【摘要】 采用均相和多相两种方法合成了壳聚糖希夫碱-Cu( )配合物,用于催化苯乙烯的不对称环丙烷反应,考察了不同制备方法和不同铜含量对催化剂催化性能的影响以及催化剂的重复使用情况.当催化剂的铜含量为4.4%时,得到20.7%的ee值.更多还原

【Abstract】 Chitosan Schiff\|base copper complexes synthesized from chitosan and derivatives of salicylaldehyde in homo\| and hetero\| methods with different copper\|containing have been applied as the catalysts for asymmetric cyclopropanation of styrene with ethyl diazoacetate. It was found that when the copper\|containing was almost the same, the catalysts synthesized in homo method were more favorable to the enantioselectivity of the reaction than the catalysts synthesized in hetero\|method. 20.7% ee for cis\|isomer and 10.0% ee for trans\|isomer was obtained at 60 ℃ when the copper\|containing was about 4.4%. The complex with electron\|withdrawn or bulky substituents on the salicylaldehyde moiety had obvious influence on the catalytic enantioselectivity. Furthermore, the catalyst can be reused without loss of cyclopropanation activity.更多还原