Hydrogen Atom Transfer Reactions of Imido Manganese(V) Corrole: One Reaction with Two Mechanistic Pathways
作者:Michael J. Zdilla、Jennifer L. Dexheimer、Mahdi M. Abu-Omar
DOI:10.1021/ja073027s
日期:2007.9.1
accumulation of a Mn(IV) intermediate. The imido complex (tpfc)Mn(V)NTs abstracts a hydrogen atom from phenols as well. For example, 2,6-di-tert-butyl phenol is oxidized to the corresponding phenoxyl radical with a second-order rate constant of 0.32 +/- 0.02 M(-1) s(-1) at 22 degrees C. The other products from imido manganese(V) are TsNH(2) and the trivalent manganese corrole. Unlike reaction with dihydroarenes
已经研究了 (tpfc)MnNT 的氢原子转移 (HAT) 反应(tpfc = 5,10,15-三(五氟苯基)corrole 和 Ts = 对甲苯磺酸盐)。9,10-二氢蒽和 1,4-二氢苯通过 HAT 还原 (tpfc)MnNT,二级速率常数分别为 0.16 +/- 0.03 和 0.17 +/- 0.01 M(-1) s(-1),在 22摄氏度。产品是各自的芳烃,TsNH(2) 和 (tpfc)Mn(III)。通过与二氢蒽反应将 (tpfc)MnNTs 转化为 (tpfc)Mn 表现出等吸收行为,并且没有观察到 9,9',10,10'-四氢联蒽的形成,这表明中间体蒽自由基在第二个快速步骤中反弹而没有Mn(IV) 中间体的积累。酰亚胺络合物 (tpfc)Mn(V)NTs 也从酚类中提取了一个氢原子。例如,2,6-二叔丁基苯酚在 22 摄氏度时被氧化为相应的苯氧基自由基,二级速率常数为