TETRAHEDRON LETTERS, vol.59, no.6, pp.541-545, 2018 (Journal Indexed in SCI)
Article / Article
Title of Journal :
Asymmetric organocatalysis, Mannich reaction, 3-Amino-2-oxindole, Isatin ketimine, Bifunctional squaramide, ENANTIOSELECTIVE MICHAEL ADDITION, PICTET-SPENGLER REACTIONS, AZA-HENRY REACTION, CONJUGATE ADDITION, ALPHA-AMINATION, CHEMICAL SPACE, CONTIGUOUS STEREOCENTERS, RECEPTOR ANTAGONIST, DERIVATIVES, 3-AMINOOXINDOLES
A highly enantioselective synthesis of 3-amino-2-oxindoles by direct Mannich reaction 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. (C) 2017 Elsevier Ltd. All rights reserved.