3,3-Dialkylated oxindoles (1,3-dihydro-2H-indol-2-ones), particularly those containing C3 quaternary stereogenic centers, occupy an important place in organic synthesis and drug discovery. The radical 1,2-alkylarylation of activated olefins with alkyl radicals has emerged as the most atom- and step-economical approach to 3,3-dialkylated oxindoles. This article covers important developments in the area of oxidative radical alkylation/cyclization cascade reactions of α,β-unsaturated amides toward the synthesis of alkyl-substituted oxindoles by employing a range of alkyl-radical precursors and various reaction conditions.
