Optically Active Titanium Complexes Containing Linked Amido‐cyclopentadienyl Ligands: Their Use as Asymmetric Hydrogenation Catalysts
1996; Wiley; Volume: 129; Issue: 12 Linguagem: Inglês
10.1002/cber.19961291205
ISSN0009-2940
AutoresJun Okuda, Sabine Verch, Thomas P. Spaniol, Rainer Stürmer,
Tópico(s)Coordination Chemistry and Organometallics
ResumoAbstract Optically active titanium complexes of the formula Ti(η 5 :η 1 −C 5 R 4 SiMe 2 NCHMePh)Cl 2 (R = H, Me), containing the cyclopentadienyl ligand linked to a chiral 1‐phenylethylamido moiety, were synthesized and characterized in both enantiomerically pure forms. A single‐crystal X‐ray structural analysis of ( S )()Ti(η 5 :η 1 −C 5 H 4 SiMe 2 NCHMePh)Cl 2 shows a conformation in which the phenyl group is turned away from the metal center. NOE measurements suggest that a related structure is retained in solution. Upon activation with n ‐butyllithium, these complexes show hydrogenation activity toward imines with slight enantioselectivity.
Referência(s)