【作者】 柴凤兰；

【导师】 王向宇； 陶京朝；

【作者基本信息】 郑州大学 ， 有机化学， 2009， 博士

【摘要】 烯烃环氧化反应是合成环氧化物的重要方法之一,烯烃环氧化催化剂的研究,特别是烯烃不对称环氧化催化剂的研究是目前化学界研究的热点之一。本文对新型二茂铁亚胺钼（Ⅵ）配合物及其用于烯烃环氧化反应催化性能进行了以下四方面的工作:1.分别以甲酰基二茂铁和5个脂肪族二胺或乙醇胺为原料合成了一系列的二茂铁基双亚胺和二茂铁基亚胺醇配体;在室温条件下,配体与MoO₂Cl₂的溶剂加合物进行配体交换合成了六种新型含二茂铁基亚胺钼（Ⅵ）配合物（Scheme1和Scheme 2）,并用元素分析、红外光谱、紫外可见吸收光谱、¹H NMR对二茂铁基亚胺及其钼（Ⅵ）配合物的结构和组成进行了表征。2.利用电化学和热分析方法对配合物的电化学性质和热稳定性进行了研究。电化学研究结果首次表明,二茂铁基亚胺配体与钼（Ⅵ）配位后影响钼（Ⅵ）的氧化还原性质和二茂铁基的稳定性。采用摩尔比法测定了配合物在四氢呋喃（THF）溶液中的配位比及稳定常数。3.首次详细考察了以二茂铁基亚胺钼（Ⅵ）配合物为催化剂、叔丁基过氧化氢为氧源催化烯烃-环己烯、1-己烯、苯乙烯和4-氯苯乙烯环氧化反应性能。实验表明,二茂铁基亚胺钼（Ⅵ）配合物对烯烃环氧化反应具有比较好的催化性能。相对而言,二茂铁基双亚胺钼（Ⅵ）配合物对环己烯、1-己烯的催化性能优于苯乙烯和4-氯苯乙烯,而二茂铁基亚胺醇钼（Ⅵ）配合物对芳香族烯烃的环氧化反应有更好的催化活性。4.本文首次发现非手性的二茂铁基双亚胺钼（Ⅵ）配合物对前手性烯烃环氧化反应具有不对称催化作用。在常温下,乙二胺双缩二茂铁亚胺钼（Ⅵ）配合物MoO₂OCl₂L¹对苯乙烯环氧化表现出比较好的不对称催化性能,其反应转化率为40%,R-（-）-氧化苯乙烯的e.e.值达到53%（Scheme 3）。反应的立体选择性受温度和配体结构影响比较明显。产物的e.e.值随着温度的升高而降低,产物的构型随着催化剂配体中桥连碳原子长度的改变发生明显的变化。本文对烯烃环氧化反应的机理进行了探讨,依据实验事实提出了新的烯烃环氧化反应机理。更多还原

【Abstract】 The epoxidation of olefins is one of the important methods for the synthesis of epoxides. The research of catalysts for olefin epoxidation, especial for asymmetric epoxidation, is a hotspot in chemistry at the present time.In this thesis, the dioxomolybdenum （Ⅵ） complexes of ferrocenylimine ligands used as novel catalyst for olefin epoxidation were studied in the following four aspects:1. A series of ferrocenyldiimine and ferrocenyliminoalcohol ligands were prepared by the condensation reaction of formylferrocene with aliphatic diamine or ethanolamine. Six novel dioxomolybdenum （Ⅵ） complexes of ferrocenylimine ligands were synthesized through the reaction of ferrocenylimine ligands with MoO₂Cl₂（THF）₂ at room temperature （Scheme 1 and Scheme 2）. The structures of the complexes were characterized by elemental analysis, FT-IR, UV-Vis spectra, ¹H NMR. 2. The characters of the dioxomolybdenum （Ⅵ） complexes of ferrocenylimine ligands were investigated by electrochemical method and thermo analysis. The redox behavior of molybdenum （Ⅵ） ion and the stability of ferrocenyl group were influenced greatly by the coordination of ferrocenylimine ligands to molybdenum （Ⅵ） ion. The coordination ratio and stability constant of the complexes were determined by Molar Ratio method in THF.3. Using the dioxomolybdenum （Ⅵ） complexes of ferrocenylimine ligands as catalyst, the epoxidation of general olefins such as cyclohexene, 1 -hexene, styrene and 4-chlorostyrene with tert-butylhydroperoxide （TBHP） took place smoothly. The results indicated that these dioxomolybdenum （Ⅵ） complexes showed the good catalytic performance for olefin epoxidation. And the dioxomolybdenum （Ⅵ） complexes bearing ferrocenyldiimine ligands showed better catalytic activity for cyclohexene and 1 -hexene epoxidation than that for 4-chlorostyrene epoxidation. In addition, the dioxomolybdenum （Ⅵ） ferrocenyliminoethanolate complex showed better performance for aromatic olefin epoxidation than that for cyclohexene and 1 -hexene epoxidation.4. It was surprisingly discovered that the achiral dioxomolybdenum （Ⅵ） complexes bearing ferrocenylimine ligands showed certain asymmetric catalytic activity for the epoxidation of prochiral olefins. The dioxomolybdenum （Ⅵ） complex bearing N, N’ -ferrocenylmethylenyl diamine can stereoselectively catalyze the epoxidation of styrene with 40% conversion at room temperature and a 53% e.e. of R-（-）-styrene oxide was obtained （Scheme 3）. The reaction temperature and structures of the ligands influenced greatly on the asymmetric catalytic behavior of the complexes. The e.e. value decreased with the increase of reaction temperature. While the length of bridge chain changed in the ligands of the complexes, the stereo structure of the products obviously changed.Moreover, the reaction mechanism of olefin epoxidation was proposed based on the experimental results.更多还原