OXOPORPHINATO-IRON(V) OXIDATION OF POLYCYCLIC AROMATICS

该项目的长期目标是提供对 通过同工酶家族，细胞色素P450的单加氧机制。 实现这一目标的战略所依据的一个前提是， 具有催化活性的中间体是氧代铁基甜菜碱阳离子 自由基（cpd I类似物）。 将采取的办法是 表征了一系列合成的氧代铁基卟啉阳离子自由基， 为了确定分子和电子结构的参数， 通过使用氧代铁基卟啉阳离子将参数与化学相关联 自由基作为氧化剂与选定的多环芳烃（PAH） 基质作为探针。 特别令人感兴趣的将是 铁基卟啉自由基自旋耦合的化学反应性， 合成模型系统 尽管模型cpd I类似物表现出强的 平行（铁磁）耦合，耦合在所有已知的酶物种是 弱的或反平行的（反铁磁的）。 虽然合成模型 不要接近酶的复杂性， 关于氧代铁基卟啉阳离子自由基的化学和 这一物种对PAH的氧化作用。 待研究的氧代铁基卟啉阳离子自由基衍生自 具有以下芳基取代基的四芳基卟啉铁络合物： 2，4，6-trimethyl phenyl（mesityl）; 2，4，6-trimethoxy phenyl; 2，6-trimethylphenyl 二氯苯基。 此外，还制备了来自2，4，6-三甲基苯基的cpd I类似物， 吡咯B位上被溴和芴取代的配合物 将被定性。 两个四芳基二氢卟酚（7，8-二氢 四苯基卟啉）络合物：2，6-二氯苯基-和2，6- 双三氟甲基二氢卟酚，将根据迹象进行研究 高价配合物具有不寻常的物理化学性质。 PAH底物是红荧烯，预计将经历一个简单的- 电子氧化为稳定的阳离子自由基，苯并蒽和苯并[k] 醋菲烯 后两种PAH应产生7，12-醌， 电子氧化和二氢二醇和/或酚类 加成-重排机理

The long-term goal of this project is to provide insight into the mechanisms of monooxygenation by the family of isozymes, cytochromes P450. A premise underlying the strategy for achieving this objective is that the catalytically competent intermediates are oxoferryl prophyrin cation radicals (cpd I analogues). The approach to be followed will be to characterize a series of synthetic oxoferryl porphyrin cation radicals in order to determine parameters of molecular and electronic structure and to correlate parameters with chemistry by using the oxoferryl porphyrin cation radicals as oxidants with selected polycyclic aromatic hydrocarbon (PAH) substrates as probes. Of particular interest will be the implications of the ferryl-porphyrin radical spin coupling for chemical reactivity in the synthetic model systems. Although model cpd I analogues exhibit strong parallel (ferromagnetic) coupling, coupling in all known enzymic species is either weak or anti-parallel (antiferromagnetic). While synthetic models do not approach the complexity of the enzymes, much will be learned concerning the chemistry of oxoferryl porphyrin cation radicals and the oxidation of PAH by this species. The oxoferryl porphyrin cation radicals to be studied are derived from tetraaryl porphinatoiron complexes with the following aryl substituents: 2,4,6-trimethylphenyl (mesityl); 2,4,6-trimethoxyphenyl; 2,6- dichlorophenyl. In addition, cpd I analogues from 2,4,6-trimethlyphenyl complexes substituted on the pyrrole B-positions with bromine and fluorene will be characterized. Two tetraaryl chlorin (7,8-dihydro tetraphenylporphyrin) complexes: 2,6-dichlorophenyl-and 2,6- bistrifluoromethyl chlorin, will be investigated in light of indications that the high-valent complexes have unusual physico-chemical properties. PAH substrates are rubrene, which is expected to undergo facile one- electron oxidation to a stable cation radical, benzanthracene and benz[k] acephenanthrylene. The latter two PAH should give 7,12-quinones by one- electron oxidation and dihydrodiols and/or phenols by an electrophilic addition-rearrangement mechanism.