Three component synthesis of 2-oxindole via sequential Michael addition, intramolecular cyclization and aromatization

An easy metal free access to the synthesis of medicinally promising 2-oxindole derivatives via a tandem enamine formation - Michael addition - regiospecific intramolecular cyclization - aromatization sequence promoted by trifluoroacetic acid has been described. This three component reaction is regiospecific with good yield and satisfactory atom economy.