非血基質三價鐵超氧及過氧氫化物之合成與反應性

Abstract

在自然界中，P450細胞色素有著非常重要的催化能力，推測其反應機制有許多不穩定的中間體生成。在數種中間體當中，鐵超氧化物在裡面擔任重要的角色。本實驗室於先前發表的研究當中，已驗證二價鐵錯合物 Fe(BDPP) (H2BDPP = 2,6-bis[[(S)-2-(diphenylhydroxy- methyl)-1-pyrrolidinyl]methyl]pyridine) 與氧氣反應會形成鐵超氧化物，再和外加的氫原子提供者進行分子間氫原子轉移反應 (HAT) 形成鐵過氧氫化物。本研究利用較 Fe(BDPP) 更為穩定之二價鐵錯合物 Fe(BDBP) (H2BDBP = 2,6-bis[[(S)-2-(dibenzylhydroxymethyl)-1- pyrrolidinyl]methyl]pyridine) 與氧氣反應形成鐵超氧化物，且經多次觀察後發現其有機會行分子內碳氫鍵活化反應；重複先前的實驗，加入氫原子提供者後可形成鐵過氧氫化物，其後加酸性受質驗證，並以生成錯碘離子之 UV-vis 光譜觀測過氧化氫生成量，以確立鐵過氧氫化物含量。

In nature, P450 cytochrome has a very important catalytic ability, and its reaction mechanism involves many active intermediates. Among these intermediates, the iron superoxo species plays an important role. In a previously published study of this laboratory, it has been verified that the iron divalent complex Fe(BDPP) (H2BDPP =2,6-bis[[(S)-2-(diphenyl- hydroxymethyl)-1-pyrrolidinyl]methyl]pyridine) is capable of activating dioxygen to form an iron superoxo complex, which reacts with hydrogen atom donor to undergo intermolecular hydrogen atom transfer (HAT) reaction to form an iron hydroperoxo intermediate. The iron divalent complex, Fe(BDBP) (H2BDBP = 2,6-bis[[(S)-2-(dibenzylhydroxymethyl) -1-pyrrolidinyl]methyl]pyridine) which is more stable than Fe(BDPP), can also activate dioxygen to form an iron superoxo species. After numerous observation, it will proceed intramolecular hydrocarbons bond abstraction reaction, and carry out the previous experiments, reacting with external hydrogen atom donor to form an iron hydroperoxo intermediate confirmed by iodometric titration.