Cyanomethylation of alkenes with C-H bond activation of acetonitrile: in situ generated diazonium salts as promoters without transition-metalsElectronic supplementary information (ESI) available. See DOI: 10.1039/c5ra23471a

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 sp 3 -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. In situ generated diazonium salts were used as radical promoters for the C sp 3 -H functionalization of acetonitrile without photocatalyst or transition-metal.