A new method for the synthesis of iron azadiene and diene complexes. Reaction of (η2-RCHCHCOR′)Fe(CO)4 with aniline and ylide

The reactions of (η 2 -RCHCHCOR′)Fe(CO) 4 (R = Ph, R′ = H; R = H, R′ = H and R = H, R′ = CH 3 ) with aniline or its derivative afforded η 4 -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 (η 2 -CH 2 CHCHO)Fe(CO) 4 with Ph 3 PCHCOOMe gave a η 2 -diene complex 4 which was converted to (η 4 -CH 2 CHCHCHCOOMe)Fe(CO) 3 on heating, or reacting with (CH 3 ) 3 NO.