Unexpected products from the Fp2-catalyzed reductive cyclization of nitroaromatics bearing pendant unsaturation

A representative o-nitroenone (Z=O) was cyclized by reduction with CO and [CpFe(CO)2]2 (Fp2) as the catalyst to give the corresponding 4-quinolone. In contrast, Baylis–Hillman adducts derived from o-nitrobenzaldehydes were cyclized to N-formylindolines and indoles under the same conditions.