Aqua iridium(III) complexes with 8-amino-5,6,7,8-tetrahydroquinolines CAMPY L1 and its derivatives as chiral ligands proved to be very efficient catalysts for the reduction of a wide range of prochiral aryl ketones, revealing a variety of behaviours in terms of reaction rate and stereoselectivity. As standard substrates, differently substituted acetophenones were studied and good enantioselectivity (86% ee) was achieved in the reduction of 1-(o-tolyl)ethan-1-one 6. Particularly interesting was the ATH reaction in the case of Î²-amino keto esters, precursors of Î²-lactams and azetidinones. The best results were obtained with [Cp*Ir(H2O)(L1)]SO4affording the corresponding diastereomeric alcohols in an (R,S)-configuration with an excellent 99% ee in the reduction of 2-(benzamido methyl)-3-oxo-3-(4-(trifluoromethyl)phenyl)propanoate 12. Â© 2014 Elsevier Ltd. All rights reserved.
|Titolo:||8-Amino-5,6,7,8-tetrahydroquinolines as ligands in iridium(III) catalysts for the reduction of aryl ketones by asymmetric transfer hydrogenation (ATH)|
|Data di pubblicazione:||2014|
|Parole Chiave:||Organic Chemistry; Inorganic Chemistry; Physical and Theoretical Chemistry; Catalysis|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/j.tetasy.2014.06.003|
|Appare nelle tipologie:||1.1 Articolo in rivista|