Exploration of new organometallic complexes which enable to generate highly reactive metallic species reversibly : Foundamental chemistry and application to molecular catalysis.

分子催化在下一代高效生产化学品和材料中的重要性已得到广泛认识。包含双金属的有机金属团簇是一种很有前途的新型分子催化材料，其合成、反应和催化作用一直受到化学家们的关注。我们有一个分子催化剂设计的概念，可以适用于单核和多核有机金属催化剂：通过适当设计金属的辅助配体来产生高活性的金属，在没有反应物的情况下稳定金属，但在与底物的反应中可逆地形成活性的金属。作为这种“柔性”配体，我们已经研究了杂共轭配体，如酰胺类和磺胺类，以及多芳烃配体，如azulenes和苊。该研究成功地制备了新的有机金属配合物，该配合物可以通过配体的动力学行为更容易地产生高活性的物质。此外，这些新的配合物被证明对几种有机反应和聚合具有活性。结果表明：(1)合成了单核和双核酰胺酸钌，其中一些是配位不饱和和高活性的。包括结构分析、动力学行为和反应在内的基础化学使它们对烯丙基底物和自由基型反应的化学转化的催化作用成为可能。(2)合成了新型磺胺钛，并对其结构和溶液动力学进行了研究。它们被证明对烯烃聚合有活性。(3)研究了三钌羰基簇与苊和azul烯的结合与有机硅烷的反应，并将这些π配体的配位灵活性应用于羧基衍生物的高效催化还原和硅烷诱导的环醚和硅氧烷的聚合。(4)分别研究了共轭π配体配位柔韧性的基础化学和杂双金属化学的新进展。因此，通过配体设计发现高活性配合物实际上为这些柔性配体提供了丰富的反应化学和分子催化的实际应用。这些都有助于分子催化化学的发展。少

Importance of molecular catalysis is widely recognized in efficient production of chemicals and materials in next generation. Organometallic clusters which include dual metallic species in a molecule are one of the promising candidates for new molecular catalysis, arid their synthesis, reactions, and catalysis have received much attention of chemists. We have a concept for the molecular catalyst design, which can be applicable to both mono and multinuclear organometallic catalysts : highly reactive metallic species is generated by appropriate design of auxiliary ligands of metallic species, which stabilize the metallic species in the absence of reactants, but reversibly form reactive species in reaction with substrates. As such "flexible" ligands, we have investigated heteroconjugate ligands such as amidinates and sulfonamides and polyaromatic hydrocarbon ligands such as azulenes and acenaphthylenes. The research has successfully produced new organometallic complexes, which can reversi … More bly generate highly reactive species by dynamic behavior of the ligand. Furthermore, these new complexes were proved to be active towards several organic reactions and polymerizations. The results are summarized as follows : (1)Mono and dinuclear ruthenium amidinates were synthesized, several of which were coordinatively unsaturated and highly reactive. Fundamental chemistry including structural analysis, dynamic behavior, and reactions made possible discovery of their catalysis towards chemical transformation of allylic substrates and radical-type reactions. (2)Titanium sulfonamides were newly synthesized and subjected to studies of their structure and solution dynamics. They were proved to be active towards olefin polymerization. (3)Reaction of triruthenium carbonyl clusters bound to acenaphthylenes and azulenes with orgnosilanes were investigated, and the results, i.e.coordinative flexibility of these π-ligands, were applied to highly efficient catalytic reduction of carboxylic derivatives, and silane-induced polymerization of cyclic ethers and siloxanes. (4)Fundamental chemistry on the coordinative flexibility of conjugated π-ligands and new aspects in heterobimetallic chemistry were studied on diiron compounds and Ti-M dinulcear complexes, respectively. Thus, discovery of highly reactive complexes by the ligandl design actually provides fruitful reaction chemistry of these flexible ligands and actual application to molecular catalysis. These contribute to progress of chemistry of molecular catalysis. Less