The carbomethylation of arylacrylamides leading to 3-ethyl-3-substituted indolin-2-one by cascade radical addition/cyclization

Abstract

An FeCl₂-promoted carbomethylation of arylacrylamides by di-tert-butyl peroxide (DTBP) is achieved, leading to 3-ethyl-3-substituted indolin-2-one in high yield. The reaction tolerates a series of functional groups, such as cyano, nitro, ethyloxy carbonyl, bromo, chloro, and trifluoromethyl groups. The radical methylation and arylation of the alkenyl group are involved in this reaction.