Cobalt‐Catalyzed Stereodivergent Semihydrogenation of Alkynes: Synthesis of <i>E</i> ‐ and <i>Z</i> ‐Alkenes

Abstract

Abstract Transition metal‐catalyzed semihydrogenation of alkynes is one of the most efficient, sustainable, and environmental‐friendly strategies for accessing stereoisomerically pure olefins. Herein, we report a tridentate nitrogen‐containing ligand (8‐OIQ) promoted cobalt‐catalyzed stereodivergent semihydrogenation of internal alkynes; a series of Z ‐ and E ‐alkenes could be synthesized with high stereoselectivity. Besides, this protocol exhibits excellent functional group tolerance and operates under mild reaction conditions (1 bar H 2 , room temperature). A preliminary mechanistic study revealed that acetonitrile plays an important role in suppressing over‐reduction and controlling the stereoselectivity in this transformation.