咪唑修饰硅胶负载乙酰丙酮钴(Ⅱ)催化分子氧氧化单萜烯研究

采用3-氯丙基三甲氧基硅烷和咪唑对硅胶表面进行修饰(SiIm), 通过咪唑环中π电子与钴离子空d轨道之间的纵轴配位作用制得非均相负载催化剂Co(acac)₂/SiIm, 用IR, UV-Vis和ICP-AES对其结构进行表征. 在乙腈溶剂中, 催化剂催化分子氧氧化单萜烯得到了相应的氧化产物. 研究表明, 负载催化剂具有良好的催化氧化性能, 获得了较高的反应转化率和产物选择性, 其中柠檬烯和α-蒎烯的氧化以环氧产物为主, 而β-蒎烯的氧化则以烯丙位氧化产物为主. 另外, 对反应机理和竞争反应进行了简单的阐述.

Autoxidation of Monoterpenes with Oxygen Catalyzed by Co(acac)2 Supported on Silica Functionalized Imidazole

Selective oxyfunctionalization of monoterpenes is an interesting route to utilize these inexpensive natural products for a number of applications,such as pharmaceutical,flavor and perfumery industry as well as useful synthetic intermediates.The use of solid materials in catalytic oxidations in the liquid-phase has recently been extensively investigated because of their easy recovery and the possibility of regeneration which results in a reduction of the environmental impact.In this work,a new heterogeneous ...