Competitive nucleophilic attack at CO and C-beta of the allenyl group in [Fe-2(CO)(6)(mu-PPh(2))(mu-eta(1):eta(2)-(H)C-alpha=C-beta=C gamma H2)]. X-ray crystal structures of [Fe-2(CO)(5)(mu-PPh(2))(mu-eta(1)(O):eta(1)(C):eta(2)(C)-{O=C(N(t)BuH)CH2}C=CH2)]center dot 0.5C(6)H(14) and [Fe-2(CO)(6)(mu-PPh(2))(mu-eta(1):eta(1)-CH2C(NCyH)CH2)]center dot MeCN

The phosphido-bridged diiron allenyl complex [Fe-2(CO)(6)(mu-PPh(2))(mu-eta(1):eta(alpha,beta)(2)-(H)C-alpha=C-beta=CgammaH2)] (1) reacts with primary amines to afford the amido-functionalized alkenyl complexes [Fe-2(CO)(5)(mu-PPh(2))(mu-eta(1)(O): eta(1)(C):eta(2)(C)-{O=C(NRH)CH2}C=CH2)] (R = (t)Bu (2a), Ph (2b)) vial a novel coupling sequence involving a terminal carbonyl, the alpha-carbon of the allenyl, and a hydrogen migration step, as well as dimetallacyclopentanes [Fe-2(CO)(6)(mu-PPh(2))(mu-eta(1):eta(1)-CH2C(NRH)CH2] (R = (t)Bu (3a), Cy (3b)) via nucleophilic attack at C-beta.