A Solely Fe-Catalyzed Sonogashira-Type Coupling of non-Activated Secondary Alkyl Iodides with Terminal Alkynes

An iron-catalyzed Sonogashira coupling of non-activated secondary alkyl iodides with terminal alkynes is described. The reaction proceeds under mild conditions in N-MethylPyrrolidone without auxiliary ligand or co-catalyst. This procedure allowed the obtention of 28 coupling products. Moreover, slow addition of LiHMDS base allows to achieve up to 89% yields. This method enables the conversion of non-activated alkyl iodides in a Fe-catalyzed Sonogashira-type cross-coupling, which was so far not achievable with iron catalysts. Preliminary mechanistic studies suggest the implication of a key single electron transfer in the catalytic process. + image