Reactive Organometallics of Transition Metals

为了获得未来化学转化的创新方法，课题组设计并制备了反应性过渡金属有机化合物，并对其作为试剂和催化剂的功能进行了研究。代表性结果如下：低价过渡金属多氢化物具有激活腈- c - h和CN键的特殊能力，已被证明可作为氧化还原路易斯酸或路易斯碱催化剂。该原理导致了各种新型催化反应的发展，如醛醇缩合、迈克尔加成和CN官能在中性条件下与亲核试剂的转化（Murahashi）。含有大块茂金属的镧系有机金属化合物在乙烯和甲基丙烯酸酯的聚合中表现出很高的活性。相应的聚合物具有高分子量、高同时性和窄多差性（Yasuda）。一系列多羟基有机体，制备了更多的6族过渡金属。光照射产生了配位不饱和活性物质，并研究了它们对有机底物如醇和酰胺的氧化加成反应（Ito）。乙烯基硫化物与刘易斯酸反应产生的活性催化物质已被证明是利用烯反应、[3+2]环加成反应和闭合环偶联反应构建碳骨架的通用合成中间体（Kuwajima）。新型三核钌配合物带有桥接多羟基配体，这些配合物对碳-碳键的裂解和环戊二烯的碳氢活化具有特殊的反应活性（Suzuki）。制备了含多乙二基配体的双金属铂钯有机金属。这些独特的配合物对芳基异氰酸酯的活性聚合具有很高的催化活性（Takahashi）。少

Aiming to acquire innovative method of chemical transformation for the future, the research group designed and prepared reactive organometallics of transition metals, and their functions as reagents and catalysts have been investigated. The representative results are as follows. Low valent transition metal polyhydrides have proven to act as either redox Lewis acid or base catalysts by their specific ability to activate of alpha-C-H and CN bonds of nitriles. The principle has led to development of a variety of novel catalytic reactions such as aldol condensation, Michael addition, and transformations of CN functionalities with nucleophiles which proceed under neutral conditions (Murahashi). Lanthanide organometallics bearing bulky metallocenes were found to show high activity for polymerization of ethylene and methacrylates. The corresponding polymers have been obtained with high molecular weight, high syndiotacticity, and narrow polydispencity (Yasuda). A series of polyhydrido organome … More tallics of group 6 transition metals have been prepared. The coordinatively unsaturated active species have been created by light irradiation, and their reactivities towards oxidative addition to organic substrates such as alcohols and amides have been investigated (Ito). The active catalytic species derived from the reaction of vinyl sulfides with Lewis acids have proven to be versatile synthetic intermediates for construction of carbon skeletons using ene reactions, [3+2] cycloaddition and ring closing coupling reactions (Kuwajima). Novel trinuclear ruthenium complexes bearing bridging polyhydrido ligands have been created, and these complexes show specific reactivity towards carbon-carbon bond cleavage and C-H activation of cyclopentadiene via multimetallic cooperation (Suzuki). Bimetallic platinum-palladium organometallics bearing mu-ethynediyl ligands have been prepared. High catalytic activity towards living polymerization of aryl isocyanides was observed with these unique complexes (Takahashi). Less