title: Easy To Synthesize, Robust Organo-osmium Asymmetric Transfer Hydrogenation Catalysts.
abstract: Asymmetric transfer hydrogenation (ATH) is an important process in organic synthesis for which the Noyori-type Ru(II) catalysts [(arene)Ru(Tsdiamine)] are now well established and widely used. We now demonstrate for the first time the catalytic activity of the osmium analogues. X-ray crystal structures of the 16-electron Os(II) catalysts are almost identical to those of Ru(II). Intriguingly the precursor complex was isolated as a dichlorido complex with a monodentate amine ligand. The Os(II) catalysts are readily synthesised (within 1 h) and exhibit excellent enantioselectivity in ATH reactions of ketones.
authors: Department of Chemistry, University of Warwick, Coventry, CV4 7AL (UK).
authors: James P C
authors: JP
authors: Coverdale
authors: Department of Chemistry, University of Warwick, Coventry, CV4 7AL (UK).
authors: Carlos
authors: C
authors: Sanchez-Cano
authors: Department of Chemistry, University of Warwick, Coventry, CV4 7AL (UK).
authors: Guy J
authors: GJ
authors: Clarkson
authors: Department of Chemistry, University of Warwick, Coventry, CV4 7AL (UK).
authors: Rina
authors: R
authors: Soni
authors: Department of Chemistry, University of Warwick, Coventry, CV4 7AL (UK). m.wills@warwick.ac.uk.
authors: Martin
authors: M
authors: Wills
authors: Department of Chemistry, University of Warwick, Coventry, CV4 7AL (UK). p.j.sadler@warwick.ac.uk.
authors: Peter J
authors: PJ
authors: Sadler
keywords: asymmetric catalysis; hydrogen transfer; ketone reduction; organometallic complexes; osmium