@article{BiermannMeierButteetal.2011, author = {Biermann, Ursula and Meier, Michael A. R. and Butte, Werner and Metzger, J{\"u}rgen O.}, title = {Cross-metathesis of unsaturated triglycerides with methyl acrylate synthesis of a dimeric metathesis product}, series = {European journal of lipid science and technology}, volume = {113}, journal = {European journal of lipid science and technology}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1438-7697}, doi = {10.1002/ejlt.201000109}, pages = {39 -- 45}, year = {2011}, abstract = {Highly functionalized dimeric triglycerides, such as compound 2, are obtained as minor products besides branched macromolecules from the acyclic triene metathesis (ATMET) polymerization of unsaturated triglycerides such as glyceryl triundec-10-enoate 1 and methyl acrylate (MA) in the presence of the second generation Hoveyda-Grubbs catalyst. The formed amount of interesting products of lower molecular weight during the ATMET reaction depends on the ratio of MA and triglyceride, reaction time, and temperature. We isolated the dimeric metathesis product 2 and synthesized the respective partially hydrogenated dimer 3 regioselectivly in a seven step reaction sequence starting from 10-undecenoic acid 7 and glycerol. Product 3 was unambiguously characterized by (13)C and (1)H NMR and MS as well as the further intermediate products of the seven step reaction including 10,11 bromo-undecanoic acid 8, the respective brominated 1,3-diglyceride 9, the brominated 1,3-triglyceride 6, and the self-metathesis products 4 and 5 which were isolated and purified.}, language = {en} } @article{BiermannMetzgerMeier2010, author = {Biermann, Ursula and Metzger, Juergen O. and Meier, Michael A. R.}, title = {Acyclic triene metathesis oligo- and polymerization of high oleic sun flower oil}, issn = {1022-1352}, doi = {10.1002/macp.200900615}, year = {2010}, abstract = {High oleic sunflower oil, a renewable raw material consisting of triglycerides with internal C=C-double bonds, was polymerized via acyclic triene metathesis (ATMET) to highly branched and functionalized polyesters. If the Hoveyda- Grubbs second generation catalyst was used and methyl acrylate was introduced as a chain stopper, the molecular weight of the obtained polymers could be tuned by varying the ratio of the triglyceride and methyl acrylate. Using the first generation Grubbs catalyst for the polymerization of high oleic sunflower oil, no cross-linking was observed, even without the use of a chain stopper. The resulting branched materials were characterized by GPC, H-1 and C-13 NMR, and ESI-MS.}, language = {en} } @article{deEspinosaMeier2011, author = {de Espinosa, Lucas Montero and Meier, Michael A. R.}, title = {Synthesis of star- and block-copolymers using ADMET head-to-tail selectivity during step-growth polymerization}, series = {Chemical communications}, volume = {47}, journal = {Chemical communications}, number = {6}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1359-7345}, doi = {10.1039/c0cc04161k}, pages = {1908 -- 1910}, year = {2011}, abstract = {Control over molecular architectures obtained via ADMET polymerization is limited by the step-growth nature of this technique. A new approach to this polycondensation method is described allowing for the synthesis of diblock and star-shaped polymers with molecular weight control by using the selectivity of olefin cross-metathesis between acrylates and terminal olefins.}, language = {en} } @article{deEspinosaMeierRondaetal.2010, author = {de Espinosa, Lucas Montero and Meier, Michael A. R. and Ronda, Juan C. and Galiß, Marina and Cßdiz, Virginia}, title = {Phosphorus-containing renewable polyester-polyols via ADMET polymerization : synthesis, functionalization, and radical crosslinking}, issn = {0887-624X}, doi = {10.1002/Pola.23887}, year = {2010}, abstract = {An alpha,omega-diene containing hydroxyl groups was prepared from plant oil-derived platform chemicals. The acyclic diene metathesis copolymerization (ADMET) of this monomer with a phosphorus-containing alpha,omega-cliene (DOPO II), also plant oil derived, afforded a series of phosphorus containing linear polyesters, which have been fully characterized. The backbone hydroxyls of these polyesters have been acrylated and radically polymerized to produce crosslinked polymers. The thermomechanical and mechanical properties, the thermal stability, and the flame retardancy of these phosphorus-based thermosets have been studied. Moreover, methyl 10-undecenoate has been used as chain stopper in selected ADMET polymerizations to study the effect of the prepolymers' molecular weights on the different properties of the final materials.}, language = {en} } @article{DjigoueMeier2009, author = {Djigou{\´e}, Guy Bertrand and Meier, Michael A. R.}, title = {Improving the selectivity for the synthesis of two renewable platform chemicals via olefin metathesis}, issn = {0926-860X}, doi = {10.1016/j.apcata.2009.08.025}, year = {2009}, abstract = {The self-metathesis of methyl 10-undecenoate as well as its cross-metathesis with methyl acrylate was investigated in detail by a systematic variation of the reaction conditions. Unsaturated ;,;-diesters with a chain length of 20 and 12 carbon atoms were thus obtained, respectively. Four different metathesis catalysts were investigated under solvent-free conditions at catalyst loadings ranging from 0.05 mol\% to 1 mol\% and at temperatures ranging from 30 °C to 90 °C. In the case of the self-metathesis reactions quantitative conversions were obtained with all catalysts, but the second generation metathesis catalysts revealed high amounts of olefin isomerization side reactions at higher temperatures. Using a small quantity of the hydrogen acceptor 1,4-benzoquinone, the isomerization process was almost completely suppressed. Thus, the second generation catalysts allowed for high conversions at very low catalyst loadings. For the cross-metathesis reaction, an interesting temperature and catalyst loading dependent selectivity was observed with the second generation catalysts. Moreover, due to these optimizations, we were able to run these cross-metathesis reactions with a 1:1 ratio of the reactants and low catalysts loadings. This is an improvement over described literature procedures. Thus, we report on the detailed investigation of the described self- and cross- metathesis reactions leading to practical and optimized reaction conditions for the synthesis of unsaturated ;,;-diesters monomers from renewable raw materials in an efficient catalytic manner.}, language = {en} } @article{FokouMeier2010, author = {Fokou, Patrice A. and Meier, Michael A. R.}, title = {Studying and suppressing olefin isomerization side reactions during ADMET polymerizations}, issn = {1022-1336}, doi = {10.1002/marc.200900678}, year = {2010}, abstract = {Olefin isomerization side reactions that occur during ADMET polymerizations were studied by preparing polyesters via ADMET and subsequently degrading these polyesters via transesterification with methanol. The resulting diesters, representing the repeating units of the previously prepared polyesters, were then analyzed by GC-MS. This strategy allowed quantification of the amount of olefin isomerization that took place during ADMET polymerization with second generation ruthenium metathesis catalysts. In a second step, it was shown that the addition of benzoquinone to the polymerization mixture prevented the olefin isomerization. Therefore, second generation ruthenium metathesis catalysts may now be used for the preparation of well-defined polymers via ADMET with very little isomerization, which was not possible before.}, language = {en} } @article{KreyeTothMeier2011, author = {Kreye, Oliver and Toth, Tommy and Meier, Michael A. R.}, title = {Copolymers derived from rapeseed derivatives via ADMET and thiol-ene addition}, series = {European polymer journal}, volume = {47}, journal = {European polymer journal}, number = {9}, publisher = {Elsevier}, address = {Oxford}, issn = {0014-3057}, doi = {10.1016/j.eurpolymj.2011.06.012}, pages = {1804 -- 1816}, year = {2011}, abstract = {Novel (co)polymers were synthesized from substances obtained from rapeseed via ADMET and thiol-ene additions. alpha,omega-Dienes derived from oleic and erucic acid were copolymerized with a ferulic acid derivative, a representative phenolic acid (p-hydroxycinnamic acid) present, for instance, in rapeseed cake. Copolymers with different ratios of these monomers were prepared via two different routes (ADMET and thiol-ene) and studied in detail. Both monomer and polymer synthesis were optimized in order to achieve high yielding synthetic procedures that meet the requirements of green chemistry. Some thermal properties of the resulting copolymer series were then studied and correlated to the co-monomer composition.}, language = {en} } @article{KreyeTothMeier2011, author = {Kreye, Oliver and Toth, Tommy and Meier, Michael A. R.}, title = {Introducing multicomponent reactions to polymer science passerini reactions of renewable monomers}, series = {Journal of the American Chemical Society}, volume = {133}, journal = {Journal of the American Chemical Society}, number = {6}, publisher = {American Chemical Society}, address = {Washington}, issn = {0002-7863}, doi = {10.1021/ja1113003}, pages = {1790 -- 1792}, year = {2011}, abstract = {Combination of the Passerini three component-reaction (3CR) and olefin metathesis led to the formation of poly[1-(alkyl carbamoyl)alkyl alkanoates], a new class of polyesters with amide moieties in their side chain, from renewable resources. Two different approaches were studied and compared to each other. First, monomers were synthesized by the Passerini-3CR and then polymerized via acyclic diene metathesis. Alternatively, bifunctional monomers were synthesized by self-metathesis and then polymerized by Passerini-3CR. Both approaches led to the formation of high-molecular-weight polymers. Moreover, Passerini-3CRs were shown to be a versatile grafting-onto method. The results clearly demonstrate that the Passerini-3CR offers an interesting new access to monomers and polymers and thus broadens the synthetic portfolio of polymer science.}, language = {en} } @article{KreyeTothMeier2011, author = {Kreye, Oliver and Toth, Tommy and Meier, Michael A. R.}, title = {Poly-alpha,beta-unsaturated aldehydes derived from castor oil via ADMET polymerization}, series = {European journal of lipid science and technology}, volume = {113}, journal = {European journal of lipid science and technology}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1438-7697}, doi = {10.1002/ejlt.201000108}, pages = {31 -- 38}, year = {2011}, abstract = {10-Undecenal, derived by pyrolysis and reduction from castor oil, was almost quantitatively transformed into the corresponding aldol condensation product under basic conditions. This alpha,omega-diene monomer was polymerized using acyclic diene metathesis (ADMET) polymerization. In a catalyst screening, four of nine different ruthenium-based metathesis catalysts showed good reactivity under neat conditions at 80 degrees C in the presence of 1,4-benzoquinone and polymers with molecular weights up to 11 kDa were formed. Furthermore, the (1)H NMR spectra showed that the metathesis catalysts tolerate the alpha,beta-unsaturated aldehyde function and due to the addition of benzoquinone, the degree of double bond isomerization was low. Further experiments investigating reduced catalyst amounts (down to 0.2 mol\%) and the temperature dependence of these ADMET polymerizations gave also satisfying results for the formation of poly-alpha,beta-unsaturated aldehydes. Moreover, ADMET polymerizations with different amounts of methyl 10-undecenoate as chain-stopper were performed and the integrals of the corresponding (1)H NMR spectra allowed the determination of an absolute degree of polymerization. Finally, a reduction of a poly-alpha,beta-unsaturated aldehyde with sodium borohydride was accomplished. The resulting poly-(allyl alcohol) could be a useful compound in the generation of polymer networks like polyesters, polyurethanes, and polycarbonates and thus be of high interest in materials research.}, language = {en} } @article{KreyeTueruencSehlingeretal.2012, author = {Kreye, Oliver and T{\"u}r{\"u}nc, Oguz and Sehlinger, Ansgar and Rackwitz, Jenny and Meier, Michael A. R.}, title = {Structurally diverse polyamides obtained from monomers derived via the Ugi multicomponent reaction}, series = {Chemistry - a European journal}, volume = {18}, journal = {Chemistry - a European journal}, number = {18}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0947-6539}, doi = {10.1002/chem.201103341}, pages = {5767 -- 5776}, year = {2012}, abstract = {The combination of the Ugi four-component reaction (Ugi-4CR) with acyclic diene metathesis (ADMET) or thiolene polymerization led to the formation of poly-1-(alkylcarbamoyl) carboxamides, a new class of substituted polyamides with amide moieties in the polymer backbone, as well as its side chains. 10-Undecenoic acid, obtained by pyrolysis of ricinoleic acid, the main fatty acid of castor oil, was used as the key renewable building block. The use of different primary amines, as well as isonitriles (isocyanides) for the described Ugi reactions provided monomers with high structural diversity. Furthermore, the possibility of versatile post-modification of functional groups in the side chains of the corresponding polymers should be of considerable interest in materials science. The obtained monomers were polymerized by ADMET, as well as thiolene, chemistry and all polymers were fully characterized. Finally, ortho-nitrobenzylamide-containing polyamides obtained by this route were shown to be photoresponsive and exhibited a dramatic change of their properties upon irradiation with light.}, language = {en} }