Reactivity of a cobalt(III)-peroxo complex in oxidative nucleophilic reactions
Reactivity of a cobalt(III)-peroxo complex in oxidative nucleophilic reactions
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DOI：
10.1016/j.jinorgbio.2008.08.008
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发表时间：
2008-12-01
影响因子：
3.9
通讯作者：
Nam, Wonwoo
中科院分区：
文献类型：
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作者：
Jo, Youngrae;Annaraj, Jamespandi;Nam, Wonwoo
[Co-II(TMC)]（2+）与H2O2在CH3CN中三乙胺存在下反应生成了一种带有大环四齿N-4配体的单核钴(III)-过氧配合物[Co-III(TMC)(O-2)](+) （TMC = 1,4,8,11-四甲基-1,4,8,11-四氮杂环十四烷）。研究了钴(III)-过氧配合物在醛脱甲酰化反应中的反应活性，并与铁(III)-过氧配合物和锰(III)-过氧配合物[Fe-III(TMC)(O-2)]（+）和[Mn-III(TMC)O-2)]（+）进行了比较。在此反应性比较中，发现金属-过氧化物的反应性依次为[Mn-III(TMC)(O-2)](+) > [Co-III(TMC)(O-2)](+) > [Fe-III(TMC)(O-2)]（+）。在[Co-III(TMC)(O-2)]（+）和对取代苯甲醛的反应中得到正的Hammett rho值为1.8，表明钴(Ill)-过氧化物通过亲核反应发生醛去甲酰化。(C) 2008爱思唯尔公司版权所有。
A mononuclear cobalt(III)-peroxo complex bearing a macrocyclic tetradentate N-4 ligand, [Co-III(TMC)(O-2)](+) (TMC = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane), was generated in the reaction of [Co-II(TMC)](2+) and H2O2 in the presence of triethylamine in CH3CN. The reactivity of the cobalt(III)-peroxo complex was investigated in aldehyde deformylation with various aldehydes and compared with that of iron(III)- and manganese(III)-peroxo complexes, such as [Fe-III(TMC)(O-2)](+) and [Mn-III(TMC)O-2)](+). In this reactivity comparison, the reactivities of metal-peroxo species were found to be in the order of [Mn-III(TMC)(O-2)](+) > [Co-III(TMC)(O-2)](+) > [Fe-III(TMC)(O-2)](+). A positive Hammett rho value of 1.8, obtained in the reactions of [Co-III(TMC)(O-2)](+) and para-substituted benzaldehydes, demonstrates that the aldehyde deformylation by the cobalt(Ill)-peroxo species occurs via a nucleophilic reaction. (C) 2008 Elsevier Inc. All rights reserved.