3-Chlorooxindoles: Versatile Starting Materials for Asymmetric Organocatalytic Synthesis of Spirooxindoles
作者:Artur Noole、Maksim Ošeka、Tõnis Pehk、Mario Öeren、Ivar Järving、Mark R. J. Elsegood、Andrei V. Malkov、Margus Lopp、Tõnis Kanger
DOI:10.1002/adsc.201300019
日期:2013.3.25
3‐Chlorooxoindoles have emerged as versatile precursors in the synthesis of spirocyclopropyl oxindoles. High enantio‐ and diastereoselectivity was attained under conditions of both iminium/enamine and H‐bonding catalysis.
Enantioselective Construction of 3-Hydroxy Oxindoles via Decarboxylative Addition of β-Ketoacids to Isatins
作者:Fangrui Zhong、Weijun Yao、Xiaowei Dou、Yixin Lu
DOI:10.1021/ol301855w
日期:2012.8.3
The first highlyenantioselectivedecarboxylativeaddition of β-ketoacids to isatins mediated by a bifunctional tertiary amine–thiourea catalyst has been developed, allowing facile synthesis of biologically important 3-hydroxyoxindoles in good yields and excellent enantioselectivities. The method reported represents a valuable approach of utilizing β-ketoacids as synthetic equivalents of aryl/alkyl
Highly Enantio- and Diastereoselective Generation of Two Quaternary Centers in Spirocyclopropanation of Oxindole Derivatives.
作者:Artur Noole、Natalia S. Sucman、Mikhail A. Kabeshov、Tõnis Kanger、Fliur Z. Macaev、Andrei V. Malkov
DOI:10.1002/chem.201203099
日期:2012.11.19
possible stereoisomers was obtained in the asymmetric cascade cyclopropanation of alkylidene oxindoles with ethyl 2‐chloroacetoacetate. Improved catalyst design ensured that spirocyclopropyl oxindoles featuring twoquaternarycenters were synthesized in high yield and high enantio‐ and diastereoselectivity (see scheme).