Asymmetric Michael addition reactions of aldehydes with nitrostyrenes catalyzed by functionalized chiral ionic liquids
作者:Qianying Zhang、Bukuo Ni、Allan D. Headley
DOI:10.1016/j.tet.2008.03.073
日期:2008.5
A new class of pyrrolidine-based functionalized chiral ionic liquids (FCILs) has been developed and shown to be effective and reusable catalysts for the asymmetric Michael addition reactions. For the Michael addition reaction involving various aldehydes and nitrostyrenes, FCIL 6, in combination with trifluoroacetic acid as an additive, was found to be a very effective catalyst, compared to FCIL 3,
已经开发出新型的基于吡咯烷的官能化手性离子液体(FCIL),并显示出它是用于不对称迈克尔加成反应的有效且可重复使用的催化剂。对于涉及各种醛和硝基苯乙烯的迈克尔加成反应,与结构略有变化的FCIL 3相比,发现FCIL 6与三氟乙酸结合作为添加剂是一种非常有效的催化剂。优异的收率(高达99%),良好的对映选择性(高达85%ee)和高非对映选择性(顺/反)对于这些反应,获得了高达97:3的比例)。FCIL催化剂易于回收和再利用至少五次,而不会显着丧失影响不对称反应结果的能力。