Creation of Innovative and Environmentally Benign Methods for Catalytic Construction of Ring Compounds via Reactive Metallacyclic Intermediates

为了人类社会在21世纪的持续繁荣，构建无副产物和废物的环境友好的有机合成催化过程是必不可少的。在科学研究B中，已经开发了新型的Rh催化的烯烃与烯烃或炔烃的交叉偶联和环加成反应，导致了构建环丙烷、2-吡啶酮、嘧啶-2，4-二酮和呋喃的有效方法，这些都构成了新的功能单体和材料。另一方面，我们开发了许多新型的Ru催化反应以及新型的Ru(0)和Ru(II)单体和簇合物，为Ru化学做出了重要贡献。最近，我们成功地开发了不同烯烃的共聚和共三聚合反应，在科研B中，我们发现我们最初的Ru(η^6-Cot)(η^2-dmfm)_2[Cot=1，3，5-环辛三烯，dmfm=富马酸二甲酯]对乙烯选择三聚合成异己烯表现出很高的催化活性。该反应似乎是通过正常的和连续的将乙烯插入烷基-Ru键来进行的。然而，目前的反应是通过苯环戊烷作为关键中间体进行的，这被不寻常的异己烯(一种支化的共三聚体)代替正常的1-己烯(一种线性共三聚体)的形成以及氚标记的实验所证实。因此，本科学研究B中开发的反应都是原子经济和环境友好的过程，通过有效地形成金属环中间体为环化合物的构建提供了创新的方法。本研究为21世纪有机合成的绿色可持续化学(GSC)做出了重要贡献。

For the continuing prosperity of human society in the 21st century, it is essential to construct environmentally benign catalytic processes without byproducts and waste, directed toward organic synthesis. In the Scientific Research B, novel rhodium-catalyzed cross-coupling and cycloaddition reactions of ketenes with alkenes or alkynes have been developed, leading to efficient methods for construction of cyclopropanes, 2-pyridones, pyrimidine-2,4-diones, and furans, which constitute new and functional monomers and materials. On the other hand, we have made an important contribution to ruthenium chemistry by developing a lot of novel ruthenium-catalyzed reactions as well as creation of novel Ru (0) and Ru (II) monomers and clusters. Recently, we have succeeded in development of codimerization and cotrimerization reactions of different alkenes, and in the Scientific Research B, we found that our original ruthenium(0) complex, Ru(η^6-cot)(η^2-dmfm)_2 [cot =1,3,5-cyclooctatriene, dmfm = dimethyl fumarate], showed high catalytic activity for selective trimerization of ethylene to isohexenes. It seems that the reaction proceeds via normal and successive insertion of ethylene into an alkyl-ruthenium bond. However, the present reaction proceeded via ruthenacyclopentanes as a key intermediate, which was confirmed by the formation of unusual isohexenes (a branched cotrimer) in place of normal 1-hexene (a linear cotrimer) as well as deuterium-labeled experiments. Accordingly, the reactions developed in this Scientific Research B are all atom-economical and environmentally benign processes, which offer innovative methods for construction of ring compounds via an efficient formation of metallacyclic intermediates. As a result, this research contributes significantly to green sustainable chemistry (GSC) for organic synthesis in the 21st century.