The reactions of (η2-RCHCHCOR′)Fe(CO)4 (R = Ph, R′ = H; R = H, R′ = H and R = H, R′ = CH3) with aniline or its derivative afforded η4-azadiene complexes 1, 2 and 3 in various yields. The azadiene ligands in 2 and 3 are too reactive to isolate at ambient temperature, but 2 and 3 are stable up to ca 110 ° C. Treatment of (η2-CH2CHCHO)Fe(CO)4 with Ph3PCHCOOMe gave a η2-diene complex 4 which was converted to (η4-CH2CHCHCHCOOMe)Fe(CO)3 on heating, or reacting with (CH3)3NO. © 1990.