Suh Yumi, Seo Mi Sook, Kim Kwan Mook, Kim Youn Sang, Jang Ho G, Tosha Takehiko, Kitagawa Teizo, Kim Jinheung, Nam Wonwoo
Department of Chemistry, Division of Nano Sciences, and Center for Biomimetic Systems, Ewha Womans University, Seoul 120-750, Republic of Korea.
J Inorg Biochem. 2006 Apr;100(4):627-33. doi: 10.1016/j.jinorgbio.2005.12.013. Epub 2006 Feb 3.
Mononuclear nonheme oxoiron(IV) complexes bearing 15-membered macrocyclic ligands were generated from the reactions of their corresponding iron(II) complexes and iodosylbenzene (PhIO) in CH(3)CN. The oxoiron(IV) species were characterized with various spectroscopic techniques such as UV-vis spectrophotometer, electron paramagnetic resonance, electrospray ionization mass spectrometer, and resonance Raman spectroscopy. The oxoiron(IV) complexes were inactive in olefin epoxidation. In contrast, when iron(II) or oxoiron(IV) complexes were combined with PhIO in the presence of olefins, high yields of epoxide products were obtained. These results indicate that in addition to the oxoiron(IV) species, there must be at least one more active oxidant (e.g., Fe(IV)-OIPh adduct or oxoiron(V) species) that effects the olefin epoxidation. We have also demonstrated that the ligand environment of iron catalysts is an important factor in controlling the catalytic activity as well as the product selectivity in the epoxidation of olefins by PhIO.
含15元大环配体的单核非血红素氧代铁（IV）配合物是由其相应的铁（II）配合物与亚碘酰苯（PhIO）在乙腈中反应生成的。用紫外可见分光光度计、电子顺磁共振、电喷雾电离质谱仪和共振拉曼光谱等多种光谱技术对氧代铁（IV）物种进行了表征。氧代铁（IV）配合物在烯烃环氧化反应中无活性。相反，当铁（II）或氧代铁（IV）配合物在烯烃存在下与PhIO混合时，可获得高产率的环氧化产物。这些结果表明，除了氧代铁（IV）物种外，必须至少还有一种活性氧化剂（例如，Fe（IV）-OIPh加合物或氧代铁（V）物种）参与烯烃的环氧化反应。我们还证明了铁催化剂的配体环境是控制PhIO对烯烃环氧化反应的催化活性以及产物选择性的重要因素。
