摘要
研究了Salen Co(Ⅱ)配合物催化苯乙烯环氧化的反应.考察了不同取代基水杨醛制备的配体所形成的Co配合物1～4及(S,S)-1,2-二苯基乙二胺与水杨醛形成的Co配合物1(S,S)～3(S,S)的催化氧化性能,其中溴取代的配合物2和2(S,S)是最有效的催化剂.以配合物(2)为催化剂,氧气为氧化剂,考察了反应温度、时间、溶剂等因素对苯乙烯环氧化反应的影响.结果表明,最佳反应条件为苯乙烯10 mmol,配合物(2)0.1%,温度90 ℃,反应时间5 h时,苯乙烯的转化率为97.1%,环氧苯乙烷的选择性为58.9%,苯甲醛与苯甲酸的选择性为36.1%.并对反应机理进行了初步探讨.
The oxidation of styrene with molecular oxygen, in 1, 4-dioxane as a solvent, using a series of Salen Cobalt (II) complexes as catalysts has been studied. The effects of different Salen Cobalt (II) complexes 1~4 and 1(S, S)~3(S, S) were investigated on the oxidation of styrene. Catalytic activities were found to be dependent {upon} both the electron effect of the substituents on the Co (Ⅱ) Salen complexes and the presence of phenyl substituents on the ethylene moiety. The highest catalytic activity was reached with the Br-substituted complex (2), which was used for further studies on the effects of temperature, time and solvent for epoxidation. The effect of solvent was noted to be critical and the higher reaction temperature (90 ℃) was needed. Conversion of styrene reached 97.1%, with a 58.9% selectivity of epoxide and 36.1% selectivity of benzaldehyde and benzoic acid when reaction was run at 90 ℃ for 5 h. Possible reaction mechanism steps were outlined.
出处
《分子催化》
EI
CAS
CSCD
北大核心
2007年第1期48-53,共6页
Journal of Molecular Catalysis(China)
基金
南京工业大学博士创新基金(BSCX200508).
