OXOPORPHINATO-IRON(V) OXIDATION OF POLYCYCLIC AROMATICS

该项目的长期目标是提供对 细胞色素P450同工酶家族的单氧合机制。 实现这一目标的战略的一个前提是 具有催化活性的中间体是氧铁基卟啉阳离子。 自由基(CPD I类似物)。将遵循的方法将是 合成的一系列氧-铁基卟啉阳离子自由基的表征 以确定分子结构和电子结构参数，并 氧铁基卟啉阳离子与化学参数的关联 选择多环芳烃(PAH)作为氧化剂的自由基 作为探针的底物。尤其令人感兴趣的是 铁基-卟啉自由基自旋偶联对化学反应活性的影响 合成模型系统。尽管CPD I模型类似物表现出很强的 平行(铁磁)偶联，在所有已知的酶类中偶联是 弱的或反平行的(反铁磁性)。虽然合成模型 不要接近酶的复杂性，我们会学到很多东西的 关于氧铁基卟啉阳离子自由基的化学和 该物种对多环芳烃的氧化作用。 所要研究的氧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： 2，4，6-三甲基苯基 二氯苯基。此外，来自2，4，6-三甲基苯基的CPD I类似物 溴和荧取代吡咯B位上的络合物 将被描述为。两个四芳基氯(7，8-二氢 四苯基卟啉)配合物：2，6-二氯苯基和2，6-二氯苯基 双三氟甲基氯，将根据适应症进行研究 高价络合物具有不同寻常的物理化学性质。 多环芳烃的底物是Rubrene，预计会发生一种简单的反应-- 电子氧化成稳定的阳离子自由基--苯并菲和苯并[k] 乙基菲。后两种多环芳烃应以1为单位给出7，12-苯二酚- 电子氧化和二氢二酚和/或苯酚 加成-重排机制。

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.