A new synthetic approach to oxindoles (1,3-dihydro-2H-indol-2-ones) by reductive dephosphorylation with hydroiodic acid of 3-(diethylphosphoryloxy)-oxindoles, derived from isatins (1H-Indole-2,3-diones)

A novel method for the synthesis of 3-unsubstituted oxindoles by the reductive dephosphorylation of 3(diethylphosphoryloxy)oxindoles with hydroiodic acid was developed. This synthetic strategy involved a twostep procedure including a phospha-Brook rearrangement of isatins with diethyl phosphite and a reductive dephosphorylation of the phosphorylated oxindoles.