Abstract:
An efficient synthetic protocol for (
E)−3−(2−phenyl−4
H−chromen−4−ylidene) indolin−2−one catalyzed by AgOTf had been developed. The cascade approach used 2−hydroxychalcone and oxindole as raw materials, involving Michael addition followed by intramolecular cyclization and dehydrogenation sequence. This cascade approach has the advantages such as operational simplicity, short reaction time and excellent yields. The effects of catalysts and scaled-up experiment on the yields were investigated. The structures of the obtained compounds were characterized by
1H NMR,
13C NMR, IR and HRMS.