کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
51432 | 46843 | 2009 | 6 صفحه PDF | دانلود رایگان |
A general method for the covalent attachment of chiral salen Mn(III) complex to zirconium oligostyrenylphosphonate-phosphate has been used. The immobilized chiral salen Mn(III) catalyst shows higher chiral induction (ee, 60–70%) compared with the corresponding homogeneous catalyst (ee, 54%) for asymmetric epoxidation of α-methylstyrene with NaClO as oxidant, while the heterogeneous catalyst exhibits relatively low ee values for asymmetric epoxidation of indene. Interestingly, the ee values for the immobilized catalyst with NaClO as oxidant are higher than those for the same catalyst with m-chloroperbenzoic acid as oxidant. This stands in contrast to the literatures reported. The heterogeneous catalyst can be recycled nine times, while the activity will decrease after use in reactions.
Journal: Catalysis Communications - Volume 10, Issue 6, 15 February 2009, Pages 788–793