Reactive Organometallics of Transition Metals

本课题组以获得未来化学转化的创新方法为目标，设计并制备了过渡金属有机反应物，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。低价过渡金属聚碳酸酯已被证明通过其活化腈的α-C-H和CN键的特定能力而充当氧化还原刘易斯酸或碱催化剂。这一原理导致了各种新型催化反应的发展，如羟醛缩合、迈克尔加成和CN官能团与亲核试剂的转化，这些反应在中性条件下进行（Murahashi）。研究了稀土金属有机化合物对乙烯和甲基丙烯酸酯的聚合反应。已获得具有高分子量、高间同立构规整度和窄多分散性的相应聚合物（Yasuda）。一系列多角体器官组 ...更多信息 已经制备了第6族过渡金属的金属氢化物。配位不饱和的活性物种已经通过光照射产生，并且已经研究了它们对有机底物如醇和酰胺的氧化加成的反应性（Ito）。由乙烯基硫醚与刘易斯酸反应得到的活性催化物种已被证明是通过烯反应、[3+2]环加成和闭环偶联反应构建碳骨架的多用途合成中间体。已经产生了带有桥连多配体的新型三核钌配合物，并且这些配合物通过多金属合作（Suzuki）对环戊二烯的碳-碳键断裂和C-H活化显示出特定的反应性。制备了含μ-乙炔基配体的双金属铂-钯有机金属化合物。用这些独特的配合物观察到对芳基异腈的活性聚合的高催化活性（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