Development ot highly selective oxygenation by oxygenase-model metal-oxygen active species and clarification of the mechanisms of selectivity control

发展了非血红素金属氧物种的高选择性氧化反应，并对选择性的控制机理进行了光谱研究。铁(III)络合物对儿茶酚的选择性氧化反应已被广泛研究。我们开发了氯代儿茶酚的选择性氧化。产品包括脱氯化氢产品，这为环境污染物氯代芳烃的脱氯开辟了新的工艺。分离出了模型中间体氯代全铁络合物。用X-射线光电子能谱、磁化率、电子顺磁共振、电子吸收光谱等分析了它们的构型和电子结构。结果表明，络合物应为铁(II)-半奎宁酸络合物，而不是铁(III)-儿茶酚络合物。其他研究的双加氧酶模型反应有：氧化亚油酸的脂肪氧合酶模型，羟化叔丁基苯酚得到邻儿茶酚的酪氨酸羟基酶模型，以及氧化烯烃得到环氧化物和烷烃得到醇的a-酮酸依赖加氧酶模型。除了合成工程外，还进行了机械研究。这些反应正在进一步研究中，以开发良好的催化氧化系统，并获得酶催化氧化的机理信息。

Highly selective oxygenations by nonheme metal-oxygen species were developed and mechanisms of the control of selectivity were studied spectroscopically.Selective intradiol oxygenation of catechols by iron(III) complexes has been extensively studied. We have developed the selective oxygenation of chlorocatechols. Products include dehydrochlorinated products, that opens the new process for the dechlorination of chloroaromatics which are environmental pollutant. The model intermediate complexes, chlorocatecholatoiron complexes have been isolated. Their configurational and electronic structures were analyzed by XAFS, magnetic susceptibility, EPR, electronic absorption spectra. It was indicated that the complexes should be represented by lron(II)-semiquinonate rather than lron(III)-catecholate complexes. Another dioxygenase model reactions studied are lipoxygenase model which oxygenates linoleic acid, tyrosine hydroxylase model which hydroxylates t-butylphenol to give o-catechol, and a-keto acid dependent oxygenase which oxygenates alkenes to give epoxides and alkanes to give alcohols. Mechanistic investigations were performed in addition to the synthetic works. These reactions are under further studies to develop good catalytic oxygenation systems and to get mechanistic information for enzymatic oxygenations.