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    Item type:Publication, Access status: without files ,
    Towards bio-based plasticizers with reduced toxicity: Synthesis and performance testing of a 3-methylphthalate
    (2020-12)
    Plass, Carmen
    ;
    Hiessl, Robert
    ;
    Kleber, Joscha
    ;
    Grimm, Axel
    ;
    Langsch, Angelika
    As a very durable material, soft polyvinyl chloride (PVC) is used for many applications in the field of consumer products. To enable the desired properties, for example for medical devices, the addition of plasticizers is required. For this purpose, mostly dialkyl phthalates are used being produced on a multi-million tons scale annually. Since some of these are associated with human health effects, there is an increasing demand for the search of alternatives. Besides reduced toxicity while maintaining excellent performance features, an economic access as well as biorenewable starting materials are further criteria, which should be ideally fulfilled by such a new plasticizer generation. Targeting these demands and in contrast to most available substitutes being based on petrochemical feedstock, we developed a synthetic route starting from bio-renewable platform chemicals. In detail, a Diels-Alder reaction of 2-methylfuran and maleic anhydride and subsequent dehydration leads to three phthalate derivatives with different alcohol components bearing a methyl group at the aromatic ring. As a representative substance, di(2-ethylhexyl) 3-methylphthalate was chosen for performance tests, and this new bio-based alternative offers properties similar to known plasticizers in such initial studies.
    Publicationtype: Journal Article
      159
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    Item type:Publication, Access status: without files ,
    Enzymatic resolution of an amine under solvent-free conditions with diethyl malonate as reagent for acylation
    (Elsevier, 2017-02-21)
    Uthoff, Florian
    ;
    Reimer, Anna
    ;
    Liese, Andreas
    ;
    Gröger, Harald
    The extension of the enzymatic resolution of amines catalyzed by an immobilized lipase in combination with diethyl malonate as acyl donor towards a solvent-free process is described. In such a resolution process the resulting chiral amide was formed with both high conversion and enantioselectivity, and this solvent-free synthetic method turned out to be robust and efficient also at an elevated 50 mmol-scale reaction, leading to the desired amide with 50% conversion, in 43.5% yield and with excellent enantiomeric excess of 99% ee. This method proceeding at a short reaction time (4.5 h) opens up a perspective for future development towards a large-scale feasible process technology for the enantioselective synthesis of chiral amines.
    Publicationtype: Journal Article
      123