7020-34-0Relevant articles and documents
Catalytic oxidative transformation of betulin to its valuable oxo-derivatives over gold supported catalysts: Effect of support nature
Kolobova,M?ki-Arvela,Grigoreva,Pakrieva,Carabineiro,Peltonen,Kazantsev,Bogdanchikova,Pestryakov,Murzin, D.Yu.
, p. 95 - 110 (2020/08/26)
Liquid-phase oxidation of betulin extracted from birch bark was studied over gold catalysts supported on a range of supports (hydrotalcite, ZrO2, ZnO, MgO, CeO2, La2O3, HMS and various alumina) with different morphology and properties. Gold catalysts as well as the corresponding supports were characterized by XRD, BET, ICP-OES, XPS and TEM. It was found that the nature of the support plays a decisive role in betulin oxidation over gold-based catalysts, expressed in the influence on the average size and distribution of gold nanoparticles and, thereby, on their catalytic performance (activity and selectivity) in betulin oxidation. Moreover, it was revealed that betulin oxidation catalyzed by gold is a structure sensitive reaction, requiring an optimal size of gold nanoparticles of ca. 3.3 nm. The most suitable support for gold was found to be alumina. Kinetic studies allowed determination of reaction orders and conditions favorable for selective formation of a particular oxo-derivative of betulin (betulone, betulinic and betulonic aldehydes, betulinic acid).
Preparation of Betulone Via Betulin Oxidation Over Ru Nanoparticles Deposited on Graphitic Carbon Nitride
Shcherban,M?ki-Arvela,Aho,Sergiienko,Skoryk,Kolobova,Simakova,Er?nen,Smeds,Hemming,Murzin, D. Yu.
, p. 723 - 732 (2019/01/25)
Derivatives of betulin obtained by oxidation have broad pharmacological applications, demonstrating anti-inflammatory, antioxidant, hepatoprotective, and anticancer activity. Ru supported catalysts based on graphitic carbon nitride or N-doped carbon were prepared via a mild reduction of the initial Ru precursor with hydrazine. These catalysts along with Ru supported on carbon nanofibers and a mesoporous carbon support Sibunit were studied in catalytic oxidation of betulin. Ru/carbon nitride demonstrated catalytic activity in betulin oxidation higher than Ru/N-doped carbon (conversion of betulin up to ca. 70% and 30%, respectively). Selectivity to different oxidation products was dependent on the properties of the carbon supports.
Selective oxidation of betulin by Cr(VI) reagents
Komissarova,Belenkova,Spirikhin,Shitikova,Yunusov
, p. 58 - 61 (2007/10/03)
Oxidation of betulin by pyridinium dichromate, pyridinium chlorochromate, and K2Cr2O7 - H2SO4 in the presence of tetrabutylammonium bromide was studied. Products of regioselective C-3, C-28-, and exha
