Intermolecular transfer of organic ligands among transition metal complexes

Transmetalation是合成有机反应的重要基础反应之一，即同源和交叉偶联和烯烃聚合化。本研究旨在对有机转化金属复合体的详细机制进行提炼。Arylpalladium alkynyl complexes with tertiary phosphime ligands react with arylpalladium iodo complexes below room temperature to cause intermoelcular alkynyl ligand transfer to give new organopalladium complexes。alkynyl-palladium键比aryl-palladium键更稳定，但更有反应性，因为alkynyl ligand的transmetalation是由高稳定性的中间二核复合体与桥接alkynyl ligand。类似的烷基配体从Pd转移到Pt复合体需要更高的术语或添加CuI催化剂。Dialkynylpalladium和platinum复合体反应与diiodo复合体的这些金属导致复合体通过transmetalation of the alkynyl配体。Distribution of the product is influenced by thermodynamic stability of the complexes and the presence or absence of CuI catalyst which enhances the reaction significantly。Arylpalladium iodo complexes with chelating diamines do not cause intermolecular aryl ligand transfer， whereas the cationic species prepared from addition of Agy BFD24エD2 to the complexes go Underportionation to give diarylpalladium complexes。通过减少性限制来提供产品乙醇，它与第10组金属复合体催化的共环反应机制有关。转移金属的比率高度依赖于某种阵列组;与氟化的阵列配体显示出低反应率到转移金属的比率。在摘要中，目前的研究揭示了有机转换金属复合体的转移金属的各种方面，并采用了多种合成有机反应的机制，其中转移金属作为一个关键步骤。

Transmetalation is one of the important fundamental reactions which constitute of synthetic organic reactions such as homo- and cross-coupling and alkene polymerization. This study aimed elucidation of detailed mechanism of transmetalation of organotransition metal complexes. Arylpalladium alkynyl complexes with tertiary phosphime ligands react with arylpalladium iodo complexes below room temperature to cause intermoelcular alkynyl ligand transfer to give new organopalladium complexes. Alkynyl-palladium bond is thermodynamically more stable than the aryl-palladium bond but much more reactive because the transmetalation of the alkynyl ligand is favored by high stability of intermediate dinuclear complexes with bridging alkynyl ligand. Similar alkynyl ligand transfer from Pd to Pt complexes requires higher termperature or addition of CuI catalyst.Dialkynylpalladium and platinum complexes react with diiodo complexes of these metals to cause the complexes via transmetalation of the alkynyl ligands. Distribution of the product is influenced by thermodynamic stability of the complexes and the presence or absence of CuI catalyst which enhances the reaction significantly.Arylpalladium iodo complexes with chelating diamines do not cause intermolecular aryl ligand transfer, whereas the cationic species prepared from addition of AgBFィイD24ィエD2 to the complexes undergo disproportionation to give diarylpalladium complexes. The product give biaryl via reductive elimination, which is related to the mechanism of homocoupling reaction catalyzed by group 10 metal complexes. Rates of the transmetalation depend highly on kinds of aryl group; the complexes with fluorinated aryl ligand exhibit low reactivity toward the transmetalation.In summary, the present study has revealed various aspects of transmetalation of organotransition metal complexes and elucidated the mechanism of several synthetic organic reactions that involve transmetalation as a crucial step.