Bioinspired Manganese Complexes and Graphene Oxide Synergistically Catalyzed Asymmetric Epoxidation of Olefins with Aqueous Hydrogen Peroxide
作者:Chengxia Miao、Xingbin Yan、Daqian Xu、Chungu Xia、Wei Sun
DOI:10.1002/adsc.201600848
日期:2017.2.2
the highly enantioselective epoxidation of olefins (up to 99% ee), which is a rare example with GO as a co‐catalyst in asymmetric catalysis. GO as a new and key additive not only successfully functions in catalytic amounts, but also has a positive effect for improving the enantioselectivity of the asymmetric epoxidation compared with the traditional stoichiometric organic carboxylic acid method [e.g
N 4配体和氧化石墨烯(GO)的生物启发性锰配合物可协同催化烯烃的高对映选择性环氧化(最高ee达99%ee),这在以GO为不对称催化助催化剂的情况下是一个罕见的例子。与传统的化学计量有机羧酸法[例如查尔酮,95%ee(3.5 mg GO )vs。84%ee(5当量,75 mg乙酸),肉桂酸乙酯,84%ee(3.5 mg GO)vs . 19%ee(5当量,75毫克乙酸)]。反应前后GO的X射线光电子能谱(XPS)表明,反应后C-O的强度增强,可能与过氧化氢(H 2 O 2)有一定的关系,并给出了合理的解释。大量消耗H 2 O 2的理由。另外,部分过氧化氢用于GO的氧化。