Chiral Squaramide-Catalyzed Enantioselective Decarboxylative Addition of β-Keto Acids to Isatin Imines
作者:Jasneet Kaur、Anita Kumari、Vimal K. Bhardwaj、Swapandeep Singh Chimni
DOI:10.1002/adsc.201700011
日期:2017.5.17
An efficient chiral squaramide‐catalyzed enantioselective decarboxylative addition reaction of β‐keto acids to isatinimines has been developed. The reaction proceeds smoothly using 20 mol% of organocatalyst to afford the chiral 3‐aminooxindoles in high yield and excellent enantioselectivities.
A highly enantioselective addition of diphenylphosphite to ketimines derived from isatins has been developed employing bifunctional thiourea-tertiary amine organocatalysts. A variety of isatins derived ketimines react well with diphenylphosphite in the presence of Cinchona-derived thiourea (epiCDT) to provide biologically important chiral 3-substituted 3-amino-2-oxindoles (3a–l) in good yield (up
Stereoselective Mannich Reaction of
<i>α</i>
‐Acetoxy‐
<i>β</i>
‐keto Esters with Isatin Imine: An Efficient Access to Vicinal Tetra‐Substituted Stereocenters
Synthesis of optically active 3-substituted-3-aminooxindoles containing vicinal quaternary stereogenic centers was achieved using a quinine thiourea organocatalyst. α-Acetoxy-β-keto esters have been introduced as nucleophiles to undergo Mannichreaction with isatinimines for asymmetric organocatalysis.
Enantioselective addition of diphenyl phosphonate to ketimines derived from isatins catalyzed by binaphthyl-modified organocatalysts
作者:Hee Seung Jang、Yubin Kim、Dae Young Kim
DOI:10.3762/bjoc.12.149
日期:——
Chiral binaphthyl-modified squaramide-catalyzed enantioselectiveaddition of diphenyl phosphonate to ketimines derived from isatins has been achieved. This method affords practical and efficient access to chiral 3-amino-3-phosphonyl-substituted oxindole derivatives in high yields with excellent enantioselectivities (up to 99% ee).
An organocatalytic asymmetric aza-Henry reaction of ketimines derived from isatins with nitroalkanes has been achieved using Cinchona alkaloid organocatalysts. This method works efficiently with several ketimines to produce a good (up to 82%) yield of the corresponding 3-substituted 3-amino-2-oxindoles with a good (up to 89%) enantiomeric excess.