Reactivity of octahedral eta(1)-allenyl iridium toward hard nucleophiles

A labile octahedral (eta(1)-allenyl)iridium complex, (OC-6-42)-Ir(Cl)(PPh(3))(2)(OTf)(CO)(eta(1)-CHCCH2) (2a), undergoes regioselective addition with water or alcohol at the allenyl central carbon to generate the (eta(3)-2-hydroxyallyl) and (eta(3)-2-alkoxyallyl)iridium complexes {Ir(Cl)-(PPh(3))(2)(CO)[eta(3)-CH2C(OR)CH2]}(OTf) (R = H (3), Me (4a), Et (4b)), respectively. The complex 3 and the eta(3)-oxa-TMM species Ir(Cl)(PPh(3))(2)(CO)[eta(3)-CH2C(O)CH2] (5) constitutes a conjugate acid-base pair. Hydrolysis of the eta(3)-alkoxyallyl complexes yields 3, which further transforms into the carbon-bound iridium enolate (OC-6-52)-{Ir(Cl)(PPh(3))(2)(OH2)(CO)[eta(1)-CH2C(O)CH3]}-(OTF) (6). The reaction of 2a with ammonia results in the substitution of NH3 for the triflate ligand instead of hydroamination to the allenyl ligand. The construction of the C-N bond, however, is alternatively achieved by replacing the alkoxy group in 4a or 4b with amino group, leading to the formation of the N-protonated and N-alkylated eta(3)-aza-TMM iridium {Ir(Cl)(PPh(3))(2)(CO)[eta(3)-CH2C(NR(2))CH2]}(OTf) (R = H (7a), Et (7b)).