Modularly Evolved 2-AminoDMAP/Squaramides as Highly Active Bifunctional Organocatalysts in Michael Addition
作者:Murat Işık、M. Yagiz Unver、Cihangir Tanyeli
DOI:10.1021/jo5022597
日期:2015.1.16
We report a new family of chiral bifunctional acid/base type organocatalysts, 2-aminoDMAP/Squaramides, which are proved to be highly active (1 mol % cat. loading) promoters in conjugate addition of dibenzoylmethane to various trans-β-nitroalkenes. Steric demand of the catalysts was clearly seen by a set-by-set modulation of the squaramide unit through electronic and steric factors. The synergistic
我们报道了一个新的手性双官能酸/碱型有机催化剂,2-aminoDMAP / Squaramides家族,被证明是在将二苯甲酰甲烷共轭加成到各种反式-β-硝基烯烃中的高活性(1 mol%催化剂负载量)促进剂。通过电子和空间因素对方酰胺单元进行逐组调节,可以清楚地看到催化剂的立体需求。2-氨基DMAP“超强碱”与空间受限的方酰胺(氢键供体)的协同作用,使得在短短几个小时内即可将一系列反应物完全转化为相应的迈克尔加成物,且选择性极高(ee高达98%)。