Easy access to bio-inspired osmium(II) complexes through electrophilic intramolecular C(sp(2))-H bond cyclometalation
Por:
Cerón-Camacho R., Morales-Morales D., Hernandez S., Le Lagadec R., Ryabov A.D.
Publicada:
2 jun 2008
Resumen:
Mild electrophilic C(sp(2))-H cyclometalation of 2-phenylpyridine and N,N-dimethylbenzylamine by the chloro-bridged osmium(II) dimer [OSCl(mu-Cl)(eta(6)-C6H6)](2) in acetonitrile affords cyclometalated pseudotetrahedral Os-II complexes [Os(C similar to N)(eta(6)-C6H6)(NCMe)]PF6 (C similar to N = o-C(6)H(4)py-kappa C,N (2) and o-C6H4CH2NMe2-kappa CN (5), respectively) in good to excellent yields. The cyclometalation reactions are super sensitive to the nature of an external base. Sodium hydroxide is essential for cyclometalation of 2-phenylpyridine, but NaOH retards metalation of N,N-dimethylbenzylamine, the tertiary amine being self-sufficient as a base. Further reactions of compounds 2 and 5 with 1,10-phenanthroline or 2,2'-bipyridine (N similar to N) lead to the substitution of the eta(6)-bound benzene to produce octahedral species [Os(C similar to N)(N similar to N)(NCMe)(2)]PF6 or [Os(C similar to N)(N similar to N)(2)]PF6 in MeCN or MeOH as solvent, respectively. The cis configura
Filiaciones:
Cerón-Camacho R.:
Univ Nacl Autonoma Mexico, Inst Quim, Mexico City 04511, DF, Mexico
Morales-Morales D.:
Univ Nacl Autonoma Mexico, Inst Quim, Mexico City 04511, DF, Mexico
Hernandez S.:
Univ Nacl Autonoma Mexico, Inst Quim, Mexico City 04511, DF, Mexico
Le Lagadec R.:
Univ Nacl Autonoma Mexico, Inst Quim, Mexico City 04511, DF, Mexico
Ryabov A.D.:
Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, United States
|