大环多胺Fe(Ⅲ)配合物催化环己烯环氧化反应

Epoxidation of Cyclohexene Catalyzed by Macrocyclic Polyamine Fe(Ⅲ) Complexes

利用2,2-二乙基丙二酰氯、2,2-二甲基丙二酰氯或2,2-二氟丙二酰氯与α-氨基异丁酸、双(三氯甲基)碳酸酯、4,5-二氯邻苯二胺以及铁离子制得大环多胺Fe(III)配合物,考察了反应温度、H2O2用量、大环多胺配体的结构和大环多胺Fe(III)配合物的用量对环己烯环氧化反应的影响。结果表明,该催化剂在CH2Cl2中,以H2O2为氧化剂,获得了较高的环己烯转化率和环氧环己烷选择性。当以2,2-二氟丙二酰氯、α-氨基异丁酸、双(三氯甲基)碳酸酯、4,5-二氯邻苯二胺以及铁离子制备的大环多胺Fe(III)配合物为催化剂,在20℃反应2 h时,环己烯的转化率和环氧环己烷的选择性分别可达98%和92%。大环多胺配体抗氧化降解的能力越强,越有利于提高环氧环己烷的选择性,而其抗氧化降解能力取决于丙二酰基的αC原子上取代基的稳定性,键能越大越稳定。

The macrocyclic polyamine Fe(Ⅲ) complexes were synthesized by the reaction of α-aminoisobutyric acid,bis(trichloromethyl)carbonate,4,5-dichloro-o-phenylenediamine and iron with 2,2-diethylmalonyldichloride,2,2-dimethylmalonyldichloride or 2,2-difluoromalonyl dichloride.The effects of the reaction temperature,the amount of H2O2,the structure of macrocyclic polyamine ligand and amount of the macrocyclic polyamine Fe(Ⅲ) complexes on the epoxidation of cyclohexene were investigated.These results indicated that the catalysts gave higher conversion and selectivity to cyclohexene epoxide with H2O2 as oxidant in dichloromethane.The cyclohexene conversion of 98% and selectivity to cyclohexene epoxide of 92% were obtained when the reaction was performed at 20 ℃ for 2 h using the macrocyclic polyamine Fe(Ⅲ) complexes prepared by 2,2-difluoromalonyldichloride,α-aminoisobutyric acid,bis(trichloromethyl)carbonate,4,5-dichloro-o-phenylenediamine and iron as a catalyst.The strong anti-oxidation degradation capacity of the macrocyclic polyamine ligand was in favor of the increase of the selectivity for epoxide in the reaction.For the macrocyclic polyamine ligands,the strong anti-oxidation degradation capacity was determined by the stability of the substituent at α-C in the malonyl.The substituent with high bond energy could increase the stability,which increased the selectivity for the epoxidation reaction.