A novel zinc-catalyzed Suzuki-type cross-coupling reaction of aryl boronic acids with alkynyl bromides

Abstract

A novel Suzuki-type cross-coupling reaction of organoboron reagents with alkynyl bromides has been developed in the presence of catalytic Et2Zn/DMEDA system. The reaction afforded a variety of internal alkynes in moderate to excellent yields under mild reaction conditions without the formation of any homo-coupling products. The resulting internal alkynes have valuable applications in pharmaceutical and industrial areas. The use of relatively non-toxic zinc, chelating amine ligand and low reaction temperature make this protocol an alternative for the synthesis of internal alkynes. The scope and limitations of this protocol are also investigated.