Iridium-Catalyzed Asymmetric Hydrogenation yielding Chiral Diarylmethines with Weakly Coordinating or Noncoordinating Substituents
2009 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 131, no 25, 8855-8860 p.Article in journal (Refereed) Published
Diarylimethine-containing stereocenters are present in pharmaceuticals and natural products, making the synthetic methods that form these chiral centers are important in industry. We have applied iridium complexes with novel N,P-chelating ligands to the asymmetric hydrogenation of trisubstituted olefins, forming diarylmethine chiral centers in high conversions and excellent enantioselectivities (up to 99% ee) for a broad range of substrates. Our results support the hypothesis that steric hindrance in one specific area of the catalyst is playing a key role in stereoselection, as the hydrogenation of substrates differing little at the prochiral carbon occurred with high enantioselectivity. As a result, excellent stereodiscrimination was obtained even when the prochiral carbon bore, for example, phenyl and p-tolyl groups.
Place, publisher, year, edition, pages
2009. Vol. 131, no 25, 8855-8860 p.
IdentifiersURN: urn:nbn:se:uu:diva-99807DOI: 10.1021/ja9013375ISI: 000267631000039PubMedID: 19552449OAI: oai:DiVA.org:uu-99807DiVA: diva2:208778