Efficient synthesis of 3,3-di(indolyl)oxindoles catalyzed by sulfonic acid-functionalized mesoporous silica nanoparticles (SAMSNs) in aqueous media

摘要

An efficient protocol has been developed for the aqueous-mediated synthesis of 3,3-di(indolyl)oxindole derivatives via the electrophilic substitution reaction of indoles with various isatins using sulfonic acid-functionalized mesoporous silica nanoparticles (SAMSNs) as a recoverable heterogeneous acid catalyst. This catalyst can be reused several times without significant loss of activity.