School of Chemical and Biomolecular Engineering, Pusan National University, Busan 609-735, Korea.
Dalton Trans. 2012 Aug 28;41(32):9633-8. doi: 10.1039/c2dt31096a. Epub 2012 Jul 13.
Well hexagonally ordered NbSBA-15 catalysts synthesized by an efficient hydrothermal method were used, for the first time, for the selective synthesis of vitamin K(3) by liquid-phase oxidation of 2-methyl-1-naphthol (2MN1-OH) under various reaction conditions. The recyclable NbSBA-15 catalysts were also reused to find their catalytic activities. To investigate the leaching of non-framework niobium species on the surface of silica networks, the results of original and recyclable NbSBA-15 catalysts were correlated and compared. To find an optimum condition for the selective synthesis of vitamin K(3), the washed NbSBA-15(2.2pH) was extensively used in this reaction with various reaction parameters such as temperature, time and ratios of reactant (2M1N-OH to H(2)O(2)), and the obtained results were also demonstrated. Additionally, the liquid-phase oxidation of 2M1N-OH was carried out with different solvents to find the best solvent with a good catalytic activity. Based on the all catalytic studies, the vitamin K(3) selectivity (97.3%) is higher in NbSBA-15(2.2pH) than that of other NbSBA-15 catalysts, and the NbSBA-15(2.2pH) is found to be a highly active and eco-friendly heterogeneous catalyst for the selective synthesis of vitamin K(3).
采用高效水热法合成的具有六方有序结构的 NbSBA-15 催化剂，首次应用于 2-甲基-1-萘酚（2MN1-OH）液相氧化选择性合成维生素 K（3），在不同反应条件下进行了研究。还对可回收的 NbSBA-15 催化剂进行了重复使用，以考察其催化活性。为了研究非骨架铌物种在硅网络表面的浸出情况，对原始和可回收的 NbSBA-15 催化剂的结果进行了关联和比较。为了找到维生素 K（3）选择性合成的最佳条件，广泛使用了经过洗涤的 NbSBA-15（2.2pH）催化剂，并考察了不同反应参数（如温度、时间和反应物（2M1N-OH 与 H（2）O（2）的比例）对反应的影响，还对得到的结果进行了论证。此外，还在不同溶剂中进行了 2M1N-OH 的液相氧化反应，以找到具有良好催化活性的最佳溶剂。基于所有的催化研究，在 NbSBA-15（2.2pH）中，维生素 K（3）的选择性（97.3%）高于其他 NbSBA-15 催化剂，并且 NbSBA-15（2.2pH）被发现是一种用于选择性合成维生素 K（3）的高效、环保的多相催化剂。
