Silica-supported aminopyridinium halides for catalytic transformations of epoxides to cyclic carbonates under atmospheric pressure of carbon dioxide
Silica-supported aminopyridinium halides for catalytic transformations of epoxides to cyclic carbonates under atmospheric pressure of carbon dioxide
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DOI：
10.1039/b916764c
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发表时间：
2009-11
期刊：
影响因子：
9.8
通讯作者：
Ken Motokura;Shintaro Itagaki;Y. Iwasawa;A. Miyaji;T. Baba
中科院分区：
文献类型：
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作者：
Ken Motokura;Shintaro Itagaki;Y. Iwasawa;A. Miyaji;T. Baba
通过4-吡咯烷基吡啶与二氧化硅负载的烷基碘的季铵化反应制备了二氧化硅负载的4-吡咯烷基吡啶碘化物。通过固态13 C CP MAS NMR证实了二氧化硅表面上的吡咯烷基吡啶鎓结构。在常压二氧化碳气氛下，二氧化硅负载的碘化4-吡咯烷吡啶对各种环氧化物转化为环状碳酸酯具有优异的催化性能。反应在没有除催化剂之外的任何溶剂或添加剂的情况下进行。该催化剂可重复使用，且活性和选择性保持不变。1-正己基-4-吡咯烷基吡啶鎓作为均相催化剂表现出比负载型催化剂低的催化性能。提出了酸性表面硅醇和碱性碘化4-吡咯烷吡啶的双功能催化。
Silica-supported 4-pyrrolidinopyridinium iodide was prepared by quaternization of 4-pyrrolidinopyridine with silica-supported alkyl iodide. The pyrrolidinopyridinium structure on the silica surface was confirmed by solid-state 13C CP MAS NMR. The silica-supported 4-pyrrolidinopyridinium iodide showed excellent catalytic performances for transformations of various epoxides to cyclic carbonates under atmospheric pressure of carbon dioxide (CO2). The reactions took place without any solvents or additives other than the catalyst. The catalyst was reusable with retention of activity and selectivity. 1-n-Hexyl-4-pyrrolidinopyridinium as a homogeneous catalyst showed a lower catalytic performance than the supported catalyst. Bifunctional catalysis involving acidic surface silanol and the basic 4-pyrrolidinopyridinium iodide was proposed.