Cyanomethylation of alkenes with C–H bond activation of acetonitrile: in situ generated diazonium salts as promoters without transition-metals

Abstract

Diazonium salts, which were in situ generated from p-anisidine and tert-butyl nitrite, could be used as a novel radical promoter for the C_sp³–H functionalization of acetonitrile. The cyanomethylation of alkenes could be performed without the use of transition-metal salts or photocatalyst and the functionalized oxindoles could be obtained with simple operation in moderate to good yields. This process tolerates a variety of functional groups and provides an alternative procedure for the synthesis of functionalized oxindoles.