Titanium-catalyzed heterogeneous oxidations of silanes, chiral allylic alcohols, 3-alkylcyclohexanes, and thianthrene 5-oxide:: A comparison of the reactivities and selectivities for the large-pore zeolite Ti-β, the mesoporous Ti-MCM-41, and the layered alumosilicate Ti-ITQ-2
Titanium-catalyzed heterogeneous oxidations of silanes, chiral allylic alcohols, 3-alkylcyclohexanes, and thianthrene 5-oxide:: A comparison of the reactivities and selectivities for the large-pore zeolite Ti-β, the mesoporous Ti-MCM-41, and the layered alumosilicate Ti-ITQ-2
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DOI：
10.1006/jcat.2000.3043
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发表时间：
2000-12-10
影响因子：
7.3
通讯作者：
Weichold, O
中科院分区：
文献类型：
--
作者：
Adam, W;Corma, A;Weichold, O
比较研究了硅烷氧化、烯烃环氧化和噻蒽5-氧化物磺基氧化与氧化剂Ti-β/H2 O2、Ti-MCM-41/t-BuOOH和Ti-ITQ-2/t-BuOOH的催化反应性，得到了Ti-β> Ti-MCM-41 > Ti-ITQ-2的催化活性顺序。窄通道的空间限制使得Ti-β沸石具有最高的选择性。对于更开放的结构的Ti-MCM-41和Ti-ITQ-2主机，这样的空间限制是不太明显，因此，较低的选择性是由这些非均相催化剂表现出。两者都通过类似于均相Ti（Oi-Pr）（4）/t-BuOOH氧化剂的过渡结构活化t-BuOOH进行氧转移。(C)北京大学出版社.
A comparative study of silane oxidation, olefin epoxidation, and thianthrene 5-oxide sulfoxidation with the oxidants Ti-beta /H2O2, Ti-MCM-41/t-BuOOH, and Ti-ITQ-2/t-BuOOH provides the catalytic reactivity order Ti-beta > Ti-MCM-41 > Ti-ITQ-2. The steric constraints of the narrow channels make the Ti-beta zeolite the most selective. For the more open structures of the Ti-MCM-41 and Ti-ITQ-2 hosts, such steric constraints are less pronounced and, therefore, a lower selectivity is exhibited by these heterogeneous catalysts. Both activate t-BuOOH for oxygen transfer through a transition structure analogous to the homogeneous Ti(Oi-Pr)(4)/t-BuOOH oxidant. (C) 2000 Academic Press.