Balcar Hynek, Žilková Naděžda, Kubů Martin, Mazur Michal, Bastl Zdeněk, Čejka Jiří
J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v.v. i. Dolejškova 2155/3, 182 23 Prague 8, Czech Republic.
Beilstein J Org Chem. 2015 Nov 4;11:2087-96. doi: 10.3762/bjoc.11.225. eCollection 2015.
Hoveyda-Grubbs type catalysts with cationic tags on NHC ligands were linker-free immobilized on the surface of lamellar zeolitic supports (MCM-22, MCM-56, MCM-36) and on mesoporous molecular sieves SBA-15. The activity of prepared hybrid catalysts was tested in olefin metathesis reactions: the activity in ring-closing metathesis of citronellene and N,N-diallyltrifluoroacetamide decreased in the order of support MCM-22 ≈ MCM-56 > SBA-15 > MCM-36; the hybrid catalyst based on SBA-15 was found the most active in self-metathesis of methyl oleate. All catalysts were reusable and exhibited low Ru leaching (<1% of Ru content). XPS analysis revealed that during immobilization ion exchange between Hoveyda-Grubbs type catalyst and zeolitic support occurred in the case of Cl(-) counter anion; in contrast, PF6 (-) counter anion underwent partial decomposition.
在N-杂环卡宾配体上带有阳离子标签的霍维达-格鲁布斯型催化剂被无连接体地固定在层状沸石载体（MCM-22、MCM-56、MCM-36）表面以及介孔分子筛SBA-15上。所制备的杂化催化剂的活性在烯烃复分解反应中进行了测试：香茅烯和N,N-二烯丙基三氟乙酰胺的闭环复分解活性按载体顺序降低，即MCM-22≈MCM-56＞SBA-15＞MCM-36；基于SBA-15的杂化催化剂在油酸甲酯的自复分解反应中被发现活性最高。所有催化剂均可重复使用，且钌的浸出率较低（＜钌含量的1%）。X射线光电子能谱分析表明，在固定化过程中，对于Cl(-)抗衡阴离子，霍维达-格鲁布斯型催化剂与沸石载体之间发生了离子交换；相反，PF6 (-)抗衡阴离子发生了部分分解。
