title: CO dissociation mechanism in racemization of alcohols by a cyclopentadienyl ruthenium dicarbonyl catalyst.
abstract: (13)CO exchange studies of racemization catalyst (η(5)-Ph(5)C(5))Ru(CO)(2)Cl and (η(5)-Ph(5)C(5))Ru(CO)(2)(Ot-Bu) by (13)C NMR spectroscopy are reported. CO exchange for the active catalyst form, (η(5)-Ph(5)C(5))Ru(CO)(2)(Ot-Bu) is approximately 20 times faster than that for the precatalyst (η(5)-Ph(5)C(5))Ru(CO)(2)Cl. An inhibition on the rate of racemization of (S)-1-phenylethanol was observed on addition of CO. These results support the hypothesis that CO dissociation is a key step in the racemization of sec-alcohols by (η(5)-Ph(5)C(5))Ru(CO)(2)Cl, as also predicted by DFT calculations.
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden.
authors.forename: Madeleine C
authors.initials: MC
authors.lastname: Warner
authors.forename: Oscar
authors.initials: O
authors.lastname: Verho
authors.forename: Jan-E
authors.initials: JE
authors.lastname: Bäckvall