Synthesis of 3,3-disubstituted oxindoles from anilines nitrosated in situ: a radical-promoted reaction of aromatic amines with N-arylacrylamides

A mild and efficient synthesis of 3,3-disubstituted oxindoles is achieved. The corresponding diazonium salts are generated in situ from aromatic amines before these salts undergo a homolytic bond cleavage to produce the aryl radicals. Various oxindoles are obtained by homolytic aromatic substitution and radical cyclization. This procedure is an alternative method to oxindole synthesis.