L-脯氨酸稳定的铱催化苯乙酮及其衍生物不对称加氢反应(英文)  

Asymmetric Hydrogenation of Acetophenone and Its Derivatives Catalyzed by L-Proline Stabilized Iridium

作　　者：杨朝芬[1] 杨俊[1] 朱艳琴[1] 孙晓东[1] 李贤均[2] 陈华[2] 

机构地区：[1]昆明理工大学分析测试研究中心,昆明650093 [2]四川大学化学学院有机金属络合催化研究所绿色化学与技术教育部重点实验室,成都610064

出　　处：《物理化学学报》2011年第12期2887-2892,共6页Acta Physico-Chimica Sinica

基　　金：supported by the Applied Basic Research Programs of Yunnan Province, China (2010ZC039)~~

摘　　要：以L-脯氨酸为稳定剂制备了负载型金属铱催化剂, 并用于苯乙酮及其衍生物不对称加氢反应. 考察了载体以及L-脯氨酸的量对催化剂性能的影响, 以透射电镜(TEM)和X射线光电子能谱(XPS)对催化剂进行了表征. 结果表明L-脯氨酸对金属铱粒子具有较好的分散和稳定作用. 通过考察反应条件发现: 碱金属离子对反应有较大影响; L-脯氨酸与手性修饰剂对催化活性和对映选择性存在一定的协同促进作用. 在手性二胺(1S,2S)-1,2- 二苯基乙二胺 ((1S,2S)-DPEN) 修饰下, 催化剂 5% (w, 质量分数)Ir/15( 脯氨酸与铱的摩尔比)(L-Proline)-γ-Al2O3催化苯乙酮不对称加氢获得了71.3%的对映选择性(ee), 2?-(三氟甲基)苯乙醇的对映选择性达到了79.8%. 该催化剂制备方法简单, 不需要膦配体做稳定剂, 催化剂性能稳定, 通过简单的离心分离可循环使用5次而无明显的活性和对映选择性降低.A supported iridium catalyst stabilized by L-proline was prepared under mild conditions and was applied to the heterogeneous asymmetric hydrogenation of acetophenone and its derivatives. The effect of the support and L-proline on the supported iridium catalyst was studied. The catalyst was characterized by transmission electron microscopy （TEM） and X-ray photoelectron spectroscopy （XPS）. The results showed that L-proline had a marked ability to stabilize and disperse the iridium particles. Reaction conditions for the asymmetric hydrogenation of acetophenone were examined in detail. LiO3 enhanced the activity and enantioselectivity of the reaction. The alkali metal cation plays an important role in influencing the enantioselectivity. In addition, a synergistic effect between （1S,2S）-1,2-diphenyl-1,2- ethylenediamine （（1S,2S）-DPEN） and L-proline was observed, which significantly accelerated the reaction rate and enhanced the enantioselectivity. In the presence of （1S,2S）-DPEN as chiral modifier the catalyst 5% （w, mass fraction）1r/15（the molar ratio of L-proline to Ir）（L-Proline）-y-AI203 exhibited good catalytic performance in the asymmetric hydrogenation of acetophenone and its derivatives. Under optimum conditions the enantiomeric excess （ee） values of （R）-phenylethanol and （R）-2＇-（trifluoromethyl） phenylethanol were 71.3% and 79.8%, respectively. Without using phosphine as a stabilizer the preparation of the catalyst was simple and the catalyst was reused several times without a significant loss in activity and enantioselectivity.

关 键 词：不对称加氢 L-脯氨酸 铱 苯乙酮 (1S 2S)-1 2-二苯基乙二胺 

分 类 号：O643.32[理学—物理化学]