O2 AS TOOL TO STUDY METAL CATALYZED OXYGENATION REACTIONS

O2 作为研究金属催化氧化反应的工具

• 批准号: 6481225
• 负责人: MATTHIAS SELKE
• 金额: $ 7.33万
• 依托单位: CALIFORNIA STATE UNIVERSITY LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6481225
• 关键词: Diels Alder reaction; adduct; chemical synthesis; chemical transfer reaction; copper; enzyme model; heavy metals; metal complex; metalloenzyme; molybdenum; nuclear magnetic resonance spectroscopy; oxidation; oxygenases; peroxides; singlet oxygen; spectrometry; thiols

Many metal complexes are able to react cleanly with singlet oxygen to make new metal-peroxo complexes. This methodology suggests a new approach toward the preparation of metal-dioxygen complexes, leading to new model systems that mimic important enzymes and to new insights into the mechanism of oxygen atom transfer to a variety of substrates. Reactions of transition metal complexes with singlet oxygen can be carried out at very low temperatures. Thus, thermodynamically very unstable metal-dioxygen complexes whose existence has previously been limited to the realm of speculation can be synthesized, directly observed, and their reactivities can be studied. At the same time, the scope of oxidative addition of singlet oxygen to metals will be studied. Thus far, no such reactions have been reported for early transition metals. We will attempt to prepare several biologically relevant peroxo complexes derived from early transition metals with singlet oxygen. Other subprojects will probe the mechanistic features of the oxidation of metal-coordinated thiolates. It will be examined whether or not oxidation of the metal followed by oxygen atom transfer to the sulfur atom is a viable reaction pathway. Another subproject involves the synthesis of an endoperoxide coordinate to a copper complex as a model for the copper enzyme quercetinase. Different reactions of singlet oxygen with dinuclear complexes will also be examined. In summary, the various rather diverse subprojects reflect the diverse areas in which the utilization of singlet oxygen as a mechanistic tool may lead to important mechanistic insights.

许多金属配合物能够与单线态氧发生干净的反应，生成新的金属过氧配合物。该方法提出了一种制备金属-双氧复合物的新方法，从而产生了模拟重要酶的新模型系统，并对氧原子转移到各种底物的机制有了新的见解。过渡金属配合物与单线态氧的反应可以在非常低的温度下进行。因此，可以合成、直接观察到热力学非常不稳定的金属-分子氧配合物，其存在以前仅限于推测领域，并且可以研究它们的反应性。同时，还将研究单线态氧对金属的氧化加成范围。到目前为止，还没有关于早期过渡金属的此类反应的报道。我们将尝试制备几种由早期过渡金属与单线态氧衍生的生物学相关的过氧配合物。其他子项目将探讨金属配位硫醇盐氧化的机理特征。将检查金属氧化随后氧原子转移到硫原子是否是可行的反应途径。另一个子项目涉及合成与铜络合物配位的内过氧化物，作为铜酶槲皮素酶的模型。还将检查单线态氧与双核配合物的不同反应。总之，各种相当不同的子项目反映了利用单线态氧作为机械工具可能带来重要机械见解的不同领域。