53250-61-6Relevant articles and documents
Oxidative transformation of the natural lignan hydroxymatairesinol with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone
Eklund, Patrik C.,Sj?holm, Rainer E.
, p. 4515 - 4523 (2003)
The oxidative transformation of the two isomers of the natural lignan hydroxymatairesinol from Norway Spruce (Picea abies) by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), has been studied. Significant differences in the outcome of the reactions were observed when the pure isomers of hydroxymatairesinol were reacted with DDQ under the same conditions. The different stereoelectronic effects in the two isomers as well as their conformational structures seem to determine the site of reaction, which results in different reaction products. Several products were identified by GC-MS and NMR spectroscopy. Oxomatairesinol was obtained in a yield of 25%.
Oxygen-assisted hydroxymatairesinol dehydrogenation: A selective secondary-alcohol oxidation over a gold catalyst
Prestianni, Antonio,Ferrante, Francesco,Simakova, Olga A.,Duca, Dario,Murzin, Dmitry Yu.
, p. 4577 - 4585 (2013)
Selective dehydrogenation of the biomass-derived lignan hydroxymatairesinol (HMR) to oxomatairesinol (oxoMAT) was studied over an Au/Al2O 3 catalyst. The reaction was carried out in a semi-batch glass reactor at 343 K under two different gas atmospheres, namely produced through synthetic air or nitrogen. The studied reaction is, in fact, an example of secondary-alcohol oxidation over an Au catalyst. Thus, the investigated reaction mechanism of HMR oxidative dehydrogenation is useful for the fundamental understanding of other secondary-alcohol dehydrogenation over Au surfaces. To investigate the elementary catalytic steps ruling both oxygen-free- and oxygen-assisted dehydrogenation of HMR to oxoMAT, the reactions were mimicked in a vacuum over an Au28 cluster. Adsorption of the involved molecular species - O2, three different HMR diastereomers (namely, one SRR and two RRR forms), and the oxoMAT derivative - were also studied at the DFT level. In particular, the energetic and structural differences between SRR-HMR and RRR-HMR diastereomers on the Au28 cluster were analyzed, following different reaction pathways for the HMR dehydrogenation that occur in presence or absence of oxygen. The corresponding mechanisms explain the higher rates of the experimentally observed oxygen-assisted reaction, mostly depending on the involved HMR diastereomer surface conformations. The role of the support was also elucidated, considering a very simple Au28 charged model that explains the experimentally observed high reactivity of the Au/Al 2O3 catalyst.Copyright
Oxidative dehydrogenation of a biomass derived lignan - Hydroxymatairesinol over heterogeneous gold catalysts
Simakova, Olga A.,Murzina, Elena V.,Maeki-Arvela, Paeivi,Leino, Anne-Riikka,Campo, Betiana C.,Kordas, Krisztian,Willfoer, Stefan M.,Salmi, Tapio,Murzin, Dmitry Yu.
experimental part, p. 54 - 64 (2011/09/20)
Synthesis of the lignan oxomatairesinol via oxidative dehydrogenation of the naturally occurring lignan hydroxymatairesinol was studied over gold catalysts supported on C, TiO2, SiO2, Al2O 3, and MgO. In order to investigate the reaction performance over the gold catalyst, synthesis of lignan oxomatairesinol was carried out in different organic solvents/water mixtures under synthetic air and nitrogen atmosphere at 373 K, and using also isolated hydroxymatairesinol isomers as a starting material. The results were compared with those obtained over palladium catalysts. Synthesized supported gold catalysts as well as the corresponding supports were characterized by TEM, XRD, ICP-OES, CO2-TPD, FTIR (using pyridine as a probe molecule), and XPS. Gold catalysts were shown to display superior performance compared with palladium ones: the activity was 4 times higher, with selectivity toward oxomatairesinol being 100%, while 60-85% were obtained over palladium catalysts. In contrast to palladium, the activity of gold catalysts is high in aerobic conditions and water-propan-2-ol mixture. However, activity and selectivity of gold catalysts were shown to be dependent on the electronic state of the metal and, similar to palladium catalysts, on the support acidity.
