4-Dimethylaminopyridine-Boryl Radical Promoted Monodefluorinative Alkylation of 3,3-Difluorooxindoles

Comprehensive Summary A selective monodefluorinative alkylation of 3,3-difluorooxindoles is achieved. The reaction starts by the attack of a 4-dimethylaminopyrine-boryl radical to the carbonyl oxygen atom of 3,3-difluorooxindoles, followed by a spin-center shift to generate radical intermediates with the elimination of a fluoride anion. The subsequent radical addition to alkenes affords a range of 3-alkyl-fluorooxindoles products. The strategy offers access to C-3 functionalized oxindoles with wide substrate scope and tolerates a wide range of functional groups.