. (2011) The importance of the N-H bond in Ru/TsDPEN complexes for asymmetric transfer hydrogenation of ketones and imines. Organic & Biomolecular Chemistry,9 (9). pp. 3290-3294. Permanent WRAP url:http://wrap.warwick.ac.uk/40377 Copyright and reuse:The Warwick Research Archive Portal (WRAP) makes this work by researchers of the University of Warwick available open access under the following conditions. Copyright © and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable the material made available in WRAP has been checked for eligibility before being made available.Copies of full items can be used for personal research or study, educational, or not-for profit purposes without prior permission or charge. Provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. Publisher's statement:Final published version : http://dx.doi.org/10.1039/C1OB05208J A note on versions:The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP url' above for details on accessing the published version and note that access may require a subscription. For more information, please contact the WRAP Team at: publications@warwick.ac.uk Ru(II) complexes of TsDPEN containing two alkyl groups on the non-tosylated nitrogen atom are poor catalysts for asymmetric transfer hydrogenation of ketones and imines; this observation provides direct evidence for the importance of the N-H interaction in the transition state for ketone reduction. CREATED USING THE RSC COMMUNICATION TEMPLATE (VER. 3.0) -SEE WWW.RSC.ORG/ELECTRONICFILES FOR DETAILS

α,α-Disubstituted ketones containing an aromatic ring or alkene are reduced in high enantiomeric excess using an asymmetric transfer hydrogenation catalyst. The sense of reduction indicates that the unsaturated region of the ketone adopts a position adjacent to the Ru-bound η(6)-arene ring in the reduction transition state.

[Chemical reaction: See text] A series of BINOL-derived ligands have been prepared and incorporated into ruthenium(II) complexes containing a diamine ligand. The complexes have proven to be excellent catalysts for the asymmetric hydrogenation of ketones, giving reduction products with enantiomeric excesses of up to 99%.

Alcohols Q 0230Ruthenium (II) Complexes of Monodonor Ligands: Efficient Reagents for Asymmetric Ketone Hydrogenation. -A number of Ru complexes such as (I) is prepared. The derivative (Ia) is found to be an excellent catalyst for the asymmetric hydrogenation of various ketones. Steric and electronic factors influence the degree of enantioselectivity. -(XU, Y.; CLARKSON, G. C.; DOCHERTY, G.; NORTH, C. L.; WOODWARD, G.; WILLS*, M.; J. Org. Chem. 70 (2005) 20, 8079-8087; Dep. Chem., Univ. Warwick, Coventry CV4 7AL, UK; Eng.) -Jannicke 06-084

The regioselective lithiation of 1,2,3-triazoles provides an opportunity to introduce additional functionality, however this simple functionalisation strategy using triazoles bearing electron-withdrawing N-substituents has not been investigated until now. Herein, we demonstrate that the lithiated triazole intermediates can readily decompose, even at −78 °C. In addition, lithiation-deuteration studies reveal lithiation can take place competitively on both the triazole and the electron-withdrawn aryl ring. Careful control of reaction conditions is therefore required to i) minimise decomposition pathways; and ii) facilitate regioselective functionalisation of the triazole.