Asymmetric Transfer Hydrogenation of Unsaturated Ketones; Factors influencing 1,4- vs 1,2- regio- and enantioselectivity, and alkene vs alkyne directing effects

Abstract A detailed study has been completed on the asymmetric transfer hydrogenation (ATH) of a series of enones using Ru(II) catalysts. Electron-rich rings adjacent to the C=O group reduce the level of C=O reduction compared to C=C. The ATH reaction can readily discriminate between double and triple bonds adjacent to ketones, reducing the double bond but leaving a triple bond intact in the major product.