摘要
在金鸡纳生物碱稳定剂存在下,通过简便的H2还原PtO2可以高效的在咪唑鎓盐离子液体中制备铂纳米颗粒(Pt NPs).TEM表明获得了平均粒径约1.78 nm且分散良好的Pt NPs.在金鸡纳生物碱的修饰下,Pt NPs催化剂在α-酮酸酯的不对称氢化中表现出优异的活性和对映选择性.在辛可尼定稳定和修饰作用下,丙酮酸乙酯催化不对称加氢TOF可达4640 h^-1,α-酮酸酯的多相对映选择性氢化中ee值可达70.0%~80.1%.研究表明稳定剂和修饰剂手性中心、立体构型及空间位阻等特性协同影响不对称催化诱导能力.BMIMPF6与乙酸的溶剂组合也是实现高活性及对映选择性的必要条件.催化剂可以重复使用多次,且活性和对映选择性没有明显降低.
Platinum nanoparticles(Pt NPs)were easily prepared in imidazolium-based ionic liquids by simple H2 reduction of PtO2 in the presence of cinchona alkaloid stabilizers.TEM showed that well-dispersed Pt NPs of about 1.78 nm were obtained.With the modification of cinchona alkaloids,the Pt NPs catalysts exhibited excellent activity and enantioselectivity in the asymmetric hydrogenation ofα-ketoesters.With the stabilization and modification of cinconidine,the ethyl pyruvate asymmetric hydrogenation could reach up to 4640 h^-1 TOF,and the ee value ofα-ketoesters heterogeneous enantioselective hydrogenation could reach 70.0%~80.1%.Studies showed that the characteristics of the chiral center,conformation as well as steric hindrance of the stabilizer and/or the modifier synergistically affected the asymmetric catalytic performance.The combination of BMIMPF6 and acetic acid solvents was also necessary for achieving high activity and enantioselectivity.Catalysts can be reused several times without significiant loss of activity and enantioselectivity.
作者
蒋和雁
成洪梅
陈诗佳
谭江伟
曾兴玲
贺洪会
JIANG He-yan;CHENG Hong-mei;CHEN Shi-jia;TAN Jiang-wei;ZENG Xing-ling;H E Hong-hui(Key Laboratory of Catalysis Science and Technology of Chongqing Education Commission,Chongqing Key Uiboratory of Catalysis and,New Environmental Materials,College of Environmental and Resources,Chongqing Technology and Business University,Chongqing 400067,China)
出处
《分子催化》
EI
CAS
CSCD
北大核心
2020年第3期193-200,I0001,共9页
Journal of Molecular Catalysis(China)
基金
重庆市自然科学基金项目(cstc2018jcyjAX0735,cstc2019jcyj-msxmX0641)
国家自然科学基金项目(No.21201184)
重庆市教委自然科学基金项目(No.KJQN201900811)
重庆工商大学自然科学基金项目(950119090)
催化与环境新材料重庆市重点实验室(KFJJ2019082)资助。
关键词
铂纳米粒子
金鸡纳碱
不对称氢化
α-酮酸酯
离子液
platinum nanoparticle
cinchona alkaloid
asymmetric hydrogenation
α-ketoester
ionic liquid
