A Tin-Tungsten Mixed Oxide as an Efficient Heterogeneous Catalyst for C-C Bond-Forming Reactions
A Tin-Tungsten Mixed Oxide as an Efficient Heterogeneous Catalyst for C-C Bond-Forming Reactions
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DOI：
10.1002/chem.200802536
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发表时间：
2009-01-01
影响因子：
4.3
通讯作者：
Mizuno, Noritaka
中科院分区：
文献类型：
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作者：
Ogasawara, Yoshiyuki;Uchida, Sayaka;Mizuno, Noritaka
通过在800摄氏度下煅烧Sn/W摩尔比为2的锡-钨氢氧化物前体（SnW 2 -800）制备的锡-钨混合氧化物充当用于C-C键形成反应的有效且可重复使用的固体催化剂，所述C-C键形成反应例如香茅醛的环化、Diels-Alder反应以及羰基化合物与三甲基甲硅烷基氰化物（TMSCN）的氰基硅烷化。各种结构多样的脂肪族、芳香族和不饱和的含杂原子的底物可以以高至优异的产率转化为所需的产物。所观察到的这些反应的催化剂是真正的非均相和回收的催化剂可以重复使用几次，而不会有明显的损失，其高催化性能。在SnW 2 -800上聚集的多钨酸盐物种上产生的Bronsted酸中心可能在C-C键形成反应中起重要作用。
The tin-tungsten mixed oxide prepared by the calcination of the tin-tungsten hydroxide precursor with a Sn/W molar ratio of 2 at 800 degrees C (SnW2-800) acts as an effective and reusable solid catalyst for C-C bond-forming reactions, such as the cyclization of citronellal, the Diels-Alder reaction, and the cyanosilylation of carbonyl compounds with trimethylsilyl cyanide (TMSCN). Various kinds of structurally diverse aliphatic, aromatic, and unsaturated, heteroatom-containing substrates could be converted into the desired products in high to excellent yields. The observed catalyses for these reactions were truly heterogeneous and the recovered catalyst could be reused several times without an appreciable loss of its high catalytic performance. The Bronsted acid sites generated on the aggregated polytungstate species on SnW2-800 likely play an important role in the C-C bond-forming, reactions.