Highly Regio‐ and Enantioselective Synthesis of γ,δ‐Unsaturated Amido Esters by Catalytic Hydrogenation of Conjugated Enamides

An efficient and highly regio‐ and enantioselective catalytic asymmetric hydrogenation of α,γ‐dienamido esters to γ,δ‐unsaturated amido esters has been achieved using Rh/TangPhos as the catalyst. A series of γ,δ‐unsaturated amido acids were furnished in excellent yields with up to 99 % ee . This effective methodology was applied in the asymmetric synthesis of key intermediate of Ramipril, an ACE inhibitor.