Large-Pore Mesoporous Organosilicas Functionalized with trans-(1R,2R)-Diaminocyclohexane: Synthesis, Postmodification, and Catalysis
Large-Pore Mesoporous Organosilicas Functionalized with trans-(1R,2R)-Diaminocyclohexane: Synthesis, Postmodification, and Catalysis
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DOI：
10.1021/cm0613307
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发表时间：
2006-11
影响因子：
8.6
通讯作者：
D. Jiang;Jinsuo Gao;Qihua Yang;Jie Yang;Can Li
中科院分区：
文献类型：
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作者：
D. Jiang;Jinsuo Gao;Qihua Yang;Jie Yang;Can Li
以三嵌段共聚物P123为模板剂，通过1，2-二（三甲氧基硅基）乙烷和N-[（三甲氧基硅基）苄基]-（-）-（1 R，2 R）-环己烷二氨基的共缩合反应，在酸性介质中合成了反式（1 R，2 R）-环己烷二氨基功能化的大孔乙烷-二氧化硅介孔材料。反式-（1 R，2 R）-环己二胺与对甲苯磺酰氯的反应进一步证实了其在乙烷-二氧化硅介孔材料中的后修饰作用。对于苯乙酮在空气气氛下在HCOONa−H2O中的不对称转移氢化，改性材料（与[RhCp* Cl 2]2络合）表现出比原始材料[18%转化率和38%ee（S）]高得多的转化率和ee [53%转化率和68%ee（R）]。各种芳香酮可以转化为相应的手性醇，具有中等至良好的对映选择性[18− 81%ee（R）]。与后修饰法相结合的共缩合法是合成介孔材料的替代方法之一。
Large-pore mesoporous ethane-silicas functionalized with trans-(1R,2R)-diaminocyclohexane were synthesized in an acidic medium by one-step co-condensation of 1,2-bis(trimethoxysilyl)ethane and N-[(trimethoxysilyl)benzyl]-(−)-(1R,2R)-diaminocyclohexane using triblock copolymer P123 as template. The postmodification of trans-(1R,2R)-diaminocyclohexane in the pore of the mesoporous ethane-silicas was further demonstrated by reaction with p-toluenesulfonyl chloride. The modified material (complexed with [RhCp*Cl2]2) exhibits much higher conversion and ee [53% conversion with 68% ee (R)] than the original material [18% conversion with 38% ee (S)] for the asymmetric transfer hydrogenation of acetophenone under air atmosphere in HCOONa−H2O. Various aromatic ketones can be converted to the corresponding chiral alcohol with moderate to good enantioselectivities [18−81% ee (R)]. The co-condensation method associated with the postmodification method is one of the alternatives for the synthesis of mesoporous material...