采用具有两个相邻位点的异双核 Ir III -Cu II配合物作为催化剂,在水中由甲酸盐驱动芳香族烯烃的有氧氧化。通过甲酸盐脱氢生成的 Ir III –H 中间体可以活化末端芳族烯烃以提供 Ir-烷基物质,并且该过程通过水中的疏水性 [Ir III –H]-[底物芳环]相互作用得到促进。 Ir-烷基物质随后与分子氧反应生成相应的甲基酮,并在酸性条件下通过 Cu II部分的存在而得到促进。 Ir III -Cu II配合物在烯烃选择性有氧氧化成相应甲基酮的过程中表现出协同催化作用,从相应的单核 Ir III和 Cu II配合物(作为 Ir III -Cu II的各个组分)中没有观察到反应性即可证明这一点。复杂的。通过反应中间体的光谱检测、动力学分析和理论计算,揭示了 Ir III -Cu II配合物在有氧氧化中的反应机理。
Formation Mechanism of Head‐to‐Head Amidato‐Bridged Acetonylplatinum(III) Binuclear Complexes – Kinetic Evidence for π‐Coordination of the Enol Form of a Ketone in a Ligand Substitution Reaction
Reactions of head-to-head (HH) α-pyridonato- and pivalamidato-bridged platinum(III) binuclearcomplexes withacetone were investigated kinetically. The reactions with acetone proceeded slowly to form acetonyl PtIII binuclearcomplexes in two steps. A mechanism, which involves π-coordination of the enol form of acetone in the first step, followed by the π–σ bond conversion in the second step, is proposed