Asymmetric organocatalytic direct Mannich reaction of acetylacetone and isatin derived ketimines: Low catalyst loading in chiral cinchona-squaramides
作者:Duygu İşibol、Seda Karahan、Cihangir Tanyeli
DOI:10.1016/j.tetlet.2017.12.081
日期:2018.2
A highly enantioselective synthesis of 3-amino-2-oxindoles by directMannichreaction between acetylacetone and N-carbamoyl isatin ketimine has been described herein. Corresponding chiral adducts were obtained in high yields (up to 98%) and with excellent enantioselectivities (up to >99% ee) by very low (1 mol%) catalyst loading of 2-adamantyl substituted bifunctional cinchona-squaramide.