期刊
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
卷 169, 期 1-2, 页码 1-10出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/S1381-1169(00)00446-5
关键词
manganeseporphyrin; cyclohexene epoxidation; iodosylbenzene; meso-phenyl ortho-OH substituent
Catalytic cyclohexene epoxidation with iodosylbenzene by the following Mn-porphyrins bearing ortho substituents on a meso group: MnTTP, MnM2-OHPTTP(5-(2-hydroxyphenyl)-10,15,20-tritolylporphyrin) and MnM2-BrPTTP(5-(2-(3-bromo-1-propoxy)phenyl)-10,15,20-tritolylporphyrin), has been studied. The effect of dioxygen and imidazole axial ligand on the yields of epoxide and allylic oxidation products, i.e. alcohol and ketone, was investigated. It was observed that the product selectivity is strongly dependent on the distribution of the Im/MnP species (M, MIm and MIm(2) obtained by spectrophotometric titrations). For MnTPP at Im/MnP = 1 the best epoxide yield associated with the maximum MIm concentration was observed. The presence of the -OH substituent produced a remarkable effect on the reactivity and catalytic properties of the porphyrin system, i.e. drastic reduction in allylic oxidation, slight increase on the epoxide yield, a decrease on the formation of the MnP/Im complexes and change of the reactivity of the Mn center with PhIO. These results are discussed in terms of a possible electronic interaction of the oxygen ortho substituent and the porphyrin ring. (C) 2001 Elsevier Science B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据