Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/128338
Title: P-Stereogenic and Non-P-Stereogenic Ir-MaxPHOX in the asymmetric hydrogenation of N-Aryl imines. Isolation and X-ray analysis of imine iridacycles
Author: Salomó, Ernest
Rojo, Pep
Hernández Lladó, Pol
Riera i Escalé, Antoni
Verdaguer i Espaulella, Xavier
Keywords: Hidrogenació
Lligands
Imines
Hydrogenation
Ligands
Imines
Issue Date: 20-Apr-2018
Publisher: American Chemical Society
Abstract: A small library of Ir-MaxPHOX catalysts has been applied to the asymmetric hydrogenation of N-aryl imines. A structure activity analysis of the three-chiral-center MaxPHOX ligand has been performed. Using complex 1b, the hydrogenation of N-aryl imines took place with up to 96% enantiomeric excess at atmospheric pressure of hydrogen and low temperature. The impact of the stereochemical information at the phosphorus center is small with respect to the selectivity, but large with respect the catalyst activity. Non-P-stereogenic analogs of MaxPHOX were also synthesized and tested, but they provided lower selectivity. The selectivity observed could be explained by taking into account that the actual catalysts were cyclometalated imine complexes formed in situ. [IrHCl(MaxPHOX)(imine)] complexes 9 and 10 were synthesized and characterized by X-ray crystallography. These complexes, via chloride abstraction, provided the active catalytic species with the same levels of selectivity. Finally, the influence of the counterion on the catalyst performance was also studied.
Note: Versió postprint del document publicat a: https://doi.org/10.1021/acs.joc.8b00361
It is part of: Journal of Organic Chemistry, 2018, vol. 83, num. 8, p. 4618-4627
URI: http://hdl.handle.net/2445/128338
Related resource: https://doi.org/10.1021/acs.joc.8b00361
ISSN: 0022-3263
Appears in Collections:Articles publicats en revistes (Química Inorgànica i Orgànica)

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