Cracow University of Technology, Warszawska 24, 31-155 Krakow, Poland.
Molecules. 2012 Jul 4;17(7):8068-78. doi: 10.3390/molecules17078068.
Hydrogen peroxide was encapsulated into a silica xerogel matrix by the sol-gel technique. The composite was tested as an oxidizing agent both under conventional and microwave conditions in a few model reactions: Noyori's method of octanal and 2-octanol oxidation and cycloctene epoxidation in a 1,1,1-trifluoroethanol/Na2WO4 system. The results were compared with yields obtained for reactions with 30% H2O2 and urea-hydrogen peroxide (UHP) as oxidizing agents. It was found that the composite has activity similar to 30% H2O2 and has a several advantages over UHP such as the fact that silica and H2O are the only products of the composite decomposition or no contamination by urea or its derivatives occurs; the xerogel is easier to heated by microwave irradiation than UHP and could be used as both an oxidizing agent and as solid support for microwave assisted solvent-free oxidations.
过氧化氢通过溶胶-凝胶技术被包裹在二氧化硅气凝胶基质中。该复合材料在几种模型反应中被测试为氧化剂,包括传统条件和微波条件下:Noyori 法辛醛和 2-辛醇的氧化以及在 1,1,1-三氟乙醇/Na2WO4 体系中环辛烯的环氧化。结果与使用 30%H2O2 和尿素-过氧化氢 (UHP) 作为氧化剂的反应产率进行了比较。结果发现,该复合材料具有与 30%H2O2 相似的活性,并且与 UHP 相比具有几个优点,例如复合材料分解仅产生二氧化硅和 H2O,或者不会发生尿素或其衍生物的污染;气凝胶比 UHP 更容易被微波辐射加热,并且可以用作微波辅助无溶剂氧化的氧化剂和固体支持物。