title: Constrained geometry organoactinides as versatile catalysts for the intramolecular hydroamination/cyclization of primary and secondary amines having diverse tethered C-C unsaturation.
abstract: A series of "constrained geometry" organoactinide complexes, (CGC)An(NMe)2 (CGC = Me2Si(eta5-Me4C5)(tBuN); An = Th, 1; U, 2), has been prepared via efficient in situ, two-step protodeamination routes 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 metal coordinative unsaturation vs the corresponding Me2SiCp' '2AnR2 (Cp' ' = eta5-Me4C5; An = Th, R = CH2(SiMe3), 3; An = U, R = CH2Ph, 4) and Cp'2AnR2 (Cp' = eta5-Me5C5 ; An = Th, R = CH2(SiMe3), 5; An = U, R = CH2(SiMe3), 6) complexes. Complexes 1-6 exhibit broad applicability for the intramolecular hydroamination of diverse C-C unsaturations, including terminal and internal aminoalkenes (primary and secondary amines), aminoalkynes (primary and secondary amines), aminoallenes, and aminodienes. Large turnover frequencies (Nt up to 3000 h-1) and high regioselectivities (>/=95%) are observed throughout, along with moderate to high diastereoselectivities (up to 90% trans ring closures). With several noteworthy exceptions, 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 C=C/CC insertion into the An-N sigma-bond.
authors: Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, USA.
authors: Bryan D
authors: BD
authors: Stubbert
authors: Tobin J
authors: TJ
authors: Marks
mesh_terms: D008671:Actinoid Series Elements / Q000737:chemistry*; D000466:Alkadienes / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry; D000586:Amination; D000588:Amines / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D003500:Cyclization; D006859:Hydrogen / Q000737:chemistry*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry
chemical_list: D008671:Actinoid Series Elements; D000466:Alkadienes; D000475:Alkenes; D000588:Amines; C025947:propadiene; D002244:Carbon; D006859:Hydrogen; D009584:Nitrogen