RESUMO
The asymmetric reduction of N-aryl imines derived from acetophenones by using Ru complexes bearing both a pybox (2,6-bis(oxazoline)pyridine) and a monodentate phosphite ligand has been described. The catalysts show good activity with a diverse range of substrates, and deliver the amine products in very high levels of enantioselectivity (up to 99 %) under both hydrogenation and transfer hydrogenation conditions in isopropanol. From deuteration studies, a very different labeling is observed under hydrogenation and transfer hydrogenation conditions, which demonstrates the different nature of the hydrogen source in both reactions.
Assuntos
2-Propanol/química , Acetofenonas/química , Complexos de Coordenação/química , Iminas/química , Rutênio/química , Catálise , Hidrogênio , Hidrogenação , Fosfitos/química , Piridinas/química , EstereoisomerismoRESUMO
New ruthenium complexes containing enantiopure 2,6-bis[4'(R)-phenyloxazolin-2'-il-pyridine] ((R,R)-Ph-pybox), 2,6-bis[4'(S)-isopropyloxazolin-2'-il-pyridine] ((S,S)-(i)Pr-pybox) or 2,6-bis[4'(R)-isopropyloxazolin-2'-il-pyridine] ((R,R)-(i)Pr-pybox) and water soluble 1,3,5-triaza-7-phosphaadamantane (PTA) or N-substituted PTA phosphanes have been synthesized in high yields and fully characterized. The interactions of these compounds with plasmidic DNA and their cytotoxic activity against the human cervical cancer HeLa cell line are reported, pointing out for the first time the different behaviour of ruthenium enantiomers affecting the cell cycle in HeLa tumor cells.
