Synthetic Reactions by Using Bimetallic Complexes

在催化合成反应中，单金属配合物得到了广泛的应用，而双金属配合物在实际合成中的应用很少。精确的双金属络合物设计有望实现独特的化学转化，多个金属中心协同参与反应。本研究制备了同金属和异双金属配合物，并研究了它们的催化活性，以实现有机转化。1)合成了磷桥联的Rh(I)配合物，并在W部分作为CO供体和/或Lewis酸性的辅助下，对Rh(I)的催化活性进行了预测。在CO分压小于0.04atm的情况下，Rh-W双金属络合物对单取代烯烃的氢甲酰化反应表现出很高的催化活性，具有广泛的官能团选择性。制备了一种氧桥或硫桥双金属，并用X-射线单晶分析对其结构进行了研究。氧桥联络合物展示…此外，在烯烃的加氢反应中有一个独特的特点，即外部的烯烃可以顺利地氢化，而配体烯烃(环辛二烯)则不是。2)乙烯基氮金属络合物的性质尚未完全阐明，它很容易从叠氮和乙烯基叠氮化物中生成，特别是用Rh(II)双金属络合物和铜(II)络合物处理。3)在研究环丙醇氧化生成β-酮自由基的过程中，发现银(I)配合物表现出较高的催化活性。通过添加适量的再氧化剂完成催化过程，并应用于分子内扩环。由于β-酮自由基催化生成稠环的能力很强，以此为关键步骤实现了(-)-索丹素的合成。较少

In catalytic synthetic reactions, monometallic complexes have been widely used, while bimetallic complexes rarely used in practical synthesis. Precise design of bimetallic complexes is expected to realize unique chemical transformations, in which multi metal centers take part in the reactions collaboratively. In this research, homo and hetero bimetallic complexes were prepared and their catalytic activities were studied to realize organic transformations.1)Phosphido-bridged rhodium-tungsten carbonyl complexes were prepared, expecting catalytic activity of Rh(I) with the assistance by the W part as a CO donor and/or Lewis acidity. A Rh-W bimetallic complex exhibited high catalytic activity in the hydroformylation of monosubstituted alkenes even under less than 0.04 atm partial pressure of CO, with a wide functional group selectivity. A oxygen- or sulfur-bridged bimetallic were prepared and their structures were studied by X-ray crystallographic analysis. The oxygen-bridged complex exhib … More ited a unique character in the hydrogenation of alkenes; that is, outer alkenes are smoothly hydrogenated, while the ligand alkene (cyclooctadiene) is not.2)Vinyl nitrene-metal complexes, the property of which is not fully clarified yet, was found to be easily generated from azirines and vinyl azides, particularly by the treatment with rhodium(II) bimetallic complexes and copper(II) complexes. Indoles and pyrroles were prepared catalytically by aromatic C-H amination and addition reaction of active methylene compounds to the vinyl nitrene-metal complexes.3)During the course of the study on the oxidative generation of β-keto radicals from cyclopropanols, silver(I) complexes are found to show high activity. Catalytic process was accomplished by adding adequate reoxidation reagent and applied for the intramolecular ring expansion. The catalytic generation of β-keto radicals was so powerful to construct fused rings that synthesis of (-)-sordarin was achieved by using the catalysis as the key step. Less