Indium Catalyzed Sequential Regioselective Remote C−H Indolylation and Rearrangement Reaction of Peroxyoxindole
Moseen A. Shaikh, Akash S. Ubale, Boopathy Gnanaprakasam
Abstract
Abstract Indium‐catalyzed sequential remote C−H functionalization (C‐6 position) and C3‐indolylation of peroxyoxindole using indole is described for the synthesis of terindolinone derivatives. Whereas, N ‐substituted 3‐phenyl peroxyoxindole derivatives undergoes consecutive skeletal rearrangement to generate transient carbocation, which has been trapped with indole nucleophile to generate 2‐(1 H ‐indol‐3‐yl)‐4‐alkyl‐benzo[ b ][1,4]oxazin‐3(4 H )‐one derivatives. In contrast with Indium (III) Chloride, FeCl 3 ⋅ 6H 2 O facilitates oxidative cleavage of the peroxyoxindole (Hock cleavage) and further reaction with indole to afford biologically important trisindoline derivatives. A plausible mechanism has been proposed for these reactions with experimental evidences. magnified image