Mechanism of the oxidation of aromatic sulfides catalysed by a water soluble iron porphyrin
作者:Enrico Baciocchi、Maria Francesca Gerini、Osvaldo Lanzalunga、Andrea Lapi、Maria Grazia Lo Piparo
DOI:10.1039/b209004j
日期:2003.1.13
the oxidant. Moreover, no fragmentation products were observed in the oxidation of a benzyl phenyl sulfide whose radical cation is expected to undergo cleavage of the beta C-H and C-S bonds. These results would seem to suggest a direct oxygen atom transfer from the iron-oxo complex to the sulfide. However, competitive experiments between thioanisole (E degree = 1.49 V vs. NHE in H2O) and N,N-dimethylaniline
在水溶性铁卟啉5,10,15催化的酸性(pH 3)水性介质中,H2O2氧化H2O2氧化了许多芳基硫化物,研究了氧原子转移-电子转移(ET)机理的二分法, 20-四苯基-21H,23H-卟啉-p,p′,p″,p″′-四磺酸氯化三铁(FeTPPSCl)。在这些反应条件下,铁-氧配合物卟啉自由基阳离子P +。Fe(IV)= O应该是活性氧化剂。当研究一系列对位X取代的苯基烷基硫化物(X = OCH3,CH3,H,Br,CN)的氧化时,相应的亚砜是唯一观察到的产物,反应收率和反应性几乎不受X的性质以及烷基的体积。使用H(2)18O或H(2)18O2进行的标记实验清楚地表明,亚砜中的氧原子仅来自氧化剂。此外,在苄基苯基硫醚的氧化中未观察到任何断裂产物,该自由基的阳离子预期会发生βCH和CS键的断裂。这些结果似乎表明氧原子直接从铁-氧配合物转移至硫化物。但是,硫代苯甲醚(H2O中的E度= 1.49 V