5-(Trifluoromethoxy)isatin (CAS number 169037-23-4), a derivative of indole, has two carbonyls at 2,3-position and a trifluoromethoxy at 5-position. In 5-(trifluoromethoxy)isatin, the carbonyl at 3-position is more reactive than the amide carbonyl at 2-position, thus it is readily functionalized under nucleophilic substitution. The nucleophilic substitution can also be enantioselective with the addition of chiral catalysts, with up to 92% ee (enantiomeric excess).
5-(Trifluoromethoxy)isatin is used to synthesize luminescent gold(I) complexes, displaying an emission at 400 nm. The isatin-gold complexes show cytotoxicity to cancer cells with half-maximal inhibitory concentration (IC50) as low as 0.28 μM. 5-(Trifluoromethoxy)isatin is also used to modify rhodamine in application of selectively detection of Cr3+. An isatin decorated fullerene (C60) has improved miscibility to P3HT in heterojunction organic solar cells.