subject: kinetics × WGL Institute: LIKAT ×

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    Catalyst Deactivation During Rhodium Complex-Catalyzed Propargylic C-H Activation
    (Weinheim : Wiley-VCH, 2021) Möller, Saskia; Jannsen, Nora; Rüger, Julia; Drexler, Hans-Joachim; Horstmann, Moritz; Bauer, Felix; Breit, Bernhard; Heller, Detlef
    Detailed mechanistic investigations on our previously reported synthesis of branched allylic esters by the rhodium complex-catalyzed propargylic C−H activation have been carried out. Based on initial mechanistic studies, we present herein more detailed investigations of the reaction mechanism. For this, various analytical (NMR, X-ray crystal structure analysis, Raman) and kinetic methods were used to characterize the formation of intermediates under the reaction conditions. The knowledge obtained by this was used to further optimize the previous conditions and generate a more active catalytic system. © 2021 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.
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    Hydrogenation of terminal and internal olefins using a biowaste-derived heterogeneous cobalt catalyst
    (Washington, DC [u.a.] : Assoc., 2018) Scharnagl, Florian Korbinian; Hertrich, Maximilian Franz; Ferretti, Francesco; Kreyenschulte, Carsten; Lund, Henrik; Jackstell, Ralf; Beller, Matthias
    Hydrogenation of olefins is achieved using biowaste-derived cobalt chitosan catalysts. Characterization of the optimal Co@Chitosan-700 by STEM (scanning transmission electron microscopy), EELS (electron energy loss spectroscopy), PXRD (powder x-ray diffraction), and elemental analysis revealed the formation of a distinctive magnetic composite material with high metallic Co content. The general performance of this catalyst is demonstrated in the hydrogenation of 50 olefins including terminal, internal, and functionalized derivatives, as well as renew-ables. Using this nonnoble metal composite, hydrogenation of terminal C==C double bonds occurs under very mild and benign conditions (water or methanol, 40° to 60°C). The utility of Co@Chitosan-700 is showcased for efficient hydrogenation of the industrially relevant examples diisobutene, fatty acids, and their triglycerides. Because of the magnetic behavior of this material and water as solvent, product separation and recycling of the catalyst are straightforward.