Multimetallic cluster complexes as well-defined nano-scale catalysts for novel organic transformations

多金属团簇配合物由于其近端金属中心作为独特有机转化反应位点的适用性而得到了广泛的研究。我们之前报道过四核锌团簇在胺官能团存在的情况下催化选择性反式酯化反应，其选择性与团簇催化剂无反应条件相反。基于四核锌团簇的独特反应性，我们应用了几种多金属团簇配合物作为酯转化的催化剂。在我们的研究中，我们发现多金属簇和氮基配体的混合物在配体与簇基基配位后形成了高活性的物质。在锌团簇催化的几种酯转化中观察到这种增强效应，此外，加入2,2 ' -联吡啶后，辛核钴团簇成为反式酯化反应的优良催化剂。因此，在催化反应中使用附加配体进行这种簇转化是显示高催化性能的一般策略。

Multimetallic cluster complexes have been extensively studied due to their applicability of proximal metal centers as a reactive site for unique organic transformations. We previously reported a tetranuclear zinc cluster catalyzed selective trans-esterification in the presence of amine functionalities, and the selectivity was opposite trend to the cluster catalyst free reaction condition. Based on the unique reactivity of the tetranuclear zinc cluster, we applied several multimetallic cluster complexes as catalysts for ester transformations. During our research, we found that the mixture of multimetallic clusters and nitrogen-based ligands led to the formation of highly reactive species after the coordination of the ligands to the cluster motif. Such enhancement effects were observed in zinc cluster catalyzed several ester transformations, and in addition, octanuclear cobalt clusters became an excellent catalyst for trans-esterification upon addition of 2,2’-bipyridine. Therefore, such cluster transformation during the catalytic reaction by using additional ligands is general strategy for showing high catalytic performance.