A new heterogeneous chiral (salen)manganese(III) system for enantioselective epoxidation of non‐functionalized olefins |
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| Authors: | Saili Wei Yuhai Tang Xiaoqian Xu Guojin Xu Yong Yu Yang Sun Yuansuo Zheng |
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| Institution: | 1. Institute of Analytical Sciences, School of Science, Xi'an Jiaotong University, Xi'an 710061, China;2. Medical School, Xi'an Jiaotong University, Xi'an 710061, China |
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| Abstract: | This communication describes the design and application of a novel catalytic epoxidation system derived from the initial immobilization of a homogeneous sulfonato (salen)Mn(III) complex on two solid carriers (silica gel and siliceous earth) and subsequent dispersion of the supported manganese complexes into ionic liquid 1‐butyl‐3‐methylimidazolium hexafluorophosphate (BMImPF6) and 1‐butyl‐3‐methylimidazolium tetrafluoroborate (BMImBF4) for recycling. The performance of chiral (salen)Mn(III) system in enantioselective epoxidation of olefins was investigated systematically. Even higher enantioselectivity than that of the homogeneous counterpart was obtained with similar catalytic activity. In particular, the best catalytic result is that the combination of the silica gel‐supported (salen)Mn(III) catalyst and BMImPF6 affords 97–100% ee for epoxidation of α‐methylstyrene, and high ee values were retained even after three cycles. Copyright © 2010 John Wiley & Sons, Ltd. |
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| Keywords: | enantioselective epoxidation heterogeneous (salen)manganese(III) ionic liquld olefins |
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