Abstract
| - A series of “constrained geometry” organoactinide complexes, (CGC)An(NMe)2 (CGC = Me2Si(η5-Me4C5)(tBuN); An = Th, 1; U, 2), has been prepared via efficient in situ, two-step protodeaminationroutes in good yields and high purity. Both 1 and 2 are quantitatively converted to the neutrally charged,solvent-free dichlorides (1-Cl2, 2-Cl2) and slightly more soluble diiodides (1-I2, 2-I2) with excess Me3Si−X(X = Cl, I) in non-coordinating solvents. The new complexes were characterized by NMR spectroscopy,elemental analysis, and (for 1 and 2) single-crystal X-ray diffraction, revealing substantially increased metalcoordinative unsaturation vs the corresponding Me2SiCp‘ ‘2AnR2 (Cp‘ ‘ = η5-Me4C5; An = Th, R = CH2(SiMe3), 3; An = U, R = CH2Ph, 4) and Cp‘2AnR2 (Cp‘ = η5-Me5C5 ; An = Th, R = CH2(SiMe3), 5; An =U, R = CH2(SiMe3), 6) complexes. Complexes 1−6 exhibit broad applicability for the intramolecularhydroamination of diverse C−C unsaturations, including terminal and internal aminoalkenes (primary andsecondary amines), aminoalkynes (primary and secondary amines), aminoallenes, and aminodienes. Largeturnover frequencies (Nt up to 3000 h-1) and high regioselectivities (≥95%) are observed throughout, alongwith moderate to high diastereoselectivities (up to 90% trans ring closures). With several noteworthyexceptions, reactivity trends track relative 5f ionic radii and ancillary ligand coordinative unsaturation.Reactivity patterns and activation parameters are consistent with a reaction pathway proceeding via turnover-limiting CC/C⋮C insertion into the An−N σ-bond.
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