The imido-amido complex [TaCp*(N t Bu)Cl(NH t Bu)], 1, was isolated from the reaction of [TaCp*Cl 4 ] with 3 equiv of LiNH t Bu. The dimethyl [TaCp*(N t Bu)Me 2 ], 2, and chloro-methyl [TaCp*(N t Bu)ClMe], 3, complexes were obtained by methylation of [TaCp*(N t Bu)Cl 2 ] with 2 equiv of LiMe and 1 equiv of ZnMe 2 , respectively. Metathetical reactions of complex 3 with alkali metal salts MX (M ) Na, X ) OMe; M ) Li, X ) O t Bu, NH t Bu) afforded the new imido-methyl compounds [TaCp*(N t Bu)MeX] (X ) OMe 4, O t Bu 5, NH t Bu 6). Insertion of CNR (R ) 2,6-Me 2 C 6 H 3 ) into the Ta-NH t Bu and Ta-Me bonds of the imido-pentamethylcyclopentadienyl complexes 1-6 gave the η 2 -iminocarbamoyl compound [TaCp*(N t Bu)Cl-{η 2 -C(NH t Bu)dNR}], 7, and the η 2 -iminoacyl compounds [TaCp*(N t Bu)X{η 2 -C(Me)dNR}] (X ) Me 8, Cl 9, OMe 10, O t Bu 11, NH t Bu 12), which under appropriate thermal conditions react with a second equivalent of CNR (R ) 2,6-Me 2 C 6 H 3 ) to give the double insertion imineη 2 -iminoacyl products [TaCp*(N t Bu)X{η 2 -C[C(Me)dNR]dNR}] (X ) Me 13, Cl 14, OMe 15, O t Bu 16, NH t Bu 17). When compound 17 was heated at 140 °C for 3 days, an intramolecular proton migration occurred to give the η 2 -diamidoalkene complex [TaCp*(N t Bu){η-N t Bu-C(NHR)dC(Me)-η-NR}], 18. All of the new compounds were characterized by IR, 1 H NMR, and 13 C NMR spectroscopy, and the molecular structures of 14 and 18 were studied by X-ray diffraction methods.