Ruthenium(II)‐Catalyzed Alkenylation of Primary Arylacetamides: En Route Synthesis of Trisubstituted Alkenes

We report a ruthenium(II)-catalyzed hydroarylation strategy for the stereoselective synthesis of trisubstituted alkenes via C─H bond activation of arylacetamides using weakly coordinating primary amides as directing groups in the presence of internal alkynes. This operationally simple and sustainable protocol demonstrates broad substrate scope and high diastereoselectivity, tolerating a wide range of electron-rich, electron-deficient, and sterically hindered arylacetamides. Both symmetrical and unsymmetrical internal alkynes are compatible with the transformation. The methodology is scalable and synthetically versatile as demonstrated through downstream functionalization. Mechanistic insights, supported by isotopic labeling and competition experiments, shed light on the reaction pathway.