Reaction of heterocumulenes R---N=C=N---R and R---P=C=P---R with a di-iron aminocarbene complex

Reaction of R---N=C=N---R (R=p-Me-C₆H₄) and R---P==C=P---R (R=2,4,6-^tBu₃C₆H₂) with the di-iron aminocarbene complex [Fe₂(CO)₇{1μ-C(Ph)C(NEt₂)}] (1c) gave corresponding complexes [Fe₂(CO)₆{C(Ph)C(NEt₂)C(NC₆H₄Me)N (C₆H₄Me)}] (2) and [Fe₂(CO)₆{C(Ph)C(NEt₂)C(PC₆H₂^tBu₃)P(C₆H₂^tBu₃)}] (4), resulting from a coupling reaction with carbon-carbon bond formation. [Fe₂(CO)₅(CNC₆H₄Me){C(Ph)C(NEt₂)N(C₆H₄Me)}], complex 3, obtained in the reaction with R---N=C=N---R, resulted from C=N bond rupture insertion of a nitrene fragment into the Fe=C bond. Complexes 2–4 were characterized by X-ray diffraction. The different geornetries of complexes 2 and 4 are discussed. The formation of these complexes may be explained by cycloaddition on the Fe =C metal-carbene bond.