Iodine-promoted insertion of the oxygen atom from water in η 4 -vinylketene[Fe(CO) 3 ] complexes.

Iodine promotes the in situ formation of iron(II) species from η 4 -vinylketene[Fe(CO) 3 ] (3a-h) as a key intermediate for the synthesis of 2(5 H )-furanones (4a-h) by a sequential water-insertion/carbon-oxygen coupling under mild reaction conditions. Compounds 4a-h were obtained in good to excellent yields. A possible reaction pathway was also proposed by DFT calculations. This methodology can be extended to the synthesis of (5 H )-pyrrol-2-ones using anilines, with moderate yields and a few limitations.