Enantioselective Synthesis of β-Aryloxycarboxylic Esters via Asymmetric Hydrogenation of β-Aryloxy-α,β-Unsaturated Esters
作者:Gavin W. Stewart、Michael Shevlin、Adam D. Gammack Yamagata、Andrew W. Gibson、Stephen P. Keen、Jeremy P. Scott
DOI:10.1021/ol302518y
日期:2012.11.2
A novel synthesis of beta-aryloxycarboxylic esters via asymmetric hydrogenation of the corresponding beta-aryloxy-alpha,beta-unsaturated esters has been demonstrated. Bis(norbornadiene)rhodium(I) tetrafluoroborate (1 mol %) and Walphos W008-1 were used to generate the saturated products with high enantioselectivity and in high yield. The tolerability of the reaction to a diverse range of substituents on the aromatic ring was also explored.
Asymmetric Hydrogenation of β-Aryloxy/Alkoxy Cinnamic Nitriles and Esters
A highly efficient and enantioselective hydrogenation of β-aryloxy/alkoxy cinnamic nitriles and esters under mild conditions has been realized by using a rhodium catalyst with a chiral f-spiroPhos ligand. The method provides efficient access to the asymmetricsynthesis of a variety of chiral β-oxy-functionalized nitriles and esters with excellent enantioselectivities (up to 99.9% ee) and high turnover