Selective Synthesis of Z-α-Iodostyrenes via Hydroiodination and Photochemical Manganese-Catalyzed Geometric Isomerization

Alkenyl iodides are essential intermediates in organic synthesis, traditionally synthesized via hydrometalation of alkynes or direct hydroiodination, which favor the formation of E isomers. However, methods for selectively producing Z-isomers remain underdeveloped. Inspired by photoinduced manganese-mediated iodine abstraction and radical rebound processes, we combined hydroiodination with double-bond isomerization. This telescoped approach efficiently synthesizes Z-α-iodostyrenes, leveraging their thermodynamic stability over that of E isomers. The method demonstrates broad substrate compatibility, good yields, and geometric selectivity, offering a streamlined solution to expand the utility of alkenyl iodides in complex molecule synthesis.