Copper‐Catalyzed Domino Cyclization/Thiocyanation of Unactivated Olefins: Access to SCN‐Containing Pyrazolines

A mild and highly efficient Cu‐catalyzed cascade cyclization/thiocyanation of unactivated alkenes bearing hydrazones has been developed. A broad range of SCN‐substituted pyrazolines have been readily obtained in good to excellent yields with commercially available and very cheap Cu(acac)2 and NH4SCN. This present method provides a rapid, facile, and practical access to valuable pyrazolines with the important SCN functionality, and it is amenable to the gram scale.