Highly enantioselective hydrogenation of N-aryl imines derived from acetophenones by using Ru-pybox complexes under hydrogenation or transfer hydrogenation conditions in isopropanol.

Chemistry

Laboratorio de Compuestos Organometálicos y Catálisis (Unidad Asociada al CSIC), Departamento de Química Orgánica e Inorgánica, Instituto de Química Organometálica "Enrique Moles", Universidad de Oviedo, 33006 Oviedo (Spain).

Published: January 2015

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.

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http://dx.doi.org/10.1002/chem.201405276DOI Listing

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