Copper-Catalyzed Asymmetric Addition to Isatins to give 3-Hydroxy-2-oxindoles by C-H Activation
作者:Tao Deng、Hongjun Wang、Chun Cai
DOI:10.1002/ejoc.201402852
日期:2014.11
A copper-catalyzedasymmetricaddition to isatins to give3-hydroxy-2-oxindoles by C–Hactivation with a fluorous bis(oxazoline) as ligand is presented. The corresponding products were obtained in 35–66 % yields with enantioselectivities up to 92 %. The fluorous ligand can be easily recovered and reused at least three times without significant loss in its activity.
First asymmetric decarboxylative cyanomethylation of isatins is reported herewith using bifunctional thiourea derived from L-proline in good yields and enantioselectivities. This strategy enables the construction of various 3-cyanomethylene substituted 3-hydroxyoxindoles in enantioselective manner. Enantioselective synthesis of CPC-1 alkaloid has been accomplished in fewer steps.