Enantioselective Synthesis of β‑Aryloxycarboxylic Esters via Asymmetric Hydrogenation of β‑Aryloxy-α,β-Unsaturated Esters

A novel synthesis of β-aryloxycarboxylic esters via asymmetric hydrogenation of the corresponding β-aryloxy-α,β-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.